Coma – Altered Consciousness

Coma – Altered Consciousness

Coma is a state of complete unresponsiveness to external stimuli.

Causes of Coma:

Metabolic Disorders:

• Hypernatremia/Hyponatremia

• Hypercalcemia

• Hyperglycemia/Hypoglycemia

• Hyperthyroidism/Hypothyroidism

• Acute Intermittent Porphyria (AIP)

• Hypertensive encephalopathy

• Hypoxemia/Hypercapnia

• Global cerebral ischemia due to hypotension

Major Causes of Coma:

• Drugs/Toxins/Poisoning:

• ALCOHOL

• Seizures:

• EPILEPSY

• Metabolic Disorders/Systemic Causes:

• INSULIN

• Nutritional Deficiencies:

• (e.g., thiamine)

• Head Trauma, Structural Lesions:

• Organ Failure:

• Infection:

• Infection (meningitis)

• Psychiatric Disorders:

• Psychogenic (hysterical coma)

• Stroke:

• A E I O U TIPS

Infectious Causes of Coma:

• Meningitis/Encephalitis

• Septicemia

• Systemic infections with central nervous system involvement

Drug/Toxic Causes of Coma:

• Withdrawal states

• Inhaled toxins

Seizure-Related Causes of Coma:

• Subclinical seizures

• Post-ictal state

Structural Lesions Causing Coma:

• Cerebral infarction

• Cerebral hemorrhage

• Cerebral edema

• Brain tumor

Organ Failure Leading to Coma:

• Liver failure

• Kidney failure

Considerations in Coma:

• EEG to rule out seizures.

• PLED – periodic lateralized epileptiform discharges

• Beta waves or decreased voltage in barbiturate intoxication

Treatment:

• Thiamine: 100mg IV, followed by dextrose infusion.

• Naloxone: 0.01 mg/kg (coma, respiratory depression, pinpoint pupils, preserved reflexes)

Alcohol Withdrawal Syndrome:

• Mild stage includes tremor, irritability, poor appetite, and nausea. These symptoms usually appear within a few hours after reduction or cessation of alcohol consumption and subside within 48 hours.

• Seizures (convulsions) from alcohol withdrawal syndrome, usually one or a few short generalized seizures, appearing 12 to 48 hours after alcohol cessation.

Treatment of Alcohol Withdrawal Syndrome:

• Chlordiazepoxide: An effective sedative in alcohol withdrawal, 100 mg IV or oral every 2 to 6 hours as needed (maximum dose 500 mg in the first 24 hours). During the next 24 hours, use half the dose of the first 24 hours, and then it can be tapered by 25 to 50 mg each day after.

• Oxazepam: In patients with severe liver failure (15 to 30 mg oral every 6 to 8 hours as needed), a drug eliminated through the kidneys, used in place of chlordiazepoxide.

Acute Porphyrias:

• Deficiencies of enzymes involved in heme synthesis lead to accumulation of heme precursors causing abdominal pain and neurological symptoms.

Manifestations of Porphyrias:

• With or without central nervous system symptoms.

• May develop blistering eruptions, particularly on the hands, forearms, face, neck, or other areas of skin exposed to sunlight.