Non-traumatic Out-of-hospital Cardiac Arrest Research Articles

Machine learning prediction of refractory ventricular fibrillation in out-of-hospital cardiac arrest using features available to EMS

BackgroundShock-refractory ventricular fibrillation (VF) or ventricular tachycardia (VT) is a treatment challenge in out-of-hospital cardiac arrest (OHCA). This study aimed to develop and validate machine learning models that could be implemented by emergency medical services (EMS) to predict refractory VF/VT in OHCA patients. MethodsThis was a retrospective study examining adult non-traumatic OHCA patients brought into the emergency department by Singapore EMS from the Pan-Asian Resuscitation Outcomes Study (PAROS) registry. Data from April 2010 to March 2020 were extracted for this study. Refractory VF/VT was defined as VF/VT persisting or recurring after at least one shock. Features were selected based on expert clinical opinion and availability to dispatch prior to arrival at scene. Multivariable logistic regression (MVR), LASSO and random forest (RF) models were investigated. Model performance was evaluated using receiver operator characteristic (ROC) area under curve (AUC) analysis and calibration plots. Results20,713 patients were included in this study, of which 860 (4.1%) fulfilled the criteria for refractory VF/VT. All models performed comparably and were moderately well-calibrated. ROC-AUC were 0.732 (95% CI, 0.695 – 0.769) for MVR, 0.738 (95% CI, 0.701 – 0.774) for LASSO, and 0.731 (95% CI, 0.690 – 0.773) for RF. The shared important predictors across all models included male gender and public location. ConclusionThe machine learning models developed have potential clinical utility to improve outcomes in cases of refractory VF/VT OHCA. Prediction of refractory VF/VT prior to arrival at patient’s side may allow for increased options for intervention both by EMS and tertiary care centres.

Epidemiology and outcome of out-of-hospital cardiac arrest in Salt Lake City: Sex-based investigations.

Prior research indicates sex disparities in the incidence and outcomes of out-of-hospital cardiac arrest (OHCA). This study investigates the presence of such differences in Salt Lake City, Utah. We analyzed data from the Salt Lake City Fire Department (2008‒2023). We included adults with non-traumatic OHCA. We calculated the annual incidence of OHCA and examined sex-specific survival outcomes using multivariable logistic regression, adjusting for OHCA characteristics known to be associated with survival. The annual incidence of OHCA was 76 per 100,000 person-years. Among the 894 OHCA cases included in the analysis, 67.5% were males, 37.3% achieved return of spontaneous circulation (ROSC), and 13.6% survived hospital discharge. Unadjusted analysis revealed that males had significantly higher OHCA in public locations (43.9%vs. 28.6%), witnessed arrests (54.5%vs. 47.8%), and shockable rhythms (33.3%vs. 22.9%). Males also showed higher rates of ROSC (37.5%vs. 36.9%), hospital discharge survival (14.5%vs. 11.7%), and neurologically intact survival. After adjusting for the OHCA characteristics, there was no significant differences between males and females in ROSC, survival to hospital discharge, and favorable neurological function with adjusted odds ratios (male vs. female) of 0.92 (95% confidence interval [CI] 0.73‒1.16), 0.85 (95% CI 0.59‒1.22), and 0.92 (95% CI 0.62‒1.40), respectively. Approximately, 128 adults suffer OHCA in Salt Lake City annually. Males initially showed higher crude survival rates, but after adjusting for OHCA characteristics, no significant sex differences in survival outcomes were found. Enhancing OHCA characteristics could benefit both sexes. Investigations into the relationship between sex- and region-specific factors influencing OHCA outcomes are needed.

Does Single Dose Epinephrine Improve Outcomes for Patients with Out-of-Hospital Cardiac Arrest and Bystander CPR or a Shockable Rhythm?

ABSTRACT Background: A single dose epinephrine protocol (SDEP) for out-of-hospital cardiac arrest (OHCA) achieves similar survival to hospital discharge (SHD) rates as a multidose epinephrine protocol (MDEP). However, it is unknown if a SDEP improves SHD rates among patients with a shockable rhythm or those receiving bystander cardiopulmonary resuscitation (CPR). Methods: This pre-post study, spanning 11/01/2016-10/29/2019 at 5 North Carolina EMS systems, compared pre-implementation MDEP and post-implementation SDEP in patients ≥18 years old with non-traumatic OHCA. Data on initial rhythm type, performance of bystander CPR, and the primary outcome of SHD were sourced from the Cardiac Arrest Registry to Enhance Survival. We compared SDEP vs MDEP performance in each rhythm (shockable and non-shockable) and CPR (bystander CPR or no bystander CPR) subgroup using Generalized Estimating Equations to account for clustering among EMS systems and to adjust for age, sex, race, witnessed arrest, arrest location, AED availability, EMS response interval, and presence of a shockable rhythm or receiving bystander CPR. The interaction of SDEP implementation with rhythm type and bystander CPR was evaluated. Results: Of 1690 patients accrued (899 MDEP, 791 SDEP), 19.2% (324/1690) had shockable rhythms and 38.9% (658/1690) received bystander CPR. After adjusting for confounders, SHD was increased after SDEP implementation among patients with bystander CPR (aOR 1.61, 95%CI 1.03-2.53). However, SHD was similar in the SDEP cohort vs MDEP cohort among patients without bystander CPR (aOR 0.81, 95%CI 0.60-1.09), with a shockable rhythm (aOR 0.96, 95%CI 0.48-1.91), and with a non-shockable rhythm (aOR 1.26, 95%CI 0.89-1.77). In the adjusted model, the interaction between SDEP implementation and bystander CPR was significant for SHD (p = 0.002). Conclusion: Adjusting for confounders, the SDEP increased SHD in patients who received bystander CPR and there was a significant interaction between SDEP and bystander CPR. Single dose epinephrine protocol and MDEP had similar SHD rates regardless of rhythm type.

Impact of intravenous accessibility and prehospital epinephrine use on survival outcomes of adult nontraumatic out-of-hospital cardiac arrest patients

BackgroundThis study compared out-of-hospital cardiac arrest (OHCA) patient outcomes based on intravenous (IV) access and prehospital epinephrine use.MethodsA retrospective study in Ulsan, South Korea, from January 2017 to December 2022, analyzed adult nontraumatic OHCA cases. Patients were grouped: Group 1 (no IV attempts), Group 2 (failed IV access), Group 3 (successful IV access without epinephrine), and Group 4 (successful IV access with epinephrine), with comparisons using logistic regression analysis.ResultsAmong 2,656 patients, Group 4 had significantly lower survival to hospital discharge (adjusted OR 0.520, 95% CI 0.346–0.782, p = 0.002) and favorable neurological outcomes (adjusted OR 0.292, 95% CI 0.140–0.611, p = 0.001) than Group 1. Groups 2 and 3 showed insignificant survival to hospital discharge (adjusted OR 0.814, 95% CI 0.566–1.171, p = 0.268) and (adjusted OR 1.069, 95% CI 0.810–1.412, p = 0.636) and favorable neurological outcomes (adjusted OR 0.585, 95% CI 0.299–1.144, p = 0.117) and (adjusted OR 1.075, 95% CI 0.689–1.677, p = 0.751). In the shockable rhythm group, Group 3 had better survival to hospital discharge (adjusted OR 1.700, 95% CI 1.044–2.770, p = 0.033).ConclusionsSuccessful IV access with epinephrine showed worse outcomes in both rhythm groups than no IV attempts. Outcomes for failed IV and successful IV access without epinephrine were inconclusive. Importantly, successful IV access without epinephrine showed favorable survival to hospital discharge in the shockable rhythm group, warranting further research into IV access for fluid resuscitation in shockable rhythm OHCA patients.

Comparative Analysis of Out-of-Hospital Cardiac Arrest Outcomes in Health Clinics, Nursing Homes, and Public Places: Implications for Optimizing Automated External Defibrillator Strategies.

Various factors, such as event location and response time, influence the outcomes of out-of-hospital cardiac arrest (OHCA). Very few studies have explored the delivery of basic life support (BLS) to patients having OHCA at health clinics or nursing homes-settings with professional BLS providers. Thus, in this study, we compared prognostic and survival outcomes between health clinics, nursing homes, and other public places (eg, workplaces and sports facilities/recreational areas) to offer insights for optimizing OHCA outcomes. This study included adults who had nontraumatic OHCA in Taoyuan City between January 2017 and December 2022. We collected data on patient characteristics, emergency medical service parameters, onsite patient management, automated external defibrillator (AED) locations, OHCA prognosis, and survival outcomes. Multivariate analyses were performed to predict survival to discharge (primary outcome) and neurological outcomes at discharge (secondary outcome). During the study period, the numbers of OHCA events at health clinics, nursing homes, and other public places were 158, 208, and 1986, respectively. The mean age of OHCA in health medical clinics, nursing home and other public places were 63.4, 81.5 and 64.7, respectively (P value<0.001). The proportion of witnessed events, rate of bystander resuscitation, and frequency of AED utilization were the highest for health clinics (53.2% (84/158), 83.4% (132/158), and 13.3% (21/158), respectively, P value<0.001). The average AED-scene distances and response times were the lowest for health clinics (388.8 m and 5.4 min, respectively). In initial shockable rhythm group, the probabilities of survival to discharge at discharge were the highest for health clinics (aOR=1.41, 95% CI=1.04-1.81, P value=0.041)) and lowest for nursing homes (aOR=0.84, 95% CI=0.76-0.93, P value=0.024). Our research shows that OHCA patients at medical health clinics have higher rates of witnessing and bystander CPR and AED usage than other public places. However, while survival rates for patients with shockable rhythms are slightly better at health clinics, the neurological outcomes are not significantly different. The AED-scene distances are too far to be used effectively.

A comparison between intraosseous and intravenous access in patients with out-of-hospital cardiac arrest: A retrospective cohort study

IntroductionThe optimal vascular access for patients with out-of-hospital cardiac arrest (OHCA) remains controversial. Increasing evidence supports intraosseous (IO) access due to faster medication administration and higher first-attempt success rates compared to intravenous (IV) access. However, the impact on patient outcomes has been inconclusive. MethodsThis retrospective cohort study in Taoyuan City, Taiwan, from January 1, 2019, to December 31, 2022, included patients aged ≥18 years with non-traumatic OHCA resuscitated by emergency medical technician paramedics (EMT-Ps) with either IVs or IOs for final vascular access. The exclusion criteria were cardiac arrest en route to the hospital and resuscitation during the coronavirus pandemic (from May 1, 2022, to October 31, 2022). The primary and secondary outcomes were sustained ROSC (≥2 h) and cerebral performance category (CPC) 1–2, respectively. Univariate logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals (CI) for the primary analysis. Multivariable logistic regression was employed, with variables selected based on a p-value of <0.05 in the univariate analysis. The survival benefits of different insertion sites and subgroups like general ambulance teams (with a composition that includes fewer EMT-Ps and limited experience in using IO access) were also analyzed. ResultsA total of 2003 patients were enrolled; 1602 received IV access and 401 IO access. The median patient age was 70 years, and most were male (66.6%). Compared to patients receiving IV access, the adjusted odds ratios (aORs) for primary and secondary outcomes in patients with IOs were 0.83 (95% confidence interval [CI], 0.61–1.11; p = 0.20) and 0.96 (95% CI, 0.39–2.40; p = 0.93), respectively. Different insertion sites showed no outcome differences. In the subgroups of females and patients resuscitated by general ambulance teams, the aORs for sustained ROSC were 0.55 (95% CI, 0.33–0.92; p = 0.02) and 0.62 (95% CI, 0.41–0.94; p = 0.02), respectively. ConclusionsFor patients with OHCA resuscitated by EMT-Ps, IO access was comparable to IV access regarding patient outcomes. However, in females and patients resuscitated by general ambulance teams, IV access might be favorable.

A retrospective comparison of mechanical cardio-pulmonary ventilation and manual bag valve ventilation in non-traumatic out-of-hospital cardiac arrests: A study from the Belgian cardiac arrest registry

BackgroundThe optimal ventilation modalities to manage out-of-hospital cardiac arrest (OHCA) remain debated. A specific pressure mode called cardio-pulmonary ventilation (CPV) may be used instead of manual bag ventilation (MBV). We sought to analyse the association between mechanical CPV and return of spontaneous circulation (ROSC) in non-traumatic OHCA. MethodsMBV and CPV were retrospectively identified in patients with non-traumatic OHCA from the Belgian Cardiac Arrest Registry. We used a two-level mixed-effects multivariable logistic regression analysis to determine the association between the ventilation modalities and outcomes. The primary and secondary study criteria were ROSC and survival with a Cerebral Performance Category (CPC) score of 1 or 2 at 30 days. Age, sex, initial rhythm, no-flow duration, low-flow duration, OHCA location, use of a mechanical chest compression device and Rankin status before arrest were used as covariables. ResultsBetween January 2017 and December 2021, 2566 patients with OHCA who fulfilled the inclusion criteria were included. 298 (11.6%) patients were mechanically ventilated with CPV whereas 2268 were manually ventilated. The use of CPV was associated with greater probability of ROSC both in the unadjusted (odds ratio: 1.28, 95% confidence interval [CI]: 1.01–1.63; p = 0.043) and adjusted analyses (adjusted odds ratio [aOR]: 2.16, 95%CI 1.37–3.41; p = 0.001) but not with a lower CPC score (aOR: 1.44, 95%CI 0.72–2.89; p = 0.31). ConclusionsCompared with MBV, CPV was associated with an increased risk of ROSC but not with improved an CPC score in patients with OHCA. Prospective randomised trials are needed to challenge these results.

Effects of physician-present prehospital care in patients with out-of-hospital cardiac arrest on return of spontaneous circulation: A retrospective, observational study in Saga, Japan.

Emergency medical services for out-of-hospital cardiac arrest (OHCA) vary according to region and country, and patient prognosis differs accordingly. In Japan, physicians may provide prehospital care. However, the effect of physician-present prehospital care on achieving return of spontaneous circulation (ROSC) in patients with cardiac arrest is not clear. Here, we aimed to examine the effect of physician-present prehospital care on the prognosis of patients with OHCA at our hospital compared with physician-absent care. In this retrospective, observational study, patients aged ≥18 years with non-traumatic OHCA from a single center in Saga City, Japan, between April 2011 and December 2019, were included. Patients were divided into two groups, based on prehospital physician presence or absence. Logistic regression analysis was used to determine the association between physician-present prehospital care and ROSC. Of 820 patients with OHCA, 151 had a physician present and 669 did not. Logistic regression analysis with no adjustment showed that the odds ratio (OR) of physician-present prehospital care for an increased ROSC rate was 1.74 (95% confidence interval [CI]: 1.22-2.48, p = 0.002). Logistic-regression analysis adjusted for ROSC-related factors indicated an ORof 1.05 (95% CI:0.47-2.34, p = 0.914) for physician-present prehospital care to ROSC. Physician-present prehospital care may not necessarily lead to increased ROSC rates. However, insufficient data limited our study findings. Further studies involving larger sample sizes are warranted.

The Public Health and Economic Impact of Drug Overdose Out-of-Hospital Cardiac Arrest in the United States

Objective To calculate disability-adjusted life years (DALY) and labor productivity loss due to drug overdose out-of-hospital cardiac arrest (DO-OHCA) and compare its contribution to the burden of disease and economic impact of all-cause nontraumatic out-of-hospital cardiac arrest (OHCA) in the US. Methods We performed a retrospective observational cohort analysis of all adult (age ≥18 years) nontraumatic emergency medical services-treated OHCA events, including those due to DO-OHCA, from the national Cardiac Arrest Registry to Enhance Survival (CARES) database from January 1, 2017 and December 31, 2020. The main outcome measures of interest were disability-adjusted life years, annual, and lifetime labor productivity loss over the 4-year study period. The findings for the study population were extrapolated to a national level using the CARES population catchment and U.S. population estimates by year. Results A total of 378,088 adult OHCA events, including 23,252 DO-OHCA (6.2%) met study inclusion criteria. The DO-OHCA DALY increased from 156,707 in 2017 to 265,692 in 2020. Per year, DO-OHCA contributed to 11.4%, 12.0%, 10.5%, and 11.4% of all OHCA DALY lost from 2017-2020, respectively. The mean annual and lifetime productivity losses for all OHCA were stable over time (annual: $47K in 2017 to $50K in 2020; lifetime: $647K in 2017 to $692K in 2020). The CARES population catchment increased by 39.8% over the study period (102.6 M in 2017 to 143.4 M in 2020). For DO-OHCA, the mean annual productivity loss was approximately 30% higher than non-DO-OHCA ($64K vs. $49K in 2020, respectively). The mean lifetime productivity loss for DO-OHCA was 2.5 times higher than non-DO-OHCA ($1.6 M vs. $630K in 2020, respectively). Conclusions The DALY due to DO-OHCA has increased over time with expansion of the CARES dataset, but its relative contribution to total OHCA DALY (all non-traumatic etiologies) remained fairly stable. The DO-OHCAs represent approximately 6% of all adult non-traumatic EMS-treated OHCA events but has a disproportionately greater economic impact. Continued efforts to reduce DO-OHCA through public health initiatives are warranted to lessen the societal impact of OHCA in the U.S.

Years of Potential Life Lost and Mean Age of Adults Experiencing Nontraumatic, Out-of-Hospital Cardiac Arrests - Chicago, 2014-2021.

Approximately 1,000 out-of-hospital cardiac arrests (OHCAs) are assessed by emergency medical services in the United States every day, and approximately 90% of patients do not survive, leading to substantial years of potential life lost (YPLL). Chicago emergency medical services data were used to assess changes in mean age and YPLL from nontraumatic OHCA in adults in biennial cycles during 2014-2021. Among 21,070 reported nontraumatic OHCAs during 2014-2021, approximately 60% occurred among men and 57% among non-Hispanic Black or African American (Black) persons. YPLL increased from 52,044 during 2014-2015 to 88,788 during 2020-2021 (p = 0.002) and mean age decreased from 64.7 years during 2014-2015, to 62.7 years during 2020-2021. Decrease in mean age occurred among both men (p<0.001) and women (p = 0.002) and was largest among Black men. Mean age decreased among patients without presumed cardiac etiology from 56.3 to 52.5 years (p<0.001) and among patients with nonshockable rhythm from 65.5 to 62.7 years (p<0.001). Further study is needed to assess whether similar trends are occurring elsewhere, and to understand the mechanisms that underlie these trends in Chicago because these mechanisms could help guide prevention efforts. Increased public awareness of the risk of cardiac arrest and knowledge of how to intervene as a bystander could help decrease associated mortality.

Resuscitative Endovascular Balloon Occlusion of the Aorta in Non-Traumatic Out-of-Hospital Cardiac Arrest: A State-of-the-Art Review

Out-of-hospital cardiac arrest (OHCA) is one of the most important causes of death worldwide. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an interesting new device that has been developed as a bridge therapy to treat trauma patients with non-compressible torso hemorrhage. REBOA has also been tested in non-traumatic OHCA, but the results are inconclusive. The aim of this review is to describe the state of the art in the use of REBOA for the management of non-traumatic out-of-hospital cardiac arrest. We performed a state-of-the-art review of the literature, searching for the therapeutic role of REBOA in the management of non-traumatic OHCA. We interviewed PubMed, Central, and Embase, and searched for citations before May 2023 using these criteria: “non-traumatic out-of-hospital cardiac arrest” and “resuscitative endovascular balloon occlusion of the aorta”. We selected only observational studies because controlled trials have not been published yet. All studies demonstrated the feasibility of REBOA placement in the management of non-traumatic OHCA and the improvement of all perfusion markers. Although some important uncertainties still remain, REBOA has the potential to become a new cornerstone in the therapy of OHCA and change the management of cardiac arrest, especially in remote locations which require a long time for scene arrival and an even longer time for metropolitan hospital arrival, where an ECPR is available.

Association between out-of-hospital cardiac arrest quality indicator and prehospital management and clinical outcomes for major trauma

IntroductionIt is unclear whether emergency medical service (EMS) agencies with good out-of-hospital cardiac arrest (OHCA) quality indicators also perform well in treating other emergency conditions. We aimed to evaluate the association of an EMS agency's non-traumatic OHCA quality indicators with prehospital management processes and clinical outcomes of major trauma. MethodsThis retrospective cross-sectional study analyzed data from registers of nationwide, population-based OHCA (adult EMS-treated non-traumatic OHCA patients from 2017 to 2018) and major trauma (adult, EMS-treated, and injury severity score ≥16 trauma patients in 2018) in South Korea. We developed a prehospital ROSC prediction model to categorize EMS agencies into quartiles (Q1-Q4) based on the observed-to-expected (O/E) ROSC ratio for each EMS agency. We evaluated the national EMS protocol compliance of on-scene management according to O/E ROSC ratio quartile. The association between O/E ROSC ratio quartiles and trauma-related early mortality was determined in a multi-level logistic regression model by adjusted odds ratios (OR) and 95 % confidence intervals (95 % CI). ResultsAmong 30,034 severe trauma patients, 4,836 were analyzed. Patients in Q4 showed the lowest early mortality rate (5.6 %, 5.5 %, 4.8 %, and 3.4 % in Q1, Q2, Q3, and Q4, respectively). In groups Q1 to Q4, increasing compliance with the national EMS on-scene management protocol (trauma center transport, basic airway management for patients with altered mentality, spinal motion restriction for patients with spinal injury, and intravenous access for patients with hypotension) was observed (p for trend <0.05). Multivariable multi-level logistic regression analysis showed significantly lower early mortality in Q4 than in Q1 (adjusted OR [95 % CI] 0.56 [0.35–0.91]). ConclusionMajor trauma patients managed by EMS agencies with high success rates in achieving prehospital ROSC in non-traumatic OHCA were more likely to receive protocol-based care and exhibited lower early mortality.

Non-prescription drug-associated out-of-hospital cardiac arrest: Changes in incidence over time and the odds of receiving resuscitation

BackgroundMultiple jurisdictions reported a significant increase in out-of-hospital cardiac arrest (OHCA) incidence over the past decade, however the reasons for this remain unclear. We investigated how drug-associated OHCA (DA-OHCA) contributed to overall OHCA incidence, and whether the likelihood of treatment by emergency medical services (EMS) was associated with DA-OHCA classification. MethodsUsing a large provincial cardiac arrest registry, we included consecutive, non-traumatic adult OHCA from 2016–2022. We classified as drug-associated if there were historical accounts of non-prescription drug use within the preceding 24 hours or evidence of paraphernalia at the scene. We examined year-by-year trends in OHCA and DA-OHCA incidence. We also investigated the association between DA-OHCA and odds of EMS treatment using an adjusted logistic regression model. ResultsOf 33,365 EMS-assessed cases, 1,985/18,591 (11%) of EMS-treated OHCA and 887/9,200 (9.6%) of EMS-untreated OHCA were DA-OHCA. Of EMS-treated DA-OHCA, the median age was 40 years (IQR 31–51), 1,059 (53%) had a known history of non-prescription drug use, and 570 (29%) were public-location. From 2016 to 2022, EMS-treated OHCA incidence increased from 60 to 79 per 100,000 person-years; EMS-treated DA-OHCA incidence increased from 3.7 to 9.1 per 100,000 person-years. The proportion of overall OHCA classified as DA-OHCA increased from 6.1% to 11.5%. DA-OHCA was associated with greater odds of EMS treatment (AOR 1.34; 95%CI 1.13–1.58). ConclusionAlthough EMS-treated DA-OHCA incidence increased by nearly three-fold, it comprised a minority of the overall OHCA increase during the study period. DA-OHCA was associated with an increased likelihood of EMS treatment.

Neurological outcome following out of hospital cardiac arrest: Evaluation of performance of existing risk prediction models in a UK cohort.

Out of hospital cardiac arrest (OHCA) is a common problem. Rates of survival are low and a proportion of survivors are left with an unfavourable neurological outcome. Four models have been developed to predict risk of unfavourable outcome at the time of critical care admission - the Cardiac Arrest Hospital Prognosis (CAHP), MIRACLE2, Out of Hospital Cardiac Arrest (OHCA), and Targeted Temperature Management (TTM) models. This evaluation evaluates the performance of these four models in a United Kingdom population and provides comparison to performance of the Acute Physiology and Chronic Health Evaluation II (APACHE-II) score. A retrospective evaluation of the performance of the models was conducted over a 43-month period in 414 adult, non-pregnant patients presenting consecutively following non-traumatic OHCA to the five units in our regional critical care network. Scores were generated for each model for where patients had complete data (CAHP = 347, MIRACLE2 = 375, OHCA = 356, TTM = 385). Cerebral Performance Category (CPC) outcome was calculated for each patient at last documented follow up and an unfavourable outcome defined as CPC ⩾ 3. Performance for discrimination of unfavourable outcome was tested by generating receiver operating characteristic (ROC) curves for each model and comparing the area under the curve (AUC). Best performance for discrimination of unfavourable outcome was demonstrated by the high risk group of the CAHP score with an AUC of 0.87 [95% CI 0.83-0.91], specificity of 97.1% [95% CI 93.8-100] and positive predictive value (PPV) of 96.3% [95% CI 92.2-100]. The high risk group of the MIRACLE2 model, which is significantly easier to calculate, had an AUC of 0.81 [95% CI 0.76-0.86], specificity of 92.3% [95% CI 87.2-97.4] and PPV of 95.2% [95% CI 91.9-98.4]. The CAHP, MIRACLE2, OHCA and TTM scores all perform comparably in a UK population to the original development and validation cohorts. All four scores outperform APACHE-II in a population of patients resuscitated from OHCA. CAHP and TTM perform best but are more complex to calculate than MIRACLE2, which displays inferior performance.

Basic life support for non-traumatic out-of-hospital cardiac arrests during school-supervised sports activities in children: A nationwide observational study in Japan

ObjectiveTo investigate the prognostic impact of bystander-initiated cardiopulmonary resuscitation (CPR) and public-access automated external defibrillator (AED) use on non-traumatic out-of-hospital cardiac arrest (OHCA) occurring during school-supervised sports activities in children. MethodsFrom a nationwide database of pediatric OHCAs occurring under school supervision in Japan, data between April 2008 and December 2020 were obtained. We analyzed non-traumatic OHCAs that occurred during school-supervised sports activities among schoolchildren from elementary, junior high, high, and technical colleges. A multivariable logistic regression model was used to evaluate the effect of basic life support (BLS) on 1-month survival with favorable neurological outcomes after OHCA. ResultsIn total, 318 OHCA cases were analyzed. The 1-month survival with favorable neurological outcomes was 64.8% (164/253) in cases receiving both bystander-CPR and AED application, 40.7% (11/27) in cases receiving CPR only, 38.5% (5/13) in patients receiving AED application only, and 28.0% (7/25) in cases receiving no bystander intervention. Compared with cases receiving no BLS, cases receiving both CPR and AED had a significantly higher proportion of 1-month survival with favorable neurological outcomes (adjusted odds ratio [AOR]: 3.97, 95% confidence interval [CI]: 1.32–11.90, p = 0.014). However, compared to cases receiving no BLS, there was no significant difference in the outcome in the cases receiving CPR only (AOR: 1.35, 95% CI: 0.34–5.29, p = 0.671) and the cases receiving AED application only (AOR: 1.26, 95% CI: 0.25–6.38, p = 0.778). ConclusionThe combination of CPR and AED as BLS performed by bystanders for non-traumatic OHCA during school-supervised sports activities improved the outcomes.

Utility of end-tidal carbon dioxide to guide resuscitation termination in prolonged out-of-hospital cardiac arrest

Study objectiveTo evaluate if the change in end-tidal carbon dioxide (ETCO2) over time has improved discriminatory value for determining resuscitation futility compared to a single ETCO2 value in prolonged, refractory non-shockable out-of-hospital cardiac arrest (OHCA). MethodsThis is a retrospective analysis of adult refractory non-shockable, non-traumatic OHCA patients in the Portland Cardiac Arrest Epidemiologic Registry (PDX Epistry) from 2018 to 2021. We defined refractory non-shockable OHCA cases as patients with lack of a shockable rhythm at any time or return of spontaneous circulation at any time prior to 30-min of on-scene resuscitation. We abstracted ETCO2 values first recorded after advanced airway placement and nearest to the 30-min mark of on-scene resuscitation (30 min-ETCO2) from EMS charts. The primary outcome was survival to hospital discharge. We compared 30 min-ETCO2 cutoffs of 10 mmHg and 20 mmHg to the trend (increasing or not) from initial to 30 min-ETCO2 (delta-ETCO2) using sensitivity, specificity, and area under the receiver operating curves (AUROC). ResultsOf 3837 adult OHCA, 2850 were initially non-shockable, and there were 617 (16.1%) cases of refractory non-shockable OHCA at 30-min. We excluded 320 cases without at least two ETCO2 recordings in the EMS chart, leaving 297 cases that met inclusion criteria. Of these, 176 (59.3%) were transported and 2 (0.7%) survived to discharge. Using absolute 30 min-ETCO2 cutoffs, both survivors were in the >10 mmHg group (sensitivity 100.0%, specificity 12.5%), whereas only one survivor was identified in the >20 mmHg group (sensitivity 50.0%, specificity 32.5%). Using delta-ETCO2, both survivors were in the increasing ETCO2 group (sensitivity 100.0%, specificity 60.7%). In comparing the two tests that did not misclassify survivors, the AUROC [95% CI] was higher when using delta-ETCO2 (0.803 [0.775–0.831]) compared to an absolute cutoff of 10 mmHg (0.563 [0.544–0.582]). ConclusionsNearly one-sixth of EMS-treated adult OHCA patients had refractory non-shockable arrests after at least 30 min of ongoing resuscitation. In this group, the ETCO2 trend following advanced airway placement may be more accurate in guiding termination of resuscitation than an absolute ETCO2 cutoff of 10 or 20 mmHg.

Outcomes with Tibial and Humeral Intraosseous Access Compared to Peripheral Intravenous Access in Out-of-Hospital Cardiac Arrest

Background The optimal initial vascular access strategy for out-of-hospital cardiac arrest (OHCA) remains unknown. Our objective was to evaluate the association between peripheral intravenous (PIV), tibial intraosseous (TIO), or humeral intraosseous (HIO) as first vascular attempt strategies and outcomes for patients suffering OHCA. Method This was a secondary analysis of the Portland Cardiac Arrest Epidemiologic Registry, which included adult patients (≥18 years-old) with EMS-treated, non-traumatic OHCA from 2018–2021. The primary independent variable in our analysis was the initial vascular access strategy, defined as PIV, TIO, or HIO based on the first access attempt. The primary outcome for this study was the return of spontaneous circulation (ROSC) at emergency department (ED) arrival (a palpable pulse on arrival to the hospital). Secondary outcomes included survival to: admission, discharge, and discharge with a favorable outcome (Cerebral Perfusion Category score of ≤2). We conducted multivariable logistic regressions, adjusting for confounding variables and for clustering using a mixed-effects approach, with prespecified subgroup analyses by initial rhythm. Results We included 2,993 patients with initial vascular access strategies of PIV (822 [27.5%]), TIO (1,171 [39.1%]), and HIO (1,000 [33.4%]). Multivariable analysis showed lower odds of ROSC at ED arrival (adjusted odds ratio [95% CI]) with TIO (0.79 [0.64–0.98]) or HIO (0.75 [0.60–0.93]) compared to a PIV-first strategy. These associations remained in stratified analyses for those with shockable initial rhythms (0.60 [0.41–0.88] and 0.53 [0.36–0.79]) but not in patients with asystole or pulseless electrical activity for TIO and HIO compared to PIV, respectively. There were no statistically significant differences in adjusted odds for survival to admission, discharge, or discharge with a favorable outcome for TIO or HIO compared to the PIV-first group in the overall analysis. Patients with shockable initial rhythms had lower adjusted odds of survival to discharge (0.63 [0.41–0.96] and 0.64 [0.41–0.99]) and to discharge with a favorable outcome (0.60 [0.39–0.93] and 0.64 [0.40–1.00]) for TIO and HIO compared to PIV, respectively. Conclusions TIO or HIO as first access strategies in OHCA were associated with lower odds of ROSC at ED arrival compared to PIV.

Updated trends in the outcomes of out-of-hospital cardiac arrest from 2017-2021: Prior to and during the coronavirus disease (COVID-19) pandemic.

This study aims to describe out-of-hospital cardiac arrest (OHCA) characteristics and trends before and during the coronavirus disease-2019 (COVID-19) pandemic in Taiwan. We conducted a retrospective cohort study using a 5-year interrupted time series analysis. Eligible adults with non-traumatic OHCAs from January 2017 to December 2021 in 3 hospitals (university medical center, urban second-tier hospital, and rural second-tier hospital) were retrospectively enrolled. Variables were extracted from the emergency medical service reports and medical records. The years 2020 and 2021 were defined as the COVID-19 pandemic period. Outcomes included survival to admission after a sustained return of spontaneous circulation, survival to hospital discharge, and good neurological outcomes (cerebral performance category score 1 or 2). We analyzed 2819 OHCA, including 1227 from a university medical center, 617 from an urban second-tier hospital, and 975 from a rural second-tier hospital. The mean age was 71 years old, and 60% of patients were males. During the COVID-19 pandemic period, video-assisted endotracheal tube intubation replaced the traditional direct laryngoscopy intubation. The trends of outcomes in the pre-pandemic and pandemic periods varied among different hospitals. Compared with the pre-pandemic period, the outcomes at the university medical center during the COVID-19 pandemic were significantly poorer in several respects. The survival rate on admission dropped from 44.6% to 39.4% (P=0.037), and the survival rate to hospital discharge fell from 17.5% to 14.9% (P=0.042). Additionally, there was a notable decrease in patients' good neurological outcomes, declining from 13.2% to 9.7% (P=0.048). In contrast, the outcomes in urban and rural second-tier hospitals during the COVID-19 pandemic did not significantly differ from those in the pre-pandemic period. COVID-19 may alter some resuscitation management in OHCAs. There were no overall significant differences in outcomes before and during COVID-19 pandemic, but there were significant differences in outcomes when stratified by hospital types.

Association of admission serum sodium and outcomes following out-of-hospital cardiac arrest

The prognostic association between dysnatremia and outcomes in out-of-hospital cardiac arrest (OHCA) is not well understood. Given hypernatremia is associated with poor outcomes in critical illness and hyponatremia may exacerbate cerebral edema, we hypothesized that dysnatremia on OHCA hospital admission would be associated with worse neurological outcomes. We studied adults (≥19 years) with non-traumatic OHCA between 2009 and 2016 who were enrolled in the British Columbia Cardiac Arrest Registry and survived to hospital admission at 2 quaternary urban hospitals. We stratified cases by admission serum sodium into hyponatremic (<135 mmol/L), normonatremic (135-145 mmol/L), and hypernatremic (>145 mmol/L) groups. We used logistic regression models, adjusted for age, sex, shockable rhythm, admission serum lactate, and witnessed arrest, to estimate the association between admission sodium and favorable neurological outcome (cerebral performance category 1-2 or modified Rankin scale 0-3). Of 414 included patients, 63 were hyponatremic, 330 normonatremic, and 21 hypernatremic. In each respective group, 21 (33.3%), 159 (48.2%), and 3 (14.3%) experienced good neurological outcomes. In univariable models, hyponatremia (OR 0.53, 95% CI 0.30-0.93) and hypernatremia (OR 0.19, 95% CI 0.05-0.65) were associated with lower odds of good neurological outcomes compared to the normonatremia group. After adjustment, only hypernatremia was associated with lower odds of good neurological outcomes (OR 0.22, 95% CI 0.05-0.98). Hypernatremia at admission was independently associated with decreased probability of good neurological outcomes at discharge post-OHCA. Future studies should focus on elucidating the pathophysiology of dysnatremia following OHCA.

Feasibility of resuscitative transesophageal echocardiography at out-of-hospital emergency scenes of cardiac arrest

Guidelines recommend the use of ultrasound in cardiac arrest. Transthoracic echocardiography, has issues with image quality and by increasing hands-off times during resuscitation. We assessed the feasibility of transesophageal echocardiography (TEE), which does not have both problems, at out-of-hospital cardiac arrest (OHCA) emergency scenes. Included were 10 adults with non-traumatic OHCA in Vienna, Austria. An expert in emergency ultrasound was dispatched to the scenes in addition to the resuscitation team. Feasibility was defined as the ability to collect specific items of information by TEE within 10 min. Descriptive statistics were compiled and hands-off times were compared to a historical control group. TEE examinations were feasible in 9 of 10 cases and prompted changes in clinical management in 2 cases (cardiac tamponade: n = 1; right ventricular dilatation: n = 1). Their mean time requirement was 5.1 ± 1.7 (2.8–8.0) min, and image quality was invariably rated as excellent or good during both compressions and pauses. No TEE-related complications, or interferences with activities of advanced life support were observed. The hands-off times during resuscitation were comparable to a historical control group not involving ultrasound (P = 0.24). Given these feasibility results, we expect that TEE can be used routinely at OHCA emergency scenes.