An Interesting Case of Severe Hyponatremia

In this report, we present an unusual and multifactorial case of severe hyponatremia with important clinical implications. The decedent was a 42-year-old woman who was discovered at her place of residence with altered mental status and profuse watery diarrhea. The scene was significant for numerous empty water bottles. She was transported to the emergency department of a local medical center and rapidly became obtunded. Imaging demonstrated cerebral edema with impending herniation. Serum chemistry was significant for severe hyponatremia (116 mEq/L) with decreased serum osmolality (245 mOsm/kg), suggestive of water overload. Over a brief course of hospitalization, she continued to deteriorate and brain death was pronounced. After brain death, she underwent organ donation. Subsequent autopsy examination demonstrated global cerebral edema with evidence of herniation. Toxicology examination of antemortem blood was positive for methamphetamine (1900 ng/mL) and amphetamine (100 ng/mL). An incidentally identified colon polyp was submitted for microscopic evaluation, which revealed the presence of Cryptosporidium , the likely cause of her diarrheal illness. Death was attributed to severe hyponatremia through the combined effects of excessive water consumption and loss of fluid and electrolytes from cryptosporidiosis, in turn leading to cerebral edema and brain herniation. Acute methamphetamine intoxication was a contributing condition.