ABSTRACT
Recognition and treatment of fluid imbalance is particularly important in the critically ill patient, especially as the normal homeostatic mechanisms (thirst, salt craving, renal elimination) may be bypassed or inoperative. Unrecognized fluid imbalance in this patient population can lead to severe metabolic derangements and shock states. Hypovolemia is a common cause of circulatory shock; patients can become relatively or absolutely volume depleted as the result of hemorrhage, fluid shifts (‘third-spacing’), obligate osmotic diuresis, sweating, therapeutic maneuvers or acute vasodilalation (i.e. SIRS or sepsis). The differential diagnosis of clinical shock states is covered in Chapter 6; common clinical situations that often require aggressive fluid resuscitation are listed in Table 7.1. Timely recognition and treatment of fluid deficits can affect ect patient survival and minimize associated morbidity such as development of acute renal failure, acute lung injury and adult respiratory distress syndrome, myocardial infarction, mesenteric ischemia, stroke, and multisystem organ dysfunction. This chapter will highlight principles of resuscitation and the advantages and disadvantages of various replacement fluids.
