Comparison Between Pressure-Regulated Volume-Controlled and Volume-Controlled Ventilation on Oxygenation Parameters, Airway Pressures, and Immune Modulation During Thoracic Surgery

Abstract

Objectives: To compare 2 different ventilatory strategies: pressure-regulated volume-controlled (PRVC) versus volume-controlled ventilation during thoracotomy.

Design: Prospective randomized study.

Setting: University hospital.

Participants: The study comprised 70 adult patients undergoing thoracic surgery.

Interventions: Evaluation of oxygenation parameters, airway pressures, and immune modulation.

Measurements and main results: The primary outcome was arterial oxygen tension/fraction of inspired oxygen (PaO₂/F_IO₂) ratio, whereas secondary outcomes included arterial and central venous blood gases, deadspace volume/tidal volume ratio, peak inspiratory pressure, mean inspiratory pressure, and plateau inspiratory pressure obtained at the following 4 time points: 20 minutes after total lung ventilation (T₀), 20 minutes after 1-lung ventilation (T₁), 20 minutes after return to total lung ventilation (T₂), and at the end of surgery (T₃). Furthermore, alveolar and plasma levels of interleukin-8 and tumor necrosis factor-α and changes in alveolar albumin levels and cell numbers were measured at the same time points. Oxygenation parameters (PaO₂/F_IO₂ and PaO₂) were significantly better in the PRVC group (PaO₂/F_IO₂ ratio at T₁ was 176 v 146 in the PRVC and volume-controlled groups, respectively, with a p value of 0.004). Deadspace volume/tidal volume ratio and inspiratory airway pressures were significantly lower in the PRVC group. Furthermore, all inflammatory parameters (alveolar and plasma interleukins, alveolar albumin levels, and cell numbers) were significantly lower in the PRVC group.

Conclusions: The PRVC mode during 1-lung ventilation in thoracic surgery caused a favorable effect on oxygenation parameters, respiratory mechanics, and immune modulation during thoracic surgery.

Keywords: pressure-regulated volume-controlled mode; thoracic surgery; volume-controlled mode.