Question 19

Outline the information that may be useful in determining the prognosis of a comatose survivor of a cardiac arrest.

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College Answer

Diagnosis of the underlying cause of the cardiac arrest ...
(eg drug overdose vs cerebral metastatic adencarcinoma) and any serious comorbidites that may be present.
•      Time to ROSC < 10 min
•      Bystander CPR
•      Rhythm VF better than asystole
•  Neurological status (assessed at 24-72 hours)
•   requires absence of sedation or neuromuscular blocking agents
•   Pupillary response to light – absent is poor prognostic sign
•   Best motor response – absent or extensor motor response is a poor prognostic
•  Biochemical evidence of neurological damage
•   Neurone specific enolase
•   S-100 neuroprotein

•  Electrophysiological evidence of neurological damage
•   Somatosensory evoked potentials

•  Cardiac status
•   Sucessful revascularisation if STEMI is underlying cause
•   Ejection fraction on ECHO


This question closely resembles several other questions from subsequent papers:

Question 4 from the second paper of 2013: "Describe the clinical signs and investigations available to predict poor neurological outcome in comatose survivors of cardiac arrest. Include in your answer the factors that may confound the interpretation of these signs and investigations. "

Question 14 from the first paper of 2011: "Outline the value of the following in determining prognosis for neurological recovery in an adult patient admitted to ICU, after successful cardiovascular resuscitation from an out-of-hospital cardiac arrest:  Peri-arrest data, Clinical examination, Neuro-imaging, Neurophysiology, Biomarkers"

In the answers to the above questions, elaborate tables display the information which is relevant in post-arrest prognostication, discuss its prognostic value, and digress upon the various confounding factors which might fuddle one's forecasts.

The AAN report referenced below is an excellent resource for all questions of this nature.