[Influence of obesity on pharmacokinetics and pharmacodynamics of isoflurane].
OBJECTIVE
To observe the effect of obesity on pharmacokinetics and pharmacodynamics of isoflurane.


METHODS
Twenty-six patients undergoing cholecystectomy were divided into obese group (Group A, BMI > or = 27, n = 13) and normal body weight group (Group N, BMI < or = 24, n = 13) according to body mass index (BMI). All patients were given to the same isoflurane anesthesia. Inspired and end-expired concentrations of isoflurane were monitored and uptake fraction of isoflurane were calculated.


RESULTS
Isoflurane concentrations of vaporizer in Group A [(1.8 +/- 0.3)%] were evidently higher than those in Group N [(1.5 +/- 0.1)%] at all observed points (P < 0.05 or P < 0.01). Uptake fraction of isoflurane in Group A were higher than those in Group N at observed points (P < 0.05, P < 0.01 or P < 0.001), but there were no differences in the time when isoflurane concentration was lowered to 50% and awake time between the two groups after discontinuing inhaling isoflurane.


CONCLUSIONS
Obese patients demand higher inspired concentration and uptake of isoflurane than those in normal weight patients but discharge of isoflurane was influenced by obesity within the observed period of (66 +/- 33) min.
Gong
Zhi-yi
ZY
Department of Anesthesiology, PUMC Hospital, CAMS and PUMC, Beijing 100730, China. gongzy@csc.pumch.ac.cn
Ye
Tie-hu
TH
Huang
Yi-dan
YD
Sang
Nuo-er
NE
Duan
He
H
Ren
Hong-zhi
HZ
D000328:Adult; D000368:Aged; D000769:Anesthesia, Inhalation; D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000493:pharmacokinetics*; D015992:Body Mass Index; D017081:Cholecystectomy, Laparoscopic; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007530:Isoflurane / Q000008:administration & dosage / Q000493:pharmacokinetics*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000378:metabolism*
D018685:Anesthetics, Inhalation; D007530:Isoflurane