Effect of Intraoperative Lung Recruitment and Transversus Abdominis Plane Block in Laparoscopic Bariatric Surgery on Postoperative Lung Functions: A Randomized Controlled Study

Abstract

Abstract Background Morbid obesity may cause a restrictive condition. general anesthesia (GA) and supine posture both result in a decrease in lung capacity and Functional residual capacity (FRC), encouraging the development of atelectasis, altering the ventilation/perfusion ratio and raising the pulmonary shunt. This study evaluated the impact of recruitment maneuver (RM) and Transversus Abdominis Plane (TAP) block performed during laparoscopic bariatric surgery on spirometry, oxygenation, hemodynamic variables, opioid requirements and pain score assessed after surgery. Methods This pilot prospective randomized controlled study included 80 patients scheduled for elective laparoscopic bariatric surgeries (e.g., laparoscopic sleeve gastrectomy, and laparoscopic gastric bypass) under GA. Patients were divided into four equal groups. All patients had received standardized postoperative analgesia regimen, group I (control group), group II received TAP block after intubation and before surgical incision, group III received RM after intubation and after pneumoperitoneal exsufflation, and group IV received RM after intubation and after pneumoperitoneal exsufflation and TAP block after intubation and before surgical incision. Results Forced Vital Capacity “FVC”, Forced Expiratory Volume “FEV1” were found to be significantly higher after operation in group IV compared to other groups. FEV1/FVC was insignificantly different among the four groups before and after operation. Intraoperative PaO2, PaO2/FiO2 were significantly higher in group III and IV compared to other groups. Numerical rating scale (NRS) at 1, 2, 4, 6 and 12hr had significantly decreased in group II and IV compared to other groups. Heart rate (HR) and mean arterial blood pressure (MAP) were insignificantly different among the four groups. Morphine consumption was significantly lower in group II and IV compared to other groups. Conclusions TAP block combined with RM group exhibited better postoperative pulmonary function tests (PFTs). Intraoperative oxygenation was higher in RM groups. NRS and opioid consumption were lower in TAP groups in postoperative period.