Risk factors for progression toward brain death after out-of-hospital cardiac arrest

Impact of age on survival for patients receiving ECPR for refractory out-of-hospital VT/VF cardiac arrest

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) has been shown to improve neurologically favorable survival for patients with refractory ventricular tachycardia (VT)/ventricular fibrillation (VF) out-of-hospital cardiac arrest. Prior studies of the impact of age on outcomes in ECPR have demonstrated mixed results and we aim to investigate this relationship.

METHODS

Patients treated with ECPR at the University of Minnesota Medical Center for refractory out-of-hospital VT/VF arrest from December 2015 to February 2023 were included. The primary endpoints included neurologically favorable survival to discharge. A receiver operating characteristic curve was used to determine an optimal predictive age limit with the highest accuracy for neurologically favorable survival.

RESULTS

391 consecutive patients were included: 22% (n = 86) were female and the mean age was 56.9 ± 11.8 years. Age was independently associated with neurologically favorable survival to discharge, with a 30% decrease in survival with every 10-year increase in age (OR 0.7 (0.57-0.87), p = 0.001. Among those with neurologically favorable survival to discharge, older patients had longer length of hospital stay compared to younger age groups (p = 0.002) while patients who failed to achieve neurologically favorable survival to discharge had similar length of stay independent of age (p = 0.51).

CONCLUSIONS

Age is associated with neurologically favorable survival to discharge for patients receiving ECPR for refractory out-of-the-hospital VT/VF cardiac arrest. However, with a survival rate of 23% in the oldest age group, caution should be used when choosing age criteria for patient selection.

Extracorporeal cardiopulmonary resuscitation-based approach to refractory out-of-hospital cardiac arrest: A focus on organ donation, a secondary analysis of a Prague OHCA randomized study

BACKGROUND

Refractory out-of-hospital cardiac arrest (OHCA) has a poor outcome. In patients, who cannot be rescued despite using advanced techniques like extracorporeal cardiopulmonary resuscitation (ECPR), organ donation may be considered. This study aims to evaluate, in refractory OHCA, how ECPR versus a standard-based approach allows organ donorship.

METHODS

The Prague OHCA trial randomized adults with a witnessed refractory OHCA of presumed cardiac origin to either an ECPR-based or standard approach. Patients who died of brain death or those who died of primary circulatory reasons and were not candidates for cardiac transplantation or durable ventricle assist device were evaluated as potential organ donors by a transplant center. In this post-hoc analysis, the effect on organ donation rates and one-year organ survival in recipients was examined.

RESULTS

Out of 256 enrolled patients, 75 (29%) died prehospitally or within 1 hour after admission and 107 (42%) during the hospital stay. From a total of 24 considered donors, 21 and 3 (p = 0.01) were recruited from the ECPR vs standard approach arm, respectively. Fifteen brain-dead and none cardiac-dead subjects were ultimately accepted, 13 from the ECPR and two from the standard strategy group. A total of 36 organs were harvested. The organs were successfully transplanted into 34 recipients. All transplanted organs were fully functional, and none of the recipients died due to graft failure within the one-year period post-transplant.

CONCLUSION

The ECPR-based approach in the refractory OHCA trial is associated with increased organ donorship and an excellent outcome of transplanted organs.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01511666. Registered January 19, 2012.

Guidelines for Neuroprognostication in Comatose Adult Survivors of Cardiac Arrest

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.

Early risk stratification for progression to death by neurological criteria following out-of-hospital cardiac arrest

BACKGROUND

Some patients resuscitated from out-of-hospital cardiac arrest (OHCA) progress to death by neurological criteria (DNC). We hypothesized that initial brain imaging, electroencephalography (EEG), and arrest characteristics predict progression to DNC.

METHODS

We identified comatose OHCA patients from January 2010 to February 2020 treated at a single quaternary care facility in Western Pennsylvania. We abstracted demographics and arrest characteristics; Pittsburgh Cardiac Arrest Category, initial motor exam and pupillary light reflex; initial brain computed tomography (CT) grey-to-white ratio (GWR), sulcal or basal cistern effacement; initial EEG background and suppression ratio. We used two modeling approaches: fast and frugal tree (FFT) analysis to create an interpretable clinical risk stratification tool and ridge regression for comparison. We used bootstrapping to randomly partition cases into 80% training and 20% test sets and evaluated test set sensitivity and specificity.

RESULTS

We included 1,569 patients, of whom 147 (9%) had diagnosed DNC. Across bootstrap samples, >99% of FFTs included three predictors: sulcal effacement, and in cases without sulcal effacement, the combination of EEG background suppression and GWR ≤ 1.23. This tree had mean sensitivity and specificity of 87% and 81%. Ridge regression with all available predictors had mean sensitivity 91 % and mean specificity 83%. Subjects falsely predicted as likely to progress to DNC generally died of rearrest or withdrawal of life sustaining therapies due to poor neurological prognosis. Two of these cases awakened from coma during the index hospitalization.

CONCLUSIONS

Sulcal effacement on presenting brain CT or EEG suppression with GWR ≤ 1.23 predict progression to DNC after OHCA.

Organ donation after out-of-hospital cardiac arrest: a population-based study of data from the Paris Sudden Death Expertise Center

BACKGROUND

Organ shortage is a major public health issue, and patients who die after out-of-hospital cardiac arrest (OHCA) could be a valuable source of organs. Here, our objective was to identify factors associated with organ donation after brain death complicating OHCA, in unselected patients entered into a comprehensive real-life registry covering a well-defined geographic area.

METHODS

We prospectively analyzed consecutive adults with OHCA who were successfully resuscitated, but died in intensive care units in the Paris region in 2011-2018. The primary outcome was organ donation after brain death. Independent risk factors were identified using logistic regression analysis. One-year graft survival was assessed using Cox and log-rank tests.

RESULTS

Of the 3061 included patients, 136 (4.4%) became organ donors after brain death, i.e., 28% of the patients with brain death. An interaction between admission pH and post-resuscitation shock was identified. By multivariate analysis, in patients with post-resuscitation shock, factors associated with organ donation were neurological cause of OHCA (odds ratio [OR], 14.5 [7.6-27.4], P < 0.001), higher pH (OR/0.1 increase, 1.3 [1.1-1.6], P < 0.001); older age was negatively associated with donation (OR/10-year increase, 0.7 [0.6-0.8], P < 0.001). In patients without post-resuscitation shock, the factor associated with donation was neurological cause of OHCA (OR, 6.9 [3.0-15.9], P < 0.001); higher pH (OR/0.1 increase, 0.8 [0.7-1.0], P = 0.04) and OHCA at home (OR, 0.4 [0.2-0.7], P = 0.006) were negatively associated with organ donation. One-year graft survival did not differ according to Utstein characteristics of the donor.

CONCLUSIONS

4% of patients who died in ICU after OHCA led to organ donation. Patients with OHCA constitute a valuable source of donated organs, and special attention should be paid to young patients with OHCA of neurological cause.

Prevalence, Outcomes, and Risk Factors for Cardiorespiratory Arrest in the Intensive Care Unit: An Observational Study

Background

Cardiorespiratory arrest is defined as an abrupt halt in the cardiac mechanical activity that is accompanied by the loss of a detectable pulse, the cessation of breathing, and the loss of consciousness. The aim of this study is to create a clinical–epidemiological profile of patients who experienced cardiorespiratory arrest and were admitted to the intensive care unit to evaluate the associated factors and their impact on the prognosis of these patients.

Patients and methods

From January to December 2019, the medical records of 135 patients who received cardiopulmonary resuscitation were reviewed for this cross-sectional observational study. The information was collected according to the Utstein model.

Results

A low return of spontaneous circulation of 22.2% was observed, with a predominance of females (53.3%) and older patients (68.9%), multiple comorbidities at admission (68.4%), and asystole as the predominant rhythm. Female sex and age >60 years were statistically significant (p = 0.017), as was the association between sex and comorbidities (p = 0.036), with heart disease being the most prevalent in females (p = 0.036).

Conclusion

In this study, even though the resuscitation maneuver time (start of resuscitation following arrest) was very short and the defibrillation was performed promptly, there was a high prevalence of cardiac arrest and low survival rates after cardiopulmonary resuscitation.

How to cite this article

Menezes da Silva A, Braga AL, Cruvinel de Souza V. Prevalence, Outcomes, and Risk Factors for Cardiorespiratory Arrest in the Intensive Care Unit: An Observational Study. Indian J Crit Care Med 2022;26(6):704–709.

Brain Death and Its Prediction in Out-of-Hospital Cardiac Arrest Patients Treated with Targeted Temperature Management

Evolution toward brain death (BD) in out-of-hospital cardiac arrest patients with targeted temperature management (TTM) provides opportunities for organ donation. However, knowledge regarding BD in these patients is limited. We retrospectively analyzed the TTM registry of one hospital where life-sustaining therapy was not withdrawn. In-hospital death patients were categorized into BD and non-BD groups. We explored the process of evolution toward BD and its predictors by comparing the serial measurements of clinical variables and the results of various prognostic tests between the two groups. Of the 121 patients who died before hospital discharge, 19 patients (15.7%) developed BD at a median of 6 (interquartile range, 5.0–7.0) days after cardiac arrest. Four patients with pupillary light reflexes at 48 h eventually developed BD. The area under the curves of the gray-to-white matter ratio (GWR) on early brain computed tomography images and the level of S100 calcium-binding protein B (S100B) at 72 h were 0.67 (95% CI, 0.55–0.77) and 0.70 (95% CI, 0.55–0.83), respectively. In conclusion, approximately one-sixth of all in-hospital deaths were diagnosed with BD at a median of 6 days after cardiac arrest. The use of GWR and serial S100B measurements may help to screen potential BD.

Neuron-Specific Enolase (NSE) Predicts Long-Term Mortality in Adult Patients after Cardiac Arrest: Results from a Prospective Trial

Background: We investigated whether Neuron-specific enolase (NSE) serum concentration predicts long-term mortality and poor neurological outcome in adult cardiac arrest patients. Methods: Within this prospective observational study, we included consecutive adult patients admitted to the intensive care unit (ICU) after cardiac arrest. NSE was measured upon ICU admission and on days 1, 2, 3, 5 and 7. Results: Of 403 patients, 176 (43.7%) survived. Median follow-up duration was 43.7 months (IQR 14.3 to 63.0 months). NSE levels on day 3 were increased more than threefold in non-survivors compared to survivors (median NSE (ng/mL) 19.8 (IQR 15.7 to 27.8) vs. 72.6 (IQR 26 to 194)) and showed the highest prognostic performance for mortality compared to other days of measurement, with an AUC of 0.81 and an adjusted hazard ratio of 1.55 (95% CI 1.41 to 1.71, p < 0.001). Subgroup analysis showed an excellent sensitivity and negative predictive value of 100% of NSE in patients <54 years of age. Conclusion: NSE measured three days after cardiac arrest is associated with long-term mortality and neurological outcome and may provide prognostic information that improves clinical decision making. Particularly in the subgroup of younger patients (<54 years), NSE showed excellent negative predictive value.

Prediction of Brain Death After Out-of-Hospital Cardiac Arrest: Development and Validation of the Brain Death After Cardiac Arrest Score

BACKGROUND

Among patients successfully resuscitated after an out-of-hospital cardiac arrest (OHCA), 10% to 15% evolve toward brain death (BD), thus becoming potential organ donors.

RESEARCH QUESTION

Is it possible to establish a score for early estimation of BD risk after OHCA?

STUDY DESIGN AND METHODS

The BD after cardiac arrest (BDCA) score was developed from data available within 24 hours after OHCA from two OHCA trials: Cyclosporine in Cardiac Arrest Resuscitation and Erythropoietin After OHCA. The BDCA score was then validated in another large prospective multicenter data set. The main outcome was the occurrence of BD. Independent prognostic covariates for BD were identified using a binomial two-stage adaptive least absolute shrinkage and selection operator procedure.

RESULTS

The development cohort included 569 patients alive 24 hours after OHCA, among whom 84 (14.8%) experienced BD. Independent predictors of BD used to build the BDCA score were being female (4 points), nonshockable rhythm (24 points), cardiac cause of OHCA (-6 points), neurological cause of OHCA (45 points), natremia at 24 hours (natremia in millimoles per liter minus 140 points), and vasoactive drug at admission (4 points) and at 24 hours (6 points). The area under the curve (AUC) of the BDCA score was 0.82 (95% CI, 0.77-0.86), and the discrimination value in the validation cohort (n = 487) was consistent (AUC, 0.81; 95% CI, 0.76-0.86). In the validation cohort, BD occurred in 4.0%, 20.4%, and 67.7% of patients with scores of < 20, 20 to 50, and > 50, respectively.

INTERPRETATION

The BDCA score allows early detection of patients with a high probability of experiencing BD, which may help increase organ donation after OHCA.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT01595958, and ClinicalTrials.gov; No.: NCT00999583; URL: www.clinicaltrials.gov.

Combined Therapy With Polyethylene Glycol-20k and MCC950 Preserves Post-Resuscitated Myocardial Function in a Rat Model of Cardiac Arrest and Cardiopulmonary Resuscitation

Background To investigate the therapeutic potential of combined therapy with polyethylene glycol-20k (PEG-20k) and MCC950 on post-resuscitation myocardial function in a rat model of cardiac arrest. Methods and Results Thirty rats were randomized into 5 groups: Sham, Control, PEG-20k, MCC950, PEG-20k+ MCC950. Except for sham, animals were subjected to 6 minutes of ventricular fibrillation followed by 8 minutes cardiopulmonary resuscitation. Two milliliters PEG-20k was administered by intravenous injection coincident with the start of cardiopulmonary resuscitation; MCC950 (10 mg/kg), a highly selective NLRP3 inflammasome inhibitor, was delivered immediately after restoration of spontaneous circulation. Myocardial function, sublingual microcirculation, mitochondrial function, plasma cardiac troponin I, and interleukin-1β, expression of proteins in SIRT1 (sirtuin 1)/PGC-1α (peroxisome proliferator-activated receptor gamma coactivator 1-alpha) and NLRP3 (the NOD-like receptor family protein 3) inflammasome pathways were evaluated. Following cardiopulmonary resuscitation, myocardial function was compromised with a significantly decreased cardiac output, ejection fraction, and increased myocardial performance index, cardiac troponin I. Sublingual microcirculation was disturbed with impaired perfused vessel density and microvascular flow index. Cardiac arrest reduced mitochondrial routine respiration, Complex I-linked respiration, respiratory control rates and oxidative phosphorylation coupling efficiency. PEG-20k or MCC950 alone restored mitochondrial respiratory function, restituted sublingual microcirculation, and preserved myocardial function, whereas a combination of PEG-20k and MCC950 further improved these aspects. PEG-20k restored the expression of SIRT1 and PGC-1α, and blunted activation of NLRP3 inflammasomes. MCC950 suppressed expression of cleaved-caspase-1/pro-caspase-1, ASC (apoptosis-associated speck-like protein), GSDMD [gasdermin d], and interleukin-1β. Conclusions Combined therapy with PEG-20k and MCC950 is superior to either therapy alone for preserving post-resuscitated myocardial function, restituting sublingual microcirculation at restoration of spontaneous circulation at 6 hours. The responsible mechanisms involve upregulated expression of SIRT1/PGC1-α in tandem with inhibition of NLRP3 inflammasomes.

Post-resuscitation shock: recent advances in pathophysiology and treatment

A post-resuscitation shock occurs in 50–70% of patients who had a cardiac arrest. It is an early and transient complication of the post-resuscitation phase, which frequently leads to multiple-organ failure and high mortality. The pathophysiology of post-resuscitation shock is complex and results from the whole-body ischemia–reperfusion process provoked by the sequence of circulatory arrest, resuscitation manoeuvers and return of spontaneous circulation, combining a myocardial dysfunction and sepsis features, such as vasoplegia, hypovolemia and endothelial dysfunction. Similarly to septic shock, the hemodynamic management of post-resuscitation shock is based on an early and aggressive hemodynamic management, including fluid administration, vasopressors and/or inotropes. Norepinephrine should be considered as the first-line vasopressor in order to avoid arrhythmogenic effects of other catecholamines and dobutamine is the most established inotrope in this situation. Importantly, the optimal mean arterial pressure target during the post-resuscitation shock still remains unknown and may probably vary according to patients. Mechanical circulatory support by extracorporeal membrane oxygenation can be necessary in the most severe patients, when the neurological prognosis is assumed to be favourable. Other symptomatic treatments include protective lung ventilation with a target of normoxia and normocapnia and targeted temperature management by avoiding the lowest temperature targets. Early coronary angiogram and coronary reperfusion must be considered in ST-elevation myocardial infarction (STEMI) patients with preserved neurological prognosis although the timing of coronary angiogram in non-STEMI patients is still a matter of debate. Further clinical research is needed in order to explore new therapeutic opportunities regarding inflammatory, hormonal and vascular dysfunction.

Duration and clinical features of cardiac arrest predict early severe cerebral edema

BACKGROUND

Severe brain edema appears early after cardiopulmonary resuscitation (CPR) in a subset of patients and portends a poor prognosis. We tested whether clinical features of patients or resuscitation during out-of-hospital cardiac arrest (OHCA) are associated with early, severe cerebral edema.

METHOD/RESEARCH DESIGN

We reviewed pre-hospital and hospital records for comatose patients surviving to hospital admission after OHCA who had computed tomography (CT) of brain at the time of hospital admission available for inspection. We measured the gray-white ratio (GWR) of X-ray attenuation between the caudate nucleus and posterior limb of the internal capsule, defining severe cerebral edema as GWR < 1.20. We calculated associations between severe cerebral edema and patient or resuscitation variables.

RESULTS

Between 2010 and 2019, 1340 subjects were admitted of whom 296 (22%) showed severe cerebral edema on initial CT. Subjects with severe edema had lower survival (5/296, 2% vs. 377/1044, 36%). Severe edema was independently associated with total CPR duration, total dose of epinephrine, younger age, non-shockable arrest rhythms, fewer total number of rescue shocks, rearrest after initial return of pulses, and non-cardiac arrest etiology. Prevalence of severe cerebral edema increased from 2% among subjects with 0-10 min of CPR to 31% among subjects with >40 min of CPR.

CONCLUSION

CPR duration along with easily measurable clinical and resuscitation characteristics predict early severe cerebral edema after OHCA. Future interventional trials should consider targeting or preventing cerebral edema after prolonged hypoxic-ischemic brain injury especially in patients with high risk clinical features.