Delirium n 2006 12 27 Delirium Early diagnosis

Delirium n 2006 -12 -27

Delirium Early diagnosis and resolution of symptoms are correlated with the most favorable outcomes. n It must be treated as a medical emergency. n Delirium is not a disease but a syndrome with multiple causes. n

Pathophysiology Hyperactive delirium -- patients in a state of alcohol withdrawal or intoxication with to phencyclidine (PCP), amphetamine, and lysergic acid diethylamide (LSD). n Hypoactive delirium -- patients in states of hepatic encephalopathy and hypercapnia. n Mixed delirium -- individuals display daytime sedation with nocturnal agitation and behavioral problems. n

Pathophysiology The mechanism of delirium still is not fully understood. n Research in these areas still is limited. n The main hypothesis is reversible impairment of cerebral oxidative metabolism and multiple neurotransmitter abnormalities. n

Mortality/Morbidity In patients who are admitted with delirium, mortality rates are 10 -26%. n Patients who develop delirium during hospitalization have a mortality rate of 2276%. n In patients who are elderly and patients in the postoperative period, delirium may result in a prolonged hospital stay, increased complications, increased cost, and long-term disability. n

History n Nursing notes can be very helpful for documentation of episodes of disorientation, abnormal behavior, and hallucinations. n Delirium is mistaken for dementia or depression, especially when patients are quiet or withdrawn.

History n Main l l l symptoms Clouding of consciousness Difficulty maintaining or shifting attention Disorientation Illusions Hallucinations Fluctuating levels of consciousness

History n Neurological l l symptoms Dysphasia Tremor Asterixis in hepatic encephalopathy and uremia Motor abnormalities

Causes n DSM-IV classification of delirium – Delirium due to general medical condition – Substance intoxication delirium – Substance withdrawal delirium – Delirium due to multiple etiologies – Delirium not otherwise specified

Causes n Some of the other common reversible causes include the following: – Hypoxia – Hypoglycemia – Hyperthermia – Anticholinergic delirium – Alcohol or sedative withdrawal

Causes n n n Other causes of delirium include the following: Infections Metabolic abnormalities Structural lesions of the brain Postoperative states Miscellaneous causes, such as sensory deprivation, sleep deprivation, fecal impaction, urinary retention, and change of environment

Workup n n n Complete blood cell count with differential - Helpful to diagnose infection and anemia Electrolytes - To diagnose low or high levels Glucose - To diagnose hypoglycemia, diabetic ketoacidosis, and hyperosmolar nonketotic states Renal and liver function tests - To diagnose liver and renal failure Thyroid function studies - To diagnose hypothyroidism Urine analysis - Used to diagnose urinary tract infection Urine and blood drug screen - Used to diagnose toxicological causes Thiamine and vitamin B-12 levels - Used to detect deficiency states of these vitamins Tests for bacteriological and viral etiologies - To diagnose infection Sedimentation rate Drug screen including alcohol level

Workup – Imaging studies n Neuroimaging – Perform CT scan of the head. – Magnetic resonance imaging (MRI) of the head may be helpful in the diagnosis of stroke, hemorrhage, and structural lesions. n Electroencephalogram n Chest x-ray is used to diagnose pneumonia or congestive heart failure

Workup – Other Tests Lumbar puncture is indicated when CNS infection is suspected as a cause of delirium or when the source for the systemic infection cannot be determined. n Pulse oximetry is used to diagnose hypoxia as a cause of delirium. n Electrocardiogram is used to diagnose ischemic and arrhythmic causes n

Treatment When delirium is diagnosed or suspected, the underlying causes should be sought. n Despite every effort, no cause for delirium can be found in approximately 16% of patients. n Components of delirium management include supportive therapy and pharmacological management. n