Neurological examination, EEG, CT scan, and MRI are important diagnostic tools for neuroprognostication after cardiac arrest.
Structural tests like CT scans and MRIs can reveal brain abnormalities, while functional tests like EEG and SSEPs assess brain activity and connectivity.
Neurofilament light chain (NFL) shows promise as a potential biomarker for prognosis, but more research is needed to validate its use in clinical practice.
Deep dives
Main Ideas
Neuro prognostication after cardiac arrest is crucial in critical care. Withdrawal of life-sustaining therapy is often the most common cause of death in post cardiac arrest patients. Neurological examination, EEG, CT scan, and MRI are important diagnostic tools. Structural tests like CT scans can show brain abnormalities such as reduced grey-white matter differentiation and edema. Functional tests like EEG and SSEPs assess brain activity and connectivity. Neurofilament light chain (NFL) shows promise as a potential biomarker for prognosis. Delayed awakening after coma should be considered and confounding variables like sedation should be avoided.
Structural Tests and Imaging
Structural tests like CT scans and MRIs can reveal brain abnormalities such as reduced grey-white matter differentiation and edema. CT scans may also show signs of anoxic or hypoxic ischemic brain injury. MRIs provide a more detailed and accurate image of the brain. It is important to interpret these scans carefully and consult an expert radiologist.
Functional Tests
Functional tests like EEG and SSEPs evaluate brain activity and connectivity. EEG can identify patterns like continuous background activity, burst suppression, and generalized suppression, which have prognostic implications. SSEPs assess sensory information transmission from nerves to the brain, helping determine prognosis. A combination of structural and functional tests provides a comprehensive assessment of brain function.
Biomarkers
Neurofilament light chain (NFL) shows promise as a biomarker for prognosis. Higher levels of NFL are associated with worse outcomes. However, more research is needed to validate its use in clinical practice.
Considerations and Pitfalls
Careful attention must be paid to confounding variables such as sedation and hypothermia, which can influence prognostic evaluations. Delayed awakening after coma should be considered, and repeated neurological examinations are crucial to assess changes over time. Structural tests and biomarkers should be interpreted in conjunction with clinical findings to avoid premature withdrawal of life support or unnecessary interventions.
In this beast of a 53 minute podcast, we tackle the approach to prognosticating neurologic function of our patients after cardiac arrest. This is hard! As Dick Cheney taught us, there are lots of known and unknown-unknowns. Read through the chapter, then come listen to all things: nuances around confounders, using structural and functional tests. How imaging can lead us astray. Is there a troponin of the brain? Josh even admits to what he'd take to the proverbial desert island.
Remember Everything You Learn from Podcasts
Save insights instantly, chat with episodes, and build lasting knowledge - all powered by AI.
