The group’s goal is for the clinical research community to develop an accurate, precise clinical test to predict brain injury recovery after resuscitation from cardiac arrest.
Romergryko G. Geocadin, MD
A writing group formed by the American Heart Association Emergency Cardiovascular Care Science Subcommittee, which included an international panel of experts in adult and pediatric specialties in neurology, cardiology, emergency medicine, intensive care medicine, and nursing, released a scientific statement that provides suggestions to improve the scientific quality of neurologic prognostication studies in adult and pediatric comatose survivors of cardiac arrest.
The goal is for the clinical research community to develop an accurate, more rigorous and precise clinical test for patients after resuscitation from a cardiac arrest to predict recovery.
The group reviewed neurological prognostication studies, the practice of neurological prognostication, and withdrawal of life-sustaining treatment and determined that the overall quality of existing neurological prognostication studies is low, which results in a low degree of confidence in predictors and subsequent outcomes.
The statement offers researchers parameters for setting up studies in enrollment, statistical methods, reassessing function in those that recover, avoiding bias, and applying protocols consistently.
Based on the findings, the writing group suggests that neurological prognostication parameters should be approached as index tests based on relevant neurological functions directly related to the functional outcome and contribute to the quality of life of cardiac arrest survivors, to provide measures of accuracy and precision for clinical studies, specify measures of functional outcome and cause of death differentiated as cardiovascular or neurologic, timing of primary and secondary outcome assessments, and consider prearrest lifestyle and comorbidity factors for impact on neurological and systemic injury and prognostication.
It’s the hope of the writing group that this statement will increase the quality of neurological prognostication studies to improve quality of care and clinical outcomes.
To speak in more detail about this statement, NeurologyLive spoke with the author, Romergryko G. Geocadin, MD, professor of neurology at Johns Hopkins Hospital.
Romergryko G. Geocadin, MD: This population is very challenging to assess neurologic function because there are many factors that make neurologic assessment difficult, including: 1) medications (ex. sedatives, paralytics); 2) treatment - therapeutic hypothermia to protect the brain; 3) blood pressure instability; 4) low temperature; and 5) systemic injury to kidney and liver. Any of these or a combination can mask the neurology function that is screened or evaluated. These confounders are more profound closest to the time of cardiac arrest, especially in the first 3 days. All these need to be minimized and ideally normalized for proper neurologic assessment to be undertaken and interpreted.
We can enhance adherence by better education especially on the confounders that make neurologic assessment unreliable or erroneous. We also need to emphasize that many patients need more time to recover to allow for more reliable testing to be undertaken. The statement does not provide which test to use, or how the tests are to be interpreted. The statement makes suggestions on how to improve the scientific studies in the development and validation of the tests used to predict outcome.
These are very sick patients and many of them can still have good functional outcomes; even those that appear comatose and gravely ill early after CPR. Early testing to determine neurologic prognosis are affected by many factors, as such errors are more likely to happen with early testing and when these factors are not properly controlled. The practical advice is, until we have more reliable tests and timing from high-quality studies, give patients more time to recover (3 days, which is what is typically practiced now, is not enough) and more tests and assessments are better considering that no one test that can determine outcome reliably. Conduct more tests and wait, give the patient a chance to recover. I like to reiterate that the purpose of the statement is to provide a roadmap to develop higher quality studies in this area.
Transcript edited for clarity.
Geocadin R, Callaway C, Fink E, et al. Standards for Studies of Neurological Prognostication in Comatose Survivors of Cardiac Arrest. Circulation. 2019. doi: 10.1161/CIR.0000000000000702.