Coma, Persistent Vegetative State, Brain Death Flashcards
What GCS level is usually associated with coma?
GSC <8
What is a persistent vegetative state?
State in which brain stem recovers to significant extent but no evidence of cortical function
Arousal and wakefulness present but patient does not regain awareness or purposeful behaviour
What is locked-in syndrome?
Total paralysis below third nerve nuclei, can open/elevate/depress eyes but no horizontal movement and no other voluntary movements
What are possible causes of reduced GCS?
Toxic/metabolic states
- hypoxia, hypercapnoea, sepsis, hypotension
- drug intoxication/renal or liver failure
Seizures
Damage to reticular activating system
Raised ICP and its causes
What investigations might be done in someone in a coma?
Temperature HR, BP, CVS Respiration Skin, breath Abdomen Meningism Fundal examination
Neurological assessment of coma
- GCS
- brainstem function
- motor function + reflexes
What are the differential diagnoses of coma without focal signs or meningism? Investigations?
Anoxic/ischaemic conditions Metabolic disturbances Intoxication Systemic infections Hyperthermia/hypothermia Epilepsy
Toxicology screen inc alcohol Blood sugar, electrolytes Assess hepatic/renal function Acid-base assessment and blood gases Measure BP, consider CO poisoning
What are the differential diagnoses of coma without focal signs but with meningism?
SAH
Meningitis
Encephalitis
CT
LP
- appearance, cell count, glucose level, capsular antigen tests
What are the differential diagnoses of coma with focal/lateralising signs?
Cerebral tumour
Cerebral haemorrhage
Cerebral infarction
Cerebral abscess
CT/MRI obligatory
If not diagnostic, investigate other causes
- metabolic screens, LP, EEG
How does prognosis vary in head injury by GCS/Length of Amnesia?
GCS 3-8/Amnesia >1 day - severe
GCS 9-12/Amnesia 1-24 hours - moderate
GCS 13-15/Amnesia <1 hour - mild
What is the general management in a patient in a coma?
Maintenance of vital functions Care of skin, avoidance of pressure sores Attention to bladder/bowel function Control of seizures Prophylaxis of DVT, peptic ulceration Prevention of contractures Consider locked-in syndrome
What initial general management should be given in head injury coma?
Stabilise cervical spine ABC Intubate/ventilate if GCS <8 Treat raised ICP Cranial imaging, may need decompressive surgery/haematoma removal Neuro-observation
How is ICP managed?
Surgery to relieve pressure - haematoma, ventricular shunt Osmotic agents e.g. mannitol Head at 30-45% for venous return Reduce pain Maintain good PO2, reduce PCO2 Reduce metabolism (temperature, barbiturates)
