Neurological prognostication after cardiac arrest

Abstract

Purpose of review Prediction of neurological prognosis in patients who are comatose after successful resuscitation from cardiac arrest remains difficult. Previous guidelines recommended ocular reflexes, somatosensory evoked potentials and serum biomarkers for predicting poor outcome within 72h from cardiac arrest. However, these guidelines were based on patients not treated with targeted temperature management and did not appropriately address important biases in literature. Recent findings Recent evidence reviews detected important limitations in prognostication studies, such as low precision and, most importantly, lack of blinding, which may have caused a self-fulfilling prophecy and overestimated the specificity of index tests. Maintenance of targeted temperature using sedatives and muscle relaxants may interfere with clinical examination, making assessment of neurological status before 72 h or more after cardiac arrest unreliable. Summary No index predicts poor neurological outcome after cardiac arrest with absolute certainty. Prognostic evaluation should start not earlier than 72 h after ROSC and only after major confounders have been excluded so that reliable clinical examination can be made. Multimodality appears to be the most reasonable approach for prognostication after cardiac arrest.

Quantitative versus standard pupillary light reflex for early prognostication in comatose cardiac arrest patients: an international prospective multicenter double-blinded study

“…However, it must be recognized that the quality of evidence supporting prognostic tests based on clinical examination is limited by both the absence of an objective quantitative assessment of pupillary function and the lack of blinded measurements, i.e. the results of the index test are usually available to clinicians involved in patient care and WLST decisions, thereby causing a self-fulfilling prophecy [ 10 ].…”

Early prediction of coma recovery after cardiac arrest with blinded pupillometry

“…Among them, clinical examination lacks quantitative assessment, electrophysiological tools are not available worldwide or lack standardization (eg, EEG reactivity), 7 and blood biomarkers of brain injury (eg, neuron-specific enolase [NSE]) are limited by variable cutoffs for poor prognosis. 4,9 Automated infrared pupillometry provides a quantitative measure of pupil size, pupillary light reflex (PLR), and constriction velocity, and is emerging as a novel modality to evaluate brainstem function at the bedside in critically ill patients. 4,9 Automated infrared pupillometry provides a quantitative measure of pupil size, pupillary light reflex (PLR), and constriction velocity, and is emerging as a novel modality to evaluate brainstem function at the bedside in critically ill patients.…”

The Benefit of Neuromuscular Blockade in Patients with Postanoxic Myoclonus Otherwise Obscuring Continuous Electroencephalography (CEEG)

“…Despite these results, none of the patients in our series survived to hospital discharge. This finding highlights the challenges of neurological prognostication after cardiac arrest and the self-fulfilling prophecy particularly since no index predicts poor neurological outcome with absolute certainty [ 16 ].…”