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

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 micrograms 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 micrograms 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.