Coma
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Basics
Description
- Light coma:
- Responds to noxious stimuli
- Deep coma:
- Does not respond to pain
- Unresponsiveness:
- Loss of either arousability or cognition:
- Loss of arousal
- Arousal is primarily a brainstem function
- Impairment of the reticular activating system
- Loss of cognition
- Requires dysfunction of both cerebral hemispheres
- Stupor:
- Deep sleep, although not unconsciousness
- Exhibits little or no spontaneous activity
- Awaken with stimuli
- Little motor or verbal activity once aroused
- Loss of either arousability or cognition:
- Obtundation:
- Mental blunting with mild or moderate reduction in alertness
- Delirium:
- Floridly abnormal mental status
- Irritability
- Motor restlessness
- Transient hallucinations
- Disorientation
- Delusions
- Clouding of consciousness:
- Disturbance of consciousness
- Impaired capacity to think clearly or perceive, respond to, and remember current stimuli
Etiology
- Diffuse brain dysfunction (69%):
- Lack of nutrients:
- Hypoglycemia
- Hypoxia
- Poisoning:
- Ethanol
- Isopropyl alcohol
- Ethylene glycol
- Methanol
- Salicylates
- Sedative-hypnotics
- Narcotics
- Anticonvulsants
- Isoniazid
- Heavy metals
- Opiates
- Benzodiazepines
- Anticholinergics
- Lithium
- Phencyclidine
- Cyanide
- Carbon monoxide
- Isoniazid
- Infection:
- Bacterial/tuberculous/syphilitic meningitis
- Encephalitis
- Falciparum meningitis
- Typhoid fever
- Rabies
- Endocrine disorders:
- Myxedema coma
- Thyrotoxicosis
- Addison disease
- Cushing disease
- Pheochromocytoma
- Metabolic disorders:
- Hepatic encephalopathy
- Uremia
- Porphyria
- Wernicke encephalopathy
- Aminoacidemia
- Reye syndrome
- Hypercapnia
- Electrolyte disorders:
- Hypernatremia, hyponatremia
- Hypercalcemia, hypocalcemia
- Hypermagnesemia, hypomagnesemia
- Hypophosphatemia
- Acidosis, alkalosis
- Temperature regulation:
- Hypothermia
- Heat stroke
- Neuroleptic malignant syndrome
- Malignant hyperthermia
- Uremia
- Postictal state, status epilepticus
- Psychiatric
- Shock
- Fat embolism
- Hypertensive encephalopathy
- Lack of nutrients:
- Supratentorial lesions (19%):
- Hemorrhage (15%):
- Intraparenchymal hemorrhage
- Epidural hematoma
- Subdural hematoma
- Subarachnoid hemorrhage
- Infarction (2%):
- Thrombotic arterial occlusion
- Embolic arterial occlusion
- Venous occlusion
- Tumor or abscess (2%):
- Hydrocephalus
- Herniation
- Hemorrhage from erosion into adjacent blood vessels
- Hemorrhage (15%):
- Subtentorial lesions (12%):
- Infarction
- Hemorrhage
- Tumor
- Basilar migraine
- Brainstem demyelination
Pregnancy Considerations
Eclampsia
-- To view the remaining sections of this topic, please log in or purchase a subscription --
Basics
Description
- Light coma:
- Responds to noxious stimuli
- Deep coma:
- Does not respond to pain
- Unresponsiveness:
- Loss of either arousability or cognition:
- Loss of arousal
- Arousal is primarily a brainstem function
- Impairment of the reticular activating system
- Loss of cognition
- Requires dysfunction of both cerebral hemispheres
- Stupor:
- Deep sleep, although not unconsciousness
- Exhibits little or no spontaneous activity
- Awaken with stimuli
- Little motor or verbal activity once aroused
- Loss of either arousability or cognition:
- Obtundation:
- Mental blunting with mild or moderate reduction in alertness
- Delirium:
- Floridly abnormal mental status
- Irritability
- Motor restlessness
- Transient hallucinations
- Disorientation
- Delusions
- Clouding of consciousness:
- Disturbance of consciousness
- Impaired capacity to think clearly or perceive, respond to, and remember current stimuli
Etiology
- Diffuse brain dysfunction (69%):
- Lack of nutrients:
- Hypoglycemia
- Hypoxia
- Poisoning:
- Ethanol
- Isopropyl alcohol
- Ethylene glycol
- Methanol
- Salicylates
- Sedative-hypnotics
- Narcotics
- Anticonvulsants
- Isoniazid
- Heavy metals
- Opiates
- Benzodiazepines
- Anticholinergics
- Lithium
- Phencyclidine
- Cyanide
- Carbon monoxide
- Isoniazid
- Infection:
- Bacterial/tuberculous/syphilitic meningitis
- Encephalitis
- Falciparum meningitis
- Typhoid fever
- Rabies
- Endocrine disorders:
- Myxedema coma
- Thyrotoxicosis
- Addison disease
- Cushing disease
- Pheochromocytoma
- Metabolic disorders:
- Hepatic encephalopathy
- Uremia
- Porphyria
- Wernicke encephalopathy
- Aminoacidemia
- Reye syndrome
- Hypercapnia
- Electrolyte disorders:
- Hypernatremia, hyponatremia
- Hypercalcemia, hypocalcemia
- Hypermagnesemia, hypomagnesemia
- Hypophosphatemia
- Acidosis, alkalosis
- Temperature regulation:
- Hypothermia
- Heat stroke
- Neuroleptic malignant syndrome
- Malignant hyperthermia
- Uremia
- Postictal state, status epilepticus
- Psychiatric
- Shock
- Fat embolism
- Hypertensive encephalopathy
- Lack of nutrients:
- Supratentorial lesions (19%):
- Hemorrhage (15%):
- Intraparenchymal hemorrhage
- Epidural hematoma
- Subdural hematoma
- Subarachnoid hemorrhage
- Infarction (2%):
- Thrombotic arterial occlusion
- Embolic arterial occlusion
- Venous occlusion
- Tumor or abscess (2%):
- Hydrocephalus
- Herniation
- Hemorrhage from erosion into adjacent blood vessels
- Hemorrhage (15%):
- Subtentorial lesions (12%):
- Infarction
- Hemorrhage
- Tumor
- Basilar migraine
- Brainstem demyelination
Pregnancy Considerations
Eclampsia
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