Rhabdomyolysis associated with severe hyponatremia after prostatic surgery

Transurethral resection of the prostate gland (TURP) has long been associated with disturbances of plasma sodium concentration. Relatively recent substitution of isotonic irrigation solutions has transformed the predominant laboratory abnormality reported from one of hypotonic hyponatremia to one of nearly isotonic hyponatremia with infrequent clinically significant manifestations. We report the unique association of acute and very severe isotonic hyponatremia with rhabdomyolysis and acute renal failure in the post-TURP setting. The mechanism for rhabdomyolysis is postulated to be an impairment of normal maintenance of cellular integrity by virtue of the acuteness and severity of hyponatremia, in the absence of a disturbance of tonicity. Survival after hyponatremia of this severity has not, to our knowledge, been previously reported.