Sudden Death Caused by Hyponatremia Related to Psychogenic Polydipsia
BACKGROUND/INTRODUCTION: Psychogenic polydipsia (PPD), a type of primary polydipsia, is a common occurrence among inpatient psychiatry patients that can present with headache, confusion, and lethargy. PPD is a diagnosis of exclusion characterized by excessive thirst and overconsumption of water in the context of a psychiatric illness, especially schizophrenia. In the context of water intoxication or renal damage, PPD can progress to hyponatremia, brain edema, seizures, coma, and death if untreated. PPD patients have significant morbidity and mortality when compared to patients with similar psychiatric diagnosis without PPD. STUDY PURPOSE: The purpose of this study is to discuss psychogenic polydipsia and its role in the sudden deaths of two schizophrenic males. MATERIALS AND METHODS: The cases review the autopsy reports and pertinent medical records of two schizophrenic Caucasian males who were concluded to have died as a result of PPD. CASE REPORTS: Case #1: A 48-year old mentally-handicapped Caucasian male was found in distress while in bed at his group home. Upon arrival of the emergency medical services, he was found in asystole and all resuscitative efforts failed. The decedent’s medical history was significant for paranoid schizophrenia, epilepsy, and renal insufficiency due to damage from lithium. The decedent had several psychiatric hospitalizations and aggressive outbursts at his group home. He was noted to have PPD within his medical records and was placed on fluid restriction. Autopsy was relatively unremarkable though the right kidney weighed 90 g (normal 125-175 g). Ancillary analysis of vitreous chemistry showed evidence of severe dilution of electrolytes with sodium at 78 mEg/L (normal: 135-150) and chloride at 58 mEg/L (normal: 105-135). Case#2: A 47-year old Caucasian male was found in bed in asystole. The decent’s medical history was significant for schizophrenia and obesity. Upon autopsy, he was noted to have cardiomegaly with biventricular hypertrophy and dilation and mild to severe atherosclerotic cardiovascular disease in the aorta, coronary arteries, and cerebral arteries. Ancillary analysis of vitreous chemistry showed evidence of severe dilution of electrolytes with sodium at 85 mEg/L. DISCUSSION/CONCLUSION: These cases show that PPD is a dangerous component of psychiatric disease, especially schizophrenia, that can potentially lead to death and results in high number of years of potential life lost.