PHARMACOLOGICAL AND CLINICAL CONSIDERATIONS IN SELECTING CRYSTALLOID,COLLOIDAL, AND OXYGEN-CARRYING RESUSCITATION FLUIDS .1.

The pharmacologic properties of crystalloid, colloidal, and oxygen-car rying resuscitation fluids are described, and the findings of clinical trials of these solutions are discussed. Fluid administration is a fu ndamental part of resuscitation therapy. Crystalloid solutions supply water and sodium to maintain the osmotic gradient between the extravas cular and intravascular compartments. Examples are lactated Ringer's i njection and 0.9% sodium chloride injection. Colloidal solutions, such as those containing albumin, dextrans, or starches, increase the plas ma oncotic pressure and effectively move fluid from the interstitial c ompartment to the plasma compartment. Oxygen-carrying resuscitation fl uids, such as whole blood and artificial hemoglobin solutions, not onl y increase plasma volume but improve tissue oxygenation. Clinically, c olloidal solutions are generally superior to crystalloids in their abi lity to expand plasma volume. However, colloids may impair coagulation , interfere with organ function, and cause anaphylactoid reactions. Cr ystalloid solutions represent the least expensive option and are less likely to promote bleeding, but they are more likely to cause edema be cause larger volumes are needed. Favorable experience with inexpensive hypertonic crystalloids with improved plasma volume expansion propert ies may favor a return to resuscitation with crystalloid solutions. Ox ygen-carrying resuscitation fluids are indicated when the patient has lost more than 25% of the total blood volume. Tailoring therapy to the individual patient and close monitoring are essential to safe and eff ective fluid resuscitation.