Preemptive Alveolar Recruitment Maneuver Followed by PEEP in Obese Patients Undergoing Laparoscopic Gastric Banding. Does it make a Difference? A Randomized Controlled Clinical Study

摘要

Background: Impaired respiratory functions during general anesthesia are commonly caused by lung atelectasis more in morbidly obese patients. This occurs more frequently with laparoscopic surgery due to trendelenburg position and pneumoperitoneum. Preemptive recruitment maneuver + PEEP results in the prevention of these changes. Aim: To quantitate the effects of RM and PEEP on intraoperative hypoxemia and respiratory mechanics during laparoscopic gastric banding in obese patients. Study Design: A randomized, double-blinded, controlled study. Method and Materials: Fifty adults ASA I-II, BMI (40-50 kg/m2) for elective laparoscopic gastric banding were randomized into, groups C, and RM, 25 patients each. Group C patients received standard ventilation, VT 6 ml/kg, I: E ratio 1: 2 PEEP 5 cm H2O, and respiratory rate 10-12 breaths/ min. RM patients received standard ventilation with one alveolar recruitment maneuver after mechanical ventilation with PEEP of 15 cm H2O till the end of the surgery. Heart rate, mean blood pressure, respiratory mechanical parameters: peak airway pressure, plateau pressure and end-expiratory lung volume, PaO2, PaO2/FiO2 and (SpO2) were assessed. Results: PaO2 and PaO2/FiO2 ratio increased significantly in the RM group after RM from T2 (before pneumoperitoneum) to T6 (end of surgery) compared with group C (P < 0.001). Peak and plateau airway pressures increased significantly in group C from T2 till T5 (60 min after pneumoperitoneum) compared with the RM group (P < 0.001). End-expiratory lung volume increased significantly in the RM group after RM compared with group C (P<0.001). Conclusion: Preemptive RM with PEEP of 15 cm H2O was effective in preventing pneumoperitoneum-induced intraoperative hypoxemia and respiratory mechanics changes.