Annoni F, et al. - This study appraised enteral urea administration as a treatment option for patients with acute brain injury and hyponatremia. In this patient population, an association was observed, of enteral urea administration with a marked attenuation in intracranial pressure (ICP) independent of alterations in sodium levels.

Methods

• In researchers' Department, enteral urea is routinely administered to patients with acute brain injury who develop hyponatremia consistent with SIADH and do not respond to an initial sodium load.
• They reviewed the records of all patients over a 2-year period, who had acute brain injury, received enteral urea because of hyponatremia, and had intracranial pressure (ICP) monitoring using an intraventricular catheter.
• They also recorded demographic, biological, and clinical data; mean ICP values during the 6 hours before and after the first dose of urea were also recorded.

Results

• They included 40 patients (23 subarachnoid hemorrhage, 8 traumatic brain injury, 6 intracranial hemorrhage, 2 postbrain tumor surgery, and 1 ischemic stroke); median age was 54 years (IQRs, 44 to 63 y) and median admission APACHE II score was 19 (13 to 19); 6-month survival was 63%.
• Findings revealed that median baseline sodium was 133 mEq/L (131 to 135 mEq/L).
• Data reported that no patients received additional therapy to decrease ICP during the 6 hours following urea initiation.
• Researchers observed that after the first urea dose (15 g), ICP decreased from 14 (13 to 18 mm Hg) to 11 mm Hg (8 to 13 mm Hg) (P<0.001).
• They also noted that changes in ICP were not correlated to changes in sodium (r²=0.02).
• In addition, it was reported that the reduction in ICP was larger in patients with ICP≥15 mm Hg (n=22) than in the others (-8 mm Hg [-14 to -3 mm Hg] vs. -2 mm Hg [-3 to 0 mm Hg], P=0.001).