Crystalloids versus colloids for resuscitation in shock.

The optimal composition of fluid for volume resuscitation in critically ill patients has been the subject of controversy for decades. Clinicians are faced with several options, including crystalloid solutions of varying tonicity, several colloid preparations (albumin and others), and blood products. Some of these solutions may be differentially distributed between the intra- and extravascular, and intra- and extracellular compartments, accounting for a variety of physiological effects. Two recently published meta-analyses concluded that colloids afford no survival benefit in critically ill patients compared with crystalloids. Albumin infusion may be of more value in patients with cirrhosis, or in those at high risk of acute renal failure. Additional randomized trials will be needed to establish the optimal composition and volume of colloid or crystalloid solutions for resuscitation in shock.