Medicolegal autopsy reconstruction of a medication-related adverse event trajectory in a psychiatric inpatient with diabetes: a case report.

BACKGROUND: Adverse drug events are common in psychiatric inpatient care because polypharmacy is frequent and metabolic comorbidities such as diabetes mellitus are prevalent. When nonspecific symptoms and reduced food intake are not promptly managed, clinically significant metabolic deterioration may be missed. We report a medicolegal autopsy case in which a review of nursing records, a postmortem investigation, and toxicology helped reconstruct a medication-related adverse event trajectory in a psychiatric inpatient with diabetes.

CASE PRESENTATION: A 47-year-old Japanese woman of Asian ethnicity with bipolar disorder, insomnia, and a 12-year history of type 2 diabetes mellitus was hospitalized in a psychiatric ward where medications were centrally managed. No blood tests were performed during hospitalization. From 8 days before death, nursing records documented frequent nonspecific symptoms and recurrent hypoglycemia. Her oral intake decreased from the evening of 2 days before death and became minimal after breakfast 1 day before death. She was found unresponsive and was pronounced dead, and the cause of death could not be determined clinically, including after postmortem computed tomography at another hospital. A medicolegal autopsy showed food material in the airway and bronchioles, with congested and edematous lungs, suggesting aspiration-related asphyxia. A femoral venous blood sample showed a metformin concentration of 46 mg/L and trihexyphenidyl concentration of 0.45 mg/L. The vitreous glucose concentration was markedly low at 0.33 mmol/L (6 mg/dL) in the left eye and 0.39 mmol/L (7 mg/dL) in the right eye. These findings suggested a complex medication-related adverse event trajectory involving reduced food intake, recurrent hypoglycemia, ongoing antidiabetic therapy, and possible contribution of metformin exposure before terminal aspiration-related death.

CONCLUSIONS: This case illustrates that clinically important metabolic deterioration may be overlooked in psychiatric inpatients when nonspecific symptoms and reduced food intake are not promptly managed. Our findings suggest that a medicolegal autopsy and postmortem toxicology can help reconstruct clinically relevant adverse event pathways when an inpatient death remains unexplained.