Fluid therapy in ICU

Abstract

Maintenance of appropriate hydration and electrolyte composition is essential in ICU and surgery patients. However, the ideal balance between under- and overhydration remains poorly understood across patient scenarios: “Volume loading” may be important for cardiovascular management and remains a cornerstone for selected surgical and trauma patients. Conversely, bolus challenges and “positive fluid balance” may contribute to poor clinical outcomes in ICU and surgical patients. Decisions to initiate, maintain and discontinue IV fluids requires careful assessment to minimize risk of: Insufficient or excess administration of fluids Electrolyte abnormalities such as hypo- or hypernatremia, hypo- or hyperkalemia and hyperchloremic acidosis. Consequences of fluid mismanagement may include: Organ dysfunction, such as renal dysfunction (and risk of renal replacement therapy), pulmonary edema (reduced oxygenation, risk of pneumonia), cardiac arrhythmias and ischemia (and risk of myocardial infarction and heart failure), reduced GI function (and risk of ileus), neurologic decline (decreased consciousness, coma) and increased risk of death. Peripheral and sacral pitting edema (reduced tissue oxygenation; potential for skin-related ulceration) if extracellular fluid is expanded by 2"3 L. Body fluid compartments Water comprises approximately 60% of body weight (2/3 intracellular fluid and 1/3 extracellular fluid). Extracellular fluid is mainly interstitial fluid, with only 15"20% consisting of blood and plasma. Critically ill patients may experience "leaky vasculature with increased extracellular fluid and edema.