Ventilatory and hemodynamic changes during retroperitoneal and transperitoneal laparoscopic nephrectomy: A prospective real-time comparison

Purpose: Nephrectomies are currently performed via the transperitoneal or retroperitoneal laparoscopic approach. We compared the ventilatory and hemodynamic effects of these approaches. Materials and Methods: After institutional ethics committee approval was obtained patients requiring nephrectomy in a 9-month period were prospectively allocated to the retroperitoneal (24) or transperitoneal (15) approach. All were initially ventilated in the volume controlled mode (10 ml kg^-1 tidal volume). Intraoperative fingertip, pulse derived arterial oxygen saturation less than 97%, end tidal CO₂ partial pressure greater than 40 mm Hg and peak inspiratory pressure greater than 36 cm H₂O necessitated changes in ventilatory parameters, as deemed necessary by the anesthetist. If tidal volume decreased greater than 25% of baseline, pressure controlled ventilation was begun instead. Results: Peak inspiratory and plateau pressures increased for the transperitoneal approach by approximately 30% more than in the retroperitoneal group (p <0.05), Volume controlled ventilation was changed to pressure controlled ventilation in 8 transperitoneal vs zero retroperitoneal cases (p <0.05). Heart rate, and systolic and diastolic blood pressure increased by approximately 13% more in the transperitoneal than in the retroperitoneal group (p <0.05). Conclusions: Nephrectomy via the retroperitoneal laparoscopic approach interferes with ven-tilatory and hemodynamic functions less than nephrectomy via the transperitoneal approach.