Diffuse headache and progressive lethargy. Medical history is significant for hypertension and he is nonadherent to his medication. There is no history of head trauma. He drinks 1-2 beers daily and occasionally more on weekends. Temperature is 37 C (98.6 F) , blood pressure is 182/95 mm Hg, pulse is 65/min, and respirations are 9/min. On physical examination, the patient responds to painful stimuli only but does not move his right extremities to pain. The left pupil is larger than the right and is sluggish to react to the light. CT scan of the head shows left basal ganglia hemorrhage causing compression of left lateral ventricle and shift of the midline structures. Endotracheal intubation is performed for airway protection, and an intravenous bolus of mannitol is administered. Which of the following is the most likely acute effect of the medication given to this patient?

Question

Quizplus · Accepted Answer

Eductional Objective: In elevated intracerebral pressure, mannitol is given to draw water from the brain parenchyma into the vasculature, reducing intracranial volume and pressure.
As a result of the plasma volume expansion, the serum sodium concentration decreases (dilutional hyponatremia) and renal blood flow increases, resulting in increased glomerular filtration and renal tubular flow. Mannitol is freely filtered at the glomerulus but is not resorbed by the renal tubules; the resultant hyperosmolar glomerular filtrate reduces tubular reabsorption of free water, causing increased diuresis.

Diffuse Headache and Progressive Lethargy