VARIABILITY IN POSTOPERATIVE FLUID AND ELECTROLYTE PRESCRIPTION

A four-week retrospective survey of intravenous fluid and electrolyte prescriptions on postoperative surgical patients revealed wide variabi lity in fluid and electrolyte prescription by medical staff. Median vo lume of intravenous fluid prescribed was 3000 mi (range 1667-5000). To tal sodium prescribed varied from 0 to 770, median 242 mmol/day), with potassium infrequently added (range 0-81, median 0 mmol/day). Patient s undergoing emergency surgery were prescribed more sodium than those undergoing routine procedures (p=0.0403); 0.9% saline was the most com mon fluid prescribed overall. There was poor correlation between serum electrolyte values and the amounts of electrolytes prescribed. Intrav enous fluid prescription should take into account the post-operative s tress response which reduces sodium requirements (unless there are oth er concomitant losses) and increases urinary potassium losses. A suita ble post-operative 'maintenance' fluid is 4% dextrose/0.18% saline wit h 1-2 g potassium chloride, particularly if serum electrolyte levels a re not known. Other fluid losses should be replaced with equivalent fl uids.