Hypervolemic hemodilution: a new approach to subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) refers to the sudden accumulation of blood in the subarachnoid space or in the ventricular system. The hemorrhage may occur with cerebral anomalies, tumors, or trauma. The presence of SAH has been associated with decreases in cerebral blood flow (CBF), which may be attributed in part to increased blood viscosity and hematocrit. Hypervolemic hemodilution is a new therapy that is used in the patient with decreased CBF. The therapy is designed to decrease the hematocrit and the viscosity of blood, subsequently increasing CBF. The patient must have a documented SAH and have a baseline neurologic status compatible with aggressive intervention to qualify for the therapy. The infusion technique is begun with 5% albumin and continued for 3 to 7 days. The dosage is gradually tapered before discontinuation. Effectiveness of the therapy is measured through improvement in neurologic function and regional CBF measurements. The critical care nurse plays a vital role in administering and monitoring the therapy and in educating the family about the disease process and interventions.