Encephalopathy, Metabolic

3.4– 11% of medical ICU admissions

12–33% of multiple-organ dysfunction pts

With predisposing conditions (e.g., hepatic insufficiency), risk of developing or exacerbating metabolic encephalopathy

Increasing severity of preexisting encephalopathy

Worsening hepatic insufficiency causing hepatic encephalopathy

Diabetics becoming hypoglycemic or with DKA/hyperosmolar coma

Postop hyponatremia

Deteriorating renal insufficiency leading to uremic encephalopathy

Preexisting encephalopathy may be exacerbated by anesthetics (e.g., benzodiazepines) in hepatic encephalopathy

Postpartum, especially with preeclampsia, eclampsia; PRES

Undiagnosed sepsis, hypothermia, high fever, CNS-acting drugs, including overdose

CNS cause: Brainstem CVA, meningitis, occult head trauma, encephalitis, brain tumor

Altered sensorium, stupor, or coma without any other explanation in the setting of a metabolic disturbance.

Process affects global cortical function by altering brain biochemistry.

Distinguished from structural lesions by a nonfocal neurologic exam.

EEG shows diffuse background slowing, triphasic waves in hepatic encephalopathy.

Increased spontaneous motor activity: Restlessness, asterixis, myoclonus, tremors, rigidity.