POSTHYSTEROSCOPIC HYPONATREMIA - EVIDENCE FOR A MULTIFACTORIAL CAUSE

Hyponatremia, caused by absorption of hypotonic irrigating fluids, is a well-documented complication of surgical procedures such as transure thral resection of the prostate (TURP). Although not commonly mentione d in the renal literature, there have been several case reports of hyp onatremia associated with hysteroscopic endometrial ablation that also were considered to be attributable to absorption of hypotonic fluid, We present a 43-year-old white woman who underwent endometrial ablatio n for menorrhagia under general anesthesia. Postoperative serum chemis tries showed a sodium of 112 mEq/L and an osmolality of 234 mOsm/L, an d urine chemistries showed a sodium of 125 mEq/L and an osmolality of 629 mOsm/L, Although fluid retention of hypotonic irrigating fluid cle arly contributed to the hyponatremia, search for associated morbidity showed an absence of either osmotic or volume stimulus to account for the apparent antidiuretic effect, suggesting the participation of a po stsurgical, stress-related ADH release. We conclude that hyponatremia associated with hysteroscopic endometrial ablation may be multifactori al. (C) 1997 by the National Kidney Foundation, Inc.