Predictors of neurologic outcome in hypothermia after cardiac arrest

Recovery and Survival of Patients After Out-of-Hospital Cardiac Arrest: A Literature Review Showcasing the Big Picture of Intensive Care Unit-Related Factors

As an important public health issue, out-of-hospital cardiac arrest (OHCA) requires several stages of high quality medical care, both on-field and after hospital admission. Post-cardiac arrest shock can lead to severe neurological injury, resulting in poor recovery outcome and increased risk of death. These characteristics make this condition one of the most important issues to deal with in post-OHCA patients hospitalized in intensive care units (ICUs). Also, the majority of initial post-resuscitation survivors have underlying coronary diseases making revascularization procedure another crucial step in early management of these patients. Besides keeping myocardial blood flow at a satisfactory level, other tissues must not be neglected as well, and maintaining mean arterial pressure within optimal range is also preferable. All these procedures can be simplified to a certain level along with using targeted temperature management methods in order to decrease metabolic demands in ICU-hospitalized post-OHCA patients. Additionally, withdrawal of life-sustaining therapy as a controversial ethical topic is under constant re-evaluation due to its possible influence on overall mortality rates in patients initially surviving OHCA. Focusing on all of these important points in process of managing ICU patients is an imperative towards better survival and complete recovery rates.

Validation of a Clinical Tool to Predict Neurological Outcomes in Critically Ill Children-A Prospective Observational Study

OBJECTIVES

To evaluate the performance of the empiric tool by Gupta et al. in predicting neurological outcomes in children admitted to the pediatric intensive care unit (PICU) and to evaluate the association of biomarkers S100B and NSE with neurological outcomes.

METHODS

This prospective observational study was conducted in 163 critically ill children aged 2 mo to 17 y admitted to the PICU from June 2020 to July 2021. The authors used the prediction tool developed by Gupta et al.; the tool was applied at admission and at PICU discharge/death. Samples for NSE and S100B were collected at admission and discharge. The performance of the new tool was assessed through discrimination and calibration. Risk factors for "unfavorable outcomes" (decline in PCPC score by > 1) were evaluated by multivariate analysis.

RESULTS

The PICU mortality was 28% (n = 45). When the tool developed by Gupta et al. was used at the time of admission, favorable neurological outcomes were predicted for 69% (112) children. The area under the curve for the new tool at admission was 0.72 and at discharge/death it was 0.99, and the calibration was excellent at both time points. Independent factors associated with unfavorable neurological outcomes were higher PCPC scores and organ failure. As the number of samples processed for NSE and S100B was less, statistical analysis was not attempted.

CONCLUSIONS

The new tool by Gupta et al. has good discrimination, calibration, sensitivity, and specificity and can be used as a prediction tool. NSE and S100B are promising biomarkers and need further evaluation.

Prognosis of Cardiac Arrest-Peri-arrest and Post-arrest Considerations

There has been only a small improvement in survival and neurologic outcomes in patients with cardiac arrest in recent decades. Type of arrest, length of total arrest time, and location of arrest alter the trajectory of survival and neurologic outcome. In the post-arrest phase, clinical markers such as blood markers, pupillary light response, corneal reflex, myoclonic jerking, somatosensory evoked potential, and electroencephalography testing can be used to help guide neurological prognostication. Most of the testing should be performed 72 hours post-arrest with special considerations for longer observation periods in patients who underwent TTM or who had prolonged sedation and/or neuromuscular blockade.

Long-Term Outcomes among Patients with Prolonged Disorders of Consciousness

PURPOSE

To evaluate the long-term survival and functional outcomes of patients with prolonged disorders of consciousness (pDoC) 1-8 years after brain injuries.

METHODS

Retrospective study to assess the long-term survival and functional outcomes of patients with pDoC was conducted. We performed Cox regression and multivariate logistic regression to calculate hazard ratios (HRs) for the outcome of survival and to identify risk factors of the functional outcome.

RESULTS

We recruited 154 patients with pDoC. The duration of follow-up from disease onset was 1-8 years. The median age was 46 years (IQR, 32-59), and 65.6% (n = 101) of them were men. During the follow-up period, one hundred and ten patients (71.4%) survived; among them, 52 patients had a good outcome. From the overall survival curve, the 1-, 3-, and 8-year survival rates of patients were about 80.5%, 72.0%, and 69.7%, respectively. Cox regression analysis revealed a significant association between the lower APACHE II score (p = 0.005) (cut-off score ≥ 18) and the presence of sleep spindles (p = 0.001) with survival. Logistic regression analysis demonstrated a higher CRS-R score (cut-off score ≥ 7), and presence of sleep spindles were related to a favorable outcome among patients with pDoC.

CONCLUSIONS

Sleep spindles are correlated with both long-term survival and long-term functional outcome in pDoC patients.

Adult Critical Care Electroencephalography Monitoring for Seizures: A Narrative Review

Electroencephalography (EEG) is an important and relatively inexpensive tool that allows intensivists to monitor cerebral activity of critically ill patients in real time. Seizure detection in patients with and without acute brain injury is the primary reason to obtain an EEG in the Intensive Care Unit (ICU). In response to the increased demand of EEG, advances in quantitative EEG (qEEG) created an approach to review large amounts of data instantly. Finally, rapid response EEG is now available to reduce the time to detect electrographic seizures in limited-resource settings. This review article provides a concise overview of the technical aspects of EEG monitoring for seizures, clinical indications for EEG, the various available modalities of EEG, common and challenging EEG patterns, and barriers to EEG monitoring in the ICU.

Prognostic value of electroencephalographic paroxysms in post-anoxic coma: A new regularity EEG-based score

OBJECTIVES

Several electroencephalographic (EEG) features -mainly the reactivity of background activity-have been suggested as reliable predictors of outcome for patients with post-anoxic coma (PAC). However, EEG in PAC often contains abundant EEG paroxysms (EP) that may hinder the detection of background EEG activity. We aimed to identify the features, among the different paroxysmal and non-paroxysmal EEG patterns, that may predict the outcome of patients with PAC.

METHODS

We retrospectively reviewed the clinical and EEG characteristics of 67 patients with PAC and selected those with abundant EP. We classified EP according to several features and assessed their prognostic value for survival at 15 days. We calculated a global regularity score, as the sum of the value (1 if regular, 0 if not) attributed to each of 4 features of EP (duration, morphology, amplitude, and frequency).

RESULTS

The 35 patient-group with abundant EP showed a higher mortality than the group without abundant EP. Among 12 features of EP, four regularity features (regularity of EP duration, morphology, amplitude, and global regularity score) had a poor prognostic value. A global regularity score ≥ 3 showed a positive predictive value of 100 % for a poor outcome and a negative predictive value of 54 %, with good interrater consistency (Cohen's kappa = .63).

CONCLUSIONS

The presence of EP and their regularity features in PAC patients are strongly associated with poor outcome. We propose a global regularity score, easily derived from visual EEG inspection, that may be a reliable prognostic tool for these patients. Prospective and larger studies are needed to confirm these findings.

Prognostic Significance of Cyclic Seizures in Status Epilepticus

PURPOSE

Status epilepticus (SE) is a commonly encountered neurologic condition associated with high mortality rates. Cyclic seizures (CS) are a common form of SE, but its prognostic significance has not been well established. In this retrospective study, the mortality of cyclic versus noncyclic forms (NCSs) of SE are compared.

METHODS

A total of 271 patients were identified as having seizures or SE on EEG reports, of which 65 patients were confirmed as having SE. Based on EEG characteristics, the patients were then classified as cyclic or noncyclic patterns. Cyclic seizures were defined as recurrent seizures occurring at nearly regular and uniform intervals. Noncyclic form included all other patterns of SE. Pertinent clinical data were collected and reviewed for each case.

RESULTS

Of the 65 patients with SE, 25 patients had CS and 40 patients had NCS. Patients with CS showed a lower rate of in-hospital mortality although not statistically significant (P = 0.19). When looking at patients younger than 75 years, the CS group had significantly lower in-hospital mortality rate (P = 0.007).

CONCLUSIONS

The findings of this study suggest that CS may have a more favorable outcome compared with NCS in patients younger than 75 years. This study is also the first to report the rate of CS among all cases of confirmed SE (38%). Future studies with a larger sample size are needed to further evaluate the difference in outcome between CS and NCS.

Differences in the gray-to-white matter ratio according to different computed tomography scanners for outcome prediction in post-cardiac arrest patients receiving target temperature management

The gray-to-white matter ratio (GWR) has been used to identify brain damage in comatose patients after cardiac arrest. However, Hounsfield units (HUs), the measurement of brain density on computed tomography (CT) images, may vary depending on the machine type or parameter. Therefore, differences in CT scanners may affect the GWR in post-cardiac arrest patients. We performed a retrospective study on comatose post-cardiac arrest patients who visited the hospital from 2007 to 2017. Two CT, Lightspeed and SOMATOM, scanners were used. Two observers independently measured the HUs of the caudate nucleus, putamen, posterior internal capsule, and corpus callosum using regions of interest. We compared the GWR calculated from the HUs measured at different CT scanners. The analysis of different scanners showed statistically significant differences in the measured HUs and GWR. The HUs and GWR of Lightspeed were measured lower than SOMATOM. The difference between the two CT scanners was also evident in groups divided by neurological prognosis. The area under the curve of the receiver operating characteristic curve to predict poor outcomes of Lightspeed was 0.798, and the cut-off value for 100% specificity was 1.172. The SOMATOM was 0.855, and the cut-off value was 1.269. The difference in scanners affects measurements and performance characteristics of the GWR in post-cardiac arrest patients. Therefore, when applying the results of the GWR study to clinical practice, reference values for each device should be presented, and an integrated plan should be prepared.

Status Myoclonus with Post-cardiac-arrest Syndrome: Implications for Prognostication

BACKGROUND

Status myoclonus (SM) after cardiac arrest (CA) may signify devastating brain injury. We hypothesized that SM correlates with severe neurologic and systemic post-cardiac-arrest syndrome (PCAS).

METHODS

Charts of patients admitted with CA to Mayo Clinic Saint Marys Hospital between 2005 and 2019 were retrospectively reviewed. Data included the neurologic examination, ancillary neurologic tests, and systemic markers of PCAS. Nonsustained myoclonus was clinically differentiated from SM. The cerebral performance category score at discharge was assessed; poor outcome was a cerebral performance category score > 2 prior to withdrawal of life-sustaining therapies or death.

RESULTS

Of 296 patients included, 276 (93.2%) had out-of-hospital arrest and 202 (68.5%) had a shockable rhythm; the mean time to return of spontaneous circulation was 32 ± 19 min. One hundred seventy-six (59.5%) patients had a poor outcome. One hundred one (34.1%) patients had myoclonus, and 74 (73.2%) had SM. Neurologic predictors of poor outcome were extensor or absent motor response to noxious stimulus (p = 0.02, odds ratio [OR] 3.8, confidence interval [CI] 1.2-12.4), SM (p = 0.01, OR 10.3, CI 1.5-205.4), and burst suppression on EEG (p = 0.01, OR 4.6, CI 1.4-17.4). Of 74 patients with SM, 73 (98.6%) had a poor outcome. A nonshockable rhythm (p < 0.001, OR 4.5, CI 2.6-7.9), respiratory arrest (p < 0.001, OR 3.5, CI 1.7-7.2), chronic kidney disease (p < 0.001, OR 3.1, CI 1.6-6.0), and a pressor requirement (p < 0.001, OR 4.4, CI 1.8-10.6) were associated with SM. No patients with SM, anoxic-ischemic magnetic resonance imaging findings, and absent electroencephalographic reactivity had a good outcome.

CONCLUSIONS

Sustained status myoclonus after CPR is observed in patients with other reliable indicators of severe acute brain injury and systemic PCAS. These clinical determinants should be incorporated as part of a comprehensive approach to prognostication after CA.

Somatosensory Evoked Potentials and Neuroprognostication After Cardiac Arrest

Improved understanding of post-cardiac arrest syndrome and clinical practices such as targeted temperature management have led to improved mortality in this cohort. Attention has now been placed on development of tools to aid in predicting functional outcome in comatose cardiac arrest survivors. Current practice uses a multimodal approach including physical examination, neuroimaging, and electrophysiologic data, with a primary utility in predicting poor functional outcome. These modalities remain confounded by self-fulfilling prophecy and the withdrawal of life-sustaining therapies. To date, a reliable measure to predict good functional outcome has not been established or validated, but the use of quantitative somatosensory evoked potential (SSEP) shows potential for this use. MEDLINE and EMBASE search using words "Cardiac Arrest" and "SSEP," "Somato sensory evoked potentials," "qSSEP," "quantitative SSEP," "targeted temperature management in cardiac arrest" was conducted. Relevant recent studies on targeted temperature management in cardiac arrest, plus studies on SSEP in cardiac arrest in the setting of hypothermia and without hypothermia, were included. In addition, animal studies evaluating the role of different components of SSEP in cardiac arrest were reviewed. SSEP is a specific indicator of poor outcomes in post-cardiac arrest patients but lacks sensitivity and has not clinically been established to foresee good outcomes. Novel methods of analyzing quantitative SSEP (qSSEP) signals have shown potential to predict good outcomes in animal and human studies. In addition, qSSEP has potential to track cerebral recovery and guide treatment strategy in post-cardiac arrest patients. Lying beyond the current clinical practice of dichotomized absent/present N20 peaks, qSSEP has the potential to emerge as one of the earliest predictors of good outcome in comatose post-cardiac arrest patients. Validation of qSSEP markers in prospective studies to predict good and poor outcomes in the cardiac arrest population in the setting of hypothermia could advance care in cardiac arrest. It has the prospect to guide allocation of health care resources and reduce self-fulfilling prophecy.

Targeted temperature management and early neuro-prognostication after cardiac arrest

Targeted temperature management (TTM) is a recommended neuroprotective intervention for coma after out-of-hospital cardiac arrest (OHCA). However, controversies exist concerning the proper implementation and overall efficacy of post-CA TTM, particularly related to optimal timing and depth of TTM and cooling methods. A review of the literature finds that optimizing and individualizing TTM remains an open question requiring further clinical investigation. This paper will summarize the preclinical and clinical trial data to-date, current recommendations, and future directions of this therapy, including new cooling methods under investigation. For now, early induction, maintenance for at least 24 hours, and slow rewarming utilizing endovascular methods may be preferred. Moreover, timely and accurate neuro-prognostication is valuable for guiding ethical and cost-effective management of post-CA coma. Current evidence for early neuro-prognostication after TTM suggests that a combination of initial prediction models, biomarkers, neuroimaging, and electrophysiological methods is the optimal strategy in predicting neurological functional outcomes.

Post-cardiac arrest myoclonus and in ICU mortality: insights from the Parisian Registry of Cardiac Arrest (PROCAT)

BACKGROUND

Post-cardiac arrest myoclonus (PCAM) is a frequent finding in resuscitated patients after cardiac arrest (CA), with rather poor prognostic significance. In this study, we evaluated the association of PCAM within intensive care unit (ICU) mortality from a university hospital CA patients' registry.

METHODS

Clinical data of consecutive CA survivors admitted in the intensive care unit (ICU) between January and December 2016 at the Paris Cochin University Hospital were assessed from the Parisian registry of cardiac arrest (PROCAT) and analyzed. Neurologic outcome was assessed using the Cerebral Performance Categories (CPC) scale at ICU discharge. Prevalence of PCAM and their association with mortality at ICU discharge were computed.

RESULTS

One hundred thirty-two (132) patients were included (73.5% males), median age of 66 years. Among them, 37 (28%) developed PCAM during their ICU stay. Only two patients with PCAM survived (5.4%). PCAM was strongly associated with mortality at ICU discharge (odds ratio 17.5 [4.2-123.2]). Sensitivity, specificity, PPV, and NPV of PCAM for prediction of death were 41%, 96%, 95%, and 46%, respectively.

CONCLUSION

PCAM was observed in nearly one-third of CA patients admitted in ICU. Patients with PCAM had a significantly higher likelihood of ICU mortality and a low likelihood of a good outcome. The prognostic value of PCAM seems rather bleak but remains nuanced and merits study in larger-scale prospective studies taking into account confounding factors.

The first national survey on practices of neurological prognostication after cardiac arrest in China, still a lot to do

AIMS

To investigate current awareness and practices of neurological prognostication in comatose cardiac arrest (CA) patients.

METHODS

An anonymous questionnaire was distributed to 1600 emergency physicians in 75 hospitals which were selected randomly from China between January and July 2018.

RESULTS

92.1% respondents fulfilled the survey. The predictive value of brain stem reflex, motor response and myoclonus was confirmed by 63.5%, 44.6% and 31.7% respondents, respectively. Only 30.7% knew that GWR value < 1.1 indicated poor prognosis and only 8.1% know the most commonly used SSEP N20. Status epilepticus, burst suppression and suppression were considered to predict poor outcome by only 35.0%, 27.4% and 20.9% respondents, respectively. Only 46.7% knew NSE and only 24.7% knew S-100. Only a few respondents knew that neurological prognostication should be performed later than 72 hours from CA either in TTM or non-TTM patients. In practice, the most commonly used method was clinical examination (85.4%). Only 67.9% had used brain CT for prognosis and 18.4% for MRI. NSE (39.6%) was a little more widely used than S-100β (18.0%). However, SSEP (4.4%) and EEG (11.4%) were occasionally performed.

CONCLUSIONS

Neurological prognostication in CA survivors had not been well understood and performed by emergency physicians in China. They were more likely to use clinical examination rather than objective tools, especially SSEP and EEG, which also illustrated that multimodal approach was not well performed in practice.

Serum proteomic analysis of novel predictive serum proteins for neurological prognosis following cardiac arrest

Early prognostication of neurological outcome in comatose patients after cardiac arrest (CA) is vital for clinicians when assessing the survival time of sufferers and formulating appropriate treatment strategies to avoid the withdrawal of life‐sustaining treatment (WLST) from patients. However, there is still a lack of sensitive and specific serum biomarkers for early and accurate identification of these patients. Using an isobaric tag for relative and absolute quantitation (iTRAQ)‐based proteomic approach, we discovered 55 differentially expressed proteins, with 39 up‐regulated secreted serum proteins and 16 down‐regulated secreted serum proteins between three comatose CA survivors with good versus poor neurological recovery. Then, four proteins were selected and were validated via an enzyme‐linked immunosorbent assay (ELISA) approach in a larger‐scale sample containing 32 good neurological outcome patients and 46 poor neurological outcome patients, and it was confirmed that serum angiotensinogen (AGT) and alpha‐1‐antitrypsin (SERPINA1) were associated with neurological function and prognosis in CA survivors. A prognostic risk score was developed and calculated using a linear and logistic regression model based on a combination of AGT, SERPINA1 and neuron‐specific enolase (NSE) with an area under the curve of 0.865 (P < .001), and the prognostic risk score was positively correlated with the CPC value (R = 0.708, P < .001). We propose that the results of the risk score assessment not only reveal changes in biomarkers during neurological recovery but also assist in enhancing current therapeutic strategies for comatose CA survivors.

Neuron-specific enolase and neuroimaging for prognostication after cardiac arrest treated with targeted temperature management

BACKGROUND

Prognostication after cardiac arrest (CA) needs a multimodal approach, but the optimal method is not known. We tested the hypothesis that the combination of neuron-specific enolase (NSE) and neuroimaging could improve outcome prediction after CA treated with targeted temperature management (TTM).

METHODS

A retrospective observational cohort study was performed on patients who underwent at least one NSE measurement between 48 and 72 hr; received both a brain computed tomography (CT) scan within 24 hr and diffusion-weighted magnetic resonance imaging (DW-MRI) within 7 days after return of spontaneous circulation (ROSC); and were treated with TTM after out-of-hospital CA between 2009 and 2017 at the Seoul St. Mary's Hospital in Korea. The primary outcome was a poor neurological outcome at 6 months after CA, defined as a cerebral performance category of 3-5.

RESULTS

A total of 109 subjects underwent all three tests and were ultimately included in this study. Thirty-four subjects (31.2%) experienced good neurological outcomes at 6 months after CA. The gray matter to white matter attenuation ratio (GWR) was weakly correlated with the mean apparent diffusion coefficient (ADC), PV400 and NSE (Spearman's rho: 0.359, -0.362 and -0.263, respectively). NSE was strongly correlated with the mean ADC and PV400 (Spearman's rho: -0.623 and 0.666, respectively). Serum NSE had the highest predictive value among the single parameters (area under the curve (AUC) 0.912, sensitivity 70.7% for maintaining 100% specificity). The combination of a DWI parameter (mean ADC or PV400) and NSE had better prognostic performance than the combination of the CT parameter (GWR) and NSE. The addition of the GWR to a DWI parameter and NSE did not improve the prediction of neurological outcomes.

CONCLUSION

The GWR (≤ 24 hr) is weakly correlated with the mean ADC (≤ 7 days) and NSE (highest between 48 and 72 hr). The combination of a DWI parameter and NSE has better prognostic performance than the combination of the GWR and NSE. The addition of the GWR to a DWI parameter and NSE does not improve the prediction of neurological outcomes after CA treatment with TTM.

Markers in Status Epilepticus Prognosis

Status epilepticus (SE) is a neurologic emergency with high morbidity and mortality. The assessment of a patient's prognosis is crucial in making treatment decisions. In this review, we discuss various markers that have been used to prognosticate SE in terms of recurrence, mortality, and functional outcome. These markers include demographic, clinical, electrophysiological, biochemical, and structural data. The heterogeneity of SE etiology and semiology renders development of prognostic markers challenging. Currently, prognostication in SE is limited to a few clinical scores. Future research should integrate clinical, genetic and epigenetic, metabolic, inflammatory, and structural biomarkers into prognostication models to approach "personalized medicine" in prognostication of outcomes after SE.

Prediction of the level of consciousness using pupillometer measurements in patients with impaired consciousness brought to the emergency and critical care center

Aim

We investigated whether the level of consciousness can be predicted using pupillometer measurements in patients with severe disturbance of consciousness.

Methods

Patients with a Glasgow Coma Scale (GCS) of 3–8, except for those after cardiac arrest, were included. Pupillary contraction rate and contraction velocity were each measured using a pupillometer.

Results

Thirty‐five patients were analyzed. At the time of discharge or changing hospitals, 16 patients had a GCS score of 3–13 and 19 patients had a GCS score of 14–15. In the non‐sedative group at about the time of arrival at our hospital, average pupillary contraction rates were 18.36% in the GCS 3–13 group and 19.67% in the GCS 14–15 group (P = 0.739), and average pupillary contraction velocities were 1.02 and 1.48, respectively (P = 0.182). Approximately 48 h after arrival, average pupillary contraction rates were 21.18% and 29.27%, respectively (P = 0.058), and average pupillary contraction velocities were 1.37 and 1.91, respectively (P = 0.172). Among the sedative group, at about the time of arrival, average pupillary contraction rates were 8.75% in the GCS 3–13 group and 19.75% in the GCS 14–15 group (P = 0.032). Average pupillary contraction velocities were 0.34 and 1.48, respectively (P = 0.001). Approximately 48 h after arrival, average pupillary contraction rates were 13.50% and 13.50%, respectively (P = 1.00), and average pupillary contraction velocities were 0.80 and 0.82, respectively (P = 0.93).

Conclusions

Pupillometer measurements could predict level of consciousness of patients with severe consciousness disorder.

Cerebral Infarction Observed on Brain MRI in Unconscious Out-of-Hospital Cardiac Arrest Survivors: A Pilot Study

BACKGROUND

Cumulative evidence regarding the use of brain magnetic resonance imaging (MRI) for predicting prognosis of unconscious out-of-hospital cardiac arrest (OHCA) survivors treated with targeted temperature management (TTM) is available. Theoretically, these patients are at a high risk of developing cerebral infarction. However, there is a paucity of reports regarding the characteristics of cerebral infarction in this population. Thus, we performed a pilot study to identify the characteristics and risk factors of cerebral infarction and to evaluate whether this infarction is associated with clinical outcomes.

METHODS

A single-center, retrospective, registry-based cohort study was conducted at Severance Hospital, a tertiary center. Unconscious OHCA survivors were registered and treated with TTM between September 2011 and December 2015. We included patients who underwent brain MRI in the first week after the return of spontaneous circulation. We excluded patients who underwent any endovascular interventions to focus on "procedure-unrelated" cerebral infarctions. We assessed hypoxic-ischemic encephalopathy (HIE) and procedure-unrelated cerebral infarction separately on MRI. Patients were categorized into the following groups based on MRI findings: HIE (-)/infarction (-), infarction-only, and HIE (+) groups. Conventional vascular risk factors showing p < 0.05 in univariate analyses were entered into multivariate logistic regression. We also evaluated if the presence of this procedure-unrelated cerebral infarction lesion or HIE was associated with a poor clinical outcome at discharge, defined as a cerebral performance category of 3-5.

RESULTS

Among 71 unconscious OHCA survivors who completed TTM, underwent MRI, and who did not undergo endovascular interventions, 14 (19.7%) patients had procedure-unrelated cerebral infarction based on MRI. Advancing age [odds ratio (OR) 1.11] and atrial fibrillation (OR 5.78) were independently associated with the occurrence of procedure-unrelated cerebral infarction (both p < 0.05). There were more patients with poor clinical outcomes at discharge in the HIE (+) group (88.1%) than in the infarction-only (30.0%) or HIE (-)/infarction (-) group (15.8%) (p < 0.001). HIE (+) (OR 38.69, p < 0.001) was independently associated with poor clinical outcomes at discharge, whereas infarction-only was not (p > 0.05), compared to HIE (-)/infarction (-).

CONCLUSIONS

In this pilot study, procedure-unrelated cerebral infarction was noted in approximately one-fifth of unconscious OHCA survivors who were treated with TTM and underwent MRI. Older age and atrial fibrillation might be associated with the occurrence of procedure-unrelated cerebral infarction, and cerebral infarction was not considered to be associated with clinical outcomes at discharge. Considering that the strict exclusion criteria in this pilot study resulted in a highly selected sample with a relatively small size, further work is needed to verify our findings.

The Use of Gray-White-Matter Ratios May Help Predict Survival and Neurological Outcomes in Patients Resuscitated From Out-of-Hospital Cardiac Arrest

Background

The gray-white-matter ratio (GWR) measured on brain computed tomography (CT) following return of spontaneous circulation (ROSC) has been reported to be helpful in the prognostication of mortality or comatose status of cardiac arrest victims. However, whether the use of GWR in predicting the outcomes in out-of-hospital cardiac arrest (OHCA) survivors in Taiwan population remains uninvestigated.

Methods

This retrospective observational study conducted in a single tertiary medical center in Taiwan enrolled all the non-traumatic OHCA adults (> 18 years old) with sustained ROSC (≥ 20 minutes) during the period from 2006 to 2014. Patients with following exclusion criteria were further excluded: no brain CT within 24 hours following ROSC; the presence of intracranial hemorrhage, severe old insult, brain tumor, ventriculoperitoneal shunt, and severe image artifact. The GWR values were obtained from the density measurement of bilateral putamen, caudate nuclei, posterior limbs of internal capsule, corpus callosum, medial cortex and medial white matter of cerebrum in Hounsfield unit with region of interest of 0.11 cm², and further compared between the patients who survived to hospital discharge or not and the patients with and without good neurological outcome (good: cerebral performance category [CPC] of 1-2, poor: CPC of 3-5), respectively.

Results

A total of 228 patients were included in the final analysis with 59.2% in male gender and mean age of 65.8-year-old. There were 106 patients (46.5%) survived to hospital discharge and 40 patients (17.5%) discharged with good neurological outcomes. The GWR values of patients who survived to hospital discharge was significantly higher than ones of those who failed (e.g. basal ganglion: 1.239 vs. 1.199, p < 0.001). Patients with good neurological outcome also had higher GWR values than those with poor outcome (e.g. basal ganglion: 1.243 vs. 1.208, p = 0.010). The Area Under Curve of Receiver of Characteristic curve demonstrated fair predicting ability of GWR for survival and neurological outcomes.

Conclusion

The use of GWR measured on bran CT within 24 hours following ROSC can help in predicting survival-to-hospital discharge and neurological outcome in OHCA survivors.

The value of cerebrospinal fluid ubiquitin C-terminal hydrolase-L1 protein as a prognostic predictor of neurologic outcome in post-cardiac arrest patients treated with targeted temperature management

AIM

We evaluated the prognostic value of serum- and cerebrospinal fluid (CSF)-ubiquitin carboxyl-terminal esterase L1 protein (UCHL1) measurements in post- post-out of hospital cardiac arrest (OHCA) patients treated with target temperature management (TTM), to predict neurologic outcome.

METHODS

This was a prospective single-centre observational cohort study, conducted from April 2018 to September 2019. Serum- and CSF-UCHL1 were obtained immediately (UCHL1_initial), 24 h (UCHL1₂₄), 48 h (UCHL1₄₈), and 72 h (UCHL1₇₂) after return of spontaneous circulation (ROSC). The area under the receiver operating characteristic curves (AUROC) and Delong method were used to identify cut-off values of serum- and CSF-UCHL1_initial, UCHL1₂₄, UCHL1₄₈, UCHL1₇₂ for predicting neurologic outcomes.

RESULTS

Of 38 patients enrolled, 16 comprised the poor outcome group. The AUROCs for serum- and CSF-UCHL1_initial were 0.71 and 0.93 in predicting poor neurological outcomes, respectively (p = 0.01). The AUROCs for serum- and CSF-UCHL1₂₄ were 0.85 and 0.91 (p = 0.24). The AUROCs for serum- and CSF-UCHL1₄₈ were 0.90 and 0.97 (p = 0.07). The AUROCs for serum- and CSF-UCHL1₇₂ were 0.94 and 0.98 (p = 0.25).

CONCLUSION

Findings of this study demonstrate that CSF-UCHL1 measured immediately, 24, 48, and 72 h after ROSC is a valuable predictor for evaluating neurologic outcomes, whereas serum-UCHL1 measured at 24, 48, and 72 h after ROSC showed a significant performance in the prognostication of poor outcomes in post-OHCA patients treated with TTM.

Electroencephalography in Predicting Short-Term Clinical Outcomes after Cardiac Arrest

BACKGROUND

Early consciousness recovery after cardiac arrest (CA) is one of the most explicit and self-evident prognostic factors for clinical outcomes. We aimed to evaluate the prognostic value of electroencephalography (EEG) phenotypes according to the American Clinical Neurophysiology Society's Critical Care EEG classification for predicting early recovery after CA.

METHODS

Consecutive patients admitted to the ICU after CA were enrolled. We analyzed Glasgow Coma Scale (GCS) score within 10 days after CA and evaluated mortality within 28 days according to EEG pattern subtype.

RESULTS

Among the total of 71 patients, 9 had periodic discharges (PDs) EEG pattern, 4 had rhythmic delta activity (RDA), 8 had spike-and-wave (SW), 22 had low voltage, 5 had burst suppression, and 23 had other EEG patterns. Initial GCS scores, GCS scores 3 days after CA (or 3 days after targeted temperature management [TTM]), and 10 days after CA (or 10 days after TTM) were significantly different among EEG subtypes (p < 0.001, respectively) (Table 2). GCS scores were significantly higher in RDA and the other EEG group compared to the PDs, SW, low voltage, and burst suppression groups (p < 0.001). Significant group × time interactions were observed for the follow-up period between EEG phenotypes (p < 0.001) demonstrating the most increase in the other EEG pattern group.

CONCLUSIONS

Consciousness states were significantly worse in the PDs, SW, burst suppression, and low-voltage groups compared to the RDA and the other EEG pattern within 10 days after CA. The degree of consciousness recovery differed significantly by EEG pattern subtype within 10 days.

Sudden Cardiac Arrest Survivorship: A Scientific Statement From the American Heart Association

Cardiac arrest systems of care are successfully coordinating community, emergency medical services, and hospital efforts to improve the process of care for patients who have had a cardiac arrest. As a result, the number of people surviving sudden cardiac arrest is increasing. However, physical, cognitive, and emotional effects of surviving cardiac arrest may linger for months or years. Systematic recommendations stop short of addressing partnerships needed to care for patients and caregivers after medical stabilization. This document expands the cardiac arrest resuscitation system of care to include patients, caregivers, and rehabilitative healthcare partnerships, which are central to cardiac arrest survivorship.

Neuroprognostication Practices in Postcardiac Arrest Patients: An International Survey of Critical Care Providers

OBJECTIVES

To characterize approaches to neurologic outcome prediction by practitioners who assess prognosis in unconscious cardiac arrest individuals, and assess compliance to available guidelines.

DESIGN

International cross-sectional study.

SETTING

We administered a web-based survey to members of Neurocritical Care Society, Society of Critical Care Medicine, and American Academy of Neurology who manage unconscious cardiac arrest patients to characterize practitioner demographics and current neuroprognostic practice patterns.

SUBJECTS

Physicians that are members of aforementioned societies who care for successfully resuscitated cardiac arrest individuals.

INTERVENTIONS

Not applicable.

MEASUREMENTS AND MAIN RESULTS

A total of 762 physicians from 22 countries responses were obtained. A significant proportion of respondents used absent corneal reflexes (33.5%) and absent pupillary reflexes (36.2%) at 24 hours, which is earlier than the recommended 72 hours in the standard guidelines. Certain components of the neurologic examination may be overvalued, such as absent motor response or extensor posturing, which 87% of respondents considered being very or critically important prognostic indicators. Respondents continue to rely on myoclonic status epilepticus and neuroimaging, which were favored over median nerve somatosensory evoked potentials for prognostication, although the latter has been demonstrated to have a higher predictive value. Regarding definitive recommendations based on poor neurologic prognosis, most physicians seem to wait until the postarrest timepoints proposed by current guidelines, but up to 25% use premature time windows.

CONCLUSIONS

Neuroprognostic approaches to hypoxic-ischemic encephalopathy vary among physicians and are often not consistent with current guidelines. The overall inconsistency in approaches and deviation from evidence-based recommendations are concerning in this disease state where mortality is so integrally related to outcome prediction.

Brain computed tomography angiography in postcardiac arrest patients and neurologic outcome

Objective

This study aimed to analyze intracranial vessels using brain computed tomography angiography (CTA) and scoring systems to diagnose brain death and predict poor neurologic outcomes of postcardiac arrest patients.

Methods

Initial brain CTA images of postcardiac arrest patients were analyzed using scoring systems to determine a lack of opacification and diagnose brain death. The primary outcome was poor neurologic outcome, which was defined as cerebral performance category score 3 to 5. The frequency, sensitivity, specificity, positive predictive value, negative predictive value, and area under receiver operating characteristic curve for the lack of opacification of each vessel and for each scoring system used to predict poor neurologic outcomes were determined.

Results

Patients with poor neurologic outcomes lacked opacification of the intracranial vessels, most commonly in the vein of Galen, both internal cerebral veins, and the mid cerebral artery (M4). The 7-score results (P=0.04) and 10-score results were significantly different (P=0.04) between outcome groups, with an area under receiver operating characteristic of 0.61 (range, 0.48 to 0.72). The lack of opacification of each intracranial vessel and all scoring systems exhibited high specificity (100%) and positive predictive values (100%) for predicting poor neurologic outcomes.

Conclusion

Lack of opacification of vessels on brain CTA exhibited high specificity for predicting poor neurologic outcomes of patients after cardiac arrest.

Current Status of Continuous Electroencephalographic Monitoring in Critically Ill Children

The utilization of continuous electroencephalographic monitoring in critical care units has increased significantly, and several consensus statements and guidelines have been published. The use of critical care electroencephalographic monitoring has become a standard of care in many centers in the United States and other countries. The most common indication is to detect electrographic seizures and status epilepticus. Other indications include monitoring treatment efficacy in patients with electrographic seizures and status epilepticus, evaluating the degree of disturbance of function in patients with encephalopathy, monitoring brain function in patients treated with sedation and neuromuscular blocking agents, and event characterization. The urgent initiation of critical care electroencephalographic monitoring is recommended in certain clinical populations, but varies among institutions. The consensus among neurologists is to start treatment after identifying electrographic seizures or electrographic status epilepticus with or without clinical signs. However, the optimal treatment of nonconvulsive and electrographic-only seizures remains controversial. Critical care electroencephalographic monitoring has significant impact on clinical management, but there is lack of clear evidence that treatment guided by critical care electroencephalographic monitoring leads to improvement of clinical and neurodevelopmental outcome. There are substantial discrepancies among institutions on personnel and technical support used for critical care electroencephalographic monitoring. The optimal critical care electroencephalographic monitoring team should include electroencephalographers with experience in critical care electroencephalographic monitoring interpretation and appropriately trained technologists certified in electroencephalography by the American Board of Registration of Electroencephalographic and Evoked Potential Technologists specializing in critical care electroencephalographic monitoring or long-term monitoring.

The Influence of Therapeutics on Prognostication After Cardiac Arrest

PURPOSE OF REVIEW

The goal of this review is to highlight the influence of therapeutic maneuvers on neuro-prognostication measures administered to comatose survivors of cardiac arrest. We focus on the effect of sedation regimens in the setting of targeted temperature management (TTM), one of the principle interventions known to improve neurological recovery after cardiac arrest. Further, we discuss the critical need for novel markers, as well as refinement of existing markers, among patients receiving extracorporeal membrane oxygenation (ECMO) in the setting of failed conventional resuscitation, known as extracorporeal cardiopulmonary resuscitation (ECPR).

RECENT FINDINGS

Automated pupillometry may have some advantage over standard pupillary examination for prognostication following TTM, sedation, or the use of ECMO after cardiac arrest. New serum biomarkers such as Neurofilament light chain have shown good predictive abilities and need further validation in these populations. There is a high-level uncertainty in brain death declaration protocols particularly related to apnea testing and appropriate ancillary tests in patients receiving ECMO. Both sedation and TTM alone and in combination have been shown to affect prognostic markers to varying degrees. The optimal approach to analog-sedation is unknown, and requires further study. Moreover, validation of known prognostic markers, as well as brain death declaration processes in patients receiving ECMO is warranted. Data on the effects of TTM, sedation, and ECMO on biomarkers (e.g., neuron-specific enolase) and electrophysiology measures (e.g., somatosensory-evoked potentials) is sparse. The best approach may be one customized to the individual patient, a precision-medicine approach.

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

OBJECTIVES

To 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.

METHODS

Review 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.

RESULTS

There 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.

CONCLUSIONS

The 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.

Brain-Specific Serum Biomarkers Predict Neurological Morbidity in Diagnostically Diverse Pediatric Intensive Care Unit Patients

BACKGROUND

Unexpected neurological morbidity in Pediatric Intensive Care Units (PICUs) remains high and is difficult to detect proactively. Brain-specific biomarkers represent a novel approach for early detection of neurological injury. We sought to determine whether serum concentrations of neuron-specific enolase (NSE), myelin basic protein (MBP), and S100B, specific for neurons, oligodendrocytes, and glia, respectively, were predictive of neurological morbidity in critically ill children.

METHODS

Serum was prospectively collected on days 1-7 from diagnostically diverse PICU patients (n = 103). Unfavorable neurological outcome at hospital discharge was defined as Pediatric Cerebral Performance Category (PCPC) score of 3-6 with a deterioration from baseline. NSE, MBP, and S100B concentrations were measured by enzyme-linked immunosorbent assay.

RESULTS

Peak biomarker levels were greater in patients with unfavorable versus favorable neurological outcome [NSE 39.4 ± 44.1 vs. 12.2 ± 22.9 ng/ml (P = 0.005), MBP 9.1 ± 11.5 vs. 0.6 ± 1.3 ng/ml (P = 0.003), S100B 130 ± 232 vs. 34 ± 70 pg/ml (P = 0.04), respectively; mean ± SD]. Peak levels were each independently associated with unfavorable neurological outcome when controlling for presence of primary neurologic admission diagnosis and poor baseline PCPC using logistic regression analysis (NSE, P = 0.04; MBP, P = 0.004; S100B, P = 0.04), and had the following receiver operating characteristics: NSE 0.75 (0.58, 0.92), MBP 0.81 (0.66, 0.94), and S100B 0.80 (0.67, 0.93) (area under the curve [95% confidence intervals]).

CONCLUSIONS

Prospectively collected brain-specific serum biomarkers predict unfavorable neurological outcome in critically ill children. Serum biomarkers used in conjunction with clinical data could be used to generate models predicting early detection of neurological injury, allowing for more timely diagnostic and therapeutic interventions, potentially reducing neurological morbidity in the PICU.

Cerebral Edema After Cardiopulmonary Resuscitation: A Therapeutic Target Following Cardiac Arrest?

We sought to review the role that cerebral edema plays in neurologic outcome following cardiac arrest, to understand whether cerebral edema might be an appropriate therapeutic target for neuroprotection in patients who survive cardiopulmonary resuscitation. Articles indexed in PubMed and written in English. Following cardiac arrest, cerebral edema is a cardinal feature of brain injury and is a powerful prognosticator of neurologic outcome. Like other conditions characterized by cerebral ischemia/reperfusion, neuroprotection after cardiac arrest has proven to be difficult to achieve. Neuroprotection after cardiac arrest generally has focused on protecting neurons, not the microvascular endothelium or blood-brain barrier. Limited preclinical data suggest that strategies to reduce cerebral edema may improve neurologic outcome. Ongoing research will be necessary to determine whether targeting cerebral edema will improve patient outcomes after cardiac arrest.

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

OBJECTIVES

Absence of somatosensory evoked potentials is considered a nearly perfect predictor of poor outcome after cardiac arrest. However, reports of good outcomes despite absent somatosensory evoked potentials and high rates of withdrawal of life-sustaining therapies have raised concerns that estimates of the prognostic value of absent somatosensory evoked potentials may be biased by self-fulfilling prophecies. We aimed to develop an unbiased estimate of the false positive rate of absent somatosensory evoked potentials as a predictor of poor outcome after cardiac arrest.

DATA SOURCES

PubMed.

STUDY SELECTION

We selected 35 studies in cardiac arrest prognostication that reported somatosensory evoked potentials.

DATA EXTRACTION

In each study, we identified rates of withdrawal of life-sustaining therapies and good outcomes despite absent somatosensory evoked potentials. We appraised studies for potential biases using the Quality in Prognosis Studies tool. Using these data, we developed a statistical model to estimate the false positive rate of absent somatosensory evoked potentials adjusted for withdrawal of life-sustaining therapies rate.

DATA SYNTHESIS

Two-thousand one-hundred thirty-three subjects underwent somatosensory evoked potential testing. Five-hundred ninety-four had absent somatosensory evoked potentials; of these, 14 had good functional outcomes. The rate of withdrawal of life-sustaining therapies for subjects with absent somatosensory evoked potential could be estimated in 14 of the 35 studies (mean 80%, median 100%). The false positive rate for absent somatosensory evoked potential in predicting poor neurologic outcome, adjusted for a withdrawal of life-sustaining therapies rate of 80%, is 7.7% (95% CI, 4-13%).

CONCLUSIONS

Absent cortical somatosensory evoked potentials do not infallibly predict poor outcome in patients with coma following cardiac arrest. The chances of survival in subjects with absent somatosensory evoked potentials, though low, may be substantially higher than generally believed.

Early Electroencephalography Findings in Cardiogenic Shock Patients Treated by Venoarterial Extracorporeal Membrane Oxygenation

OBJECTIVES

We aimed to assess early electroencephalography findings in patients treated by venoarterial extracorporeal membrane oxygenation and their association with neurologic outcome.

DESIGN

Single-center observational study.

SETTING

Medical ICU of a university hospital.

PATIENTS

An early standardized electroencephalography assessment, that is, standard electroencephalography followed by continuous electroencephalography, was performed in consecutive cardiogenic shock patients requiring venoarterial extracorporeal membrane oxygenation. Associations between electroencephalography findings and outcome, defined as a composite of acute brain injury or death at 14 days, were investigated.

MEASUREMENTS AND MAIN RESULTS

Twenty-two patients with a median Full Outline of Unresponsiveness score of 4 (interquartile range, 3-6) were studied. Pupillary light reflex, corneal reflex, and cough reflex were preserved in 20 (90%), 17 (77%), and 17 (77%) patients, respectively. Overall, standard electroencephalography findings consisted of diffuse slowing in 21 patients (95%) and severe background abnormalities in 13 patients (59%) (i.e., a discontinuous [n = 5; 23%] and/or an unreactive background [n = 9; 41%]). Severe background abnormalities on standard electroencephalography (poor outcome rate: 69% vs 22%; p = 0.03) and absence of sleep transients on continuous electroencephalography (poor outcome rate: 67% vs 14%; p = 0.02) were associated with a poor outcome, whereas neurologic findings and doses of sedation were not. Patients without sleep transients on continuous electroencephalography tended to have lower Full Outline of Unresponsiveness scores than patients with preserved sleep transients-appearing patterns.

CONCLUSIONS

In patients treated by venoarterial extracorporeal membrane oxygenation, early severe background abnormalities on standard electroencephalography provide important information on neurologic outcome. The lack of sleep transients on continuous electroencephalography reflects the severity of brain dysfunction and might represent an additional prognostic marker.

Standards for Studies of Neurological Prognostication in Comatose Survivors of Cardiac Arrest: A Scientific Statement From the American Heart Association

Significant improvements have been achieved in cardiac arrest resuscitation and postarrest resuscitation care, but mortality remains high. Most of the poor outcomes and deaths of cardiac arrest survivors have been attributed to widespread brain injury. This brain injury, commonly manifested as a comatose state, is a marker of poor outcome and a major basis for unfavorable neurological prognostication. Accurate prognostication is important to avoid pursuing futile treatments when poor outcome is inevitable but also to avoid an inappropriate withdrawal of life-sustaining treatment in patients who may otherwise have a chance of achieving meaningful neurological recovery. Inaccurate neurological prognostication leading to withdrawal of life-sustaining treatment and deaths may significantly bias clinical studies, leading to failure in detecting the true study outcomes. The American Heart Association Emergency Cardiovascular Care Science Subcommittee organized a writing group composed of adult and pediatric experts from neurology, cardiology, emergency medicine, intensive care medicine, and nursing to review existing neurological prognostication studies, the practice of neurological prognostication, and withdrawal of life-sustaining treatment. The writing group determined that the overall quality of existing neurological prognostication studies is low. As a consequence, the degree of confidence in the predictors and the subsequent outcomes is also low. Therefore, the writing group suggests that neurological prognostication parameters need to be approached as index tests based on relevant neurological functions that are directly related to the functional outcome and contribute to the quality of life of cardiac arrest survivors. Suggestions to improve the quality of adult and pediatric neurological prognostication studies are provided.

Neuron-specific enolase (NSE) improves clinical risk scores for prediction of neurological outcome and death in cardiac arrest patients: Results from a prospective trial

AIM

Neuron-specific enolase (NSE) increases in response to brain injury and is recommended for outcome prediction in cardiac arrest patients. Our aim was to investigate whether NSE measured at different days after a cardiac arrest and its kinetics would improve the prognostic ability of two cardiac arrest specific risk scores.

METHODS

Within this prospective observational study, we included consecutive adult patients after cardiac arrest. We calculated the Out-of-hospital cardiac arrest (OHCA) score and the Cardiac Arrest Hospital Prognosis (CAHP) score upon ICU admission and measured serum NSE upon admission and days 1, 2, 3, 5 and 7. We calculated logistic regression models to study associations of scores and NSE levels with neurological outcome defined by Cerebral Performance Category (CPC) scale and in-hospital death.

RESULTS

From 336 included patients, 180 (54%) survived until hospital discharge, of which 150 (45%) had a good neurological outcome. NSE at day 3 showed the highest prognostic accuracy (discrimination) for neurological outcome (area under the curve (AUC) 0.89) and in-hospital mortality (AUC 0.88). These results were robust in reclassification statistics and across different subgroups. NSE kinetics with admission levels serving as a baseline did not further improve prognostication. NSE on day 3 significantly improved discrimination of both clinical risk scores (CAHP from AUC 0.81 to 0.91; OHCA from AUC 0.79 to 0.89).

CONCLUSION

NSE measured at day 3 significantly improves clinical risk scores for outcome prediction in cardiac arrest patients and may thus add to clinical decision making about escalation or withdrawal of therapy in this vulnerable patient population.

Early electroencephalography for outcome prediction of postanoxic coma: A prospective cohort study

Objective

To provide evidence that early electroencephalography (EEG) allows for reliable prediction of poor or good outcome after cardiac arrest.

Methods

In a 5‐center prospective cohort study, we included consecutive, comatose survivors of cardiac arrest. Continuous EEG recordings were started as soon as possible and continued up to 5 days. Five‐minute EEG epochs were assessed by 2 reviewers, independently, at 8 predefined time points from 6 hours to 5 days after cardiac arrest, blinded for patients’ actual condition, treatment, and outcome. EEG patterns were categorized as generalized suppression (<10 μV), synchronous patterns with ≥50% suppression, continuous, or other. Outcome at 6 months was categorized as good (Cerebral Performance Category [CPC] = 1–2) or poor (CPC = 3–5).

Results

We included 850 patients, of whom 46% had a good outcome. Generalized suppression and synchronous patterns with ≥50% suppression predicted poor outcome without false positives at ≥6 hours after cardiac arrest. Their summed sensitivity was 0.47 (95% confidence interval [CI] = 0.42–0.51) at 12 hours and 0.30 (95% CI = 0.26–0.33) at 24 hours after cardiac arrest, with specificity of 1.00 (95% CI = 0.99–1.00) at both time points. At 36 hours or later, sensitivity for poor outcome was ≤0.22. Continuous EEG patterns at 12 hours predicted good outcome, with sensitivity of 0.50 (95% CI = 0.46–0.55) and specificity of 0.91 (95% CI = 0.88–0.93); at 24 hours or later, specificity for the prediction of good outcome was <0.90.

Interpretation

EEG allows for reliable prediction of poor outcome after cardiac arrest, with maximum sensitivity in the first 24 hours. Continuous EEG patterns at 12 hours after cardiac arrest are associated with good recovery. ANN NEUROL 2019;86:203–214

Value of EEG reactivity for prediction of neurologic outcome after cardiac arrest: Insights from the Parisian registry

PURPOSE

To evaluate the predictive value of EEG reactivity assessment and confounders for neurological outcome after cardiac arrest.

METHODS

All consecutive patients admitted in a tertiary cardiac arrest center between 2007 and 2016 still alive 48 h after admission with at least one EEG recorded during coma. EEG reactivity was defined as a reproducible waveform change in amplitude or frequency following standardized stimulation. Each EEG was classified based on American Clinical Neurophysiology Society nomenclatures and classified in highly malignant (including status epilepticus), malignant, or benign EEG. We assessed the predictive values of EEG reactivity and sedation effect for neurologic outcome at ICU discharge using the Cerebral Performance Category scale (with CPC 1-2 assumed as favorable outcome and CPC 3-4-5 considered as poor outcome).

RESULTS

Among 428 patients, a poor outcome was observed in 80% patients. The median time to EEG recording was 3 (1-4) days and 51% patients had a non-reactive EEG. The positive predictive value (PPV) of a non-reactive EEG to predict an unfavorable outcome was 97.1% (IC95% 93.6-98.9), increasing to 98.3% (IC95 94.1-99.8) when the EEG had been performed without sedation. In multivariate analysis, a non-reactive EEG was associated with poor outcome (OR 12.6 IC95% 4.7-33.6; p < 0.001). In multivariate analysis, concomitant sedation was not statistically associated with EEG non-reactivity. The PPV of a benign EEG to predict favorable outcome was 49.7% (IC95% 41.5-57.9), increasing to 66.2% (IC95% 54.3-76.8) when EEG was recorded earlier, with ongoing sedation.

CONCLUSIONS

After cardiac arrest, absence of EEG reactivity was predictive of unfavorable outcome. By contrast, a benign EEG was slightly predictive of a favorable outcome. Reactivity assessment may have important implications in the neuroprognostication process after cardiac arrest and could be influenced by sedation.

Intracranial pressure and compliance in hypoxic ischemic brain injury patients after cardiac arrest

INTRODUCTION

In hypoxic ischemic brain injury (HIBI), increased intracranial pressure (ICP) can ensue from cerebral edema stemming from cytotoxic and vasogenic mechanisms. Downstream sequelae of restricted cerebral blood flow lead to neurologic braindeath. There is limited data characterizing the temporal trends and patterns of ICP and compliance in human HIBI patients.

METHODS

Patients underwent invasive ICP monitoring with a parenchymal probe (Camino) and were managed with a tier-based management algorithm for elevated ICP. Data pertaining to mean arterial pressure (MAP), ICP, brain tissue oxygenation (PbtO₂), end tidal carbon dioxide (ETCO₂), core body temperature and RAP (moving correlation coefficient between mean ICP and its mean pulse amplitude) as a measure of intracranial compliance were recorded in the ICM + software. Data pertaining to ICP lowering interventions was also collected.

RESULTS

Ten patients were included with a median age of 47 (range 20-71) and seven were male (7/10). The mean ICP was 14 mmHg (SD 11) and time of ICP> 20 mmHg was 22% (range 0-100). The mean MAP, ETCO₂ and temperature were 89 mmHg (SD 13), 31 mmHg (SD 7), 35.7 °C (SD 0.9), respectively. The mean RAP was 0.58 (SD 0.34) and time of RAP > 0.4 was 78% (range 57-97). There were no significant relationships between ETCO₂ and temperature with ICP.

CONCLUSIONS

In our cohort, HIBI was characterized by normal ICP but with limited intracranial compliance. However, significant in between patient heterogeneity exists with respect to temporal patterns of intracranial pressure - volume relationships in HIBI.

TRIAL REGISTRATION

clinicaltrials.gov (NCT03609333).

Inter-predictability of Neuroprognostic Modalities After Cardiac Arrest

Introduction

At present, there is an emphasis on a multi-modal approach to neuro-prognostication after cardiac arrest using clinical examination, neurophysiologic testing, laboratory biomarkers, and radiological studies. However, this necessitates significant resource utilization and can be challenging in under-resourced clinical settings. Hence, we sought to determine the inter-predictability and correlation of prognostic tests performed in patients after cardiac arrest.

Methods

Fifty patients were included through neurophysiology laboratory data for this retrospective study. Clinical, radiological and neurophysiological data were collected. Neurophysiological data were re-evaluated by a board-certified neurophysiologist for the purpose of the study. Chi-square testing was used to evaluate the correlation between different diagnostic modalities.

Results

We found that a non-reactive electroencephalogram (EEG) had a predictive value of 79% for absent bilateral cortical responses (N20) with somatosensory evoked potentials (SSEP). On the other hand, absent bilateral cortical responses N20 had 87% predictive value for a non-reactive EEG. Also, absent cortical responses and non-reactive EEG had predictive values of 78% and 72% for anoxic injury on magnetic resonance imaging (MRI) brain respectively with a non-significant difference on chi-square testing. Individually, absent bilateral N20 SSEP, a non-reactive EEG and anoxic brain injury on MRI studies were highly predictive of poor outcome [modified Rankin scale (mRS) > 4] at hospital discharge.

Conclusion

Neuroprognostication in a post-cardiac arrest setting is often limited by self-fulfilling prophecy. Given the lack of absolute correlation between different modalities used in post-cardiac arrest patients, the value of the multi-modal approach to neuro-prognostication is highlighted by this study.

Change in neuron specific enolase levels in out-of-hospital cardiopulmonary arrest survivors as a simple and useful tool to predict neurological prognosis

INTRODUCTION AND OBJECTIVES

Neuron-specific enolase (NSE) is a prognostic marker in out-of-hospital cardiopulmonary arrest (OHCA) survivors treated with mild therapeutic hypothermia (MTH). The objectives were to analyze the correlation between dynamic changes in NSE and outcomes and to determine the measurement timing that best predicts neurological status.

METHODS

Multicenter cohort study including patients admitted after shockable rhythm OHCA and treated with MTH. Serum NSE was sampled at 2 different times and Δ-NSE (%) was calculated as 100 x (NSE2-NSE1)/NSE1. In-hospital mortality and neurological outcome, as assessed by the Cerebral Performance Category (CPC) scale, were evaluated during admission and after a 6-month follow-up.

RESULTS

We included 166 patients admitted to 4 hospitals. In-hospital mortality was 31.9%. Almost 60% of patients had a good neurological recovery (CPC 1-2). On univariate and multivariate logistic regression analyses, an increase in NSE levels was associated with higher in-hospital mortality and worse CPC on discharge and after 6-months (P<.001). Positive Δ-NSE showed an OR=9.28 (95% CI 4.40-19.57) for mortality, OR=11.23 (95% CI 5.24-24.11) for CPC 3-5 at discharge and OR=11.14 (95% CI 5.05-24.55) for CPC 3-5 after 6-months' follow-up (P<.001). The first NSE measurement, conducted at 18 to 24hours, and the second measurement at 69 to 77hours after OHCA showed a high area under the curve in predicting CPC at discharge (0.9389 and 0.9909, respectively; 0.8096 for the whole cohort).

CONCLUSIONS

Dynamic changes in NSE serum levels are good markers of hard clinical outcomes after an OHCA due to shockable rhythm in an MTH-treated cohort. NSE measurements at specific intervals after OHCA may predict events even more precisely.

Early-SEPs' amplitude reduction is reliable for poor-outcome prediction after cardiac arrest?

OBJECTIVE

The bilateral absence of cortical Somatosensory Evoked Potentials (SEPs), after cardiac arrest (CA), is a high reliable predictor of poor outcome but it is present in no more than 40% of patients. An amplitude reduction of cortical SEPs was found in about 30% of subjects, but few papers analysed its prognostic significance. The aim of our study is to identify a value of SEP amplitude reduction below which all the CA patients had poor outcome and the relationship between SEP and Electroencephalogram (EEG) patterns.

MATERIAL AND METHODS

We analysed comatose patients in whom SEPs and EEG were recorded at 6-12 hours after CA. We evaluated the sensitivity at specificity of 100% of SEP amplitude in predicting the non-recovery of consciousness by plotting Receiver Operating Characteristic (ROC) curves. We also analysed the relationship between SEP amplitude and EEG patterns. Outcome was evaluated at 6 months by Glasgow Outcome Scale.

RESULTS

We analysed 119 subjects. According to the ROC analysis (area under the curve = 0.95/CI 0.91-0.99), all patients with a cortical SEP amplitude <0.65 μV did not recover consciousness (GOS 1-2), with a sensitivity of 71.8%. Severe EEG abnormalities (suppression and burst-suppression patterns) were also observed in all these patients.

CONCLUSION

Not only the absence but also a bilateral amplitude reduction of cortical SEPs (<0.65 μV) is associated with ominous prognosis (death or non-recovery of consciousness) with a very high predictive value. However, we emphasize that great caution should be applied before adopting amplitude reduction as a criterion for the poor prognosis of CA patients.

Multimodal approach for neurologic prognostication of out-of-hospital cardiac arrest patients undergoing targeted temperature management

AIM

Since the introduction of targeted temperature management (TTM), the accuracy and timing of prognostic tests for post-cardiac arrest patients have changed. Although previous studies have demonstrated the effectiveness of a multimodal approach in assessing the prognosis of TTM patients, few studies have investigated an optimised strategy that sequentially combines different prognostic modalities. This study identified an optimal sequential combination of prognostic modalities to predict poor neurologic outcomes in patients undergoing TTM.

METHODS

We performed a retrospective analysis using TTM management registry data. All patients underwent an identical sequence of prognostic tests at fixed timings. The sequence included brain computed tomography (CT), serum neuron-specific enolase (NSE), electrophysiological examination, neurologic examination, and diffusion-weighted imaging. We used hierarchical classification and regression tree analysis to find the optimal prognostic model. The primary measure was a poor neurologic outcome at one month after cardiac arrest.

RESULTS

A total of 192 patients were included and 103 patients (53.6%) had poor neurologic outcomes. The final model consisted of brain CT, serum NSE, electroencephalogram, somatosensory-evoked potentials, and pupil light reflex. Our model predicted poor outcomes with a 0% false positive rate. Moreover, our model had an area under the receiver operating characteristic curve value of 0.911 (95% confidence interval, 0.872-0.950), which was significantly higher than that of each prognostic modality alone.

CONCLUSIONS

Our stepwise model showed excellent prognostic ability to predict poor outcomes at one month after cardiac arrest and may be used to minimise the risk of false pessimistic predictions in patients undergoing TTM.

[Relationship between body temperature, neuron-specific enolase, and clinical course in patients after out-of-hospital cardiac arrest]

BACKGROUND

According to ILCOR (International Liaison Committee on Resuscitation) recommendations (released in 2003), use of therapeutic hypothermia is recommended for unconscious adult patients who have survived a cardiac arrest regardless of the initial monitored cardiac rhythm. Thereby, the treatment goal is to achieve and maintain a body temperature of 32-34 °C for a period of 12-24 h. According to the October 2015 recommendations of the European Resuscitation Council (ERC), targeted temperature management (TTM) remains part of treatment, but, as an option, it is advised that the targeted body temperature be 36 °C rather than 32-34 °C.

PATIENT POPULATION AND METHODS

For a non-randomized retrospective observational study, a total of 149 patients were treated with cardiopulmonary resuscitation (CPR) between May 1999 and September 2009. For the first 4 days after CPR, data associated with demography, resuscitation, therapy (temperature course, neuron-specific enolase [NSE]) and clinical-neurological development (Glasgow Outcome Scale [GOS]) were collected. In the study, patients receiving mild hyperthermia were compared with those who did not receive hypothermia.

RESULTS

Of the 149 patients included, 90 were treated with mild hypothermia (as decided by the attending physician), while 59 received no hypothermia therapy. Assessment reveals that mild hypothermia positively influences clinical-neurological progression, but not survival. On day three and four, patients with an unfavorable neurological progression exhibited significantly increased serum levels of NSE (day 4: 108.7 ± 137.3 ng/ml versus 25.5 ± 15.4 ng/ml). Patients receiving hypothermia showed lower average NSE levels compared with persons not receiving hypothermia. Furthermore, during the first 4 days, their NSE values tended to increase slower (NSE value at day 4: 55.9 ± 64.9 ng/ml versus 129.9 ± 174.9 ng/ml). The best cut-off-value for an unfavorable neurological result was 74.2 ng/ml at day four (specificity 100%, sensitivity 48.6%). For the group of patients who received hypothermia, the best cut-off-value was 74.2 ng/ml at day four (specificity 100%, sensitivity 40.9%), and, for the comparison group, best cut-off-value was 25.5 ng/ml at day three (specificity 100%, sensitivity 88.2%).

CONCLUSION

After out-of-hospital resuscitation, there is a trend for improved clinical-neurological progression with mild hypothermia but it does not influence the prognostic significance of serum NSE. After assessment of available data, it is not possible to recommend uniform cut-off values for patients who received mild therapeutic hypothermia and for those who did not receive hypothermia treatment.