title: Biochemical and etiological characteristics of acute hyponatremia in the emergency department.
abstract: Hyponatremia can be classified as acute or chronic depending on its duration, and treatment options are tailored to this classification. However, it is sometimes difficult to differentiate acute from chronic hyponatremia in the Emergency Department (ED). The objective of this study was to identify characteristics to help diagnose and manage acute hyponatremia in the ED. Patients with acute hyponatremia in the ED were enrolled from a retrospective 2-year chart review. Eleven patients (0.8%) were identified with acute hyponatremia out of a total of 1321 hyponatremic patients. There were nine women and two men. The mean age was 48.9 years. The mean sodium (Na(+)) level was 115+/-4 mmol/L. Accompanying biochemical abnormalities included hypouricemia and hypouremia with increased fractional excretions of uric acid (UA) and urea. The estimated amount of water intake ranged from 2.5 to 10 liters (mean, 5.1+/-2.3 liters) during the day before ED presentation. All patients were treated with hypertonic saline and furosemide at a correction rate of 1.6+/-0.5 mmol/L/h. No patients had neurological sequelae after treatment. The causes of acute hyponatremia included induction of abortion with oxytocin (n=1), primary polydipsia on neuroleptic agents (n=2), polyethylene glycol (PEG) preparation for colonoscopy (n=1), diuretic therapy for hypertension (n=4), ecstasy use (n=1), and weight-reducing herbal teas (n=2). We conclude that in the right clinical setting, high free water intake and low serum urea and UA favor acute hyponatremia. A detailed drug history may be helpful in the differential diagnosis of acute hyponatremia.
authors.affiliation: Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Yu-Juei
authors.initials: YJ
authors.lastname: Hsu
authors.forename: Jainn-Shiun
authors.initials: JS
authors.lastname: Chiu
authors.forename: Kuo-Cheng
authors.initials: KC
authors.lastname: Lu
authors.forename: Tom
authors.initials: T
authors.lastname: Chau
authors.forename: Shih-Hua
authors.initials: SH
authors.lastname: Lin
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D004326:Drinking; D004636:Emergency Service, Hospital; D005260:Female; D005665:Furosemide / Q000627:therapeutic use; D006801:Humans; D007010:Hyponatremia / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D012189:Retrospective Studies; D012965:Sodium Chloride / Q000627:therapeutic use; D013624:Taiwan
chemical_list: D012965:Sodium Chloride; D005665:Furosemide