Impact of 30° Reserve Trendelenburg Position on Lung Function in Morbidly Obese Patients Undergoing Laparoscopic Sleeve Gastrectomy

Abstract

Background: This study aimed to evaluate the impact of patients' positioning before and after intubation with mechanical ventilation, and after extubation on the lung function and blood oxygenation of patients with morbid obesity, who had a laparoscopic sleeve gastrectomy. Methods: Patients with morbid obesity (BMI ≥ 30 kg/m2, ASA I – II grade) who underwent laparoscopic sleeve gastrectomy at our hospital from June 2018 to January 2019 were enrolled in this prospective study. Before intubation, after intubation with mechanical ventilation, and after extubation, arterial blood was collected for blood oxygenation and gas analysis after posturing the patients at supine position or 30° reverse Trendelenburg position (30°-RTP). Results: A total of 15 patients with morbid obesity were enrolled in this self-compared study. Pulmonary shunt (Qs/Qt) after extubation was significantly lower at 30°-RTP (18.82 ± 3.60%) compared to that at supine position (17.13 ± 3.10%, p < 0.01). Patients' static lung compliance (Cstat), during mechanical ventilation, was significantly improved at 30°-RTP (36.8 ± 6.7) compared to that of those in a supine position (33.8 ± 7.3, p < 0.05). The PaO2 and oxygen index (OI) before and after intubation with mechanical ventilation were significantly higher at 30°-RTP compared to that at supine position, and in contrast, the PA−aO2 before and after intubation with mechanical ventilation was significantly reduced at 30°-RTP compared to that at supine position. Conclusion: During and after laparoscopic sleeve gastrectomy, patients with morbid obesity had improved lung function, reduced pulmonary shunt, reduced PA−aO2 difference, and increased PaO2 and oxygen index at 30°-RTP compared to that supine position.