The present study aims to define the optimal and safe pneumoperitoneal pressure in patients undergoing various transperitoneal laparoscopic renal surgeries at a tertiary care centre considering its effects on patient’s clinical parameters as well as technical feasibility for the surgeons.

This will be a prospective single blinded randomised study performed at a tertiary care teaching hospital in India of 3 months duration. Approximately 80 patients aged 18 years and above, undergoing any of the transperitoneal laparoscopic renal surgery (LRS) under general anesthesia will be included in the study. The study population will be randomized into three strata according to pneumoperitoneal pressure by computer-generated number (Group I pressure 8-10 mmHg, Group II pressure 10-12 mmHg and group III pressure 12-14 mmHg). Patients will be induced by general anesthesia. All patient’s hemodynamic and respiratory parameters and blood gas alterations will be assessed at four specific points during surgery: before insufflation (T1), 10 min after insufflation (T2), 10 min before desufflation (T3), and 10 min after desufflation (T4). The first set of parameters will be noted after induction of anesthesia after obtaining a steady state ventilation and prior to creating pneumoperitoneum (T1) including heart rate (HR), mean arterial pressure (MAP), pH, arterial O2 pressure(pO2), arterial CO2 pressure (pCO2), base excess (BE), end tidal CO2 (ETCO2), , and peak inspiratory pressure (PIP), plateau pressure (PlP) and minute ventilation (MV).

Then, the peritoneal cavity will be insufflated with CO2 after placing umbilical port under vision (Hasson’s technique) using electronic laparoscopic insufflators with an initial flow rate of 3-4 L/min. Other ports will be subsequently placed as per standard steps.

Further sets of same parameters will be recorded 10 min after insufflation (T2), 10 min before desufflation (T3) and 10 min after desufflation (T4) of the peritoneum. Technical feasibility from surgeon’s point of view will be evaluated in terms of successful completion of surgery without conversion to open method at planned pressure with acceptable duration of the surgery, and intraoperative and early postoperative complications. To assess postoperative stress on patient’s physiology, postoperative pain score will be assessed using visual analog scale (VAS) at 1, 6, and 12 h. The time to resume normal solid feeding (as a surrogate marker of disappearance of postoperative nausea and vomiting) will also be noted for all patients.

All the results will be analysed by appropriate statistical methods.