A good outcome after absence of bilateral N20 SSEPs post-cardiac arrest

Karunasekara, Niroshini; Salib, S; MacDuff, Andrew

doi:10.1177/1751143715616137

Cited by 5 publications

(3 citation statements)

References 8 publications

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“…We identified five cases with good outcome that initially had absent cortical responses and afterwards recovered N20 responses on repeat testing - two recovered cortical responses soon after cooling was completed and two, just a few days after. (5, 12, 18, 23) This observation contrasts with reports suggesting that effects of sedation and therapeutic hypothermia at 32–34°C do not influence SSEP results. (40, 41) Additionally, interrater reliability of SSEP testing is limited, especially for patterns predicting poor outcome.…”

Section: Discussioncontrasting

confidence: 78%

Estimating the False Positive Rate of Absent Somatosensory Evoked Potentials in Cardiac Arrest Prognostication

Amorim

Ghassemi

Lee

et al. 2018

Critical Care Medicine

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Objective: Absence of short-latency cortical median nerve somatosensory evoked potentials (“absent SSEPs”) is considered a nearly perfect predictor of poor outcome after cardiac arrest. However, reports of good outcomes despite absent SSEPs and high rates of withdrawal of life-sustaining therapies (WLST) have raised concerns that estimates of the prognostic value of absent SSEPs may be biased by self-fulfilling prophecies. We aimed to develop an unbiased estimate of the false positive rate (FPR) of absent SSEPs as a predictor of poor outcome after cardiac arrest. Data Sources: PubMed. Study Selection: We selected 35 studies in cardiac arrest prognostication that reported SSEP results. Data Extraction: In each study, we identified rates of WLST and good outcomes despite absent SSEPs. We appraised studies for potential biases using the Quality in Prognostic Studies tool. Using these data, we developed a statistical model to estimate the FPR of absent SSEPs adjusted for WLST rate. Data Synthesis: Two thousand, one hundred and thirty-three subjects underwent SSEP testing. Five hundred and ninety-four had absent SSEPs; of these,14 had good functional outcomes. The rate of WLST for subjects with absent SSEP could be estimated in 14 of the 35 studies (mean 80%, median 100%). The FPR for absent SSEP in predicting poor neurologic outcome, adjusted for a WLST rate of 80%, is 7.7% (95% Confidence Interval: 4–13%). Conclusions: Absent cortical SSEPs do not infallibly predict poor outcome in patients with coma following cardiac arrest. The chances of survival in subjects with absent SSEPs, though low, may be substantially higher than generally believed.

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Section: Discussioncontrasting

confidence: 78%

Estimating the False Positive Rate of Absent Somatosensory Evoked Potentials in Cardiac Arrest Prognostication

Amorim

Ghassemi

Lee

et al. 2018

Critical Care Medicine

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“…Karunasekara et al describe a 51-year-old male who had a CA after a failed attempted hanging [58]. He underwent CPR for pulseless electrical activity rhythm.…”

Section: Discussionmentioning

confidence: 99%

SSEP retains its value as predictor of poor outcome following cardiac arrest in the era of therapeutic hypothermia

Rothstein

2019

Crit Care

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ObjectivesTo re-evaluate the role of median nerve somatosensory evoked potentials (SSEPs) and bilateral loss of the N20 cortical wave as a predictor of unfavorable outcome in comatose patients following cardiac arrest (CA) in the therapeutic hypothermia (TH) era.MethodsReview the results and conclusions drawn from isolated case reports and small series of comatose patients following CA in which the bilateral absence of N20 response has been associated with recovery, and evaluate the proposal that SSEP can no longer be considered a reliable and accurate predictor of unfavorable neurologic outcome.ResultsThere are many methodological limitations in those patients reported in the literature with severe post anoxic encephalopathy who recover despite having lost their N20 cortical potential. These limitations include lack of sufficient clinical and neurologic data, severe core body hypothermia, specifics of electrophysiologic testing, technical issues such as background noise artifacts, flawed interpretations sometimes related to interobserver inconsistency, and the extreme variability in interpretation and quality of SSEP analysis among different clinicians and hospitals.ConclusionsThe absence of the SSEP N20 cortical wave remains one of the most reliable early prognostic tools for identifying unfavorable neurologic outcome in the evaluation of patients with severe anoxic-ischemic encephalopathy whether or not they have been treated with TH. When confounding factors are eliminated the false positive rate (FPR) approaches zero.

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“…It is also critical that the study be performed and interpreted correctly. Confirmation of the presence of responses at Erb’s point and the cervical spine is a prerequisite because extracranial injury, including at the level of the cervical spine with hanging or other trauma, may abolish the N20 response [ 134 ]. Although interrater reliability to determine the absence of N20 responses appears to be high [ 135 , 136 ], inaccurate interpretation may occur in the context of background electrical noise, which is common in the ICU [ 47 ].…”

Section: Methodsmentioning

confidence: 99%

Guidelines for Neuroprognostication in Comatose Adult Survivors of Cardiac Arrest

et al. 2023

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Background Among cardiac arrest survivors, about half remain comatose 72 h following return of spontaneous circulation (ROSC). Prognostication of poor neurological outcome in this population may result in withdrawal of life-sustaining therapy and death. The objective of this article is to provide recommendations on the reliability of select clinical predictors that serve as the basis of neuroprognostication and provide guidance to clinicians counseling surrogates of comatose cardiac arrest survivors. Methods A narrative systematic review was completed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Candidate predictors, which included clinical variables and prediction models, were selected based on clinical relevance and the presence of an appropriate body of evidence. The Population, Intervention, Comparator, Outcome, Timing, Setting (PICOTS) question was framed as follows: “When counseling surrogates of comatose adult survivors of cardiac arrest, should [predictor, with time of assessment if appropriate] be considered a reliable predictor of poor functional outcome assessed at 3 months or later?” Additional full-text screening criteria were used to exclude small and lower-quality studies. Following construction of the evidence profile and summary of findings, recommendations were based on four GRADE criteria: quality of evidence, balance of desirable and undesirable consequences, values and preferences, and resource use. In addition, good practice recommendations addressed essential principles of neuroprognostication that could not be framed in PICOTS format. Results Eleven candidate clinical variables and three prediction models were selected based on clinical relevance and the presence of an appropriate body of literature. A total of 72 articles met our eligibility criteria to guide recommendations. Good practice recommendations include waiting 72 h following ROSC/rewarming prior to neuroprognostication, avoiding sedation or other confounders, the use of multimodal assessment, and an extended period of observation for awakening in patients with an indeterminate prognosis, if consistent with goals of care. The bilateral absence of pupillary light response > 72 h from ROSC and the bilateral absence of N20 response on somatosensory evoked potential testing were identified as reliable predictors. Computed tomography or magnetic resonance imaging of the brain > 48 h from ROSC and electroencephalography > 72 h from ROSC were identified as moderately reliable predictors. Conclusions These guidelines provide recommendations on the reliability of predictors of poor outcome in the context of counseling surrogates of comatose survivors of cardiac arrest and suggest broad principles of neuroprognostication. Few predictors were considered reliable or moderately reliable based on the available body of evidence.

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A good outcome after absence of bilateral N20 SSEPs post-cardiac arrest

Cited by 5 publications

References 8 publications

Estimating the False Positive Rate of Absent Somatosensory Evoked Potentials in Cardiac Arrest Prognostication

Estimating the False Positive Rate of Absent Somatosensory Evoked Potentials in Cardiac Arrest Prognostication

SSEP retains its value as predictor of poor outcome following cardiac arrest in the era of therapeutic hypothermia

Guidelines for Neuroprognostication in Comatose Adult Survivors of Cardiac Arrest

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