Disclosures: Michael J. Matthews, DO: No financial relationships or conflicts of interest

Case Description: 71-year-old male sustained a frontal subdural hematoma, requiring surgical evacuation when he slipped on ice. The post-operative course was complicated by hyponatremia, treated with hypertonic saline. He arrived on the acute rehabilitation unit (ARU) 11 days post-injury, on 6 grams of salt tablets total daily, with serum sodium at 134mEq/L. Over the following days, his sodium drifted downward and salt tablets were increased to 12 gram total daily. On post-injury day 18, with serum sodium 128mEq/L, intravenous normal saline was added. On post-injury 23, however, his sodium dropped to 122mEq/L. It increased to mid-120s with restriction of free water intake. Nephrology was consulted. He was diagnosed with a curious amalgam of cerebral salt wasting syndrome and syndrome of inappropriate antidiuretic hormone (SIADH). Complicating factors included intermittent diarrhea and sub-optimal oral fluid intake in the setting of dysphagia and impaired cognition. Urea was started on post-injury day 25 and continued for 3 days. His sodium increased to 128mEq/L on day 27 and 133mEq/L on day 29.

Setting: Acute Inpatient Rehabilitation

Patient: A 71-year-old male with severe TBI Assessment/

Results: Sodium concentration normalized over the next week. His ability to participate and make gains in therapies improved as well.

Discussion: Urea, which induces water loss via an osmotic mechanism, has been used pharmacologically as a diuretic for decades. It does not have significant known adverse effects. The associated risk of renal toxicity and osmotic demyelination syndrome are low. Recently, urea has been used as an effective treatment for cases of recalcitrant SIADH, primarily by nephrologists. Urea has not been widely described as a treatment of hyponatremia after TBI.

Conclusion: In this novel case, a patient’s dangerously low sodium level was successfully treated with urea, an oral medication. During treatment, he was able to stay in the ARU to continue his rehabilitation amidst an intricate medical course.

Level of Evidence: Level V

« Back to AAPM&R Annual Assembly 2020

PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/urea-as-effective-treatment-for-hyponatremia-following-severe-traumatic-brain-injury-tbi-a-case-report/