Effect of volume-controlled and pressure-controlled ventilation modes on cerebral oximetry in laparoscopic cholecystectomy: a randomized controlled trial

This study aimed to compare the effect of volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) modes on cerebral oximetry during laparoscopic cholecystectomy using near-infrared spectroscopy (NIRS). Seventy patients who underwent elective laparoscopic cholecystectomy were randomized to receive either VCV (group V) or PCV (group P). Demographic and operative data (anesthesia, surgery and insufflation durations) were recorded. The primary outcome was the NIRS value, while the secondary outcomes were peripheral oxygen saturation (SpO2), blood gas parameters and peak and plateau pressures in mechanical ventilation. Measurements were conducted at the start of anesthesia (T0), end of intubation (T1), 5 min after insufflation (T2), just before desufflation (T3), and 5 min after desufflation (T4). Both groups were comparable in terms of age, sex, body mass index, intraoperative time, anesthesia and insufflation durations. The average NIRS right T1–T2–T3 and left T2–T3 values were significantly higher in group P than in group V (p = 0.030, p = 0.001, p = 0.001, p = 0.006 and p = 0.002 respectively). In contrast, the mean peak and mean plateau pressures in group P at T1, T2 and T4 were significantly lower than those in group V (p = 0.003, p = 0.001, p < 0.001, p = 0.011, p = 0.001 and p < 0.001 respectively).The PCV mode allows better cerebral oxygenation than VCV while maintaining lower peak pressure and plateau pressures.