Out-of-hospital Cardiac Arrest Cohort Research Articles

Return to Work After Refractory Out-of-Hospital Cardiac Arrest in Patients Managed With or Without Extracorporeal Cardiopulmonary Resuscitation: A Nationwide Register-Based Study.

Extracorporeal cardiopulmonary resuscitation (ECPR) is increasingly used for refractory out-of-hospital cardiac arrest (OHCA). However, survivors managed with ECPR are at risk of poor functional status. The purpose of this study was to investigate return to work (RTW) after refractory OHCA. Of 44 360 patients with OHCA in the period of 2011 to 2020, this nationwide registry-based study included 805 patients with refractory OHCA in the working age (18-65 years) who were employed before OHCA (2% of the total OHCA cohort). Demographics, prehospital characteristics, status at hospital arrival, employment status, and survival were retrieved through the Danish national registries. Sustainable RTW was defined as RTW for ≥6 months without any long sick leave relapses. Median follow-up time was 4.1 years. ECPR and standard advanced cardiovascular life support were applied in 136 and 669 patients, respectively. RTW 1 year after OHCA was similar (39% versus 54%; P=0.2) and sustainable RTW was high in both survivors managed with ECPR and survivors managed with standard advanced cardiovascular life support (83% versus 85%; P>0.9). Younger age and shorter length of hospitalization were associated with RTW in multivariable Cox analysis, whereas ECPR was not. In refractory OHCA-patients employed prior to OHCA, approximately 1 out of 2 patients were employed after 1 year with no difference between patients treated with ECPR or standard advanced cardiovascular life support. Younger age and shorter length of hospitalization were associated with RTW while ECPR was not.

Joint Modeling of Social Determinants and Clinical Factors to Define Subphenotypes in Out-of-Hospital Cardiac Arrest Survival: Cluster Analysis.

Machine learning clustering offers an unbiased approach to better understand the interactions of complex social and clinical variables via integrative subphenotypes, an approach not studied in out-of-hospital cardiac arrest (OHCA). We conducted a cluster analysis for a cohort of OHCA survivors to examine the association of clinical and social factors for mortality at 1 year. We used a retrospective observational OHCA cohort identified from Medicare claims data, including area-level social determinants of health (SDOH) features and hospital-level data sets. We applied k-means clustering algorithms to identify subphenotypes of beneficiaries who had survived an OHCA and examined associations of outcomes by subphenotype. We identified 27,028 unique beneficiaries who survived to discharge after OHCA. We derived 4 distinct subphenotypes. Subphenotype 1 included a distribution of more urban, female, and Black beneficiaries with the least robust area-level SDOH measures and the highest 1-year mortality (2375/4417, 53.8%). Subphenotype 2 was characterized by a greater distribution of male, White beneficiaries and had the strongest zip code-level SDOH measures, with 1-year mortality at 49.9% (4577/9165). Subphenotype 3 had the highest rates of cardiac catheterization at 34.7% (1342/3866) and the greatest distribution with a driving distance to the index OHCA hospital from their primary residence >16.1 km at 85.4% (8179/9580); more were also discharged to a skilled nursing facility after index hospitalization. Subphenotype 4 had moderate median household income at US $51,659.50 (IQR US $41,295 to $67,081) and moderate to high median unemployment at 5.5% (IQR 4.2%-7.1%), with the lowest 1-year mortality (1207/3866, 31.2%). Joint modeling of these features demonstrated an increased hazard of death for subphenotypes 1 to 3 but not for subphenotype 4 when compared to reference. We identified 4 distinct subphenotypes with differences in outcomes by clinical and area-level SDOH features for OHCA. Further work is needed to determine if individual or other SDOH domains are specifically tied to long-term survival after OHCA.

Brain-derived extracellular vesicles as serologic markers of brain injury following cardiac arrest: A pilot feasibility study

AimAssessment of neurologic injury within the immediate hours following out-of-hospital cardiac arrest (OHCA) resuscitation remains a major clinical challenge. Extracellular vesicles (EVs), small bodies derived from cytosolic contents during injury, may provide the opportunity for “liquid biopsy” within hours following resuscitation, as they contain proteins and RNA linked to cell type of origin. We evaluated whether micro-RNA (miRNA) from serologic EVs were associated with post-arrest neurologic outcome. MethodsWe obtained serial blood samples in an OHCA cohort. Using novel microfluidic techniques to isolate EVs based on EV surface marker GluR2 (present on excitatory neuronal dendrites enriched in hippocampal tissue), we employed reverse transcription quantitative polymerase chain reaction (RT-qPCR) methods to measure a panel of miRNAs and tested association with dichotomized modified Rankin Score (mRS) at discharge. ResultsEVs were assessed in 27 post-arrest patients between 7/3/2019 and 7/21/2022; 9 patients experienced good outcomes. Several miRNA species including miR-124 were statistically associated with mRS at discharge when measured within 6 hours of resuscitation (AUC = 0.84 for miR-124, p < 0.05). In a Kendall ranked correlation analysis, miRNA associations with outcome were not strongly correlated with standard serologic marker measurements, or amongst themselves, suggesting that miRNA provide distinct information from common protein biomarkers. ConclusionsThis study explores the associations between miRNAs from neuron-derived EVs (NDEs) and circulating protein biomarkers within 6 hours with neurologic outcome, suggesting a panel of very early biomarker may be useful during clinical care. Future work will be required to test larger cohorts with a broader panel of miRNA species.

Abstract 176: Development Of A Novel Score To Predict Brain Death After Out Of Hospital Cardiac Arrest

Introduction: Brain death occurs in 10-15% of successfully resuscitated out-of-hospital cardiac arrest (OHCA) patients. Early identification of potential organ donors is critical to prevent withdrawal of life sustaining therapy (WLST) and ensure adequate organ perfusion. To predict brain death after OHCA, we developed a novel brain death risk (BDR) score. Methods: The BDR score was developed from a retrospective, single center cohort of OHCA patients admitted from 2011-2020. After excluding patients with early WLST (defined as &lt; 72 hours from OHCA), univariate regression models identified independent predictors of brain death, which were used to build the BDR score. We included the following variables: non-shockable rhythm (1 point), drug overdose as etiology of arrest (1 point), evidence of grey-white differentiation loss or sulcal effacement on head computed tomography (CT) within 24 hours of arrest (2 points), Full-Outline-Of-UnResponsiveness (FOUR) score of 0 (2 points), FOUR score 1-5 (1 point), and age &lt; 45 years (1 point). Head CT findings were based on neuroradiology reports. We validated the BDR score in an independent single center OHCA cohort. The primary outcome was occurrence of brain death. Using the area under the receiving operator characteristic curve (AUC), we assessed the score’s prediction of brain death. Results: The development cohort included 256 OHCA patients; 15.6% (40/256) experienced brain death. The AUC (95% CI) of the BDR score was 0.921 (0.870-0.971). In the validation cohort, 24.4% (21/86) experienced brain death. The AUC (95% CI) of the BDR score was 0.830 (0.7266-0.9335). Table 1 shows the rate of brain death at each BDR score. In both cohorts, a BDR score ≥ 5 was the optimal cut off (sensitivity 0.9 and 0.714, specificity 0.843 and 0.831, respectively). Conclusion: Early scoring systems may be able to identify those at highest risk for brain death after OHCA. Our data suggest that a BDR score ≥ 5 could help predict progression to brain death.

Abstract 14264: National Comparison of Hospital Market Share for Out-of-Hospital Cardiac Arrest and Elective Cardiac Surgery

Introduction: Competition in the healthcare market is a theoretical driver of innovation, cost-savings, and improved quality. When patients are treated for certain emergent conditions, such as out-of-hospital cardiac arrest (OHCA), individuals have less choice in their treating hospital. For patients undergoing elective cardiac valve replacement surgery (EVRS), hospital choice may reflect distinct referral patterns and preferences. Our objective was to compare hospital market share for different cardiac services, thus allowing for better understanding of the care landscape and target interventions to improve outcomes. Methods: Using age-eligible Medicare fee-for-service institutional claims, an emergency department (ED) treated OHCA cohort was identified via ICD-9/10 diagnosis codes and ED charges. EVRS, an inpatient referral procedure, were identified from in-patient summary claims using procedure codes. Market shares were built for each hospital by sequential addition of ZIP-code areas and calculating the hospital’s cumulative market share. Geographic market share areas were defined for each hospital at 90%, 25% and 10% cut-offs if present. Correlation between corresponding market shares and patient counts were assessed using Pearson’s r. Results: Between 1/2013 and 12/2015, we identified 206,162 EVRS claims and 222,018 OHCA claims. Median age was similar (77 vs 78 yrs), as was percent of female patient (43% vs 44%). Very few beneficiaries (0.38%) appeared in both cohorts. Many more hospitals cared for OHCA than EVRS (4482 vs 1170). More OHCA treating hospitals achieved a 25% market share (68% vs 57%) however, EVRS hospital with a 25% market share covered more population (420,294 vs 66,394) and had a greater client radius (21 vs 15 miles). Among the hospitals providing care to both cohorts, the cumulative market share and patient counts were positively correlated (r = 0.49 and 0.46 respectively, p&lt;0.001 for both). Conclusion: Despite many more hospitals providing care for OHCA, the market share for EVRS and OHCA trend together. This market trend, combined with the association of better outcomes with higher OHCA volume suggests that OHCA should be regionalized within markets to facilities that provide elective cardiac surgical procedures.

Abstract 11759: Survival Among Medicare Beneficiaries After Out-of-Hospital Cardiac Arrest Undergoing Interhospital Transfer

Intro: Among individuals treated for out-of-hospital cardiac arrest (OHCA), there is hospital-level variability in mortality, but the relationship between interhospital transfer (IHT) OHCA volume and survival remain unclear. We sought to examine the association of OHCA volume and survival for individuals undergoing IHT. Methods: Utilizing age-eligible Medicare fee-for-service claims, we identified an emergency department treated OHCA cohort using ICD-9/10 diagnosis codes. Hospital OHCA volume was defined as the total number of index (first-treated) OHCA claims during the study period and were binned into quartiles. Each claim was assigned the OHCA volume quartile of the index hospital and the index volume of the receiving hospital. Multiple logistic regression was conducted to assess the association between initial and receiving hospital volume categories and survival to 30 days among IHT patients while controlling for patient-level characteristics (age, sex, race), comorbidity index, urbanicity of index hospital and days to transfer. Results: We identified a cohort of 222,018 claims at 4,461 hospitals between 1/2013-12/2015. Median age was 78 years (IQR 71-85); 44% were female; 11% of the cohort was alive at 30 days. IHT occurred in 12,245 cases (5.5%) and 59% of transfers occurred on the day of admission or day 1. Transfers originated from 3411 index hospitals and 1566 receiving hospitals. Median OHCA hospital index volume was 25 [IQR 9, 67]. Adjusted odds of survival at 30 days was significantly lower at index hospitals with lower OHCA volumes compared to the highest volume category (aOR [95%CI] Q2: 0.71 [0.6, 0.83] p&lt;0.001). Additionally, odds of survival at 30 days was significantly lower at low volume receiving hospitals (aOR [95%CI] Q1: 0.73 [0.55, 0.99] p&lt;0.001), and increased for higher OHCA volume receiving hospitals, but these groups did not achieve statistical significance. Conclusion: For Medicare beneficiaries who suffer an OHCA and undergo IHT, lower index and receiving hospital OHCA volume was significantly associated with decreased adjusted odds of 30-day survival. Further exploration of hospital characteristics, timing, and transfer patterns is needed to understand differences in benefit for OHCA patients undergoing IHT.

Video laryngoscopy for out of hospital cardiac arrest

IntroductionEndotracheal intubation is an import component of out-of-hospital cardiac arrest (OHCA) resuscitation. In this analysis, we evaluate the association of video laryngoscopy (VL) with first pass success and return of spontaneous circulation (ROSC) using a national OHCA cohort. MethodsWe analyzed 2018 data from ESO Inc. (Austin, TX), a national prehospital electronic health record. We included all adult, non-traumatic cardiac arrests undergoing endotracheal intubation. We defined VL and direct laryngoscopy (DL) based on paramedic recorded intubation device. The primary outcomes were first pass success, ROSC, and sustained ROSC. Using multivariable, mixed models, we determined the association between VL and first pass success rate, ROSC, and sustained ROSC (survival to ED or ROSC in the field for greater than 20 min), fitting agency as a random intercept and adjusting for confounders. ResultsWe included 22,132 patients cared for by 914 EMS agencies, including 5702 (25.7%) VL and 16,430 (74.2%) DL. Compared to DL, VL had a lower rate of bystander CPR, but other characteristics were similar between the groups. VL exhibited higher first pass success than DL (75.1% v 69.5%, p < .001). On mixed model analysis, VL was associated with a higher first pass success (OR 1.5, CI 1.3−1.6) but not ROSC (OR 1.1, CI 0.97–1.2) or sustained ROSC (OR 1.1, CI 0.9−1.2). ConclusionWhile associated with higher FPS, VL was not associated with increased rate of ROSC. The role of VL in OHCA remains unclear.

Abstract 336: Data-driven Classification of Arrest Location for Emergency Department Cardiac Arrests

Introduction: Out-of-hospital cardiac arrest (OHCA), in-hospital cardiac arrest (IHCA), and emergency department (ED) cardiac arrests differ in epidemiology, etiology, and outcomes. Resuscitation research is inconsistent in how ED arrests are classified. We used unsupervised learning to compare ED arrests to non-ED OHCA and to non-ED IHCA. Hypothesis: Clinical features of ED cardiac arrest patients who achieve return of spontaneous circulation (ROSC) are more similar to IHCA than to OHCA. Methods: We performed a retrospective study including all patients resuscitated from cardiac arrest who were treated at a single academic medical center from January 2010 to December 2019. We abstracted clinical information from our prospective registry, including the details of arrest location (ED arrests, OHCA, or IHCA); age; sex; initial arrest rhythm; number of doses of epinephrine, bicarbonate and shocks given during the arrest; duration of arrest; most advanced airway placed intra-arrest; number of rearrests; early post-arrest illness severity (Pittsburgh Cardiac Arrest Category: PCAC); and survival to hospital discharge. We used unsupervised learning (K-prototypes) to identify clusters within the OHCA and IHCA cohorts. We determined the number of subgroups using Scree plots. Finally, we assigned individual ED arrest patients the nearest OHCA or IHCA cluster based on the shortest Gower distance from that patient to the nearest cluster center. Results: We included 2,723 patients: 1,709 (63%) OHCA, 642 (23%) IHCA, and 372 (14%) ED arrests. We identified 3 clusters in the OHCA cohort, and 4 clusters in the IHCA cohort. Of the total ED arrest cases, 292 (78%) most closely resembled an IHCA cluster and 80 (22%) most closely resembled an OHCA cluster. The large majority (64%) of ED arrests that were closest to an IHCA cluster survived to hospital discharge; 50% of this subset were awake post-arrest (PCAC I), and 16% were deeply comatose (PCAC IV). In contrast, only 13% of ED arrests that were closest to an OHCA cluster survived to hospital discharge; 65% of this subset were deeply comatose (PCAC IV) and only 5% were awake post arrest (PCAC I). Conclusion: Among cardiac arrest patients with ROSC, the large majority of ED arrests resemble IHCA more than OHCA.

Relationship between serum potassium level and survival outcome in out-of-hospital cardiac arrest using CAPTURES database of Korea: Does hypokalemia have good neurological outcomes in out-of-hospital cardiac arrest?

Sudden cardiac arrest is a major cause of death worldwide. Serum potassium level is an initial laboratory test that serves as part of an electrolyte panel easily obtainable by most emergency departments (EDs). To evaluate the relationship between serum potassium level and the survival outcome for out-of-hospital cardiac arrest (OHCA) patients. We used the Cardiac Arrest Pursuit Trial with Unique Registration and Epidemiological Surveillance (CAPTURES) database, which made up the OHCA cohort of 27 EDs in Korea from January to December 2014. The inclusion criteria were all OHCA patients in the cohort who had received cardiopulmonary resuscitation (CPR) in the hospital. The patients were excluded if they were transferred from another hospital, had a pre-hospital return of spontaneous circulation (ROSC), or if the potassium level and clinical outcome data were missing or not captured. The main parameter was serum potassium level on ED arrival. According to the serum potassium level, the patients were divided into a hypokalemia group (K+ < 3.5 mEq/L), a normokalemia group (K+ = 3.5-5.4 mEq/L) and a hyperkalemia group (K+ ≥ 5.5 mEq/L). The primary outcome was neurologically favorable survival discharge. Among the 1,616 patients in the CAPTURES cohort, 913 patients were included in the analysis, of whom 46 patients (5.9%) were assigned to the hypokalemia group, 370 patients (40.5%) were assigned to the normokalemia group and 497 patients (54.4%) were assigned to the hyperkalemia group. The hypokalemia group has a significantly higher percentage of good neurological outcomes (26.1%). There was a significant positive correlation with neurologically favorable survival (odds ratio (OR) = 4.45; 95% confidence interval (95% CI) = 1.67-11.91) and a significant positive correlation with survival discharge (OR = 2.25; 95% CI = 1.05-4.82). In OHCA patients, serum potassium level measured in the hospital showed a significant association with survival outcome. Hypokalemia had a significant association with good neurological outcome and survival discharge.

Clinical experience of whole-body computed tomography as the initial evaluation tool after extracorporeal cardiopulmonary resuscitation in patients of out-of-hospital cardiac arrest

BackgroundThe routine application of whole-body CT after extracorporeal cardiopulmonary resuscitation (ECPR) in out-of-hospital cardiac arrest (OHCA) has not been extensively investigated. We aimed to evaluate the benefit of CT in this context.MethodsWe retrospectively analyzed all OHCA patients who had received ECPR between January 2006 to May 2019. Electronic records were reviewed to filter out patients who had a whole-body CT as their first clinical evaluation after ECPR. CT findings and major hospital outcomes were evaluated.ResultsFrom January 2006 to May 2019, 700 patients had received ECPR in our institution. We identified 93 OHCA patients who received whole-body CT as the first clinical evaluation after ECPR. 22.6% of those had no acute findings detected on CT requiring immediate treatment. In the remaining 77.4%, CT had findings that might lead to alterations in clinical course. Most important findings were myocardial infarction (57.0%), hypoxic brain injury (29.0%), sternal/rib fractures (16.1%), aortic dissection (7.5%), pulmonary embolism (5.4%), and cardiac tamponade (5.4%). There were no significant differences in ICU/hospitalization days, time on ECMO support, survival and neurological outcomes between those with and without immediate CT. In our OHCA cohort, there were 27 patients with CT evidence of hypoxic brain injury, of whom 22.2% (n = 2) managed to wean from ECMO support, 14.8% (n = 4) survived to discharge, but only 3.7% (n = 1) survived with good neurological outcome. Hypoxic brain injury on CT has a 95% specificity in predicting poor neurological outcome, with a false positive rate of only 3.7%. Logistic regression suggested a potential correlation between CT findings of hypoxic brain injury and poor neurological outcome [Odds ratio (OR) = 12.53 (1.55 to 10.1), p = 0.02)].ConclusionsRoutine whole-body CT after ECPR in OHCA patients appears to have a limited role, as the majority is caused by ACS. However, it may be a useful tool when CPR-related injury or non-ACS causes of OHCA are suspected, as well as in cases where the cause of OHCA is unknown. On the contrary, routine brain CT may be a valuable tool in guiding anticoagulant therapy during ECMO and in aiding outcome prediction.

An Utstein-based model score to predict survival to hospital admission: The UB-ROSC score

AimsTo develop and validate a multi-parametric practical score to predict the probability of survival to hospital admission of an out-of-hospital cardiac arrest (OHCA) victim by using Utstein Style-based variables. MethodsAll consecutive OHCA cases occurring from 2015 to 2017 in two regions, Pavia Province (Italy) and Canton Ticino (Switzerland) were included. We used random effect logistic regression to model survival to hospital admission after an OHCA. We computed the model area under the ROC curve (AUC ROC) for discrimination and we performed both internal and external validation by considering all OHCAs occurring in the aforementioned regions in 2018. The Utstein-Based ROSC (UB-ROSC) score was derived by using the coefficients estimated in the regression model. The score value was obtained adding the pertinent score components calculated for each variable. The score was then plotted against the probability of survival to hospital admission. Results1962 OHCAs were included (62% male, mean age 73 ± 16 years). Age, aetiology, location, witnessed OHCA, bystander CPR, EMS arrival time and shockable rhythm were independently associated with survival to hospital admission. The model showed excellent discrimination (AUC 0.83, 95%CI 0.81–0.85) for predicting survival to hospital admission, also at internal cross-validation (AUC 0.82, 95%CI 0.80–0.84). The model maintained good discrimination after external validation by using the 2018 OHCA cohort (AUC 0.77, 95%CI 0.74–0.80). ConclusionsUB-ROSC score is a novel score that predicts the probability of survival to hospital admission of an OHCA victim. UB-ROSC shall help in setting realistic expectations about sustained ROSC achievement during resuscitation manoeuvres.

Abstract 428: Cause of Death Among Patients Resuscitated From Out-Of-Hospital Cardiac Arrest at a Single Urban Academic Hospital

Background: Approximately 30% of patients resuscitated following Out of Hospital Cardiac Arrest (OHCA) survive to hospital admission, but only 10% of these patients survive to hospital discharge. Reasons for in hospital death of these patients is not well known or categorized. Understanding the principle reason for death among successfully resuscitated OHCA patients could guide the development of therapeutic and management strategies Methods: Using a retrospective OHCA cohort database at a single urban academic hospital, death of admitted adult OHCA patients from January 1, 2016 until June 30, 2019 was classified as primarily due to withdrawal of life-sustaining treatments (WOLST), in-hospital cardiac arrest, or formal declaration of death by neurologic criteria (brain death). Family/caregiver decisions to WOLST were categorized as occurring primarily in the setting of isolated severe neurological injury, multi-organ failure, in hospital cardiac arrest, severe hemodynamic shock, pre-existing comorbidities/terminal health condition, or prior unknown DNR status. Traumatic arrests were excluded. Results: During the study period there were 578 cardiac arrests brought to the emergency department; 291 (50%) patients survived to hospital admission. Of admitted patients, 95 patients (33%) survived to hospital discharge and 194 patients (67%) died. In non-surviving patients, death was attributable to WOLST (77%), brain death 25 (13%), in-hospital cardiac arrest (9%), and failure to achieve return of spontaneous circulation on ECMO 1 (1%). Decisions to WOLST by family members were complex and multi-factorial but were determined in the context of poor neurologic prognosis 93 (62%), multi-organ failure 27 (18%), in hospital cardiac arrest 11 (7%), severe shock 11 (7%), unknown prior DNR status 7 (5%), and pre-existing terminal illness 2 (1%). Conclusion: In this single center study, the majority of OHCA patients who survived to hospital admission from the emergency department subsequently died in the hospital due to the severity of their neurological injury in the context of WOLST. Death in the setting of multiorgan failure, re-arrest, or severe hemodynamic shock was less common.

An Utstein-based model score to predict survival to hospital admission: The UB-ROSC Score

Abstract Aims To develop and validate a multi-parametric practical score to predict the probability of survival to hospital admission of an out-of-hospital cardiac arrest (OHCA) victim by using Utstein Style-based variables. Methods All consecutive OHCA cases occurring from 2015 to 2017 in two regions, Pavia Province (Italy) and Canton Ticino (Switzerland) were included. We used random effect logistic regression to model survival to hospital admission after an OHCA. We computed the model area under the ROC curve (AUC ROC) for discrimination and we performed both internal and external validation by considering all OHCAs occurring in the aforementioned regions in 2018. The Utstein-Based ROSC (UB-ROSC) score was derived by using the coefficients estimated in the regression model. The score value was obtained adding the pertinent score components calculated for each variable. The score was then plotted against the probability of survival to hospital admission. Results 1962 OHCAs were included (62% male, mean age 73 ± 16 years). Age, aetiology, location, witnessed OHCA, bystander CPR, EMS arrival time and shockable rhythm were independently associated with survival to hospital admission. The model showed excellent discrimination (AUC 0.83, 95%CI 0.81–0.85) for predicting survival to hospital admission, also at internal cross-validation (AUC 0.82, 95%CI 0.80–0.84). The model maintained good discrimination after external validation by using the 2018 OHCA cohort (AUC 0.77, 95%CI 0.74–0.80). Conclusions UB-ROSC score is a novel score that predicts the probability of survival to hospital admission of an OHCA victim. UB-ROSC shall help in setting realistic expectations about sustained ROSC achievement during resuscitation manoeuvres.

Abstract 140: Utilization of Mechanical CPR Is Highly Variable Within the National EMS Information System Dataset

Background: Randomized controlled trials have demonstrated neither survival benefit nor harm from use of mechanical CPR (mCPR). Retrospective analyses have shown an association between mCPR and worse survival outcomes, even when controlling for differences in patient mix and arrest duration. Nonetheless, studies have suggested mCPR use increased from 2013 to 2016. Objective: We sought to quantify the proportion of out-of-hospital cardiac arrest (OHCA) cases in the US with utilization of mCPR and use in conjunction with other procedures. Methods: Using Emergency Medical Services (EMS) call data from the National EMS Information System (NEMSIS) Dataset, we identified non-traumatic OHCA with EMS resuscitation. Procedure codes were classified as “Mechanical CPR”, “Advanced Airway”, “IO”, “IV”, “Defibrillation”, “Other” and “No Procedures”. The NEMSIS Dataset includes US Census Region, Division, and urbanicity for each call. Results: In 2016, there were 29,919,652 EMS activations reported, 151,333 met inclusion criteria and 138,555 included procedure codes. Of the OHCA cohort, the mean age was 63±20 yrs, 39% were female, 86% occurred prior to EMS arrival, 62% occurred in a home/residence, 18% in public, and 14% in healthcare facilities. mCPR was used in 10% of all cases. Reported regional utilization varied from 4.8% in the Northeast to 14.9% in the South (p&lt;0.001). mCPR did not vary significantly based on urbanicity (range: 10.4% to 11.4%, p=0.34). In multiple logistic regression controlling for age, gender, location of arrest, race and ethnicity, and region, mCPR utilization was more likely if an advanced airway was placed (OR: 1.74, CI: 1.58-1.91), and less likely if an IV or IO was placed (IV: OR 0.75, CI 0.71 - 0.79; IO: OR 0.37, CI 0.28 - 0.48). 4,928 cases contained information on survival to admission. Of these, overall survival to admission was 27%, with no significant difference between mCPR and no mCPR groups. Survival to discharge data was available for 2,476 subjects (1.8% of OHCA cohort). Survival to discharge was higher among the non-mCPR group (13.8% vs. 10.3%, p = 0.011). Conclusion: In NEMSIS, reported mCPR utilization is highly variable across the US. The overall proportion of cases receiving mCPR is lower than previous registry-based studies.

Association of the Emergency Medical Services–Related Time Interval with Survival Outcomes of Out-of-Hospital Cardiac Arrest Cases in Four Asian Metropolitan Cities Using the Scoop-and-Run Emergency Medical Services Model

BackgroundResponse time interval (RTI) and scene time interval (STI) are key time variables in the out-of-hospital cardiac arrest (OHCA) cases treated and transported via emergency medical services (EMS). ObjectiveWe evaluated distribution and interactive association of RTI and STI with survival outcomes of OHCA in four Asian metropolitan cities. MethodsAn OHCA cohort from Pan-Asian Resuscitation Outcome Study (PAROS) conducted between January 2009 and December 2011 was analyzed. Adult EMS-treated cardiac arrests with presumed cardiac origin were included. A multivariable logistic regression model with an interaction term was used to evaluate the effect of STI according to different RTI categories on survival outcomes. Risk-adjusted predicted rates of survival outcomes were calculated and compared with observed rate. ResultsA total of 16,974 OHCA cases were analyzed after serial exclusion. Median RTI was 6.0 min (interquartile range [IQR] 5.0–8.0 min) and median STI was 12.0 min (IQR 8.0-16.1). The prolonged STI in the longest RTI group was associated with a lower rate of survival to discharge or of survival 30 days after arrest (adjusted odds ratio [aOR] 0.59; 95% confidence interval [CI] 0.42–0.81), as well as a poorer neurologic outcome (aOR 0.63; 95% CI 0.41–0.97) without an increasing chance of prehospital return of spontaneous circulation (aOR 1.12; 95% CI 0.88–1.45). ConclusionsProlonged STI in OHCA with a delayed response time had a negative association with survival outcomes in four Asian metropolitan cities using the scoop-and-run EMS model. Establishing an optimal STI based on the response time could be considered.

Gains of Continuing Resuscitation in Refractory Out-of-hospital Cardiac Arrest: A Model-based Analysis to Identify Deaths Due to Intra-arrest Prognostication

Objective: Prognostication bias, in which a clinician predicts a negative outcome and terminates resuscitation (TR) thereby ensuring a poor outcome, is a rarely identified limitation of out-of-hospital cardiac arrest (OHCA) research. We sought to estimate the number of deaths due to intra-arrest prognostication in a cohort of OHCA's, and use this data to estimate the incremental benefit of continuing resuscitation. Methods: This study examined a cohort of consecutive non-traumatic EMS-treated OHCAs from a provincial ambulance service, between 2007 and 2011 inclusive. We used Cox and logistic regression modeling, adjusting for Utstein covariates, to estimate the probability of ROSC, survival, and favorable neurological outcomes as a function of resuscitation time, and applied these models to estimate the number of missed survivors in those who had TR (prior to 20, 30, or 40 minutes). We determined the time juncture at which (1) the likelihood of survival fell below 1%, and (2) the proportion of survivors who had achieved ROSC exceeded 99%. Results: Of 5674 adult EMS-treated cases, 46% achieved ROSC, and 12% survived. The median time of TR was 27.0 minutes (IQR 19.0–35.0). Continuing resuscitation until 40 minutes yielded an estimated 17 additional survivors (95% CI 13–21), 10 (95% CI 7–13) with favorable neurological outcomes. The probability of survival of those in refractory arrest decreased below 1% at 28 minutes (95% CI 24–30 minutes). At 36 minutes (95% CI 34–38 minutes) >99% of survivors had achieved ROSC. Conclusion: We identified possible deaths due to intra-arrest prognostication. Resuscitation should be continued for a minimum of 30 minutes in all patients, however for those with initial shockable rhythms 40 minutes appears to be warranted. Interventional trials and observational studies should standardize or adjust for duration of resuscitation prior to TR.

Availability and Accuracy of EMS Information about Chronic Health and Medications in Cardiac Arrest.

IntroductionField information available to emergency medical services (EMS) about a patient’s chronic health conditions or medication therapies could help direct patient care or be used to investigate outcome disparities. However, little is known about the field availability or accuracy of information of chronic health conditions or chronic medication treatments in emergent circumstances, especially when the patient cannot serve as an information resource. We evaluated the prehospital availability and accuracy of specific chronic health conditions and medication treatments among out-of-hospital cardiac arrest (OHCA) patients.MethodsThe investigation was a retrospective cohort study of adult persons suffering ventricular fibrillation OHCA treated by EMS in a large metropolitan county from January 1, 2007, to December 31, 2013. The study was designed to determine the availability and accuracy of EMS ascertainment of selected chronic health conditions and medication treatments. We evaluated chronic health conditions of “any heart disease,” congestive heart failure (CHF), and diabetes and medication treatments of beta blockers and loop diuretics using two distinct sources: 1) EMS report, and 2) hospital record specific to the OHCA event. Because hospital information was considered the gold standard, we restricted the primary analysis to those who were admitted to hospital.ResultsOf the 1,496 initially eligible patients, 387 could not be resuscitated and were pronounced dead in the field, one patient was left alive at scene due to Physician’s Orders for Life-sustaining Treatment (POLST) orders, 125 expired in the emergency department (n=125), and 983 were admitted to hospital. A total of 832 of 1,496 (55.6%) had both sources of data for comparison and comprised the primary analytic group. Using the hospital record as the gold standard, EMS ascertainment had a sensitivity of 0.79 (304/384) and a specificity of 0.88 (218/248) for any prior heart disease; sensitivity 0.45 (47/105) and specificity 0.87 (477/516) for CHF; sensitivity 0.71 (143/201) and specificity 0.98 (416/424) for diabetes; sensitivity 0.70 (118/169) and specificity 0.94 (273/290) for beta blockers; sensitivity 0.70 (62/89) and specificity 0.97 (358/370) for loop diuretics.ConclusionIn this cohort of OHCA, information about selected chronic health conditions and medication treatments based on EMS ascertainment was available for many patients, generally revealing moderate sensitivity and greater specificity.

Comparison of team-focused CPR vs standard CPR in resuscitation from out-of-hospital cardiac arrest: Results from a statewide quality improvement initiative

BackgroundTeam-focused CPR (TFCPR) is a choreographed approach to cardiopulmonary resuscitation (CPR) with emphasis on minimally interrupted high-quality chest compressions, early defibrillation, discourages endotracheal intubation and encourages use of the bag-valve-mask (BVM) and/or blind-insertion airway device (BIAD) with a ventilation rate of 8–10 breaths/min to minimize hyperventilation. Widespread incorporation of TFCPR in North Carolina (NC) EMS agencies began in 2011, yet its impact on outcomes is unknown. ObjectivesTo determine whether TFCPR improves survival with good neurological outcome in out-of-hospital cardiac arrest (OHCA) patients compared to standard CPR. MethodsThis retrospective cohort analysis of NC EMS agencies reporting data to the Cardiac Arrest Registry for Enhanced Survival (CARES) database from January 2010 to June 2014 included adult, non-traumatic OHCA with presumed cardiac etiology where EMS performed CPR or patient received defibrillation. Exclusions were arrest terminated per EMS policy or DNR. EMS agencies self-reported the TFCPR implementation dates. Patients were categorized as receiving either TFCPR or standard CPR. The primary outcome was good neurologic outcome at time of hospital discharge defined as Pittsburgh Cerebral Performance Category (CPC) 1–2. ResultsOf 14,994 OHCAs, 14,129 patients were included for analysis with a mean age 65 (IQR 50–81) years, 61% male, 7.3% with good neurologic outcome, 24.3% with shockable initial rhythm, and 71.5% receiving TFCPR. Of the 3427 (24.3%) with an initial shockable rhythm, 739 (71.9%) had a good neurological outcome. Good neurologic outcome was higher with TFCPR [836 (8.3%, 95%CI 7.7–8.8%)] vs. standard CPR [193 (4.8%, 95%CI 4.2–5.5%)]. Logistic regression controlling for demographic and arrest characteristics revealed TFCPR (OR 1.5), witnessed arrest (OR 4.3), initial shockable rhythm (OR 7.1), and in-hospital hypothermia (OR 3.3) were associated with good neurologic outcome. Mechanical CPR device (OR 0.68), CPR feedback device (OR 0.47), and endotracheal intubation (OR 0.44) were associated with less likelihood for a good neurologic outcome. ConclusionIn our statewide OHCA cohort, TFCPR was associated with improved survival with good neurological outcome.

Effect of therapeutic hypothermia on the outcomes after out-of-hospital cardiac arrest according to initial ECG rhythm and witnessed status: A nationwide observational interaction analysis

BackgroundThe use of mild therapeutic hypothermia (TH) in out-of-hospital cardiac arrest (OHCA) with shockable rhythms is recommended and widely used. However, it is unclear whether TH is associated with better outcomes in non-shockable rhythms. MethodsThis is a retrospective observational study using a national OHCA cohort database composed of emergency medical services (EMS) and hospital data. We included adult EMS-treated OHCA patients of presumed cardiac etiology who were admitted to the hospital during Jan. 2008 to Dec. 2013. Patients without hospital outcome data were excluded. The primary outcome was good neurological outcome at discharge; secondary outcome was survival to discharge. The primary exposure was TH. We compared outcomes between TH and non-TH groups using multivariable logistic regression, adjusting for individual and Utstein factors. Interactions of initial ECG rhythm and witnessed status on the effect of TH on outcomes were tested. ResultsThere were 11,256 patients in the final analysis. TH was performed in 1703 patients (15.1%). Neurological outcome was better in TH (23.5%) than non-TH (15.0%) (Adjusted OR=1.25, 95% CI 1.05–1.48). The effect of TH on the odds for good neurological outcome was highest in the witnessed PEA group (Adjusted OR=3.91, 95% CI 1.87–8.14). Survival to discharge was significantly higher in the TH group (55.1%) than non-TH (35.9%) (Adjusted OR=1.76, 95% CI 1.56–2.00). ConclusionsIn a nationwide observational study, TH is associated with better neurological outcome and higher survival to discharge. The effect of TH is greatest in witnessed OHCA patients with PEA as the initial ECG rhythm.

Extracorporeal life support and survival after out-of-hospital cardiac arrest in a nationwide registry: A propensity score-matched analysis

BackgroundThe benefit of extracorporeal life support (ECLS) in highly selective patients with out-of-hospital cardiac arrest (OHCA) is supported by previous studies; however, it is unclear whether the effects of ECLS are observed at a population level. This study aimed to determine whether ECLS is associated with improved survival outcomes compared to conventional CPR (cardiopulmonary resuscitation) at a national level. MethodsWe used a Korean national OHCA cohort database from 2009 to 2013. The inclusion criteria were OHCA adults with presumed cardiac aetiology and resuscitation by emergency medical services (EMS). Patients were excluded if their information on prehospital time intervals or clinical outcomes at hospital discharge was incomplete or not captured. The primary outcome was neurologically favourable survival to discharge. We compared the primary outcomes between the ECLS and non-ECLS groups using a multivariable logistic regression and a propensity score matching analysis. ResultsOf the 119,077 patients with OHCA, 36,547 were included in the analysis. There were 320 patients who received ECLS. There was no significant difference in neurologically favourable survival to discharge between the ECLS group and the non-ECLS group after adjusting for covariates (adjusted OR, 0.65; 95% CI, 0.41–1.04). In the propensity score-matched cohort, there was also no significant difference between the two groups (adjusted OR, 0.94; 95% CI, 0.41–2.14). ConclusionsIn this propensity score-matched cohort using a nationwide OHCA database, OHCA victims who received ECLS did not show better survival outcomes than those who did not receive ECLS.