Evaluation of colloids, crystalloids, whole blood, and red cell therapy in the critically ill patient

Experimental and clinical aspects of fluid management problems are reviewed; clinical and physiological criteria for efficacy of various plasma expanders are evaluated. Reduced extracellular water is considered the primary defect of shock by those favoring the use of crystalloids, but hypovolemia is regarded as primary by those favoring the use of colloids. The immediate direct effects of various agents in critically ill patients are evaluated using physiologic criteria associated with survival from life-threatening postoperative illness. In general, colloids improved hemodynamic and oxygen transport, while sodium-rich crystalloids increased arterial pressure and peripheral resistance, but not flow and oxygen transport. Indications for various agents and protocols (clinical algorithms) for resuscitation and critical illness are proposed.