Coma Flashcards
What is 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?
Intact ascending reticular activating system - to give arousal
A functioning cerebral cortex of both hemispheres - to give awareness of environment
What can cause low GCS?
Toxic/metabolic states
Seizures
Damage to reticular activating system
Causes of raised ICP
What can cause raised ICP?
Tumour Stroke Epidural heamtoma Subdural haemorrhage Subarachnoid haemorrhage Hydrocephalus
What is persistent vegetative state?
vegetative state is absence of responsiveness and awareness due to overwhelming dysfunction of the cerebral hemispheres, with sufficient sparing of the diencephalon and brain stem to preserve autonomic and motor reflexes and sleep-wake cycles
What recovers in persistent vegetative state?
Brain stem
So there is arousal and wakefulness
What is locked in syndrome?
Condition where damages part of the brainstem, in which the body and most of the facial muscles are paralysed but consciousness remains and the ability to perform certain eye movements is preserved
Where does paralysis begin in locked in syndrome?
Below the level of CN III
What can a patient do in locked in syndrome?
Has consciousness
and can perform certain eye movements
What are the steps for resuscitation?
Airway
Breathing
Circulation
What can depressed respiration tell you about coma?
Drug overdose
Metabolic disturbance
What can increased respiration tell you about a patient?
Potential
hypoxia
Hypercapnia
acidosis
What can fluctuating respiration tell you about a patient?
Potential brainstem lesion
What blood samples should be done on admission?
glucose, biochemistry, haematology, blood gas
toxicology
What should a coma patient be examined for?
Evidence of meningitis
What basic tests should be carried out on a coma patient on admission (very basic)?
Baseline BP
Pulse
Temperature
IV access
What should be monitored in a potential coma patient?
Temperature Heart rate, Blood Pressure, CVS Respiration Skin, breath Abdomen Meningism potential Fundal examination
How do you examine and assess a coma patient?
GCS
Brainstem function
Motor function and reflexes
What are the 4 level of eye opening in GCS?
Spontaneous - 4
To speech - 3
To pain - 2
None - 1
What are the 5 levels of verbal response in GCS?
Orientated - 5 Confused - 4 Inappropriate words - 3 Incomprehensible sounds - 2 None - 1
What are the 6 levels of motor response for GCS?
Obeying commands - 6 Localising to pain - 5 Withdrawing from pain - 4 Flexing to pain - 3 Extending to pain - 2 None - 1
What is the GCS for coma?
< or equal to 8
What is eye opening score in coma?
2 or less
What is verbal response score in coma?
2 or less
What is motor response in coma?
4 or less
Which cranial nerves control pupillary reactions?
II and III
Which cranial nerves control corneal responses?
V and VII
Which cranial nerves control eye movements?
CN III, IV, VI
Which cranial nerves control oculovestibular responses?
III, IV, VI , VII
Which factors affecting the prediction outcome for coma?
Age Cause of coma Depth of coma Duration of coma Certain clinical signs the most important of which are brainstem reflexes
What care need to continued for a patient in a coma?
Maintenance of vital functions Care of skin - avoidance of pressure sores Attention to bladder and bowel function Control of seizures Prophylaxis of DVT, peptic ulceration Prevention of contractures Consider the “Locked - in” Syndrome
Which head injuries can lead to focal neurological signs/epilepsy?
Diffuse axonal injury Contusion Intracerebral haematoma Extra-cerebral haematoma Extra-dural haematoma Sub-dural haematoma
How do you treat raised ICP?
Surgery to relieve the pressure
Osmotic agents
Maintain good PO2 and reduce PCO2
Reduce the pain
What investigations are obligatory for coma/
CT or MRI
Which other investigations can be done for coma patients?
Metabolic screens
LP
EEG
What can cause a coma without focal or lateralising signs and without meningism?
Anoxic/ ischaemic conditions
Metabolic disturbances
Intoxications
Systemic infections
Epilepsy
What investigations should be done forcoma without focal or lateralising signs and without meningism?
Toxicology screen including alcohol level Measure blood sugar and electrolytes Assess hepatic and renal function Acid - base assessment and blood gases Measure blood pressure Consider carbon monoxide poisoning
What are some causes of coma without focal or lateralising signs but with meningism?
SAH
Meningitis
Encephalitis
What investigations should be done forcoma without focal or lateralising signs but with meningism?
CT
LP
What things should be assessed on LP?
Appearance
Cell count
Glucose level
Capsular antigen test
What can cause Coma with focal brainstem or lateralising cerebral signs?
Cerebral tumour
Cerebral haemorrhage
Cerebral infarction
Cerebral abscess
What investigations should be done for coma with focal brainstem or lateralising cerebral signs?
CT or MRI obligatory If not diagnostic investigate: Metabolic screens LP EEG
What % of patients in non-traumatic coma >6 hours will make a good recovery?
15%
Other 85% will die or remain in a state of vegetative/severe disability
