OBJECTIVETo observe the effect of obesity on pharmacokinetics and pharmacodynamics of isoflurane.

METHODSTwenty-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.

RESULTSIsoflurane 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.

CONCLUSIONSObese 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.

Adult ; Aged ; Anesthesia, Inhalation ; Anesthetics, Inhalation ; administration & dosage ; pharmacokinetics ; Body Mass Index ; Cholecystectomy, Laparoscopic ; Dose-Response Relationship, Drug ; Female ; Humans ; Isoflurane ; administration & dosage ; pharmacokinetics ; Male ; Middle Aged ; Obesity ; complications ; metabolism

Objective To evaluate the application of adding ondansetron in morphine intravenous analgesia pump for prevention of postoperative nausea and vomiting(PONV)in women. Methods Data of surgical female inpatients who received general anesthesia and postoperative intravenous analgesia with morphine in our center from January 1st,2013 to December 31st,2014 were retrospectively analyzed. Based on whether ondansetron was added,patients were divided into the observation group(n=834) and the control group(n=856). Outcome variables including morphine consumption,visual analogue scale(VAS) score,nausea score,and total times of vomiting within 48 hours after surgery were collected and compared. Results Age(t=0.432,P=0.665),morphine consumption during the first post-operative day(t=0.599,P=0.548) and during the second post-operative day(t=0.236,P=0.813),maximum VAS score of postoperative pain during movement during the first post-operative day [3(2,4) vs. 3(2,5);Z=1.850,P=0.064] and at rest during the second post-operative day [0(0,1) vs. 0(0,1);Z=1.511,P=0.131] were not significantly different between two groups. While the maximum VAS score of postoperative pain at rest during the first post-operative day [0(0,2) vs.0(0,2);Z=2.435,P=0.015] and during movement during the second post-operative day [3(1,3)vs.3(2,4);Z=3.445,P=0.001] were significantly different between two groups. The maximum score of postoperative nausea(χ=9.810,P=0.020) and cumulative frequency of postoperative vomiting(Z=3.726,P=0.002)in the observation group were significantly lower than those in the control group during the first post-operative day;however,there was no significant difference during the second post-operative day(χ=5.017,P=0.170;Z=0.000,P=1.000). Logistic regression analysis showed that adding ondansetron in morphine intravenous analgesia pump was an independent influencing factor of reduced postoperative nausea. The probability of nausea during the first post-operative day was 0.781 time(P=0.015)of that in the control group and 0.736 time(P=0.030)during the second post-operative day. Conclusion Adding ondansetron in morphine intravenous analgesia pump may reduce PONV in women.