Effect of intraoperative fluid optimisation on renal function in patients undergoing emergency abdominal surgery: a randomised controlled pilot study (ISRCTN 11799696).

BACKGROUND

Emergency abdominal surgery carries a high risk of postoperative morbidity and mortality. Goal directed therapy has been advocated to improve outcome in high-risk surgery. The aim of the present pilot study was to examine the effect of goal directed therapy using fluid alone on postoperative renal function and organ failure score in patients undergoing emergency abdominal surgery.

METHODS

This prospective randomised pilot study included patients over the age of 50 undergoing emergency abdominal surgery. In the intervention group pulse pressure variation measurements were used to guide fluid boluses of 6% Hydroxyethylstarch 130/0.4. The control group received standard care. Serum urea, creatinine and cystatin C levels were measured prior to and at the end of surgery and postoperatively on day 1, day 3 and day 5.

RESULTS

Thirty patients were recruited. One patient died prior to surgery and was excluded from the analysis. The intervention group received a median of 750 ml of hydroxyethylstarch. The peak values of postoperative urea were 6.9 (2.7-31.8) vs. 6.4 (3.5-11.5)mmol/l (p=0.425), creatinine 100 (60-300) vs. 85 (65-150) micromol/l (p=0.085) and cystatin C 1.09 (0.66-4.94) vs. 1.01 (0.33-2.29)mg/dl (p=0.352) in the control and intervention group, respectively.

CONCLUSIONS

In the present pilot study replacing the identified fluid deficit was not associated with a change in renal function. These results do not preclude that goal directed therapy using fluid alone may have an effect on renal function but they would suggest that the effect size of fluid optimisation alone on renal function is small.