Pressure-controlled versus Volumecontrolled Ventilation during One Lung Ventilation for Empyema Thoracis: A Randomised Control Trial

Abstract

Introduction: Volume Controlled Ventilation (VCV) is traditionally used during One Lung Ventilation (OLV); however, it is associated with complications such as volutrauma and barotrauma. On the other hand, Pressure Controlled Ventilation (PCV) allows the delivery of a required tidal volume at lower airway pressures, leading to enhanced oxygenation and ventilation. Aim: To compare VCV and PCV modes for OLV in patients undergoing surgery for empyema thoracis. Materials and Methods: A randomised controlled trial was conducted among 50 patients requiring OLV. The participants were divided into two groups, namely Group-V and Group-P, with each group receiving VCV and PCV, respectively. The two groups were compared based on the partial pressure of oxygen (during the intraoperative and post-operative period), peak and plateau airway pressures, lung compliance, and complications. The groups were analysed using the Chi-square test, and the threshold of statistical significance was set at a p-value <0.05. Results: Fifty participants were divided into two groups: VCV (n=25) and PCV (n=25). Both study groups were found to be comparable in terms of demographic details, haemodynamic parameters, and duration of surgery. The mean age of the patients was 27.80 years in Group-V and 31.04 years in Group-P. The authors observed improved PaO2 levels, lung compliance, and reduced peak pressures during OLV in the PCV group. After lung isolation, PaO2 levels of Group-P patients (93.64±5.154 mmHg) were higher compared to Group-V (81.38±7.975 mmHg) at 50% FiO2 (p-value <0.001). Similarly, post-extubation PaO2 levels were better in Group-P (99.24±18.58 mmHg) than in Group-V (84.35±7.677 mmHg) at 36% FiO2 (p-value <0.001). The mean peak pressures were lower in Group-P (25.17±4.34 cm H2 O) than in Group-V (28.22±4.51 cm H2 O). Additionally, there was a statistically significant improvement in lung compliance among Group-P patients (p-value=0.0144). Conclusion: Thus, it can be inferred that PCV improves oxygenation and reduces airway pressures during OLV. However, there was no significant difference seen between the two modes in terms of post-operative pulmonary complications.