Evaluation of the Effect of Pressure-Controlled Ventilation-Volume Guaranteed Mode vs. Volume-Controlled Ventilation Mode on Atelectasis in Patients Undergoing Laparoscopic Surgery: A Randomized Controlled Clinical Trial

Background and Objectives: Laparoscopic surgery, which results in less bleeding, less postoperative pain, and better cosmetic results, may affect the lung dynamics via the pneumoperitoneum. After laparoscopic surgery, atelectasis develops. The primary aim of the present study is to demonstrate the effects of two different ventilation modes on the development of atelectasis using lung ultrasound, and the secondary outcomes include the plateau pressure, peak inspiratory pressure, and compliance differences between the groups. Materials and Methods: In this study, 62 participants aged 18-75 years undergoing laparoscopic cholecystectomy were enrolled. The patients were randomly assigned into two groups: the volume-controlled ventilation (VCV) group (group V) or the pressure-controlled-volume guaranteed ventilation (PCV-VG) group (group PV). The lung ultrasound score (LUS) was obtained thrice: prior to induction (T1), upon the patient's initial arrival in the recovery room (T2), and just before departing the recovery unit (T3). The hemodynamic data and mechanical ventilation parameters were recorded at different times intraoperatively. Results: The LUS score was similar between the groups at all the times. The change in the LUS score of the right lower anterior chest was statistically higher in the VCV group than the PCV group. The peak inspiratory pressure (PIP) was found to be statistically higher in the V group than the PV group five minutes after induction (T5) (20.84 +/- 4.32 p = 0.021). The plateau pressure was found to be higher in the V group than the PV group at all times (after induction (Tind) 17.29 +/- 5.53 p = 0.004, (T5) 17.77 +/- 4.89 p = 0.001, after pneumoperitoneum (TPP) 19.71 +/- 4.28 p = 0.002). Compliance was found to be statistically higher in the PV group than the V group at all times ((Tind) 48.87 +/- 15.37 p = 0.011, (T5) 47.94 +/- 13.71 p = 0.043, (TPP) 35.65 +/- 6.90 p = 0.004). Before and after the pneumoperitoneum, the compliance was determined to be lower in the V group than the PV group, respectively (40.68 +/- 13.91 p = 0.043, 30.77 +/- 5.73 p = 0.004). Conclusions: LUS score was similar between groups at all times. The PCV-VG mode was superior to the VCV mode in providing optimal ventilatory pressures and maintaining high dynamic compliance in patients undergoing laparoscopic abdominal surgery.