Korean Journal of Nephrology 1998;17(2):236-242.

신경증상을 동반한 심한 저나투륨혈증의 임상분석

박근태 , 문희식 , 조균석 , 김호중

Abstract

Objective: Severe hyponatremia is rare but con- stitute a true medical emergency since it has dele- terious effects on the central nervous system. The etiology and clinical presentation of severe hypona- tremia are diverse and nonspecific, furthermore, the opt.imal therapeutic approach is debatable at the present time. Therefore, the purpose of this study is to analyze the clinical manifestations of severe hypo- natremic patients and to assess the outcomes with special reference to the rate of its correction. Methods: This retrospective study analyzed the clinical course of 27 consecutive patients(pts) at a single medical center who presented with neurologic hyponatremic symptoms as well as a serum sodium (Na) concentration less than 125mEq/L. Results " Of 27 hyponatremic patients, male to female ratio was almost equal, 13 to 14, and mean age was 67.1 years. The most common cause of hyponatremia was SIADH(11 pts, 40.7%), followed by hypovolemia(11 pts, 37.1%), and edema(4 pts, 14.8%), Hyponatremic neurologic symptoms included lethargy(33.3%), confusion with drowsy mentality (33.3%), dizziness(18.6%), and semicoma(7.4%), res- pectively. The rate of increase to a serum Na con- centration to 125mEq/L during correction of hypo- natremic averaged 0.56±0.49mEq/L/hr while the ma- ximum increase in serum Na concentration during any period of the hospital course, mostly initial phase, averaged 0.69+0.63mEq/L/hr in all 27 pts, of whom 18 pts(66.7%) was less than 0.5mEq/L/hr, 3 pts from 0.5 to 1.0mEr(11.1%), and 6 pts more than 1.0mEq/L/hr(22.2%). All 27 pts but one reco- vered from neurologic symptoms due to hypona- tremia without neurologic sequale. Extrapontine mye- linolysis with locked in condition was developed during the course of treating hyponatremia in a pts, of whom serum Na concentration before treatment was the lowest(92mEq/L) with the rate of correction to 125mEq/L by 1.26mEq/L/hr and the initial rate of correction within the first 6 hour by 3.17mEq/L/hr. No one died of hyponatremia itself during the course of its treatment but 3 deaths of 27 pts were attri- buted to the pts severe underlying diseases. Conclusion - Surprisingly, these data revealed the relatively benign course of severe symptomatic hy- ponatremia. However, in assessing the outcome of severe symptomatic hyponatrernia, the initial degree of hyponatremia as well as the rate of correction du- ring its treatment, particularly the initial rate of co- rrection within the first 6 hour, would be considered.