Abstract
Objectives: Water intoxication is often caused by polydipsia in psychiatric disorders such as schizophrenia. Patients with water intoxication sometimes develop rhabdomyolysis (RML). However, the underlying mechanism and risk of RML in these patients have not yet been elucidated. Therefore, we examined the pathogenesis and prognosis of RML in patients with water intoxication.
Methods: The characteristics of patients diagnosed with water intoxication from January 2006 to August 2012 were retrospectively examined. These patients were divided into RML and non-RML groups. The following data for the 2 groups were examined: patient background, laboratory data on admission, transition of laboratory data, intensive care unit stay length, hospital stay length, complications, and prognoses.
Results: 33 patients were diagnosed with water intoxication; among them, 18 (55%) also had RML. The median peak serum creatine kinase level was 22,640 IU/l (6,652-55,020 IU/l, interquartile range). There was no significant difference in serum sodium or plasma osmolality upon admission (p=0.354, p=0.491, respectively) between the groups. However, the serum sodium correction rate differed significantly between the groups (p=0.001). Acute kidney injury developed in 5 patients in the RML group. However, no patients required renal replacement therapy, and the renal function of all patients improved immediately. No cases of central pontine myelinolysis (CPM) or mortality were noted.
Conclusion: Patients with water intoxication often develop RML. Our findings here suggest that the onset of RML may be related to rapid serum sodium correction. RML is a complication of water intoxication that must be noted in conjunction with CPM.
