I.V. fluid therapy. Part 2. I.V. fluid selection.

I.v. fluid selection depends on the estimated fluid loss, the primary fluid compartment involved, the patient's underlying problem and the physiological and haemodynamic impact of the i.v. solution. Clinically, the most important problem is intravascular fluid volume deficit, which is associated with hypotension, inadequate tissue oxygenation and hypoperfusion of essential organs. Intravascular volume resuscitation is therefore of primary importance. Crystalloid solutions have the disadvantage of only small amounts remaining in the IVS whereas colloids are known as plasma volume expanders due to predominantly remaining in the IVS in the presence of an intact capillary endothelium. Managing i.v. fluid administration requires close observation of the patient's subtle responses that may indicate states of fluid depletion or overload. Understanding the physiological principles of the body's fluid distribution in relation to the clinical assessment of the patient's hydration status, together with knowledge of the selected i.v. solution's properties, will enable the nurse to provide quality nursing care and improve patient outcomes.