Serum lactate in refractory out-of-hospital cardiac arrest: Post-hoc analysis of the Prague OHCA study

Extracorporeal cardiopulmonary resuscitation for pediatric out-of-hospital cardiac arrest: A review of the Extracorporeal Life Support Organization Registry

AIMS

Current data are insufficient for the leading resuscitation societies to advise on the use of extracorporeal cardiopulmonary resuscitation (ECPR) for pediatric out-of-hospital cardiac arrest (OHCA). The aim of this study was to explore the current utilization of ECPR for pediatric OHCA and characterize the patient demographics, arrest features, and metabolic parameters associated with survival.

METHODS

Retrospective review of the Extracorporeal Life Support Organization Registry database from January 2020 to May 2023, including children 28 days to 18 years old who received ECPR for OHCA. The primary outcome was survival to hospital discharge.

RESULTS

Eighty patients met inclusion criteria. Median age was 8.8 years [2.0-15.8] and 53.8% of patients were male. OHCA was witnessed for 65.0% of patients and 46.3% received bystander cardiopulmonary resuscitation (CPR). Initial rhythm was shockable in 26.3% of patients and total CPR duration was 78 min [52-106]. Signs of life were noted for 31.3% of patients and a cardiac etiology precipitating event was present in 45.0%. Survival to discharge was 29.9%. Initial shockable rhythm was associated with increased odds of survival (unadjusted OR 4.7 [1.5-14.5]; p = 0.006), as were signs of life prior to ECMO (unadjusted OR 7.8 [2.6-23.4]; p < 0.001). Lactate levels early on-ECMO (unadjusted OR 0.89 [0.79-0.99]; p = 0.02) and at 24 h on-ECMO (unadjusted OR 0.62 [0.42-0.91]; p < 0.001) were associated with decreased odds of survival.

CONCLUSIONS

These preliminary data suggest that while overall survival is poor, a carefully selected pediatric OHCA patient may benefit from ECPR. Further studies are needed to understand long-term neurologic outcomes.

Blood glucose and lactate levels as early predictive markers in patients presenting with cardiogenic shock: A retrospective cohort study

Lactate and glucose are widely used biochemical parameters in current predictive risk scores for cardiogenic shock. Data regarding the relationship between lactate and glucose levels in cardiogenic shock are limited. Thus, we aimed to analyze glucose and lactate as early markers for in-hospital mortality in cardiogenic shock. In this retrospective cohort study, 312 patients presenting with cardiogenic shock to a tertiary-care hospital between 2016 and 2018 were included. Apparent cardiogenic shock was defined as hypoperfusion with hemodynamic compromise and biochemical marker increase due to diminished tissue perfusion, corresponding to SCAI shock stages. In-hospital mortality was assessed as the primary endpoint. The median age of the study population was 71 (60-79) years and the etiology of cardiogenic shock was acute myocardial infarction in 45.8%. Overall in-hospital mortality was 67.6%. In the receiver operating curve analysis, the area under the receiver-operating curve (AUC) for prediction of in-hospital mortality was higher for lactate (AUC: 0.757) than for glucose (AUC: 0.652). Both values were significantly associated with outcome (groups created with best cutoff values obtained from the Youden index). Correlation analysis showed a significant non-linear association of both values. In a multivariable stepwise Cox regression analysis, lactate remained an independent predictor for in-hospital mortality, whilst glucose, despite being implicated in energy metabolism, was not independently predictive for mortality. Together, these data suggest that lactate at admission is superior for mortality prediction in patients with apparent cardiogenic shock. Glucose was not independently predictive for mortality.

Neuron-Specific Enolase as a Predictor of Neurologic Outcomes in Extracorporeal Cardiopulmonary Resuscitation Patients

Background: Neuron-specific enolase (NSE) has traditionally been used as a biomarker to predict neurologic outcomes after cardiac arrest. This study aimed to evaluate the utility of NSE in predicting neurologic outcomes in patients undergoing extracorporeal cardiopulmonary resuscitation (ECPR). Methods: This observational cohort study included 47 consecutive adult ECPR patients (median age, 59.0 years; 74.5% males) treated between January 2018 and December 2021 at a tertiary extracorporeal life support center. The primary outcome was a poor neurologic outcome, defined as a Cerebral Performance Category score of 3-5 at hospital discharge. Results: Twelve (25.5%) patients had abnormal findings on computed tomography of the brain. A poor neurologic outcome was demonstrated in 22 (46.8%) patients. The NSE level at 72 h after ECPR showed the best prediction power for a poor neurologic outcome compared with NSE at 24 and 48 h. A cutoff value exceeding 61.9 μg/L for NSE at 72 h yielded an area under the curve (AUC) of 0.791 for predicting poor neurologic outcomes and exceeding 62.1 μg/L with an AUC of 0.838 for 30-day mortality. Conclusions: NSE levels at 72 h after ECPR appear to be a reliable biomarker for predicting poor neurologic outcomes and 30-day mortality in ECPR patients.

Physiology-Guided Resuscitation: Monitoring and Augmenting Perfusion during Cardiopulmonary Arrest

Given the high morbidity and mortality associated with cardiopulmonary arrest, there have been multiple trials aimed at better monitoring and augmenting coronary, cerebral, and systemic perfusion. This article aims to elucidate these interventions, first by detailing the physiology of cardiopulmonary resuscitation and the available tools for managing cardiopulmonary arrest, followed by an in-depth examination of the newest advances in the monitoring and delivery of advanced cardiac life support.

Favorable resuscitation characteristics in patients undergoing extracorporeal cardiopulmonary resuscitation: A secondary analysis of the INCEPTION-trial

Introduction

Extracorporeal cardiopulmonary resuscitation (ECPR) is increasingly used as a supportive treatment for refractory out-of-hospital cardiac arrest (OHCA). Still, there is a paucity of data evaluating favorable and unfavorable prognostic characteristics in patients considered for ECPR.

Methods

We performed a previously unplanned post-hoc analysis of the multicenter randomized controlled INCEPTION-trial. The study group consisted of patients receiving ECPR, irrespective of initial group randomization. The patients were divided into favorable survivors (cerebral performance category [CPC] 1-2) and unfavorable or non-survivors (CPC 3-5).

Results

In the initial INCEPTION-trial, 134 patients were randomized. ECPR treatment was started in 46 (66%) of 70 patients in the ECPR treatment arm and 3 (4%) of 74 patients in the conventional treatment arm. No statistically significant differences in baseline characteristics, medical history, or causes of arrest were observed between survivors (n = 5) and non-survivors (n = 44). More patients in the surviving group had a shockable rhythm at the time of cannulation (60% vs. 14%, p = 0.037), underwent more defibrillation attempts (13 vs. 6, p = 0.002), and received higher dosages of amiodarone (450 mg vs 375 mg, p = 0.047) despite similar durations of resuscitation maneuvers. Furthermore, non-survivors more frequently had post-ECPR implantation adverse events.

Conclusion

The persistence of ventricular arrhythmia is a favorable prognostic factor in patients with refractory OHCA undergoing an ECPR-based treatment. Future studies are warranted to confirm this finding and to establish additional prognostic factors.Clinical trial Registration:clinicaltrials.gov registration number NCT03101787.

Biomarkers for neuroprognostication after standard versus extracorporeal cardiopulmonary resuscitation - A sub-analysis of Prague-OHCA study

BACKGROUND

Limited evidence exists for prognostic performance of biomarkers in patients resuscitated from out-of-hospital cardiac arrest (OHCA) with extracorporeal CPR (ECPR). We hypothesized that (1) the time course and (2) prognostic performance of biomarkers might differ between CPR and ECPR in a sub-analysis of Prague-OHCA study.

METHODS

Patients received either CPR (n = 164) or ECPR (n = 92). The primary outcome was favorable neurologic survival at 180 days [cerebral performance category (CPC) 1-2]. Secondary outcomes included biomarkers of neurologic injury, inflammation and hemocoagulation.

RESULTS

Favorable neurologic outcome was not different between groups: CPR 29.3% vs. ECPR 21.7%; p = 0.191. Biomarkers exhibited similar trajectories in both groups, with better values in patients with CPC 1-2. Procalcitonin (PCT) was higher in ECPR group at 24-72 h (all p < 0.01). Neuron-specific enolase (NSE), C-reactive protein and neutrophil-to-lymphocyte ratio did not differ between groups. Platelets, D-dimers and fibrinogen were lower in ECPR vs. CPR groups at 24-72 h (all p < 0.001). ROC analysis (24-48-72 h) showed the best performance of NSE in both CPR and ECPR groups (AUC 0.89 vs. 0.78; 0.9 vs. 0.9; 0.91 vs. 0.9). PCT showed good performance specifically in ECPR (0.72 vs. 0.84; 0.73 vs. 0.87; 0.73 vs. 0.86). Optimal cutoff points of NSE and PCT were higher in ECPR vs. CPR.

CONCLUSIONS

Biomarkers exhibited similar trajectories although absolute values tended to be higher in ECPR. NSE had superior performance in both groups. PCT showed a good performance specifically in ECPR. Additional biomarkers may have modest incremental value. Prognostication algorithms should reflect the resuscitation method.

Evaluating the impact of ELSO guideline adherence on favorable neurological outcomes among patients requiring extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest

AIM

Selecting the appropriate candidates for extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA) is challenging. Previously, the Extracorporeal Life Support Organization (ELSO) guidelines suggested the example of inclusion criteria. However, it is unclear whether patients who meet the inclusion criteria of the ELSO guidelines have more favorable outcomes. We aimed to evaluate the relationship between the outcomes and select inclusion criteria of the ELSO guidelines.

METHODS

We conducted a post-hoc analysis of a multicenter prospective study conducted between 2019 and 2021. Adult patients with OHCA treated with ECPR were included. The primary outcome was a favorable neurological outcome (Cerebral Performance Category of 1 or 2) at 30 days. An ELSO criteria score was assigned based on four criteria: (i) age < 70 years; (ii) witness; (iii) bystander CPR; and (iv) low-flow time (<60 min). Subgroup analysis based on initial cardiac rhythm was performed.

RESULTS

Among 9,909 patients, 227 with OHCA were included. The proportion of favorable neurological outcomes according to the number of ELSO criteria met were: 0.0% (0/3), 0 points; 0.0% (0/23), 1 point; 3.0% (2/67), 2 points; 7.3% (6/82), 3 points; and 16.3% (7/43), 4 points. A similar tendency was observed in patients with an initial shockable rhythm. However, no such relationship was observed in those with an initial non-shockable rhythm.

CONCLUSION

Patients who adhered more closely to specific inclusion criteria of the ELSO guidelines demonstrated a tendency towards a higher rate of favorable neurological outcomes. However, the relationship was heterogeneous according to initial rhythm.

Lactate and lactate clearance as predictors of one-year survival in extracorporeal cardiopulmonary resuscitation - An international, multicentre cohort study

AIM

Extracorporeal cardiopulmonary resuscitation (ECPR) can be considered in selected patients with refractory cardiac arrest. Given the risk of patient futility and high resource utilisation, identifying ECPR candidates, who would benefit from this therapy, is crucial. Previous ECPR studies investigating lactate as a potential prognostic marker have been small and inconclusive. In this study, it was hypothesised that the lactate level (immediately prior to initiation of ECPR) and lactate clearance (within 24 hours after ECPR initiation) are predictors of one-year survival in a large, multicentre study cohort of ECPR patients.

METHODS

Adult patients with refractory cardiac arrest at three German and four Danish tertiary cardiac care centres between 2011 and 2021 were included. Pre-ECPR lactate and 24-hour lactate clearance were divided into three equally sized tertiles. Multivariable logistic regression analyses and Kaplan-Meier analyses were used to analyse survival outcomes.

RESULTS

297 adult patients with refractory cardiac arrest were included in this study, of which 65 (22%) survived within one year. The pre-ECPR lactate level and 24-hour lactate clearance were level-dependently associated with one-year survival: OR 5.40 [95% CI 2.30-13.60] for lowest versus highest pre-ECPR lactate level and OR 0.25 [95% CI 0.09-0.68] for lowest versus highest 24-hour lactate clearance. Results were confirmed in Kaplan-Meier analyses (each p log rank < 0.001) and subgroup analyses.

CONCLUSION

Pre-ECPR lactate levels and 24 hour-lactate clearance after ECPR initiation in patients with refractory cardiac arrest were level-dependently associated with one-year survival. Lactate is an easily accessible and quickly available point-of-care measurement which might be considered as an early prognostic marker when considering initiation or continuation of ECPR treatment.

Wolf Creek XVII Part 8: Neuroprotection

Introduction

Post-cardiac arrest brain injury (PCABI) is the primary determinant of clinical outcomes for patients who achieve return of spontaneous circulation after cardiac arrest (CA). There are limited neuroprotective therapies available to mitigate the acute pathophysiology of PCABI.

Methods

Neuroprotection was one of six focus topics for the Wolf Creek XVII Conference held on June 14-17, 2023 in Ann Arbor, Michigan, USA. Conference invitees included international thought leaders and scientists in the field of CA resuscitation from academia and industry. Participants submitted via online survey knowledge gaps, barriers to translation, and research priorities for each focus topic. Expert panels used the survey results and their own perspectives and insights to create and present a preliminary unranked list for each category that was debated, revised and ranked by all attendees to identify the top 5 for each category.

Results

Top 5 knowledge gaps included developing therapies for neuroprotection; improving understanding of the pathophysiology, mechanisms, and natural history of PCABI; deploying precision medicine approaches; optimizing resuscitation and CPR quality; and determining optimal timing for and duration of interventions. Top 5 barriers to translation included patient heterogeneity; nihilism & lack of knowledge about cardiac arrest; challenges with the translational pipeline; absence of mechanistic biomarkers; and inaccurate neuro-triage and neuroprognostication. Top 5 research priorities focused on translational research and trial optimization; addressing patient heterogeneity and individualized interventions; improving understanding of pathophysiology and mechanisms; developing mechanistic and outcome biomarkers across post-CA time course; and improving implementation of science and technology.

Conclusion

This overview can serve as a guide to transform the care and outcome of patients with PCABI. Addressing these topics has the potential to improve both research and clinical care in the field of neuroprotection for PCABI.