Background: Intra-abdominal pressure (IAP) is variably influenced by surgical positioning.  and increased IAP has diverse systemic effects. Both prone and lateral positions are used during neurosurgery. Studies on IAP available in the literature mostly included critically ill / intensive care unit patients. However, there are very few studies specifically addressing the IAP variations in prone / lateral surgical positions during neurosurgery.  We aimed at studying the changes of IAP and its impact on renal and hepatic injury in prone and lateral neurosurgical positions. 

Methodology: In this prospective observational study, 40 adult patients undergoing elective craniotomy in prone (Group P, 20 patients) or lateral (Group L, 20 patients) were included. Intraoperative goal directed fluid was administered. IAP was measured using intravesical pressure monitoring method at baseline, after surgical positioning, then every 2hourly till skin closure. Intra-operative variables; post operative IAP (4hrly for 24 hrs), acute kidney injury   (with AKI scoring and NGAL study)/liver injury, complications; hospital and ICU stay as well as outcome (Glasgow Outcome Scale) were compared between the two groups. 

Results: Demographic variable, baseline IAP, intraoperative fluid/ blood transfusion amount, vitals, inotrope use and duration of surgery and anesthesia were comparable between the two groups.  Mean intra-operative and post operative IAP value was significantly higher in Group P. Patient in Group P had significantly more incidence of AKI as compared to group L. However, other complications, hospital/ ICU stay and neurological outcome between the two groups were similar.

Conclusion: Neurosurgical patients operated in prone position have significantly higher intra-operative and post-operative IAP and incidence of AKI as compared to lateral position.