Postoperative fluid management in major elective plastic surgery

To document the current practice of postoperative fluid management and evaluate its effectiveness in major elective plastic surgery.

We conducted a retrospective review on consecutive adult patients undergoing major elective plastic surgery necessitating intensive care unit or high dependency unit admission between May 2005 and May 2007. Hourly fluid input, output and vital signs were recorded for the first 48h postoperatively. Hourly urine output was used as a measure of adequacy of tissue perfusion with 0.5-1.5mlkg(-1)h(-1) being considered normal. Urine output outside of this range for more than four consecutive hours was considered clinically abnormal. These measurements were related temporally to any adjustment of the rates of fluid administration. Intra-operative balance and daily total fluid balance were recorded.

Twenty-four out of 85 patients were excluded because of pre-existing renal impairment (n=12), regular diuretic use (n=8) or incomplete documentation (n=4). No patients had pre-existing cardiac failure. The mean intra-operative positive fluid balance was 3687ml (range 1300-8711), with a mean cumulative volume of 4522ml (range 2560-9465) on postoperative day 1 and this increased with the length of hospital stay. A brisk diuresis (range 1.5-9.0; mean, 3.6mlkg(-1)h(-1)) occurred in 41 (67%) patients, half of them within 7h postoperatively. 26 (43%) patients received excessive fluid, which were responded to within 1-31h (mean 13.5). Six (10%) patients developed cardiac failure, requiring fluid restriction and/or diuretics.

Patients undergoing major elective plastic surgery are in massive positive fluid balance. Majority of these patients develop a brisk diuresis in the early postoperative period. Current practice centres on preventing oliguria, often with excessive and unnecessary fluid being administered resulting in cardiac failure in some patients. Postoperative fluid management should be guided by a protocol with minimal fluid administration that maintains adequate tissue perfusion, guided by lower and upper limits of desirable urine output. The rates of fluid administration should be adjusted dynamically by the surgical or the nursing staff using such a protocol.