Delayed awakening

Delayed awakening

1. The most frequent cause of delayed awakening is persistent effects of anesthetics (see Section VI.B). Less common but possibly life-threatening causes include the organic cerebral events described below.
2. Decreased cerebral perfusion of sufficient duration, during or after surgery, may cause diffuse or localized cerebral damage responsible for obtundation and delayed awakening. In patients with cerebrovascular disease, short periods of hypotension may cause a critical reduction of cerebral perfusion resulting in brain damage. If such an event is suspected, a neurologic consultation should be obtained as soon as possible, and specific tests (eg, computed tomography [CT], magnetic resonance imaging [MRI], or angiography) should be considered. If cerebral edema is suspected, treatment should be started immediately (see Chapter 29).
3. Metabolic causes of delayed awakening include hypothermia, sepsis, preexisting encephalopathies, hypoglycemia, and electrolyte or acid-base derangements.