Trial Outcomes & Findings for Physiological Effects of Nitrous Oxide on Anaesthesia (NCT NCT01092923)

Results Overview

Rate of fall in the arterial partial pressure of sevoflurane relative to baseline at 2 minutes (Pa 2/Pa0 Sevo), 5 minutes (Pa 5/Pa0 Sevo, and 30 minutes (Pa 30/Pa0 Sevo)

Recruitment status

COMPLETED

Study phase

PHASE4

Target enrollment

20 participants

Primary outcome timeframe

Baseline, 2 minutes, 5 minutes, and 30 minutes after emergence

Results posted on

2012-10-12

Participant Flow

Dates of recruitment: December 2009 to April 2010 Location: Austin Health

Exclusion criteria: patients with history of severe lung disease (defined as FEV1\<1.5 L or FEV1/FVC\<50%), symptomatic ischemic heart disease, super obesity (BMI\>45), pregnancy, prior severe post-operative nausea/vomiting, critically ill/immunocompromised, Vitamin B12/folate deficiency, or presence of any gas-filled, space-occupying lesion.

Participant milestones

Participant milestones
Measure	Air/Oxygen Sevoflurane with Air/Oxygen Mix	Sevoflurane in N2O/O2 Sevoflurane in 2:1 N2O/O2
Overall Study STARTED	10	10
Overall Study COMPLETED	10	10
Overall Study NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Physiological Effects of Nitrous Oxide on Anaesthesia

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Air/Oxygen n=10 Participants Sevoflurane with Air/Oxygen Mix	Sevoflurane in N2O/O2 n=10 Participants Sevoflurane in 2:1 N2O/O2	Total n=20 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	3 Participants n=5 Participants	5 Participants n=7 Participants	8 Participants n=5 Participants
Age, Categorical >=65 years	7 Participants n=5 Participants	5 Participants n=7 Participants	12 Participants n=5 Participants
Age Continuous	65 years STANDARD_DEVIATION 18 • n=5 Participants	67 years STANDARD_DEVIATION 13 • n=7 Participants	66 years STANDARD_DEVIATION 16 • n=5 Participants
Sex: Female, Male Female	5 Participants n=5 Participants	6 Participants n=7 Participants	11 Participants n=5 Participants
Sex: Female, Male Male	5 Participants n=5 Participants	4 Participants n=7 Participants	9 Participants n=5 Participants
Region of Enrollment Australia	10 participants n=5 Participants	10 participants n=7 Participants	20 participants n=5 Participants

PRIMARY outcome

Timeframe: Baseline, 2 minutes, 5 minutes, and 30 minutes after emergence

Population: based on data collected during previous pilot study investigating the magnitude of the second gas effect on sevoflurane partial pressures after anaesthesia induction, we expected an effect of roughly similar magnitude would be present during elimination of nitrous oxide.

Rate of fall in the arterial partial pressure of sevoflurane relative to baseline at 2 minutes (Pa 2/Pa0 Sevo), 5 minutes (Pa 5/Pa0 Sevo, and 30 minutes (Pa 30/Pa0 Sevo)

Outcome measures

Outcome measures
Measure	Sevoflurane in N2O/O2 n=10 Participants N20 with Oxygen (2:1) and Sevoflurane	Sevoflurane in Air/O2 n=10 Participants Air/Oxygen and Sevoflurane
Pa t/Pa0 Sevo (Arterial Partial Pressure of Sevoflurane), t=Time(Minutes) At 2 minutes	0.32 ratio Standard Deviation 0.08	0.44 ratio Standard Deviation 0.13
Pa t/Pa0 Sevo (Arterial Partial Pressure of Sevoflurane), t=Time(Minutes) At 5 minutes	0.23 ratio Standard Deviation 0.07	0.32 ratio Standard Deviation 0.06
Pa t/Pa0 Sevo (Arterial Partial Pressure of Sevoflurane), t=Time(Minutes) At 30 minutes	0.16 ratio Standard Deviation 0.08	0.20 ratio Standard Deviation 0.10

PRIMARY outcome

Timeframe: Baseline, 2 minutes, and 5 minutes after emergence

Population: based on data collected during previous pilot study investigating the magnitude of the second gas effect on sevoflurane partial pressures after anaesthesia induction, we expected an effect of roughly similar magnitude would be present during elimination of nitrous oxide.

Rate of fall in the end-tidal partial pressure of sevoflurane relative to baseline at 2 minutes (PA2/PA0 sevo) and 5 minutes (PA5/PA0 sevo)

Outcome measures

Outcome measures
Measure	Sevoflurane in N2O/O2 n=10 Participants N20 with Oxygen (2:1) and Sevoflurane	Sevoflurane in Air/O2 n=10 Participants Air/Oxygen and Sevoflurane
PA t/PA0 Sevo (End Tidal Partial Pressure of Sevoflurane), t=Time (Minutes) At 2 minutes	0.18 ratio Standard Deviation 0.04	0.22 ratio Standard Deviation 0.07
PA t/PA0 Sevo (End Tidal Partial Pressure of Sevoflurane), t=Time (Minutes) At 5 minutes	0.14 ratio Standard Deviation 0.02	0.17 ratio Standard Deviation 0.06

SECONDARY outcome

Timeframe: 20 Minutes

The time to eye opening to command after cessation of inhalational anaesthetic administration

Outcome measures

Outcome measures
Measure	Sevoflurane in N2O/O2 n=10 Participants N20 with Oxygen (2:1) and Sevoflurane	Sevoflurane in Air/O2 n=10 Participants Air/Oxygen and Sevoflurane
Time to Eye Opening	8.7 Minutes Standard Deviation 1.3	11.0 Minutes Standard Deviation 1.4

Adverse Events

N20 With Oxygen (2:1)

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 Phil Peyton

Austin Health

Phone: 9496 5000

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place