Impact of Overweight and Pneumoperitoneum on Hemodynamics and Oxygenation during Prolonged Laparoscopic Surgery

摘要

BACKGROUND: Anesthesia adversely affects respiratory function and hemodynamics in obese patients. Although many studies have been performed in morbidly obese patients, data are limited concerning overweight patients [BMI 25-29.9 kg m(-2)]. The aim of this study was to evaluate the effects of prolonged pneumoperitoneum in Trendelenburg position on hemodynamics and gas exchange in normal and overweight patients. METHODS: We studied 15 overweight and 15 non-obese [BMI 18.5-24.9 kg m(-2)] patients who underwent totally endoscopic robot-assisted radical prostatectomy under general anesthesia with an inspired oxygen fraction of 0.5. A standardized anesthetic regimen was used, and patients were examined at standard times: after induction of anesthesia and Trendelenburg posture, every 30 minutes after establishing pneumoperitoneum, and after the release of the pneumoperitoneum with the patient still in Trendelenburg position. RESULTS: After induction of anesthesia and Trendelenburg positioning arterial oxygen pressure [P(a)O2] and alveolar-arterial difference in oxygen tension [A(a)DO2] differed significantly between both groups with lower P(a)O2 [235 +/- 27 versus 164 +/- 51 mmHg] and higher A(a)DO2 [149 +/- 48 versus 76 +/- 28 mmHg] values in overweight patients. During pneumoperitoneum, P(a)O2 transient increased above baseline values in overweight patients, whereas A(a)DO2 decreased. Hemodynamic parameters [HR, MAP, and CVP] did not differ significantly between groups. CONCLUSIONS: Arterial oxygenation and A(a)DO2 are significantly impaired in overweight patients under general anesthesia in Trendelenburg posture. In overweight patients pneumoperitoneum transient reduced the impairment of arterial oxygenation and lead to a decrease in A(a)DO2. Hemodynamic parameters were not affected by body weight.