Assessment of Perioperative Atelectasis Using Lung Ultrasonography in Patients Undergoing Pneumoperitoneum Surgery in the Trendelenburg Position: Aspects of Differences according to Ventilatory Mode

Abstract

Background During robotic gynecologic pneumoperitoneum surgery in the Trendelenburg position, aeration loss leads to perioperative atelectasis. Recently developed ventilator mode pressure-controlled ventilation volume-guaranteed (PCV-VG) mode could provide adequate ventilation with lower inspiratory pressure compared to volume-controlled ventilation (VCV); we hypothesized that PCV-VG mode may be beneficial in reducing perioperative atelectasis via low tidal volume (V T ) of 6 mL/kg ventilation during robotic gynecologic pneumoperitoneum surgery in the Trendelenburg position. We applied lung ultrasound score (LUS) for detecting perioperative atelectasis. We aimed to compare perioperative atelectasis between VCV and PCV-VG with a low V T of 6 mL/kg during pneumoperitoneum surgery in the Trendelenburg position using LUS. Methods Patients scheduled for robotic gynecologic surgery were randomly allocated to the VCV (n = 41) or PCV-VG group (n = 41). LUS, ventilatory, and hemodynamic parameters were evaluated at T1 (before induction), T2 (10 minutes after induction in the supine position), T3 (10 minutes after desufflation of CO 2 in the supine position), and T4 (30 minutes after emergence from anesthesia in the recovery room). Results Eighty patients (40 with PCV-VG and 40 with VCV) were included. Demographic data showed no significant differences between the groups. The total LUS has changed from baseline to T4, 0.63 (95% confidence interval [CI], 0.32, 0.94) to 1.77 (95% CI, 1.42, 2.21) in the VCV group and 0.86 (95% CI, 0.56, 1.16) to 1.43 (95% CI, 1.08, 1.78) in the PCV-VG group ( P = 0.170). In both groups, total LUS increased significantly compared to the baseline values. Conclusion Using a low V T of 6 mL/kg during pneumoperitoneum surgery in the Trendelenburg position, our study showed no evidence that PCV-VG ventilation was superior to VCV in terms of perioperative atelectasis. Trial Registration Clinical Research Information Service Identifier: KCT0006404

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Intraoperative lung protection: strategies and their impact on outcomes

“…One noteworthy concern is the operator dependency of ultrasound [73], introducing a learning curve that may impact its seamless integration into surgical practice. Additionally accessing dependent portions of the patients' lungs proves inherently difficult due to the constrained positioning on the operative bed [74]. This difficulty is further compounded in the context of robotic surgeries, where achieving comprehensive access to the patient becomes intricate.…”

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“…The role of ultrasonography in pulmonary imaging has recently gained importance. A Lung ultrasound score (LUS) has been proposed to assess changes in lung aeration based on examination of 12 regions in the chest wall after therapeutic interventions in mechanically ventilated patients [1,2]. LUS depending on the degree of aeration loss is graded between 0 and 3 in each segmental aeration of the examined area of lung [3,4].…”