Coma, Persistent Vegetative State, Brain Death Flashcards
What are the features of bells palsy?
Whole half of the face is paralysed - LMNL
What is the definition of a coma?
“ A state of unrousable psychological unresponsiveness in which the subjects lie with eyes closed and show no psychologically understandable response to external stimulus or inner need”
What does consciousness depend on?
An intact ascending reticular activating system to act as the alerting or awakening element of consciousness
Functioning cerebral cortex of both hemispheres which determines the content of that consciousness
Interesting graph
What are causes of reduced consciousness?
Toxic/metabolic states:
- Hypoxia/hypercapnia/sepsis/hypotension
- Drug intoxication/renal or liver failure
- Hypoglycaemia, ketoacidosis
Seizures
Damage to reticular activating system
Causes of raised intracranial pressure
(tumour, stroke, EDH, SDH, SAH, hydrocephalus)
What is meant by a persistent vegetative state?
Brainstem recovers to a considerable extent but there is no evidence of recovery of cortical function
Arousal and wakefulness but the patient does not regain awareness or purposeful behaviour of any kind
What is locked in syndrome?
The patient has total paralysis below the level of the third nerve nuclei and can only open, elevate and depress the eyes
How do you manage a patient who is in a coma?
Airway
Breathing
Circulation
How can breathing give a clue as to the reason for the coma?
Depressed respiration - drug overdose, metabolic disturbance
Increased respiration - hypoxia, hypercapnia, acidosis
Fluctuating respiration - brainstem lesion
What are other means to try and determine the cause of coma?
Blood samples - glucose (hypoglycaemia), biochemistry, haematology (sepsis?ketoacidosis), blood gas (hypoxia, hypercapnia)
Toxicology
HISTORY - predictable progression of an underlying disease?
- unpredicatable event of a patient with a previosuly known disease
- Totally unexpected event - head injury, sudden collapse, limb twitching, previous history of drug or alcohol abuse?
What do you have to examine and monitor for a patient in a coma?
Temperature
Heart rate, Blood Pressure, CVS
Respiration
Skin, breath
Abdomen
Meningism
Fundal examination
How do you assess a coma?
Glasgow coma scale
Brainstem function
Motor function and reflexes
What are the parts of the glasgow coma scale?
Eye opening:
Spontaneous 4
To speech 3
To pain 2
None 1
Best verbal response:
Orientated 5
Confused 4
Inappropriate words 3
Incomprehensible sounds 2
None 1
Best motor response:
Obeying Commands 6
Localising to pain 5
Withdrawing from pain 4
Flexing to pain 3
Extending to pain 2
None 1
What is defined as being in a coma according to the glasgow coma scale?
“Patients who fail to show eye opening in response to voice, perform no better than weak flexion in response to pain and make, at best, only unrecognisable grunting noises in response to pain are regarded as being in coma”
Eye opening 2 or less
Verbal response 2 or less
Motor response 4 or less
GCS equal or less than 8
which cranial nerves are required for the following assessments of the brainstem function?
Pupillary reactions
Corneal responses
Spontaneous eye movements
Oculocephalic responses (Doll’s eye) - eyes move to contralateral direction of head movement
Oculovestibular responses - hot or cold water is placed in into the ear, result is nystagmus or occular deviation (hot water causes deviation upwwards and cold water casues deviation downwards)
Respiratory pattern
Brainstem function
Summary
What are ‘medical’ causes of coma?
