Trial Outcomes & Findings for The Effect of Intravenous Lidocaine on Normal Sensation and Pain in Healthy Volunteers (NCT NCT00657358)

Results Overview

The right arm was exsanguinated by elevating it above heart level for 30 seconds, after which the arm was occluded with a standard blood pressure cuff positioned proximal to the elbow inflated to twice the participant's mean arterial pressure. Participants then performed 20 handgrip exercises of 2-second duration at 4-second intervals at 50% of their maximum grip strength. Pain was rated on a scale from 0 - 10 with 0 being no pain to 10 being the worst pain imaginable.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

22 participants

Primary outcome timeframe

baseline, during 20 minute lidocaine infusion, and 30 minutes after discontinuation of lidocaine infusion

Results posted on

2017-05-17

Participant Flow

Participant milestones

Participant milestones
Measure	Lidocaine Healthy Volunteers receiving Lidocaine
Overall Study STARTED	22
Overall Study COMPLETED	16
Overall Study NOT COMPLETED	6

Reasons for withdrawal

Reasons for withdrawal
Measure	Lidocaine Healthy Volunteers receiving Lidocaine
Overall Study Lack of Efficacy	6

Baseline Characteristics

The Effect of Intravenous Lidocaine on Normal Sensation and Pain in Healthy Volunteers

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Lidocaine n=16 Participants Healthy Volunteers receiving Lidocaine
Age, Categorical <=18 years	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	16 Participants n=5 Participants
Age, Categorical >=65 years	0 Participants n=5 Participants
Age, Continuous	25 years STANDARD_DEVIATION 4 • n=5 Participants
Sex: Female, Male Female	9 Participants n=5 Participants
Sex: Female, Male Male	7 Participants n=5 Participants
Region of Enrollment United States	16 participants n=5 Participants

PRIMARY outcome

Timeframe: baseline, during 20 minute lidocaine infusion, and 30 minutes after discontinuation of lidocaine infusion

Population: health volunteers

The right arm was exsanguinated by elevating it above heart level for 30 seconds, after which the arm was occluded with a standard blood pressure cuff positioned proximal to the elbow inflated to twice the participant's mean arterial pressure. Participants then performed 20 handgrip exercises of 2-second duration at 4-second intervals at 50% of their maximum grip strength. Pain was rated on a scale from 0 - 10 with 0 being no pain to 10 being the worst pain imaginable.

Outcome measures

Outcome measures
Measure	Lidocaine Administration n=16 Participants Lidocaine 2% (2mg/ml) was administered via a computer assisted infusion to achieve a target plasma concentration of 2 mcg/ml; infused within 20 minutes.
Ischemic Pain Baseline (prior to administration)	4.31 units on a scale Standard Error .48
Ischemic Pain During 20 Infusion	3.49 units on a scale Standard Error .48
Ischemic Pain 30 After Infusion completed	3.44 units on a scale Standard Error .48

PRIMARY outcome

Timeframe: Baseline, during 20 minutes lidocaine infusion, and 30 minutes after completion of lidocaine infusion

Peripheral nerve stimulation electrodes were attached to the base and the tip of the third digit and connected to a constant current stimulator (DS7A, Digitimer Ltd, Hertfordshire, England). Ascending electrical stimuli of 2000 mu duration, ranging from 0.5 to 35 mA (ampere) was administered one per second in 0.5 mA increments. Participants were instructed to indicate when they first felt the slightest sense of pain (electrical pain threshold, EPTh) and when they were unable to tolerate a further increase (electrical pain tolerance, EPTo). For each measure, the average of three trials was computed for use in subsequent analyses. Each of the three electrical pain stimuli were presented three times and balanced in order using a Graeco-Latin square design. The pain scale is between 0 and 10, with 0 being no pain and 10 being the worst pain imaginable

Outcome measures

Outcome measures
Measure	Lidocaine Administration n=16 Participants Lidocaine 2% (2mg/ml) was administered via a computer assisted infusion to achieve a target plasma concentration of 2 mcg/ml; infused within 20 minutes.
Electrical Pain Baseline - at time of lidocaine administration	2.40 units on a scale Standard Error 0.34
Electrical Pain During 20 minute lidocaine Infusion	2.04 units on a scale Standard Error .34
Electrical Pain 30 minutes after compleition of lidocaine infusion	2.52 units on a scale Standard Error .34

PRIMARY outcome

Timeframe: baseline, during 20 minute lidocaine infusion, and 30 minutes after completion of lidocaine infusion

The thermal procedure involved a baseline assessment of heat pain threshold and tolerance. Contact heat stimuli were delivered using a computer-controlled Medoc Thermal Sensory Analyzer (TSA-II; Ramat Yishai, Israel), which is a peltier elementbased stimulator. Temperature levels were monitored by a thermistor and returned to a preset baseline of 32°C by active cooling at a rate of 10°C/s. The 3 × 3 cm contact probe was applied to the right forearm. The pain scale is between 0 and 10 with 1 being no pain and 10 being the worst pain imaginable

Outcome measures

Outcome measures
Measure	Lidocaine Administration n=16 Participants Lidocaine 2% (2mg/ml) was administered via a computer assisted infusion to achieve a target plasma concentration of 2 mcg/ml; infused within 20 minutes.
Heat Pain Baseline - at start of lidocaine infusion	3.01 units on a scale Standard Error 0.42
Heat Pain During 20 minute lidocaine infusion	2.83 units on a scale Standard Error .42
Heat Pain 30 minutes after completion of lidocaine infusion	2.82 units on a scale Standard Error .42

PRIMARY outcome

Timeframe: baseline, during 20 minute infusion, and 30 minutes after lidocaine infusion

The participant's foot was immersed up to the ankle into a container filled with ice water of 3°C. Participants were instructed to maintain their foot in the container until the cold pain became intolerable (cold pain tolerance). The length of time was recorded in seconds. This procedure was repeated once with a gap of at least fifteen minutes in-between repeated tests. The range was 0 seconds to 120 seconds

Outcome measures

Outcome measures
Measure	Lidocaine Administration n=16 Participants Lidocaine 2% (2mg/ml) was administered via a computer assisted infusion to achieve a target plasma concentration of 2 mcg/ml; infused within 20 minutes.
Cold Pain Baseline - at start of infusion	42 time in seconds to withdrawal Standard Error 10.9
Cold Pain During 20 minute lidocaine infusion	50.6 time in seconds to withdrawal Standard Error 10.9
Cold Pain 30 minutes after completion of lidocaine infusion	51.2 time in seconds to withdrawal Standard Error 11.0

PRIMARY outcome

Timeframe: baseline, during 20 minute infusion, and 30 minutes after completion of infusion

Pin prick sensory thresholds (PPT) were obtained by touching the skin in-between the first and second metacarpal bone with a 23-gauge needles which moved freely out of a 10 mL plastic syringe barrel. The pin prick sensation was modified by adding small weights to the 23-gauge needles (from 0.2 to 5.2 mg). A syringe barrel of tuberculin (TB) needles that were cut to different lengths to add the desired weight to the 23-gauge needle. The PPT was determined using the weighted 23-gauge needle in ascending order, according to the method of limits. This assessment was to evaluate whether participants were able to feel the touch of the needle. The participant's arm was placed on a tray table. A linen sheet was suspended in-between two IV poles in such a fashion that the subject's view of his/her hand was blocked. Normal values are between 0.21mg and 5mg.

Outcome measures

Outcome measures
Measure	Lidocaine Administration n=16 Participants Lidocaine 2% (2mg/ml) was administered via a computer assisted infusion to achieve a target plasma concentration of 2 mcg/ml; infused within 20 minutes.
Tactile Sensation Baseline - at start of lidocaine administration	.28 weight in mg Standard Error .02
Tactile Sensation During 20 minute Infusion	.27 weight in mg Standard Error .02
Tactile Sensation 30 Minutes after completion of infusion	.27 weight in mg Standard Error .02

Adverse Events

Lidocaine

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Michael Froelich

UAB

Phone: 205-975-0145

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place

Restriction type: GT60