Lung Ultrasound Versus Dynamic Lung Compliance to Detect the Optimum Positive End-Expiratory Pressure After Alveolar Recruitment for Patients Undergoing Laparoscopic Gastric Sleeve Surgery: A Randomized Trial

Background: Various maneuvers are used to maintain oxygenation and prevent atelectasis and desaturation during general anesthesia in bariatric surgery. These maneuvers include alveolar recruitment (ARM) and positive end-expiratory pressure (PEEP). The current study aimed to illustrate the role of transthoracic lung ultrasound (LUS) as a clinical tool in comparison to dynamic lung compliance Cdyn for the detection of optimum PEEP after ARM for obese patients undergoing laparoscopic gastric sleeve surgery.

Materials and Methods: Sixty patients who were scheduled for laparoscopic gastric sleeve surgery, 18-60 years old, of both sex, American Society of Anesthesiologists physical status ASA II, and body mass index BMI>30kg/m2 were enrolled in the study. They were randomly allocated into two groups to detect the optimum PEEP after ARM, group I lung Cdyn (n=30) and group II LUS (n=30). In both groups, hemodynamic parameters HR and MAP, SpO2, PaO2, and PaO2/FiO2 were recorded. A lung ultrasound score (LUSS) was used in the US group.

Results:  Both techniques effectively detected optimum PEEP after ARM without significant differences. Hemodynamics (HR, MBP) significantly changed within groups without significant differences between the groups regarding such changes. Regarding SpO2, PaO2, and PaO2/FiO2, there was a considerable increase within groups, especially after ARM, without substantial differences regarding such changes. Postoperative pulmonary complications (PPCS); PaO2<80mmHg, and SpO2<94% were non-significantly more frequent in the Cdyn group.

Conclusion: Both lung Cdyn and LUS were effective methods to detect the optimum PEEP needed after ARM in laparoscopic gastric sleeve surgery.