Hemodynam?c Effects And Emergence T?mes Of Desflurane, Sevoflurane And Propofol Infus?on In Laparoscop?c Gastr?c Band?ng

摘要

Objective: Bariatric surgery is a widely used method for achieving sustained weight loss in severly obese patients. The aim of this study was to investigate the emergence times and hemodynamic changes during laparoscopic gastric bypass in morbid obese patients with different anaesthetic agents. Methods: After receiving local ethics commitee written consent, 60 morbid obese (BMI>35) patients aged 19-61 scheduled for elective laparoscopic gastric banding surgery and randomly allocated to 3 groups. Anesthesia induction was standart for all groups and maintained by TIVA 8-10 mg kg-1hr-1 ,6% desflurane and 2% sevoflurane in groups T, D and S respectively. Hemodynamic variables were measured and recorded before induction(A), after induction(B), before insuflation(C), 5 minutes after(D) and 15 minutes after insuflation of CO2 (E). Emergence times are also recorded.Results: There was no significant difference between the baseline(A) hemodynamic variables among the groups (p>0.05). In group D, there is a statistically significant decrease in systolic arterial blood pressure (SABP) after induction(B) and before insuflation(C) compared to baseline values(A) (p<.05). There was no significant difference in emergence and in extubation times(p>0.05). Conclusion: These findings showed us that desflurane, sevoflurane and propofol are ideally suited both for maintenance of anaesthesia in obese patients with stable hemodynamic variables and all groups had similar emergence times as measured by time to eye opening and extubation. Introduction The prevalence of obesity has markedly increased worldwide in the last years, not only in industrialized western countries but also in the developing countries. The prevalence of obesity has been reported to be about 37% in the United States, and almost 5% of the population are morbidly obese status(1). A BMI30 kg.m-1 or BMI >35 kgm-1 are defined as obese and morbid obese respectively(2). Obesity is associated with many other conditions, some of which have important implications for the administration of anaesthesia. There is an increase in the frequency of chronic diseases such as diabetes mellitus, hypercholesterolemia, hypertensive heart disease, gastro-oesophageal reflux and cardiorespiratory complications e.g. obesity-hypoventilation sendrome, pulmonary arterial hypertension, obstructive sleep apne syndrome and right and left ventricular failure(3). Morbid obesity is associated with reductions in functional residual capacity (FRC), expiratory reserve volume (ERV) and total lung capacity (TLC) (4). Oxygen consumption and carbon dioxide production are increased in the obese as a result of the metabolic activity of the excess fat and the increased workload on supportive tissues(5,6). Morbidly obese individuals usually have only a modest defect in gas exchange preoperatively with a reduction in PaO2 and increases in alveolar-to-arterial oxygen difference and shunt fraction. These deteriorate markedly on induction of anaesthesia and high inspired fractions of oxygen are required to maintain adequate arterial oxygen tension(7). Reduced compliance is associated with a decrease in the FRC, encroachment on the closing volume and impairment of gas exchange(8,9).Pharmacokinetics should also be given special consideration in obese patients. Obese patients have a smaller than normal fraction of total body water, greater than normal tissue content and increased blood volume, volume distrubition, and renal blood flow. Thus, drug distribution and effect may be different in this patient population and should be considered carefully before surgery. Desflurane has the lowest coefficient of the currently marketed anaesthetics and has been empricially favored as the volatile agent for morbid obese (MO) patients because of its presumed faster emergence profile. However, it has several cardiovascular and respiratory side effects related to its airway irritating properties(10). Sevoflurane also has a lower blood-gas solubility