Coma Flashcards
What is coma?
Coma is a state of unresponsiveness in which a person cannot be aroused and has closed eyes.
What are the two main causes of coma?
Structural causes (e.g., stroke, trauma) and nonstructural causes (e.g., metabolic, toxic).
What is the role of the reticular activating system (RAS) in consciousness?
The RAS is responsible for maintaining arousal and wakefulness.
What are some disorders of consciousness apart from coma?
Stupor, lethargy, obtundation, and altered conscious states.
What is stupor?
A state in which a patient can only be awakened by vigorous physical stimulation.
What is lethargy?
A less severe alteration in alertness where a person is drowsy but can be aroused.
What is obtundation?
A more severe reduction in alertness with slowed responses to stimuli.
What are coma mimics?
Conditions resembling coma but without disruption of the ARAS-thalamo-cortical pathway, such as locked-in syndrome, akinetic mutism, and psychogenic unresponsiveness.
What is locked-in syndrome?
A condition where a patient is awake but unable to move or speak, except for eye movements.
What is akinetic mutism?
A state of profound apathy and decreased response to stimuli, typically due to frontal lobe damage.
What are common causes of coma?
Stroke, trauma, infections, metabolic disorders, toxins, and cardiac arrest.
What does the acronym STONE stand for in coma causes?
S: Structural, T: Toxins, O: Oxygen (hypoxia), N: Nutritional, E: Endocrine/metabolic.
What is the first step in managing a comatose patient?
Resuscitation and stabilization, including airway protection and circulation assessment.
What key history elements should be obtained for a comatose patient?
Onset, preceding symptoms, seizure activity, medical history, and toxin exposure.
What are some clues from physical examination for coma etiology?
Foul breath (e.g., ketoacidosis), hyperthermia (e.g., infections), hypertension (e.g., stroke).
What is the Glasgow Coma Scale (GCS)?
A scale used to assess consciousness based on eye, verbal, and motor responses.
What is a GCS score that indicates severe coma?
A GCS score of ≤8.
What is the FOUR Score?
The Full Outline of UnResponsiveness (FOUR) Score assesses coma using eye, motor, brainstem, and respiratory function.
What are signs of meningeal irritation in coma?
Neck stiffness, Kernig’s sign, and Brudzinski’s sign.
What are abnormal pupillary findings in coma?
Pinpoint pupils (pontine lesions, opioid toxicity), mid-position pupils (midbrain lesion), unilateral dilated pupil (3rd nerve compression).
What is the oculocephalic reflex?
Also known as the ‘Doll’s eye reflex,’ it tests brainstem integrity by moving the head and observing eye movement.
What is the oculovestibular reflex?
Cold caloric test where ice water is instilled into the ear; normal response is slow deviation towards the stimulus.
What motor responses indicate brainstem damage?
Decorticate posturing (flexion of arms, extension of legs) and decerebrate posturing (extension of arms and legs).
What are abnormal respiratory patterns in coma?
Cheyne-Stokes, central neurogenic hyperventilation, cluster breathing, and ataxic breathing.
What are essential lab investigations in coma?
Blood glucose, electrolytes, liver/kidney function, arterial blood gases, and toxicology screening.
When is lumbar puncture indicated in coma?
Suspected meningitis, encephalitis, or subarachnoid hemorrhage (after ruling out raised ICP).
What imaging is preferred in coma evaluation?
CT scan for acute causes (e.g., stroke, trauma); MRI for deeper lesions.
What is the emergency management of coma?
Maintain airway, oxygenation, circulation, and correct metabolic derangements.
When should intubation be performed in a comatose patient?
If GCS <8 or if the patient cannot protect the airway.
What is the first-line treatment for suspected opioid overdose in coma?
Naloxone administration.
What is the first-line treatment for hypoglycemia-induced coma?
Intravenous dextrose (50% glucose bolus).
What are the criteria for brain death?
Absence of brainstem reflexes, no motor response to pain, absent pupillary and corneal reflexes, and apnea test confirmation.
What is the apnea test for brain death?
A test where mechanical ventilation is removed to check for spontaneous respiratory effort.
What is persistent vegetative state?
A state of wakefulness without awareness, with preserved autonomic functions but no purposeful responses.
How does minimal conscious state differ from vegetative state?
Patients may have intermittent awareness, eye tracking, and minimal verbalization.
What are long-term management strategies for coma patients?
DVT prophylaxis, prevention of pressure ulcers, bowel/bladder care, and early physiotherapy.
What are signs of poor prognosis in coma?
Absent brainstem reflexes, low GCS, no motor response, and prolonged duration of coma.
What is the typical outcome of traumatic coma?
Varies from full recovery to permanent disability or death, depending on severity and treatment.
What is neuroprognostication?
Assessment of likelihood of recovery in coma patients based on clinical, imaging, and electrophysiologic criteria.
What is the role of EEG in coma evaluation?
Helps assess brain activity, diagnose seizures, and determine prognosis.
What is toxic-metabolic encephalopathy?
A reversible cause of coma due to systemic illness, infections, or organ failure.
What are examples of metabolic causes of coma?
Hypoglycemia, hyperglycemia, uremia, hepatic encephalopathy, and thyroid dysfunction.
What is the main treatment for hepatic encephalopathy coma?
Lactulose to reduce ammonia levels.
What is the significance of Cheyne-Stokes respiration in coma?
Suggests bilateral cerebral hemisphere dysfunction or metabolic disorders.
What medications can induce coma?
Benzodiazepines, barbiturates, opioids, and tricyclic antidepressants.
What is end-of-life care in coma patients?
Supportive care, pain management, palliative decisions, and advanced directives.
What are the ethical considerations in coma management?
Withholding/withdrawing life support, brain death declaration, and family counseling.
