An Unusual Case of Hypernatremia in Patient With Ulcerative Colitis.

Abstract

To the Editors: A 56-year-old woman, without past medical or surgical history, presented with chronic watery diarrhea for a month. Physical examination revealed memory loss, reaction dullness, and muscle strength decline. Laboratory testing suggested severe hypernatremia of 182 mmol/L, increased blood osmotic pressure of 343.5 mOsm/L, and decreased 24-hour urinary sodium of 83 mmol/d. The remainder of the laboratory workup including blood urea nitrogen, serum creatinine, serum potassium, and hormone levels were within normal limits. Pathogenic microorganism detection and cerebral imaging tests do not reveal any abnormality. Computed tomography of the abdomen revealed thickening of the colonic wall with surrounding exudation (Figure 1A). Further colonoscopy showed continuous mucosal swelling, erosion with ulcers, and punctate hemorrhage (Figure 1B) in the sigmoid colon and rectum. Biopsies demonstrated severe active inflammation, represented as mucosal erosions, lymphocytic infiltration, and crypt distortion (Figure 1C). After excluding other possible causes, a diagnosis of severe ulcerative colitis was eventually made. Considering the patient’s current severe inflammatory condition and the potential risk of hypernatremia-induced cerebral edema, multidisciplinary management with pulsed intravenous methylprednisolone and continuous hemofiltration was administrated consecutively for 7 days and 3 days, respectively. This resulted in serum sodium and blood pressure gradually returning to normal range with symptoms relieved. After discharge, the patient continued treatment with oral prednisone and mesalazine, the serum sodium remained at normal levels, and the frequency of defecation was reduced to 1 to 2 times a day during follow-up.