Coma + PVS + Brain Death Flashcards
Define Coma [3]
“State of unrousable psychologcial unresponsiveness” [1]
Eyes closed [1] & no perceivable response to external stimulus or inner needs [1]
Consciousness depends on 2 things [4]
Arousal:
Intact Ascending Reticular Activating System [1] to alert/awaken consciousness [1]
Awareness:
Functional Cerebral Cortex [1] to determine the content of your consciouness [1]
What could cause your GCS to fall (alter consciousness) [4]
- Toxic/Metabolic states such as intoxication, hypoxia/hypercapnia, sepsis, hypotension, hypoglycaemia, acidosis
- Seizures
- Damage to Reticular Activating System
- Raised ICP such as tumour, stroke, haematoma, SAH or hydrocephalus
Define a Persistent Vegetative State? [3]
Describe in terms of levels of wakefulness vs awareness [1]
After reduced consciousness (mainly comas) the Brain stem recovers to a considerable extent [1] but no recovery of coritcal function [1]
High wakefulness but very low awareness [1]
Define Locked in Syndrome? [3]
Describe in terms of levels of wakefulness vs awareness [1]
Total Paralysis below III nuclei so: [1]
- Can open and vertically move eyes [1]
- But cant move horizontal [1]
Both high wakefullness and awareness [1]
What causes locked in syndrome? [3]
Brainstem Strokes (e.g. Pontine Arteries)
Brainstem Lesions
Traumatic Brain Injury
Whats involved in resus for a patient with reduced consciousness?
ABCD
(Breathing patterns can indicate a specific condition)
Bloods (Glc, biochem, haematology, ABGs, toxicology)
BP/pulse/temp/IV access
Stabilise neck in case of trauma
Look for evidence of meningitis
Neuro exam of coma? [3]
GCS
Brainstem function
Motor function & reflexes
At what glasgow coma scale score do we call it Coma [1]
GCS 8 or less, specifically:
Eye - 2 or less (pain or none)
Verbal - 2 or less (grunting)
Motor - 4 or less (weak flexion)
How do we assess brainstem function? [6]
Brainstem reflexes:
- Pupill reflexes (2&3)
- Corneal Reflex (5 & 7)
- Spontaneous eye movement (3/4/6)
- Oculovestibular (Caloric Stimulation) (3/4/6/8)
- Resp Pattern (Medullary Centres)
- Oculocephalic (normal nystagmus) (3/4/6/8)
Causes of Coma without focal brainstem or lateralizing cerebral signs or meningism? [6]
- Ischaemia
- Metabolic
- Intoxication
- Epilepsy
- Infection
- Hyper/Hypothermia
How would you investigate someone with coma without focal signs or meningism? [5]
Toxicology Bloods Hepatic/renal function ABGs BP
Causes of Coma - 3 broad categories
Meningism = SAH/meningitis/encephalitis
Focal brainstem or lateralizing signs = Tumour, infarct etc
No focal signs or meningism = Toxic(Alcohol)/metabolic(hypoxia)/systemic
How would you continue to care for a coma patient? [7]
- Maintain their vital functions
- Care for their skin, particularly pressure sores
- Attend to bowel/bladder function
- Control seizures
- Prophylaxis for DVTs or Peptic ulcers
- Prevent Contractures
- Assess for Locked in Syndrome
What results of a head injury could lead to focal neuro signs or epilepsy? [3]
- Diffuse axonal injury
- contusions
- Haematoma (intracerebral, extradural, subdural)
How do you manage a head injury? [5]
- Stabilize the C spine
- ABC
- If in coma (GCS <8) intubate and ventilate
- Treat raised ICP
- CT (may need surgery)
Coma with focal brainstem or lateralising cerebral signs differentials [4]
Cerebral tumor
Cerebral hemorrhage
Cerebral infarction
Cerebral abscess
Coma with focal brainstem or lateralising cerebral signs - investigations [4]
CT or MRI obligatory If not diagnostic then investigate other causes of coma: - Metabolic screens - LP - EEG
Medical causes of coma lasting more than 5h [4]
Drug ingestion eg alcohol
Hypoxia secondary to MI
CVA
Metabolic eg diabetes, hepatic failure, renal failure, sepsis
Factors affecting prognosis of coma [4]
Age
Cause
Depth
Duration
GCS Total score? Lowest score? Score breakdown: Motor? Verbal? Eyes?
Total score 15
Lowest score 3
Motor 6
Verbal 5
Eye 4
GCS
Describe what qualifies for motor scoring
- Obeys commands
- Localises to pain
- Withdraws from pain
- Abnormal flexion to pain (decorticate posture)
- Extending to pain
- None
GCS
Describe what qualifies for verbal scoring
- Orientated
- Confused
- Words
- Sounds
- None
GCS
Describe what qualifies for eye opening scoring
- Spontaneous
- To speech
- To pain
- None
