thiopental and Obesity--Morbid

The effect of etomidate administration on the adrenal cortex in obese patients is still unclear. The objective of the study was to determine the influence of a single dose of etomidate on cortisol secretion in the morbidly obese.. 127 healthy patients were enrolled into the study. Data from 82 patients scheduled for elective laparoscopic surgery were analyzed. 62 of them were morbidly obese, while 20 had normal body mass. The participants were divided equally into etomidate and thiopental groups, depending on the kind of intravenous anaesthetic used for the induction of anaesthesia. Each patient's serum cortisol concentration was measured five times: on the day before surgery (sample A), two hours after the induction of anaesthesia (sample B), after a short tetracosactide test (sample C), 24 hours after the induction of anaesthesia (sample D), and after a second short stimulation test (sample E).. The mean cortisol concentration in obese patients in the etomidate group was lower two hours after the induction of anaesthesia (sample B, P < 0.001), and 30 minutes after the first tetracosactide test (sample C, P < 0.001) compared to obese patients in the thiopental group. There were no differences between the groups in sample A (P = 0.833), D (P = 0.614) and E (P = 0.769). We found no changes in haemodynamic parameters between both groups.. Etomidate decreased serum cortisol concentration and decreased reactivity to tetracosactide both in morbidly obese and in normal weight patients. This effect was reversible within 24 hours.

Topics: Adult; Anesthetics, Intravenous; Etomidate; Hemodynamics; Humans; Hydrocortisone; Middle Aged; Obesity, Morbid; Thiopental

Obese patients have a decreased functional residual capacity and, hence, a reduced oxygen supply during periods of apnea. To determine whether obese patients are at greater risk of developing hypoxemia during induction of anesthesia than patients of normal weight, 24 patients undergoing elective surgical procedures were studied. Group 1 (normal) were within 20% of their ideal body weight. Group 2 (obese) were more than 20% but less than 45.5 kg over ideal body weight. Group 3 (morbidly obese) were more than 45.5 kg over ideal body weight. Patients were preoxygenated for 5 min or until expired nitrogen was less than 5%. After induction of anesthesia and muscle relaxation the patients were allowed to remain apneic until arterial saturation as measured by pulse oximetry reached 90%. The time taken for oxygen saturation to decrease to 90% was 364 +/- 24 s in group 1, 247 +/- 21 s in group 2, and 163 +/- 15 s in group 3; these times are significantly different at P less than 0.05 between groups. Regression analysis of the data demonstrated a significant negative linear correlation (r = -0.83) between time to desaturation and increasing obesity. These results show that obese patients are at an increased risk of developing hypoxemia when apneic.

Topics: Adult; Anesthesia; Apnea; Humans; Hypoxia; Middle Aged; Obesity; Obesity, Morbid; Risk; Thiopental