Coma

Background

• State of reduced alertness and responsiveness from which the pt cannot be aroused
• Must quickly determine if coma is from diffuse or focal impairment
• Peds
  • Most common causes are toxic ingestion, infection, and child-abuse induced trauma

Clinical Features

• Depends on cause
  • Diffuse brain dysfunction - lack of focal findings
  • Focal brain dysfunction - hemiparesis, loss of motor tone, loss of ocular reflexes

DDX

1. Diffuse brain dysfunction
   1. Encephalopathies
      1. Hypoxic encephalopathy
      2. Metabolic encephalopathy
         1. Hypoglycemia
         2. Hyperosmolar state (e.g., hyperglycemia)
         3. Electrolyte abnormalities (hypernatremia or hyponatremia, hypercalcemia)
         4. Organ system failure
         5. Hepatic encephalopathy
         6. Uremia/renal failure
         7. Endocrine (Addison disease, hypothyroidism)
         8. Hypoxia
         9. CO2 narcosis
      3. Hypertensive encephalopathy
   2. Toxins
   3. Drug reactions (NMS)
   4. Environmental causes
      1. Hypothermia
      2. Hyperthermia
   5. Deficiency state
      1. Wernicke encephalopathy
   6. Sepsis
2. Primary CNS disease or trauma
   1. Direct CNS trauma
      1. Diffuse axonal injury
      2. Subdural/epidural hematoma
   2. Vascular disease
      1. Intraparenchymal hemorrhage
   3. SAH
   4. Infarction
      1. Hemispheric, brainstem
   5. CNS infections
   6. Neoplasms
   7. Seizures
      1. Nonconvulsive status epilepticus
         1. Consider if motor activity of seizure has stopped but pt is not alert w/in 30min
      2. Postictal state

Work-Up

• Head CT

Treatment

• Pts w/ focal findings may have surgically treatable cause
• Coma cocktail
  • Glucose, thiamine, naloxone

See Also

• Glasgow Coma Scale (GCS)
• GCS (Peds)
• AVPU Scale
• Brain Death

Source

Tintinalli