Effects of sodium nitroprusside-induced controlled hypotension on pancreatic function assessed by pancreatitis-associated protein in patients undergoing radical prostatectomy

Abstract

Background and objective: Controlled hypotension may alter organ blood flow and tissue oxygenation. The aim of the study was to investigate whether induced hypotension using sodium nitroprusside alters pancreatic function assessed by pancreatitis-associated protein concentrations in the blood.

Methods: Thirty patients undergoing elective radical prostatectomy were allocated randomly into two groups: (a) hypotension group: sodium nitroprusside was administered to lower mean arterial pressure to approximately 50 mmHg; (b) control group: no hypotension was used, mean arterial pressure was kept >70 mmHg. Pancreatitis-associated protein and lipase were measured in arterial blood samples: after induction of anaesthesia (T1), at the end of surgery (T2), 2 h (T3) and 24 h (T4) postoperatively.

Results: Pancreatitis-associated protein plasma concentrations increased significantly in patients in the hypotensive group (from 2.8 ± 1.1 to 5.5 ± 2.0 µg L⁻¹ at T4) and pancreatitis-associated protein plasma concentrations were significantly higher in comparison with controls (5.5 ± 2.0 versus 3.5 ± 2.4 µg L⁻¹) at T4. Lipase concentrations showed a similar course in both groups. None of the patients showed clinical signs of pancreatitis.

Conclusions: Controlled hypotension during surgery was associated with a small but significant increase in pancreatitis-associated protein compared with controls. The absence of concomitant elevation in lipase concentrations and a lack of clinical evidence of pancreatitis damage suggest that hypotension induces mild pancreatic stress.