Coma Flashcards
Define 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 (arousal)
A functioning cerebral cortex of both hemispheres (environmental awareness)
What are some causes of decreased GCS?
Seizures Damage to reticular activating system Causes of raised ICP Drug intoxication Liver/renal failure Sepsis/ hypoxia/ hypercapnia, hypotension Hypoglycaemia, ketoacidosis
Define persistent vegetative state?
A state in which the brainstem recovers to an extent but there is no evidence of recovery cortical function. Arousal and wakefulness but no regain or purposeful behaviour
What is locked in syndrome?
Total paralysis below level of third nerve nuclei. Can open, elevate, depress eyes but no horizontal movement and no voluntary eye movements
What are the causes of depressed respiration?
Drug overdose
Metabolic disturbance
What are the causes of increased respiration?
Hypoxia
Hypercapnia
Acidosis
What is a cause of fluctuating respiration?
Brainstem lesion
What must be done during resuscitation?
Airway Breathing Circulation Blood samples Establish baseline BP, pulse, temp, IV access, stabilise neck Examine for meningitis
What should be monitored during a coma?
Temperature Heart rate, BP, CVS Respiration Skin, breath Abdomen Meningism Fundal examination
What is the neurological assessment of coma?
Glasgow coma scale
Brainstem function
Motor function and reflexes
What are some causes of coma without focal or lateralising signs and without meningism?
Epilepsy Intoxications Hyper/hypothermia Systemic infections Metabolic disturbances Anoxic/ ischaemic conditions
What investigations should be used coma without focal or laterlising signs and without meningism?
Toxicology screen incl alcohol level Measure blood sugar and electrolytes Acid-base hepatic and renal function Measure blood pressure Consider carbon monoxide poisoning
What are the causes for a coma without focal or lateralising but with meningsm?
Subarachnoid haemorrhage
Meningitis
Encephalitis
What are the investigations for a coma without focal or lateralising but with meningsm?
CT head scan
Lumbar puncture
What are the causes of coma with focal brainstem or laterlising cerebral signs?
Cerebral tumour
Cerebral haemorrhage
Cerebral infarction
Cerebral abscess
What are the investigations for a coma with focal brainstem or lateralising cerebral signs?
CT or MRI obligatory
Metabolic screens
Lumbar puncture
EEG
What are the medical causes of coma lasting more than 5 hours?
Drug ingestion +/- alcohol
Hypoxia
Haemorrhage/infarction
Metabolic
What factors can affect the prediction of outcome in coma?
Age
Cause, depth and duration of coma
What should be done to continue care for patients in coma?
Vital functions maintenance Skincare (avoid pressure sores) Bladder and bowel function attention Control of seizures Prophylaxis of DVT, peptic ulceration Prevention of contractures
How should a head injury be managed?
Stabilise cervical spine Airway/breathing/circulation Intubation/ventilation if GCS <8 Treat raised ICP Cranial imaging
What are the treatment options for raised ICP?
Surgery to relieve pressure Osmotic agents (Mannitol) Reduce pain Maintain good PO2, reduce PCO2 Reduce metabolism Nurse with head at 30-45% (venous return)
