Comparison of peri-operative anaesthetic outcomes in patients undergoing percutaneous nephrolithotomy (PCNL) surgery in supine versus prone position: A prospective observational Study

A change in dietary habits as well as global warming have attributed to an increased incidence and prevalence of renal calculi across the globe. The traditional and oldest methods described for the removal of kidney stones are through an open nephrolithotomy access. The advent of endourological procedures since the availability of ureteroscopes and nephroscopes, has been a great advantage with better patient outcomes, a much less incidence of complications and faster discharge from hospital. Percutaneous nephrolithotomy (PCNL) is a minimally invasive technique that provides a direct approach to the renal calculus while the kidney and the surrounding structures are subjected to lesser trauma as compared to the open approach. Thus PCNL is currently considered the technique of choice to remove large renal calculi.  Traditionally PCNL is done in the prone position, which allows a direct access to the posterior calyx, provides a safer procedure regarding the location of the bowel and allows a wider field for instrumentation. Apart from complications such as blood loss, sepsis, pleural injury resulting in pneumothorax/ hydrothorax/haemothorax, renal collecting system injury resulting in urinary leakage and hypothermia, providing anaesthesia for PCNL is a challenge with the positioning in the prone position with its associated implications and complications as well. This is more so in the patients with cardiorespiratory comorbidities and in those who are obese. Recently, in our institution, PCNL surgeries are being carried out in the supine or modified supine positions as well. In our prospective, observational study, we plan to evaluate the impact of prone versus supine position with regard to the hemodynamic profile and respiratory parameters. We also plan to assess the other  perioperative anaesthetic  outcomes such as recovery form anaesthesia and the quality of recovery as assessed by quality of recovery score (QoR 15) at 24 hours after surgery and the DREAM time (time to DR-DRink, E-EAt, and Mobilize- M) after surgery. We will also assess the incidence of post-operative pain, shivering, perioperative complications, duration of hospital stay  and compare  these parameters between the prone and supine positions.