Prophylactic intravenous mannitol and normal saline in patients with poor renal function prior to cardiac surgery:...

Postoperative acute renal failure requiring dialysis has a poor prognosis, which has remained unaltered for 50 years. Therefore, in cardiac surgical patients at increased risk of postoperative oliguric acute renal failure (preoperative serum creatinine >0.13 mmol/L), we assessed the use of prophylactic intravenous (i.v) 20% mannitol and normal saline therapy in addition to traditional methods of therapeutic renal support.

Seventy-five patients with a mean preoperative serum creatinine of 0.192 mmol/L received i.v. 20% mannitol and normal saline pre-, intra- and postoperatively. This treatment was continued postoperatively until serum creatinine returned to baseline.

No patient required dialysis, no patient died, developed a myocardial infarction nor a stroke in the first 30 days post-surgery. Serum creatinine and urea increased to a mean peak on day 3 of 0.233 +/- 94 and 24.6 +/- 13 mmol/L, respectively. However, all patients maintained a high urine output (>2 L/day) and no patient required haemodialysis.

Therapy with i.v. 20% mannitol and normal saline appears safe and effective in maintaining a diuresis and may avoid the need for dialysis. A randomised controlled trial of this treatment in patients at increased risk of postoperative acute renal failure is warranted.