Features of Mechanical Lung Ventilation During Robot-Assisted Radical Prostatectomy in Patients with Different Body Mass Index

Abstract

The aim of the study. To evaluate effects of carboxyperitoneum and steep Trendenburg position on respiratory biomechanics and gas exchange indicators in patients with different body mass index (BMI) during robotic-assisted radical prostatectomy (RRP). To develop an algorithm for choosing the optimal mechanical lung ventilation (MLV) regimen. Materials and methods. The study included 141 patients with verified prostate cancer who were candidates for RPR. Participants were divided into 2 groups based on BMI: group I included 88 patients with BMI30 kg/m2, group II — 53 patients with BMI30 kg/m2. Indicators of respiratory biomechanics and gas exchange during ventilation in various modes (Volume Controlled Ventilation (VCV), Pressure Controlled Ventilation (PCV), Pressure Controlled– Inverse Ratio Ventilation (PC-IRV) were analyzed in each group at 5 consecutive stages of the procedure.Results. The key parameters evidencing the effectiveness and safety of MLV during RRP procedure did not vary significantly under various ventilation regimens in the group of patients with a BMI30 kg/m2. Whilst in obese patients the use of VCV mode resulted in a significant increase of airway peak pressure (Ppeak) already at the stage of placing them into a steep Trendelenburg position (35°), thus endangering with the development of ventilator-induced lung injury. Increased Ppeak was also accompanied by the drop in oxygen saturation and significantly lower SpO₂ values, starting from the stage of applying carboxyperitoneum and until the end of surgical intervention.Conclusion. In non-obese patients, there’s no particular ventilator regimen that is crucial for achieving the safety and effectiveness of RRP anesthesia management, all regimens can be used. In patients with BMI30 kg/m2 PCV regimen and PC-IRV with inhalation/exhalation ratio of 1.5:1  can be considered as the optimal strategy for MLV during anesthesia for RRP surgery.