BACKGROUND AND AIMS- The laparoscopic surgeries create pneumoperitoneum which has adverse hemodynamic and respiratory consequences. Several ventilatory strategies exist to prevent intra-operative atelectasis and improve arterial oxygenation in laparoscopic surgeries but they remain controversial. Application of PEEP (Positive end expiratory pressure) in mechanical ventilation during laparoscopic surgery provides beneficial effects on respiratory functions, prevents atelectasis and improves ventilation-perfusion mismatch. We performed this study to compare the effects of Pressure controlled ventilation (PCV) VS VCV (Volume controlled ventilation) with PEEP of 7 cmH2o on lung mechanics and oxygenation parameters in patients undergoing laparoscopic cholecystectomy.
METHODOLOGY- The study included a total of 98 patients allocated to PCV (Group A) and VCV (Group B) groups with 49 patients in each group. After intubation the patients were put on ventilatory settings chosen based on a specifically derived algorithm. Peak airway pressure (P peak), mean airway pressure (P mean), dynamic compliance, mean arterial pressure, PaO2, PaCo2, pH were noted at specific time intervals.
RESULTS- The peak airway pressure was higher in group B compared to group A at T3-6. The mean airway pressure was higher in group A compared to B from T3-6. The dynamic compliance was better in group A compared to group B from T3-6. The PaO2 measured at T2 and T4 was higher in group A, the PaCo2 and pH were comparable in two groups. The hemodynamics were comparable in both groups at various time intervals.
CONCLUSION-PCV is a better mode of ventilation than VCV in patients of laparoscopic cholecystectomies.