Hyperosmolar Therapy for Raised Intracranial Pressure

A 49-year-old female passenger was thrown against the doorframe during an automobile accident. After being pulled from the car, she opened her eyes intermittently, moaned, and had flexion withdrawal of her limbs (Glasgow Coma Scale score, 8). Her pupils were 5 mm in diameter and reactive to light. Her blood pressure was 165/85 mm Hg, her heart rate 112 beats per minute, and her breathing regular. After her spine was stabilized, she was conveyed to an intensive care unit (ICU). In the ICU, she no longer opened her eyes, had flexion posturing of her arms, and made no verbal responses (Glasgow Coma Scale score, 5). There was a contusion on her right frontal scalp but no sign of other organ injury. Computed tomography showed large regions of frontal brain contusion with surrounding edema (Fig. 1). The patient was intubated, and an external ventricular drain was placed in order to measure intracranial pressure, which was 29 mm Hg with periodic elevations to 36 mm Hg. After drainage of cerebrospinal fluid, the intracranial pressure transiently decreased to 26 mm Hg. The serum sodium concentration was 139 mmol per liter. The neurointensivist recommended an intravenous bolus infusion of 23% saline to reduce intracranial pressure and attain a serum sodium concentration of 150 mmol per liter. The patient's weight was 55 kg.