Existence of reverse second gas effect with enflurane.
OBJECTIVE
To investigate the existence of 'reverse second gas effect' with enflurane and to find out any influence of the variables; age, gender, body weight and American society of anaesthesiologist (ASA) status of the patient over the existence of reverse second gas effect.


METHODS
This double blinded randomized control trial included forty eight adult ASA I and II patients divided in two groups 'A' and 'B'. The existence of reverse second gas effect was investigated in terms of rate of decline of exhaled concentration of enflurane with and without nitrous oxide. Collected data included age, weight, gender, ASA status, rate of decline of exhaled enflurane, heart rate & blood pressure of patients during the research protocol.


RESULTS
Independent 't' test was used to compare the rate of decline and exhaled concentration of enflurane with and without nitrous oxide (p = 0.22). 'T' test was also used (p = 0.45 & 0.97 respectively) to observe the influence of age and weight. For the influence of ASA status and gender, chi square test was applied (p = 0.99 and 0.77 respectively).


CONCLUSIONS
From the results of our study, we concluded that reverse second gas effect does not exist with enflurane. Furthermore, no influence of the variables age, gender, ASA status and body weight could be found on the existence of reverse second gas effect.
Ahmed
Tauseef
T
Department of Anaesthesia, Aga Khan University Hospital, Karachi.
Khan
Mueenullah
M
Chohan
Ursula
U
D000328:Adult; D000768:Anesthesia, General / Q000379:methods; D018685:Anesthetics, Inhalation / Q000493:pharmacokinetics*; D004311:Double-Blind Method; D004737:Enflurane / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D008297:Male; D009609:Nitrous Oxide / Q000493:pharmacokinetics*
D018685:Anesthetics, Inhalation; D004737:Enflurane; D009609:Nitrous Oxide