A 53 year old patient was admitted with a GCS of 3. The GCS has remained unchanged for 24 hours. The cause of the coma is unclear. He has had no sedation or paralysis for more than 24 hours. His temperature is 36.50C
- Na+ 149 mmol/L (135-145)
- K+ 4.6 mmol/L (3.5-5.0)
- Glucose 6.2 mmol/L (4-6)
- Liver function tests normal
- Renal functions normal
You find the following on neurological examination
- Train of four neuromuscular testing – 4 twitches elicited
- Pupils (R & L) Fixed and dilated
- Corneals, conjunctivals Absent
Facial reflexes Absent
- Cough and Gag Absent
- Spontaneous respiration Absent
Arterial blood gases during apnoea test:
PCO2 65 mm Hg (8.75kPa)
PO2 146 mm Hg (19.4 kPa)
What is your assessment of the neurological status and why?
Patient clearly has no evidence of brain stem reflexes, however, can’t be declared brain dead as there is no known cause of coma.
As in the above college answer, this patient cannot be declared brain dead.
The preconditions for brain death testing are not met; according to the ANZICS statement (linked below), "Brain death cannot be determined without evidence of sufficient intracranial pathology". In this, Asutralians differ to the British; in Britain it is sufficient to have a dead brainstem for a diagnosis of brain death, even with ample blood flow to the rest of the cortex.
So at this stage, one could not declare this patient brain dead without imaging which might demonstrate an absence of cerebral perfusion (or without shipping the patient to Britain).
ANZICS Death and Organ Donation Committee, THE ANZICS STATEMENT ON DEATH AND ORGAN DONATION Edition 3.2 2013