Postoperative Delirium

Excerpt

Delirium is a neurocognitive syndrome caused by reversible neuronal disruption due to an underlying systemic perturbation. It is a form of acute end-organ dysfunction which can be used as a marker of brain dysfunction. The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), published by the American Psychiatric Association, establishes diagnostic criteria and descriptions to guide the classification and diagnosis of mental disorders. According to DSM-5, diagnostic criteria for delirium include a disturbance in attention, cognition, or awareness that develops over a short period and has a fluctuating course. The alterations in brain function should differ from the patient's baseline brain function. Experts have identified 3 types of delirium, namely, hyperactive, hypoactive, and mixed varieties. Postoperative delirium (POD) can occur from 10 minutes after anesthesia to up to 7 days in the hospital or until discharge. It is commonly recognized in the post-anesthesia care unit (PACU) as a sudden, fluctuating, and usually reversible disturbance of mental status with some degree of inattention. Severely reduced arousal or deep sedation should not be confused with alterations in brain function. Hypoactive delirium is the most common form of POD.