Unrecognized medical emergencies admitted to psychiatric units.

Alteration of mental status secondary to medical illness may occasionally be incorrectly attributed to a psychiatric problem. The cases of 64 patients with unrecognized medical emergencies inappropriately admitted to psychiatric units from emergency departments were reviewed to determine the cause of the misdiagnoses. Medical diagnoses most often missed included severe intoxication with alcohol or other illicit substance (34.4%), drug or alcohol withdrawal or delirium tremens (12.5%), and prescription drug overdose (12.5%). In none of the cases (0%) was an appropriate mental status examination performed. Other common causes of misdiagnosis included inadequate physical examination (43.8%), failure to obtain indicated laboratory studies (34.4%), and failure to obtain available history (34.4%). A systematic approach is required for patients with altered mental status, including those with psychiatric presentations.