Effects of nonsteroidal anti-inflammatory drugs on postoperative renal function in adults with normal renal function

Nonsteroidal anti-inflammatory drugs (NSAIDs) can play a major role in the management of acute pain in the peri-operative period. However, there are conflicting views on whether NSAIDs are associated with adverse renal effects.

The primary objective of this review was to determine the effects of NSAIDs on postoperative renal function in adults with normal preoperative renal function.

Electronic searches for relevant randomised and quasi-randomised controlled trials in Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE were performed. Attempts were also made to identify trials from citation lists of relevant trials, review articles and clinical practice guidelines. Handsearching of conference abstracts published in major anaesthetic journals was also performed. Date of most recent search: May 2006

The inclusion criteria were randomised or quasi-randomised comparisons of individual NSAIDs with either each other or placebo for treatment of postoperative pain, with relevant postoperative renal outcome measures, in adult surgical patients with normal renal function.

The data were extracted independently by two authors. The primary outcome measure was creatinine clearance within the first two days after surgery. Secondary outcome measures included serum creatinine, urine volume, urinary sodium level, urinary potassium level, fractional excretion of sodium, fractional excretion of potassium and need for dialysis. Weighted mean differences for continuous outcomes and relative risk (RR) and risk difference (RD) for dichotomous outcomes were estimated with 95% confidence intervals (CI).

Twenty-three trials (1459 patients) fulfilled the selection criteria for this review. NSAIDs reduced creatinine clearance by 16 mL/min (95%CI 5 to 28) and potassium output by 38 mmol/day (95%CI 19 to 56) on the first day after surgery compared to placebo. There was no significant difference in serum creatinine on the first day (0 umol/L, 95%CI -3 to 4) compared to placebo. No significant reduction in urine volume during the early postoperative period was found. There was no significant difference in serum creatinine in the early postoperative period between patients receiving diclofenac, ketorolac, indomethacin, ketoprofen or etodolac. No cases of postoperative renal failure requiring dialysis were described. The trials were not heterogeneous for the primary outcome.

NSAIDs caused a clinically unimportant transient reduction in renal function in the early postoperative period in patients with normal preoperative renal function. NSAIDs should not be withheld from adults with normal preoperative renal function because of concerns about postoperative renal impairment.