ISSN: 2155-6148
Martin Zoremba, Gerald Kalmus, Thorsten Steinfeldt, Helge Müller, Hinnerk Wulf and Frank Dette
Background: Respiratory impairment is common in the perioperative period, especially in the obese. In this study we evaluated the impact of anesthesia related factors, use of neuromuscular blocking agents, choice of anesthesia maintenance, duration of surgery and patient related factors such as age, gender and body-mass index on postoperative pulse oximetry and lung function in the obese. Methods: We studied postoperative lung function and pulse oximetry saturation in 397 obese or overweight patients (Body Mass Index 25-40) undergoing minor surgery . Inspiratory and exspiratory lung function as well as pulse oximetry were measured preoperatively (baseline) and at 10min, 0.5h, 2h and 24h after surgery, with the patient supine, in a 30° head-up position. All factors were added within stepwise regression analysis to create a statistical model. Further analysis was performed using the t-test and Wilcoxon-test. Results: Stepwise regression analysis revealed that, relaxation, in particular using rocuronium rather than cisatracurium (p<0.008) as well as anesthesia maintenance with propofol in contrast to desflurane (p<0.0028), are the most important factors affecting postoperative respiratory impairment and pulse oximetry saturation within the first 24 postoperative hours. Patient related factors as age, body-mass index and surgery time exhibit a minor effect. Conclusion: Anaesthesia related factors rather than patient related factors exhibit a greater effect on lung function impairment within the immediate postoperative period. Lung function impairment occurs independently from fast-track criteria and can be attenuated by choosing well predictable agents for general anaesthesia.