The sevoflurane-sparing effect of nitrous oxide: a clinical study.
BACKGROUND
We studied the sevoflurane-sparing effect of nitrous oxide in a prospective randomised study.


METHODS
Forty-two ASA I-II patients scheduled for elective knee arthroscopy under general anaesthesia were randomly assigned to a fresh gas flow consisting of oxygen in air or oxygen in nitrous oxide 1:2. All patients received a standardised anaesthesia consisting of induction with fentanyl and propofol and maintenance with sevoflurane adjusted according to clinical signs. The sevoflurane consumption was studied by means of weighing the vaporiser before and after every anaesthesia.


RESULTS
The mean sevoflurane consumption was reduced from 0.62 to 0.25 g/min, a 60% reduction, by the use of oxygen in nitrous oxide 1:2 in the fresh gas flow. The emergence was faster for the patients receiving nitrous oxide. No major differences were observed during recovery.


CONCLUSIONS
Nitrous oxide was found to be cost-effective for use during short ambulatory knee arthroscopy.
Jakobsson
I
I
Department of Anaesthesia and Orthopaedic Surgery, Sabbatsberg Närsjukhuset, M&M Medical Inc., Stockholm, Sweden.
Heidvall
M
M
Davidson
S
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D000762:Anesthesia Recovery Period; D000768:Anesthesia, General; D000769:Anesthesia, Inhalation / Q000295:instrumentation; D018685:Anesthetics, Inhalation / Q000008:administration & dosage* / Q000191:economics; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D001182:Arthroscopy; D003362:Cost-Benefit Analysis; D016527:Drug Costs; D017558:Elective Surgical Procedures; D004724:Endoscopy; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage; D006801:Humans; D007719:Knee Joint / Q000601:surgery; D008297:Male; D008738:Methyl Ethers / Q000008:administration & dosage*; D008875:Middle Aged; D009330:Nebulizers and Vaporizers; D009609:Nitrous Oxide / Q000008:administration & dosage* / Q000191:economics; D010100:Oxygen / Q000008:administration & dosage; D015742:Propofol / Q000008:administration & dosage; D011446:Prospective Studies; D000077149:Sevoflurane
D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D008738:Methyl Ethers; D000077149:Sevoflurane; D009609:Nitrous Oxide; D010100:Oxygen; D005283:Fentanyl; D015742:Propofol