coma Flashcards
GCS what are assessed
eye opening, motor response, verbal response
what are the scorings on GCS eye opening
spontaneous (4), to speech (3), to pain (2), no response (1)
what are the scorings on GCS motor response
obeys (6), localises to pain (5), withdraws to pain (4), flexion to pain (3), extension to pain (2), no response to pain (1)
what are the scorings on GCS verbal response
orientated (5), confused (4), inappropriate speech (3), incomprehensible sounds (2), none (1)
what is conciousness dependent on
ascending reticular activating system (RAS), cerebral cortex
what is coma
state of unrousable unresponsiveness
what are the four mechanisms of coma
brainstem lesion, brainstem compression, diffuse brain dysfunction, massive cortical damage
example of brainstem lesion causing coma
stroke, haemorrhage, infarction, demyelination, neoplasm
examples of brainstem compression causing coma
brain tumour, cerebellar mass, haematoma, abscess
examples of diffuse brain dysfunction causing coma
drug overdose, CO poisoning, resp failure with CO2 retention, metabolic- Na,Ca, glucose, trauma, severe uraemia, hepatic encephalopahty, meningitis, encephalitis, seizures
does a single focal hemisphere lesion cause a coma
no, only if it is compressing the brainstem
what is damaged in persistent vegetative state
cortex and hemispheres. brainstem and ARAS intact so breathing is normal
what is persistent vegetative state
no awareness or response to stimuli. appears awake as opens eye and sleep-wake cycle. permanent when over 12m no recovery following trauma or 6m other causes
what is damaged in locked in syndrome
ventral pons (within the brainstem). intact ARAS and cortex
what is minimally conscious state
some limited awareness.may emerge from vegetative to this
what is brainstem death
all brainstem reflexes are absent. oculocephalic reflex- when move head, eyes follow so stationary relative to orbit; pupils fixed and unresponsive, absent corneal reflexes, no vestibular ocular reflex, no motor response cranial nerves, no cough/gag. spontaneous respiration absent
what is Cheyne Stokes resp pattern
fluctuating hyperpnoea and apnoea indicating bilateral cerebral or upper brainstem
what is Kussmauls breathing
deep sighing hyperventilation- DKA and uraemia
what are lateralising signs used for
coma makes it difficult to recognise lateralising signs so a specific few are used
what lateralising signs are used in coma
asymmetry of response to visual threat, face, tone (hemiparesis), posturing, response to painful stimuli, tendon reflexes
what investigations can be done in coma
blood and urine- drugs; biochem, metabolic and endocrine, ABG, check for porphyria or malaria
what brain imaging can be used
CT is best although might not pick up early infarcts
