The crystalloid vs colloid controversy in the era os hypertonic/hyperoncotic resuscitations: is the debate over?

ABSTRACT

The crystalloid vs. colloid controversy has been further complicated by the inclusion of hypertonic levels of sodium chloride (HTS) in both types of regimens. In this paper the recent literature on the controversy is reviewed. Colloids raise the intravascular colloid osmotic pressure and increase the fluid retention in the vessels. Crystalloids however, distribute into the interstitial and intravascular spaces at a ratio of approximately 3 to 1. It is therefore necessary to infuse a large volume of crystalloids in order to complete resuscitation. The advantage of colloids over isotonic crystalloids focuses primarily on the incidence of pulmonary edema. In an analysis of clinical trials, however, colloids were not proven to be superior to crystalloids. The use of HTS decreases the amount of crystalloid required for resuscitation. Pulmonary and systemic vasodilation, an increase in cardiac output and stroke volume, decreased intracranial pressure and an enhanced immunologic response have been noted experimentally, and the clinical evidence seems to corroborate these findings. HTS with dextran (HSD) has been used in an attempt to combine the rapid cellular fluid shift of hypertonicity with the vascular fluid shift of colloids. The experimental evidence is compelling. Whereas HTS has proven itself to be a superior resuscitation regimen, HSD has not yet warranted in a clinical setting the optimism which its experimental studies seem to indicate.