Neurologic prognosis in cardiac arrest patients treated with therapeutic hypothermia

Therapeutic hypothermia is now commonly used to improve neurologic outcomes in eligible patients after cardiac arrest. The physiologic effects of cooling and pharmacologic effects of sedatives and neuromuscular blocking agents can affect the clinical exam and neurophysiologic findings. This can lead to uncertainty in neurologic prognostication. In this article, we review data on assessing prognosis in patients treated with therapeutic hypothermia.

Features of the clinical examination, neurophysiologic testing (including somatosensory-evoked potentials and electroencephalography), serum/cerebrospinal fluid biomarkers and neuroimaging can be used to help predict prognosis. However, no single test can predict poor prognosis with absolute certainty. Given the features that help to predict poor, indeterminate, or good outcome, we provide practical advice in assessing neurologic prognosis after cardiac arrest in patients treated with therapeutic hypothermia.

The American Academy of Neurology practice parameters for assessing prognosis after cardiac arrest may not be accurate for patients treated with therapeutic hypothermia. Application of these guidelines may lead to overly pessimistic prognostication and premature withdrawal of care. If uncertainty exists regarding the prognosis in a given patient after cardiac arrest, additional time should be allowed to pass, as patients may ultimately recover with good neurologic outcome.