Which intravenous fluid for the surgical patient?

PURPOSE OF REVIEW: This review appraises recent evidence and provides clinical guidance on optimal perioperative fluid therapy. RECENT FINDINGS: Choice of perioperative intravenous fluid continues to be the source of much debate. Not all crystalloids are equivalent, and there is growing evidence that balanced solutions are superior to 0.9% saline in many situations. Recent evidence from the critical care population has highlighted risks associated with synthetic colloids; this and the absence of demonstrable benefit in the surgical population make it difficult to recommend their use in the perioperative period. Giving the correct amount of fluid may be as important as the choice of the fluid used. There is increasing evidence that excessive positive fluid balance is harmful to patients but there have been no randomized trials comparing maintenance fluid strategy. A knowledge of the physiology and accurate estimation of fluid balance is important for water and electrolyte homeostasis until the patient is able to resume adequate enteral nutrition. SUMMARY: Balanced crystalloids are the fluid of choice for perioperative resuscitation and optimization in patients not requiring blood products. Avoidance of a grossly positive sodium and water balance during the maintenance phase is likely to be important, but has not been assessed in randomized trials.