Survival after a cardiac arrest is dependent on many factors.
Factors before cardiac arrest:
- Poor health including diabetes, cancer, infection, kidney disease and stroke
Factors during cardiac arrest:
- Time between collapse and start of CPR/defibrillation
- Quality of CPR/defibrillation
- Whether survivor had neurological function during or immediately after CPR
Factors after cardiac arrest and resuscitation:
- Neurological function: Generally, poor function equals poor prognosis. But it could be complicated by medical instability and treatments. Some patients suffer a stroke after a cardiac arrest.
- Neurophysiologic function: Tests include somatosensory evoked potentials (SSEP) and electroencephalogram (EEG).
- Neuroimaging and monitoring: Cranial CT, MRI, magnetic resonance spectroscopy and positron emission tomography (PET) determine structural brain injury, mostly to exclude hemorrhage or stroke.
- Biochemistry: from blood or cerebrospinal fluid
- Therapeutic hypothermia: Intentionally lowering the patient's body temperature.