Trial Outcomes & Findings for Timely Intravenous Magnesium for Asthma in Children (NCT NCT05166811)

Last Updated: 2024-12-18

Results Overview

The primary outcome in this pilot trial is demonstration of the ability to enroll severely ill children with asthma in a randomized trial requiring timely delivery of IVMg or placebo. The investigators anticipate that the primary outcome of the future large trial will be the proportion of children hospitalized at the index visit in each arm.

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

52 participants

Primary outcome timeframe

7 months of enrollment.

Results posted on

2024-12-18

Participant Flow

The study was conducted at three sites within the Pediatric Emergency Care Applied Research Network (PECARN). The three enrolling sites are EDs at tertiary pediatric hospitals and are geographically and demographically diverse. Eligible participants were identified from children presenting to the ED for treatment of acute asthma. Screening occurred at sites from September 2022 through May 2023.

Participant milestones

Participant milestones
Measure	Placebo For the placebo arm, 40 mL of 0.9% sodium chloride solution will be drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist will draw dosages (1 mL/kg, with max of 40 mL) from previously prepared vials. The dose will be delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg Doses for each intravenous magnesium sulfate (IVMg) arm will be prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this will be accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist will draw dosages (1 mL/kg, with max of 40 mL) from previously prepared vials. The dose will be delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg Doses for each intravenous magnesium sulfate (IVMg) arm will be prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this will be accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist will draw dosages (1 mL/kg, with max of 40 mL) from previously prepared vials. The dose will be delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Overall Study STARTED	18	17	17
Overall Study COMPLETED	18	17	17
Overall Study NOT COMPLETED	0	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Timely Intravenous Magnesium for Asthma in Children

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	Total n=52 Participants Total of all reporting groups
Age, Continuous	7.0 years STANDARD_DEVIATION 5.9 • n=5 Participants	7.4 years STANDARD_DEVIATION 7.4 • n=7 Participants	7.3 years STANDARD_DEVIATION 4.3 • n=5 Participants	7.3 years STANDARD_DEVIATION 6.4 • n=4 Participants
Age, Customized Age	5.9 years n=5 Participants	7.4 years n=7 Participants	5.8 years n=5 Participants	6.4 years n=4 Participants
Age, Customized Age Group · 2-4 years	7 Participants n=5 Participants	4 Participants n=7 Participants	6 Participants n=5 Participants	17 Participants n=4 Participants
Age, Customized Age Group · 5-17 years	10 Participants n=5 Participants	12 Participants n=7 Participants	11 Participants n=5 Participants	33 Participants n=4 Participants
Age, Customized Age Group · Unknown	1 Participants n=5 Participants	1 Participants n=7 Participants	0 Participants n=5 Participants	2 Participants n=4 Participants
Sex/Gender, Customized Sex · Male	12 Participants n=5 Participants	11 Participants n=7 Participants	12 Participants n=5 Participants	35 Participants n=4 Participants
Sex/Gender, Customized Sex · Female	5 Participants n=5 Participants	5 Participants n=7 Participants	5 Participants n=5 Participants	15 Participants n=4 Participants
Sex/Gender, Customized Sex · Unknown	1 Participants n=5 Participants	1 Participants n=7 Participants	0 Participants n=5 Participants	2 Participants n=4 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	3 Participants n=5 Participants	5 Participants n=7 Participants	0 Participants n=5 Participants	8 Participants n=4 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	13 Participants n=5 Participants	11 Participants n=7 Participants	16 Participants n=5 Participants	40 Participants n=4 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	2 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants	4 Participants n=4 Participants
Race (NIH/OMB) American Indian or Alaska Native	1 Participants n=5 Participants	0 Participants n=7 Participants	2 Participants n=5 Participants	3 Participants n=4 Participants
Race (NIH/OMB) Asian	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants	2 Participants n=4 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants	1 Participants n=4 Participants
Race (NIH/OMB) Black or African American	5 Participants n=5 Participants	8 Participants n=7 Participants	6 Participants n=5 Participants	19 Participants n=4 Participants
Race (NIH/OMB) White	10 Participants n=5 Participants	6 Participants n=7 Participants	4 Participants n=5 Participants	20 Participants n=4 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants	2 Participants n=4 Participants
Race (NIH/OMB) Unknown or Not Reported	1 Participants n=5 Participants	2 Participants n=7 Participants	2 Participants n=5 Participants	5 Participants n=4 Participants
Weight	20.8 kilograms n=5 Participants	28.4 kilograms n=7 Participants	18.1 kilograms n=5 Participants	21.1 kilograms n=4 Participants
Prior hospitalizations for asthma	9 Participants n=5 Participants	12 Participants n=7 Participants	14 Participants n=5 Participants	35 Participants n=4 Participants
ED visit for asthma in the last 12 months	9 Participants n=5 Participants	12 Participants n=7 Participants	14 Participants n=5 Participants	35 Participants n=4 Participants
Prescribed a daily controller medication	18 Participants n=5 Participants	17 Participants n=7 Participants	17 Participants n=5 Participants	52 Participants n=4 Participants
Taking controller medication 4+ days a week	8 Participants n=5 Participants	10 Participants n=7 Participants	7 Participants n=5 Participants	25 Participants n=4 Participants
Personal history of eczema	8 Participants n=5 Participants	9 Participants n=7 Participants	6 Participants n=5 Participants	23 Participants n=4 Participants
Personal history of anaphylaxis	2 Participants n=5 Participants	2 Participants n=7 Participants	1 Participants n=5 Participants	5 Participants n=4 Participants
Personal history of prematurity	5 Participants n=5 Participants	2 Participants n=7 Participants	5 Participants n=5 Participants	12 Participants n=4 Participants
Parent with asthma	12 Participants n=5 Participants	10 Participants n=7 Participants	12 Participants n=5 Participants	34 Participants n=4 Participants
Parent with eczema	6 Participants n=5 Participants	8 Participants n=7 Participants	8 Participants n=5 Participants	22 Participants n=4 Participants
Parent with seasonal allergies	10 Participants n=5 Participants	11 Participants n=7 Participants	12 Participants n=5 Participants	33 Participants n=4 Participants
Arrival pulse oximeter reading 95% or higher	4 Participants n=5 Participants	5 Participants n=7 Participants	4 Participants n=5 Participants	13 Participants n=4 Participants
Arrival pulse oximeter reading 92-94%	5 Participants n=5 Participants	5 Participants n=7 Participants	6 Participants n=5 Participants	16 Participants n=4 Participants
Arrival pulse oximeter reading 91% or lower	9 Participants n=5 Participants	7 Participants n=7 Participants	7 Participants n=5 Participants	23 Participants n=4 Participants

PRIMARY outcome

Timeframe: 7 months of enrollment.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Enrollment	18 Participants	17 Participants	17 Participants

SECONDARY outcome

Timeframe: Actual disposition from chart review 1 week after enrollment.

Population: Participants who were enrolled were included in the intention-to-treat (ITT) population regardless of whether they received study drug according to their randomization arm.

Actual patient disposition from medical record review after completion of ED treatment. Hospitalization will be defined as any outcome other than discharge from the ED, including hospitalization in an ICU, hospital unit, or observation area.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Hospitalization	12 Participants	12 Participants	14 Participants

SECONDARY outcome

Timeframe: Physician-anticipated hospitalization 2 hours after the start of study drug infusion

Population: Participants who were enrolled were included in the intention-to-treat (ITT) population regardless of whether they received study drug according to their randomization arm.

The treating clinician's stated disposition two hours after the start of study infusion.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Hospitalization Anticipated by Treating Physician 2 Hours After Start of Study Infusion	13 Participants	12 Participants	13 Participants

SECONDARY outcome

Timeframe: 2 hours after study drug infusion.

Population: Participants in whom the study drug infusion was started were included in the safety population.

Decrease in blood pressure was categorized based on degree of associated symptoms and defined as occurring less than 2 hours after the start of study drug infusion or 2 hours and later. Hypotension is defined by age-based Pediatric Advanced Life Support guidelines.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=16 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=15 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Adverse Events and Safety Profiles - Hypotension and Perfusion Hypotension within 2 hours of start of study infusion	2 Participants	1 Participants	1 Participants
Adverse Events and Safety Profiles - Hypotension and Perfusion Hypotension more than 2 hours after start of study infusion	2 Participants	4 Participants	3 Participants
Adverse Events and Safety Profiles - Hypotension and Perfusion Poor perfusion during hypotension within 2 hours of start of study infusion	0 Participants	0 Participants	0 Participants
Adverse Events and Safety Profiles - Hypotension and Perfusion No hypotension measured	14 Participants	11 Participants	11 Participants

SECONDARY outcome

Timeframe: One week after enrollment

Population: Participants who were enrolled were included in the intention-to-treat (ITT) population for this measure.

Count of the number of participants that were administered subcutaneous (SQ) or intramuscular (IM) epinephrine while in the ED during the index visit, recorded by chart review approximately one week after enrollment.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Rescue Therapies Used During ED Care - SQ or IM Epinephrine SQ or IM epinephrine	1 Participants	1 Participants	0 Participants
Rescue Therapies Used During ED Care - SQ or IM Epinephrine not administered SQ or IM epinephrine	17 Participants	16 Participants	17 Participants

SECONDARY outcome

Timeframe: Within 10 days after ED discharge

Population: Participants who were enrolled were included in the intention-to-treat (ITT) population.

In patients discharged from the ED, any ED visit and/or hospitalization following discharge.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Return ED Visit	5 Participants	0 Participants	1 Participants

SECONDARY outcome

Timeframe: At IV placement before infusion of study drug

Population: Participants in whom the study drug infusion was started were included in the safety population used for these results.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=16 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=15 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Baseline Serum Magnesium	1.95 mg/dL Standard Deviation 0.13	1.95 mg/dL Standard Deviation 0.23	2.20 mg/dL Standard Deviation 0.55

SECONDARY outcome

Timeframe: At IV placement before infusion of study drug

Population: Participants in whom the study drug infusion was started were included in the safety population used for these results.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=16 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=15 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Baseline Ionized Magnesium	0.57 mg/dL Standard Deviation 0.04	0.57 mg/dL Standard Deviation 0.10	0.70 mg/dL Standard Deviation 0.24

SECONDARY outcome

Timeframe: 20-40 minutes after the start of study drug infusion

Population: Participants in whom the study drug infusion was started were included in the safety population used for these results.

Outcome measures

Outcome measures
Measure	Placebo n=16 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=16 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=15 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Post-infusion Serum Magnesium 1	1.86 mg/dL Standard Deviation 0.20	4.13 mg/dL Standard Deviation 3.32	3.79 mg/dL Standard Deviation 0.92

SECONDARY outcome

Timeframe: 20-40 minutes after the start of study drug infusion

Population: Participants in whom the study drug infusion was started were included in the safety population used for these results.

Outcome measures

Outcome measures
Measure	Placebo n=16 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=16 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=15 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Post-infusion Ionized Magnesium 1	0.54 mg/dL Standard Deviation 0.05	1.06 mg/dL Standard Deviation 0.25	1.15 mg/dL Standard Deviation 0.24

SECONDARY outcome

Timeframe: 90-150 minutes after the start of study drug infusion

Population: Participants in whom the study drug infusion was started were included in the safety population used for these results.

Outcome measures

Outcome measures
Measure	Placebo n=14 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=14 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=14 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Post-infusion Serum Magnesium 2	1.91 mg/dL Standard Deviation 0.14	2.54 mg/dL Standard Deviation 0.24	2.84 mg/dL Standard Deviation 0.21

SECONDARY outcome

Timeframe: 90-150 minutes after the start of study drug infusion

Population: Participants in whom the study drug infusion was started were included in the safety population used for these results.

Outcome measures

Outcome measures
Measure	Placebo n=14 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=14 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=14 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Post-infusion Ionized Magnesium 2	0.57 mg/dL Standard Deviation 0.04	0.76 mg/dL Standard Deviation 0.09	0.85 mg/dL Standard Deviation 0.12

SECONDARY outcome

Timeframe: One week after enrollment

Population: Participants who were enrolled were included in the intention-to-treat (ITT) population for this measure.

Count of the number of participants that were administered intravenous (IV) epinephrine while in the ED during the index visit, recorded by chart review approximately one week after enrollment.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Rescue Therapies Used During ED Care - IV Epinephrine IV epinephrine	0 Participants	0 Participants	0 Participants
Rescue Therapies Used During ED Care - IV Epinephrine not administered IV epinephrine	18 Participants	17 Participants	17 Participants

SECONDARY outcome

Timeframe: One week after enrollment

Population: Participants who were enrolled were included in the intention-to-treat (ITT) population for this measure.

Count of the number of participants that were administered intravenous (IV) terbutaline while in the ED during the index visit, recorded by chart review approximately one week after enrollment.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Rescue Therapies Used During ED Care - IV Terbutaline IV terbutaline	0 Participants	0 Participants	0 Participants
Rescue Therapies Used During ED Care - IV Terbutaline not administered IV terbutaline	18 Participants	17 Participants	17 Participants

SECONDARY outcome

Timeframe: One week after enrollment

Population: Participants who were enrolled were included in the intention-to-treat (ITT) population for this measure.

Count of the number of participants that were administered intravenous (IV) magnesium while in the ED during the index visit aside from any study infusion administered, recorded by chart review approximately one week after enrollment.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=17 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Rescue Therapies Used During ED Care - IV Magnesium IV magnesium	2 Participants	2 Participants	4 Participants
Rescue Therapies Used During ED Care - IV Magnesium not administered IV magnesium	16 Participants	15 Participants	13 Participants

SECONDARY outcome

Timeframe: 1 week

Population: Participants in whom the study drug infusion was started were included in the safety population.

Adverse events were assessed through chart review and phone call with the parent of the participant one week after enrollment. Timing after start of study infusion was not recorded.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=16 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=15 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Adverse Events and Safety Profiles - Supraventricular Tachycardia supraventricular tachycardia	0 Participants	0 Participants	1 Participants
Adverse Events and Safety Profiles - Supraventricular Tachycardia No supraventricular tachycardia	18 Participants	16 Participants	14 Participants

SECONDARY outcome

Timeframe: 1 week

Population: Participants in whom the study drug infusion was started were included in the safety population.

Adverse events were assessed through chart review and phone call with the parent of the participant one week after enrollment. Timing after start of study infusion was not recorded.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=16 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=15 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Adverse Events and Safety Profiles - Abdominal Discomfort abdominal discomfort	0 Participants	0 Participants	1 Participants
Adverse Events and Safety Profiles - Abdominal Discomfort no abdominal discomfort	18 Participants	16 Participants	14 Participants

SECONDARY outcome

Timeframe: 1 week

Population: Participants in whom the study drug infusion was started were included in the safety population.

Adverse events were assessed through chart review and phone call with the parent of the participant one week after enrollment. Timing after start of study infusion was not recorded.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=16 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=15 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Adverse Events and Safety Profiles - Vomiting vomiting	0 Participants	0 Participants	1 Participants
Adverse Events and Safety Profiles - Vomiting no vomiting	18 Participants	16 Participants	14 Participants

SECONDARY outcome

Timeframe: 1 week

Population: Participants in whom the study drug infusion was started were included in the safety population.

Adverse events were assessed through chart review and phone call with the parent of the participant one week after enrollment. Timing after start of study infusion was not recorded.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=16 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=15 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Adverse Events and Safety Profiles - Fatigue fatigue	0 Participants	1 Participants	0 Participants
Adverse Events and Safety Profiles - Fatigue no fatigue	18 Participants	15 Participants	15 Participants

SECONDARY outcome

Timeframe: 1 week

Population: Participants in whom the study drug infusion was started were included in the safety population.

Adverse events were assessed through chart review and phone call with the parent of the participant one week after enrollment. Timing after start of study infusion was not recorded.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=16 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=15 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Adverse Events and Safety Profiles - Hypokalemia hypokalemia	0 Participants	1 Participants	0 Participants
Adverse Events and Safety Profiles - Hypokalemia no hypokalemia	18 Participants	15 Participants	15 Participants

SECONDARY outcome

Timeframe: 1 week

Population: Participants in whom the study drug infusion was started were included in the safety population.

Adverse events were assessed through chart review and phone call with the parent of the participant one week after enrollment. Timing after start of study infusion was not recorded.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=16 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=15 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Adverse Events and Safety Profiles - Delirium delirium	0 Participants	0 Participants	1 Participants
Adverse Events and Safety Profiles - Delirium no delirium	18 Participants	16 Participants	14 Participants

SECONDARY outcome

Timeframe: 1 week

Population: Participants in whom the study drug infusion was started were included in the safety population.

Adverse events were assessed through chart review and phone call with the parent of the participant one week after enrollment. Timing after start of study infusion was not recorded.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=16 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=15 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Adverse Events and Safety Profiles - Hypoxia hypoxia	1 Participants	1 Participants	2 Participants
Adverse Events and Safety Profiles - Hypoxia no hypoxia	17 Participants	15 Participants	13 Participants

SECONDARY outcome

Timeframe: 1 week

Population: Participants in whom the study drug infusion was started were included in the safety population.

Adverse events were assessed through chart review and phone call with the parent of the participant one week after enrollment. Timing after start of study infusion was not recorded.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=16 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=15 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Adverse Events and Safety Profiles - Respiratory Distress respiratory distress	2 Participants	0 Participants	0 Participants
Adverse Events and Safety Profiles - Respiratory Distress no respiratory distress	16 Participants	16 Participants	15 Participants

SECONDARY outcome

Timeframe: 1 week

Population: Participants in whom the study drug infusion was started were included in the safety population.

Adverse events were assessed through chart review and phone call with the parent of the participant one week after enrollment. Timing after start of study infusion was not recorded.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=16 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=15 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Adverse Events and Safety Profiles - Metabolic Acidosis metabolic acidosis	1 Participants	0 Participants	0 Participants
Adverse Events and Safety Profiles - Metabolic Acidosis no metabolic acidosis	17 Participants	16 Participants	15 Participants

SECONDARY outcome

Timeframe: 1 week

Population: Participants in whom the study drug infusion was started were included in the safety population.

Adverse events were assessed through chart review and phone call with the parent of the participant one week after enrollment. Timing after start of study infusion was not recorded.

Outcome measures

Outcome measures
Measure	Placebo n=18 Participants For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=16 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=15 Participants Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Adverse Events and Safety Profiles - Duodenal Ulcer Perforation duodenal ulcer perforation	1 Participants	0 Participants	0 Participants
Adverse Events and Safety Profiles - Duodenal Ulcer Perforation no duodenal ulcer perforation	17 Participants	16 Participants	15 Participants

Adverse Events

Placebo

Serious events: 2 serious events

Other events: 4 other events

Deaths: 0 deaths

50 mg/kg

Serious events: 0 serious events

Other events: 5 other events

Deaths: 0 deaths

75 mg/kg

Serious events: 0 serious events

Other events: 6 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Placebo n=18 participants at risk For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=16 participants at risk Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=15 participants at risk Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Gastrointestinal disorders Duodenal Ulcer Perforation	5.6% 1/18 • Number of events 1 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	0.00% 0/16 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	0.00% 0/15 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.
Respiratory, thoracic and mediastinal disorders Respiratory Distress	5.6% 1/18 • Number of events 1 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	0.00% 0/16 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	0.00% 0/15 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.
Metabolism and nutrition disorders Metabolic Acidosis	5.6% 1/18 • Number of events 1 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	0.00% 0/16 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	0.00% 0/15 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.

Other adverse events

Other adverse events
Measure	Placebo n=18 participants at risk For the placebo arm, 40 mL of 0.9% sodium chloride solution was drawn into a polyvinylchloride container identical in appearance to the containers used for the IVMg arms. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. 0.9% saline: A single dose of intravenous 0.9% sodium chloride given over 20 minutes through a peripheral intravenous line as the placebo arm of the study.	50 mg/kg n=16 participants at risk Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 50 mg/kg arm, this was accomplished by mixing 25 mL of IVMg (80 mg/mL) with 15 mL of sterile water for a final concentration of 50 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was delivered by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.	75 mg/kg n=15 participants at risk Doses for each IVMg arm were prepared in identical manner, by drawing a specified volume of IVMg from the commercial container using sterile technique and mixing in a polyvinylchloride container with a specified volume of sterile water. For the 75 mg/kg arm, this was accomplished by mixing 37.5 mL of IVMg (80 mg/mL) with 2.5 mL of sterile water for a final concentration of 75 mg/mL and volume of 40 mL. After randomization the institutional pharmacist prepared the dosage (1 mL/kg, with max of 40 mL) from previously prepared container. The dose was by the clinical nurse over 20 minutes through a peripheral IV. Magnesium Sulfate, Heptahydrate: A single dose of intravenous magnesium sulfate given over 20 minutes through a peripheral intravenous line.
Cardiac disorders supraventricular tachycardia	0.00% 0/18 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	0.00% 0/16 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	6.7% 1/15 • Number of events 1 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.
Gastrointestinal disorders abdominal pain	0.00% 0/18 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	0.00% 0/16 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	6.7% 1/15 • Number of events 1 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.
Gastrointestinal disorders vomiting	0.00% 0/18 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	0.00% 0/16 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	6.7% 1/15 • Number of events 1 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.
General disorders fatigue	0.00% 0/18 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	6.2% 1/16 • Number of events 1 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	0.00% 0/15 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.
General disorders hypokalemia	0.00% 0/18 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	6.2% 1/16 • Number of events 1 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	0.00% 0/15 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.
Psychiatric disorders delirium	0.00% 0/18 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	0.00% 0/16 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	6.7% 1/15 • Number of events 1 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.
Respiratory, thoracic and mediastinal disorders hypoxia	5.6% 1/18 • Number of events 1 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	6.2% 1/16 • Number of events 1 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	13.3% 2/15 • Number of events 2 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.
Respiratory, thoracic and mediastinal disorders respiratory distress	5.6% 1/18 • Number of events 1 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	0.00% 0/16 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	0.00% 0/15 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.
Cardiac disorders hypotension	11.1% 2/18 • Number of events 2 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	25.0% 4/16 • Number of events 4 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.	20.0% 3/15 • Number of events 3 • Adverse events were evaluated 1 week after enrollment through review of the medical record and phone call with parent of the participant. No different that expected definitions.

Additional Information

Dr. Michael D. Johnson

University of Utah

Phone: (801) 935-0503

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place