Prehospital Return Of Spontaneous Circulation Research Articles

Advanced airway management in the prehospital setting during traumatic out-of-hospital cardiac arrest following traffic collision in Japan, 2013-2019

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Okinaka Memorial Institute for Medical Research; Toranomon Hospital. Background The European guideline on management of major bleeding and coagulopathy following trauma (sixth edition) recommend that endotracheal intubation or alternative airway management be performed without delay to facilitate adequate ventilation and oxygenation during trauma resuscitation. However, controversy remains as to whether advanced airway management should be provided for out-of-hospital cardiac arrest (OHCA) in the prehospital setting. Purpose This study aimed to examine the association of prehospital advanced airway management with outcomes after traumatic OHCA. Methods This observational study analyzed the Japanese government-led nationwide population-based registry data of OHCA patients. Patients with traumatic OHCA following traffic collision who received advanced life support in the prehospital setting from 2013 to 2019 were included. Propensity score matching was used to examine the association of advanced airway management with outcomes after traumatic OHCA following traffic collision. The primary outcome was one-month survival. Results A total of 5,617 patients (mean [SD] age, 60.1 [21.6] years; 68.6% male) were included. 3,822 (68.0%) received advanced airway management, and 1,795 (32.0%) did not. After adjusting for potential confounders using propensity score matching, advanced airway management was associated with decreased chance of one-month survival (23/1452 [1.6%] vs 43/1452 [3.0%]; RR, 0.53; 95%CI, 0.32-0.88; P=0.0128). Similar association was observed for prehospital return of spontaneous circulation (88/1452 [6.1%] vs 139/1452 [9.6%]; RR, 0.63; 95%CI, 0.49-0.82; P=0.0004). Conclusion Among patients with traumatic OHCA following traffic collision, advanced airway management was associated with decreased chance of one-month survival and prehospital return of spontaneous circulation.

Survival After Out-of-Hospital Cardiac Arrest Before and After Legislation for Bystander CPR

The lack of evidence-based implementation strategies is a major contributor to increasing mortality due to out-of-hospital cardiac arrest (OHCA) in developing countries with limited resources. To evaluate whether the implementation of legislation is associated with increased bystander cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) use and improved clinical outcomes for patients experiencing OHCA and to provide policy implications for low-income and middle-income settings. This observational cohort study analyzed a prospective city registry of patients with bystander-witnessed OHCA between January 1, 2010, and December 31, 2022. The Emergency Medical Aid Act was implemented in Shenzhen, China, on October 1, 2018. An interrupted time-series analysis was used to assess changes in outcomes before and after the law. Data analysis was performed from May to October 2023. The Emergency Medical Aid Act stipulated the use of AEDs and CPR training for the public and provided clear legal guidance for OHCA rescuing. The primary outcomes were rates of bystander-initiated CPR and use of AEDs. Secondary outcomes were rates of prehospital return of spontaneous circulation (ROSC), survival to arrival at the hospital, and survival at discharge. A total of 13 751 patients with OHCA (median [IQR] age, 59 [43-76] years; 10 011 men [72.83%]) were included, with 7858 OHCAs occurring during the prelegislation period (January 1, 2010, to September 30, 2018) and 5893 OHCAs occurring during the postlegislation period (October 1, 2018, to December 31, 2022). The rates of bystander-initiated CPR (320 patients [4.10%] vs 1103 patients [18.73%]) and AED use (214 patients [4.12%] vs 182 patients [5.29%]) increased significantly after legislation implementation vs rates before the legislation. Rates of prehospital ROSC (72 patients [0.92%] vs 425 patients [7.21%]), survival to arrival at the hospital (68 patients [0.87%] vs 321 patients [5.45%]), and survival at discharge (44 patients [0.56%] vs 165 patients [2.80%]) were significantly increased during the postlegislation period. Interrupted time-series models demonstrated a significant slope change in the rates of all outcomes. These findings suggest that implementation of the Emergency Medical Aid Act in China was associated with increased rates of CPR and public AED use and improved survival of patients with OHCA. The use of a systemwide approach to enact resuscitation initiatives and provide legal support may reduce the burden of OHCA in low-income and middle-income settings.

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.

Development and validation of a prehospital termination of resuscitation (TOR) rule for out - of hospital cardiac arrest (OHCA) cases using general purpose artificial intelligence (AI)

BackgroundPrehospital identification of futile resuscitation efforts (defined as a predicted probability of survival lower than 1%) for out-of-hospital cardiac arrest (OHCA) may reduce unnecessary transport. Reliable prediction variables for OHCA 'termination of resuscitation' (TOR) rules are needed to guide treatment decisions. The Universal TOR rule uses only three variables (Absence of Prehospital ROSC, Event not witnessed by EMS and no shock delivered on the scene) has been externally validated and is used by many EMS systems. Deep learning, an artificial intelligence (AI) platform is an attractive model to guide the development of TOR rule for OHCA. The purpose of this study was to assess the feasibility of developing an AI-TOR rule for neurologically favorable outcomes using general purpose AI and compare its performance to the Universal TOR rule. Methods: We identified OHCA cases of presumed cardiac etiology who were 18 years of age or older from 2016 to 2019 in the All-Japan Utstein Registry. We divided the dataset into 2 parts, the first half (2016–2017) was used as a training dataset for rule development and second half (2018–2019) for validation. The AI software (Prediction One®) created the model using the training dataset with internal cross-validation. It also evaluated the prediction accuracy and displayed the ranking of influencing variables. We performed validation using the second half cases and calculated the prediction model AUC. The top four of the 11 variables identified in the model were then selected as prognostic factors to be used in an AI-TOR rule, and sensitivity, specificity, positive predictive value, and negative predictive value were calculated from validation cohort. This was then compared to the performance of the Universal TOR rule using same dataset. ResultsThere were 504,561 OHCA cases, 18 years of age or older, 302,799 cases were presumed cardiac origin. Of these, 149,425 cases were used for the training dataset and 153,374 cases for the validation dataset. The model developed by AI using 11 variables had an AUC of 0.969, and its AUC for the validation dataset was 0.965. The top four influencing variables for neurologically favorable outcome were Prehospital ROSC, witnessed by EMS, Age (68 years old and younger) and nonasystole. The AUC calculated using the 4 variables for the AI-TOR rule was 0.953, and its AUC for the validation dataset was 0.952 (95%CI 0.949 –0.954). Of 80,198 patients in the validation cohort that satisfied all four criteria for the AI-TOR rule, 58 (0.07%) had a neurologically favorable one-month survival. The specificity of AI-TOR rule was 0.990, and the PPV was 0.999 for predicting lack of neurologically favorable survival, both the specificity and PPV were higher than that achieved with the universal TOR (0.959, 0.998). ConclusionsThe accuracy of prediction models using AI software to determine outcomes in OHCA was excellent and the AI-TOR rule’s variables from prediction model performed better than the Universal TOR rule. External validation of our findings as well as further research into the utility of using AI platforms for TOR prediction in clinical practice is needed.

Health-related quality of life and cognitive function after out-of-hospital cardiac arrest; a comparison of prehospital return-of-spontaneous circulation and refractory arrest managed with extracorporeal cardiopulmonary resuscitation

BackgroundExtracorporeal cardiopulmonary resuscitation (ECPR) for selected refractory out-of-hospital cardiac arrest (OHCA) is increasingly used. Detailed knowledge of health-related quality of life (HRQoL) and long-term cognitive function is limited. HRQoL and cognitive function were assessed in ECPR-survivors and OHCA-survivors with prehospital return of spontaneous circulation after standard advanced cardiac life support (sACLS). MethodsFifteen ECPR-survivors and 22 age-matched sACLS-survivors agreed to participate in this follow-up study. Participants were examined with echocardiography, 6-minute walk test, and neuropsychological testing, and answered HRQoL (EQ-5D-5L and Short Form 36 (SF-36)), and mental health questionnaires. ResultsMost patients were male (73 % and 82 %) and median age at follow-up was similar between groups (55 years and 60 years). Low flow time was significantly longer for ECPR-survivors (86 min vs. 15 min) and lactate levels were significantly higher (14.1 mmol/l vs. 3.9 mmol/l). No between-group difference was found in physical function nor in cognitive function with scores corresponding to the 23rd worst percentile of the general population. SACLS-survivors had HRQoL on level with the Danish general population while ECPR-survivors scored lower in both EQ-5D-5L (index score 0.73 vs. 0.86, p = 0.03, visual analog scale: 70 vs. 84, p = 0.04) and in multiple SF-36 health domains (role physical, bodily pain, general health, and mental health). ConclusionsDespite substantially longer low flow times with thrice as high lactate levels, ECPR-survivors were similar in cognitive and physical function compared to sACLS-survivors. Nonetheless, ECPR-survivors reported lower HRQoL overall and related to mental health, pain management, and the perception of limitations in physical role.

Sequence of Epinephrine and Advanced Airway Placement After Out-of-Hospital Cardiac Arrest

While epinephrine and advanced airway management (AAM) (supraglottic airway insertion and endotracheal intubation) are commonly used for out-of-hospital cardiac arrest (OHCA), the optimal sequence of these interventions remains unclear. To evaluate the association of the sequence of epinephrine administration and AAM with patient outcomes after OHCA. This cohort study analyzed the nationwide, population-based OHCA registry in Japan and included adults (aged ≥18 years) with OHCA for whom emergency medical services personnel administered epinephrine and/or placed an advanced airway between January 1, 2014, and December 31, 2019. The data analysis was performed between October 1, 2022, and May 12, 2023. The sequence of intravenous epinephrine administration and AAM. The primary outcome was 1-month survival. Secondary outcomes were 1-month survival with favorable functional status and prehospital return of spontaneous circulation. To control imbalances in measured patient demographics, cardiac arrest characteristics, and bystander and prehospital interventions, propensity scores and inverse probability of treatment weighting (IPTW) were performed for shockable and nonshockable initial rhythm subcohorts. Of 259 237 eligible patients (median [IQR] age, 79 [69-86] years), 152 289 (58.7%) were male. A total of 21 592 patients (8.3%) had an initial shockable rhythm, and 237 645 (91.7%) had an initial nonshockable rhythm. Using IPTW, all covariates between the epinephrine-first and AAM-first groups were well balanced, with all standardized mean differences less than 0.100. After IPTW, the epinephrine-first group had a higher likelihood of 1-month survival for both shockable (odds ratio [OR], 1.19; 95% CI, 1.09-1.30) and nonshockable (OR, 1.28; 95% CI, 1.19-1.37) rhythms compared with the AAM-first group. For the secondary outcomes, the epinephrine-first group experienced an increased likelihood of favorable functional status and prehospital return of spontaneous circulation for both shockable and nonshockable rhythms compared with the AAM-first group. These findings suggest that for patients with OHCA, administration of epinephrine before placement of an advanced airway may be the optimal treatment sequence for improved patient outcomes.

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.

Enhancing global pediatric cardiac arrest outcomes through bystander cardiopulmonary resuscitation: A comprehensive systematic review

This systematic review investigates the impact of global bystander cardiopulmonary resuscitation (CPR) on outcomes in pediatric cardiac arrest cases. Through a meticulous examination of relevant worldwide studies retrieved from PubMed spanning 2018 to 2022, employing keywords such as “worldwide Bystander CPR (BCPR),” “worldwide out-of-hospital CPR,” and “pediatric CPR” with Boolean operators “OR” and “AND,” the study incorporates 10 selected articles out of the initially identified 13. Findings reveal that bystander-initiated CPR, predominantly chest-only CPR, is administered at rates ranging from 48% to 89% globally, with no significant gender-based disparity, but a lower likelihood observed among worldwide Black children. Return of spontaneous circulation (ROSC) is achieved in 20%–35% of cases and survival to hospital discharge in 5%–10% of instances. Factors associated with worldwide prehospital ROSC include epinephrine administration, bystander intervention before emergency medical services (EMS) arrival, older age, reduced time to EMS response, and worldwide automated external defibrillators. Notably, a shorter time to EMS arrival is the sole significant predictor of worldwide survival to hospital discharge. The study discerns no substantial distinction in achieving prehospital ROSC and favorable outcomes on a global scale. The conclusion underscores the varied worldwide outcomes in out-of-hospital cardiac arrest studies, attributing these variations to multifarious confounding factors. It identifies crucial predictors of prehospital ROSC and recommends targeted CPR training for underserved communities to enhance worldwide BCPR rates and ameliorate pediatric cardiac arrest outcomes.

Prehospital interventions and outcomes in traumatic cardiac arrest: a population-based cohort study using the Danish Helicopter Emergency Medical Services data

Background and importance Traumatic cardiac arrest is associated with poor prognosis, and timely evidence-based treatment is paramount for increasing survival rates. Physician-staffed helicopter emergency medical service use in major trauma has demonstrated improved outcomes. However, the sparsity of data highlights the necessity for a comprehensive understanding of the epidemiology of traumatic cardiac arrest. Objectives The primary objective of the present study was to evaluate survival and return of spontaneous circulation (ROSC) and to investigate the characteristics of patients with traumatic cardiac arrest assessed by the Danish HEMS. Design This was a population-based cohort study based on data from the Danish helicopter emergency medical service database. Settings and participants The study included all patients assessed by the Danish helicopter emergency medical services between 2016 and 2021. Outcome measures and analysis Data were analysed using descriptive statistics, non-parametric testing and logistic regression analyses. Descriptive analysis of prehospital interventions included cardiopulmonary resuscitation, defibrillation, airway management, administration of blood products, and thoracic decompression. The primary outcome was 30-day survival, and the key secondary outcome was prehospital ROSC. Main results A total of 223 patients with TCA were included. The median age was 54 years (IQR 34–68), and the majority were males. Overall, 23% of patients achieved prehospital ROSC, and the 30-day survival rate was 4%. Factors associated with an increased likelihood of ROSC were an initial shockable cardiac rhythm, odds ratio (OR) of 3.78 (95% CI 1.33–11.00) and endotracheal intubation, OR 7.10 (95% CI 2.55–22.85). Conclusion This study highlights the low survival rates observed among patients with traumatic cardiac arrest assessed by helicopter emergency medical services. The findings support the positive impact of an initial shockable cardiac rhythm and endotracheal intubation in improving the likelihood of ROSC. The study contributes to the limited literature on traumatic cardiac arrests assessed by physician-staffed helicopter emergency services. Finally, the findings emphasise the need for further research to understand and improve outcomes in this subgroup of cardiac arrest.

Comparing outcomes of out-of-hospital cardiac arrest patients with initial shockable rhythm in Singapore and Osaka using population-based databases

BackgroundPrevious research indicated outcomes among refractory out-of-hospital cardiac arrest (OHCA) patients with initial shockable rhythm were different in Singapore and Osaka, Japan, possibly due to the differences in access to extracorporeal cardiopulmonary resuscitation. However, this previous study had a risk of selection bias. To address this concern, this study aimed to evaluate the outcomes between Singapore and Osaka for OHCA patients with initial shockable rhythm using only population-based databases.MethodsThis was a secondary analysis of two OHCA population-based databases in Osaka and Singapore, including adult OHCA patients with initial shockable rhythm. A machine-learning-based prediction model was derived from the Osaka data (n = 3088) and applied to the PAROS-SG data (n = 2905). We calculated the observed-expected ratio (OE ratio) for good neurological outcomes observed in Singapore and the expected derived from the data in Osaka by dividing subgroups with or without prehospital ROSC.ResultsThe one-month good neurological outcomes in Osaka and Singapore among patients with prehospital ROSC were 70% (791/1,125) and 57% (440/773), and among patients without prehospital ROSC were 10% (196/1963) and 2.8% (60/2,132). After adjusting patient characteristics, the outcome in Singapore was slightly better than expected from Osaka in patients with ROSC (OE ratio, 1.067 [95%CI 1.012 to 1.125]), conversely, it was worse than expected in patients without prehospital ROSC (OE ratio, 0.238 [95%CI 0.173 to 0.294]).ConclusionThis study showed the outcomes of OHCA patients without prehospital ROSC in Singapore were worse than expected derived from Osaka data even using population-based databases.(249/250 words).

Epidemiology and outcomes of out of hospital cardiac arrest in Saudi Arabia: Findings from the Saudi Out of Hospital cardiac Arrest Registry (SOHAR)

AimThe Saudi Out-of-Hospital Cardiac Arrest Registry (SOHAR) is the first out-of-hospital cardiac arrest (OHCA) registry in Saudi Arabia. This study aimed to describe the epidemiology and outcomes of OHCA in Saudi Arabia. MethodsThe SOHAR is a prospective data collection system. Data were collected monthly from defined regions, and registry measured variables were adopted from the Utstein recommendations. ResultsDuring the period from 01/01/2019 to 31/12/2022, 3671 patients were included in the registry. The mean age was 62 years, and 6.5% (240) of patients were under the age of 18 years. The most common cause of OHCA was medical 3439 (93.6%). A total of 641 (17.4%) and 129 (3.9%) had presumed cardiac and respiratory causes. Additionally, most OHCA in Saudi Arabia (3034, 82.6%) occurred at home. Prehospital Return Of Spontaneous Circulation (ROSC) was achieved in 275 (7.4%) cases, and 491 (13.3%) patients were pronounced dead upon arrival at the hospital. Survival to hospital discharge was achieved in 107 (2.9%) of the cases, and good neurological outcomes, defined as a Cerebral Performance Category (CPC) of 1–3, occurred in < 0.5% of patients. ConclusionThe Saudi out-of-hospital ROSC was 7.4%. The survival to hospital discharge rate was 2.9%, and less than 1% of patients were discharged with good neurological outcomes. Further research and the continuation of registry data collection is highly recommended. Additionally, a national-level out-of-hospital cardiac arrest system is recommended to ensure the standardization of medical care provided to patients with OHCA.

Association of intraosseous and intravenous access with patient outcome in out-of-hospital cardiac arrest

Here we report the results of a study on the association between drug delivery via intravenous route or intraosseous route in out-of-hospital cardiac arrest. Intraosseous drug delivery is considered an alternative option in resuscitation if intravenous access is difficult or impossible. Intraosseous uptake of drugs may, however, be compromised. We have performed a retrospective cohort study of all Danish patients with out-of-hospital cardiac arrest in the years 2016–2020 to investigate whether mortality is associated with the route of drug delivery. Outcome was 30-day mortality, death at the scene, no prehospital return of spontaneous circulation, and 7- and 90-days mortality. 17,250 patients had out-of-hospital cardiac arrest. 6243 patients received no treatment and were excluded. 1908 patients had sustained return of spontaneous circulation before access to the vascular bed was obtained. 2061 patients were unidentified, and 286 cases were erroneously registered. Thus, this report consist of results from 6752 patients. Drug delivery by intraosseous route is associated with increased OR of: No spontaneous circulation at any time (OR 1.51), Death at 7 days (OR 1.94), 30 days (2.02), and 90 days (OR 2.29). Intraosseous drug delivery in out-of-hospital cardiac arrest is associated with overall poorer outcomes than intravenous drug delivery.

Termination-of-resuscitation rule in the emergency department for patients with initial pulseless electrical activity after out-of-hospital cardiac arrest

Abstract Background/Introduction In several Asian countries including Japan, emergency medical service (EMS) providers are prohibited from performing field termination-of-resuscitation (TOR) in patients with refractory out-of-hospital cardiac arrest (OHCA). In 2022, we developed a TOR rule in the emergency department for patients with initial asystole after refractory OHCA, which includes three criteria: unwitnessed arrest, EMS-initiated cardiopulmonary resuscitation (CPR) duration was more than 20 min, and there was no prehospital return of spontaneous circulation (ROSC). However, until now a TOR rule in the emergency department for patients with initial pulseless electrical activity (PEA) has not been developed. Purpose This study aimed to develop and validate a TOR rule in the emergency department for patients with initial PEA after refractory OHCA. Methods We analysed the records of 137,230 adult patients (≥18 years-old) with initial PEA from the nationwide all-Japan Utstein registry from 2016 to 2020. Patients were divided into two groups: development (n=109,642, 2016 to 2019) and validation (n=27,588, 2020). The primary outcome measures were specificity, false positive rate (FPR), and positive predictive value (PPV) of the TOR rule for patients with initial PEA in the emergency department for predicting 1-month mortality. Using recursive partitioning analysis, we developed a new TOR rule for patients with initial PEA after OHCA. Results The overall 1-month survival rate of the participants was 7.4% (95% confidence interval [CI], 7.2–7.5%). Recursive partitioning analysis for the development group in predicting 1-month mortality revealed that a TOR rule for patients with PEA could be defined if patients with OHCA met all the following four criteria immediately after hospital arrival: (1) unwitnessed arrest by any laypersons, (2) EMS-initiated CPR duration more than 20 min, (3) no prehospital ROSC, and (4) age greater than or equal to 80 years. The specificity, FPR, and PPV of the rule for predicting 1-month mortality were 99.1% (95% CI, 98.9–99.3%), 0.87% (95% CI, 0.69–1.09%), and 99.2% (95% CI, 98.9–99.3%), respectively. The proportion of patients who fulfilled the rule and the area under the receiver operating curve (AUC) was 7.8% (95% CI, 7.7–8.0%), and 0.80 (95% CI, 0.79–0.80), respectively. In the validation group, the specificity, FPR, PPV, proportion of patients who met the rule, and AUC were 99.1% (95% CI, 98.5–99.4%), 0.93% (95% CI, 0.58–1.49%), 99.3% (95% CI, 98.8–99.5%), 8.3% (95% CI, 8.0–8.6%), and 0.789 (95% CI, 0.775–0.797), respectively. Conclusions We developed and validated a TOR rule in the emergency department for patients with initial PEA after OHCA. The rule includes four criteria (unwitnessed arrest, EMS-initiated CPR duration was more than 20 min, no prehospital ROSC, and age was greater than or equal to 80 years) with a more than 99% predictor of 1-month mortality.

Association between body mass index and clinical outcomes in patients with out-of-hospital cardiac arrest undergoing extracorporeal cardiopulmonary resuscitation: A multicenter observational study

BackgroundWe examined the association between body mass index (BMI) and outcomes in patients with out-of-hospital cardiac arrest (OHCA) undergoing extracorporeal cardiopulmonary resuscitation (ECPR). MethodsWe retrospectively analyzed the database of an observational multicenter cohort in Japan. Adult patients with OHCA of cardiac etiology who received ECPR between 2013 and 2018 were categorized as follows: underweight, BMI < 18.5; normal weight, BMI = 18.5–24.9; overweight, BMI = 25–29.9; and obese, BMI ≥ 30 kg/m2. The primary outcome was in-hospital mortality; secondary outcomes were unfavorable neurological outcomes at discharge (cerebral performance category ≥ 3) and ECPR-related complications. BMI’s association with outcomes was assessed using a logistic regression model adjusted for age, sex, comorbidities, witness/bystander CPR, initial rhythm, prehospital return of spontaneous circulation, and low-flow time. ResultsIn total, 1,044 patients were analyzed. Their median age was 61 (IQR, 49–69) years; the median BMI was 24.2 (21.5–26.9) kg/m2. The overall rates of in-hospital mortality, unfavorable neurological outcome, and ECPR-related complications were 62.2%, 79.9%, and 31.7%, respectively. In multivariate analysis, the overweight and obese groups had higher in-hospital mortality odds than the normal BMI group (odds ratio [95%CI], 1.37 [1.02–1.85], p = 0.035; and 2.09 [1.31–3.39], p < 0.001, respectively). The odds ratio for unfavorable neurological outcomes increased more in the obese than in the normal BMI group (3.17 [1.69–6.49], p < 0.001). ECPR-related complications were not significantly different among groups. ConclusionsIn OHCA patients undergoing ECPR, a BMI ≥ 25 kg/m2 was associated with increased in-hospital mortality, and a BMI ≥ 30 kg/m2 was also associated with a worse neurological outcome.

Abstract 391: Association Between Defibrillation to Epinephrine Interval and Short-Term Outcomes in Out-of-Hospital Cardiac Arrest Patients With Shockable Rhythm

Background: The optimal timing of epinephrine administration after defibrillation in out-of-hospital cardiac arrest (OHCA) patients with shockable rhythm is unknown. Aim: We evaluated the association between defibrillation to epinephrine interval and short-term outcomes. Methods: Between 2011 and 2020, we enrolled 1,259,960 OHCA patients from a nationwide prospective population-based registry in Japan. After applying exclusion criteria, 20,905 patients with shockable rhythm as the first documented rhythm at emergency medical services (EMS) arrival who received epinephrine after defibrillation were eligible for the study. Clinical outcomes included prehospital return of spontaneous circulation (ROSC), survival, and favorable neurological outcome at 30 days. To examine whether each variable predicted a good short-term outcome, multivariable logistic regression models were constructed using age, gender, year, district, origin of cardiac arrest, witnessed arrest, bystander-initiated cardiopulmonary resuscitation, call to EMS arrival interval, EMS arrival to defibrillation interval, and defibrillation to epinephrine interval. Results: At 30 days, 1,618 patients (8%) had a favorable neurological outcome. The defibrillation to epinephrine interval in these patients was significantly shorter than the interval in patients with an unfavorable neurological outcome [8 (5-12) vs 11 (7-16) min; P&lt;0.001]. The proportion of patients who achieved prehospital ROSC, survived, or had a favorable neurological outcome at 30 days decreased as time to epinephrine after defibrillation increased (P&lt;0.001 for trend). Multivariable analysis showed that shorter defibrillation to epinephrine interval independently predicted good outcomes ( Table ). Conclusion: A shorter defibrillation to epinephrine interval is significantly associated with good short-term outcomes in OHCA patients with shockable rhythm.

Abstract 128: Gender Differences in Out-of-Hospital Cardiac Arrest Incidence, Characteristics, and Prehospital Outcome in Qatar

Introduction: Research on gender differences in OHCA incidence, characteristics, and outcomes is lacking in the Middle East. We evaluated gender differences in adult non-traumatic OHCA by incidence, characteristics, and achieving prehospital ROSC in Qatar. Methods: We analyzed data obtained from Hamad Medical Corporation on adult, non-traumatic, EMS-attended OHCA in Qatar (2017-2022). We calculated the annual incidence of OHCA and ran descriptive statistics for OHCA characteristics for the full cohort and by gender. This was followed by multivariable logistic regression to examine association between gender and ROSC, adjusting for variables known to be associated with ROSC. Results: We included 4306 OHCA patients, 79.8% were males. The annual incidence of OHCA was 27.4 per 100,000 population. The annual incidence was higher in males than females (30.1 per 100,000 population vs. 20.4 per 100,000 population). Males had higher proportions of OHCA cases in public locations, receiving bystander CPR, and having an initial shockable rhythm. No significant difference was detected in crude ROSC. The adjusted analysis, however, demonstrated that male gender was associated with greater odds of ROSC (OR 1.38, 95% CI 1.15 - 1.66). This advantage of ROSC in males was observed in the full cohort and in subgroups with shockable and unshockable rhythms. Conclusion: Approximately 717 adult patients suffer non-traumatic OHCA in Qatar annually, with a higher occurrence in males. OHCA characteristics were disadvantageous for females. Male gender was associated with greater odds of achieving ROSC, highlighting the need for additional gender-specific research in pre-OHCA care in Qatar.

43 Night-shift attendance may decrease prehospital return of spontaneous circulation in out-of-hospital cardiac arrest

43 Night-shift attendance may decrease prehospital return of spontaneous circulation in out-of-hospital cardiac arrest

Establishment of a prediction model for prehospital return of spontaneous circulation in out-of-hospital patients with cardiac arrest.

Out-of-hospital cardiac arrest (OHCA) is a leading cause of death worldwide. To explore factors influencing prehospital return of spontaneous circulation (P-ROSC) in patients with OHCA and develop a nomogram prediction model. Clinical data of patients with OHCA in Shenzhen, China, from January 2012 to December 2019 were retrospectively analyzed. Least absolute shrinkage and selection operator (LASSO) regression and multivariate logistic regression were applied to select the optimal factors predicting P-ROSC in patients with OHCA. A nomogram prediction model was established based on these influencing factors. Discrimination and calibration were assessed using receiver operating characteristic (ROC) and calibration curves. Decision curve analysis (DCA) was used to evaluate the model's clinical utility. Among the included 2685 patients with OHCA, the P-ROSC incidence was 5.8%. LASSO and multivariate logistic regression analyses showed that age, bystander cardiopulmonary resuscitation (CPR), initial rhythm, CPR duration, ventilation mode, and pathogenesis were independent factors influencing P-ROSC in these patients. The area under the ROC was 0.963. The calibration plot demonstrated that the predicted P-ROSC model was concordant with the actual P-ROSC. The good clinical usability of the prediction model was confirmed using DCA. The nomogram prediction model could effectively predict the probability of P-ROSC in patients with OHCA.

Prehospital predicting factors using a decision tree model for patients with witnessed out-of-hospital cardiac arrest and an initial shockable rhythm

The effect of prehospital factors on favorable neurological outcomes remains unclear in patients with witnessed out-of-hospital cardiac arrest (OHCA) and a shockable rhythm. We developed a decision tree model for these patients by using prehospital factors. Using a nationwide OHCA registry database between 2005 and 2020, we retrospectively analyzed a cohort of 1,930,273 patients, of whom 86,495 with witnessed OHCA and an initial shockable rhythm were included. The primary endpoint was defined as favorable neurological survival (cerebral performance category score of 1 or 2 at 1 month). A decision tree model was developed from randomly selected 77,845 patients (development cohort) and validated in 8650 patients (validation cohort). In the development cohort, the presence of prehospital return of spontaneous circulation was the best predictor of favorable neurological survival, followed by the absence of adrenaline administration and age. The patients were categorized into 9 groups with probabilities of favorable neurological survival ranging from 5.7 to 70.8% (areas under the receiver operating characteristic curve of 0.851 and 0.844 in the development and validation cohorts, respectively). Our model is potentially helpful in stratifying the probability of favorable neurological survival in patients with witnessed OHCA and an initial shockable rhythm.

Prehospital Advanced Airway Management and Ventilation for Out-of-Hospital Cardiac Arrest with Prehospital Return of Spontaneous Circulation: A Prospective Observational Cohort Study in Japan

Background The relationship among advanced airway management (AAM), ventilation, and oxygenation in patients with out-of-hospital cardiac arrest (OHCA) who achieve prehospital return of spontaneous circulation (ROSC) has not been validated. This study was designed to evaluate ventilation and oxygenation for each AAM technique (supraglottic devices [SGA] or endotracheal intubation [ETI]) using arterial blood gas (ABG) results immediately after hospital arrival. Methods This observational cohort study, using data from the Japanese Association for Acute Medicine OHCA Registry, included patients with OHCA with prehospital and hospital arrival ROSC between July 1, 2014, and December 31, 2019. The primary outcomes were the partial pressure of carbon dioxide in the arterial blood (PaCO2) and partial pressure of oxygen in the arterial blood (PaO2) in the initial ABG at the hospital for each AAM technique (SGA or ETI) performed by paramedics. The secondary outcome was favorable neurological outcome (cerebral performance category [CPC] 1 or 2) for specific PaCO2 levels, which were defined as good ventilation (PaCO2 ≤45 mmHg) and insufficient ventilation (PaCO2 >45 mmHg). Results This study included 1,527 patients. Regarding AAM, 1,114 and 413 patients were ventilated using SGA and ETI, respectively. The median PaCO2 and PaO2 levels were 74.50 mmHg and 151.35 mmHg in the SGA group, while 66.30 mmHg and 173.50 mmHg in the ETI group. PaCO2 was significantly lower in the ETI group than in the SGA group (12.55 mmHg; 95% CI 15.27 to 8.20, P-value < 0.001), while no significant difference was found in PaO2 by multivariate linear regression analysis. After stabilizing inverse probability of weighting (IPW), the adjusted odds ratio for favorable neurological outcome at 1 month was significant in the good ventilation group compared to the insufficient ventilation cohort (adjusted odds ratio = 2.12, 95%CI: 1.40 to 3.19, P value < 0.001). Conclusion The study showed that in OHCA patients with prehospital ROSC, the PaCO2 levels in the initial ABG were lower in the group with AAM by ETI than in the SGA group. Furthermore, patients with prehospital ROSC and PaCO2 ≤45 mmHg on arrival had an increased odds of favorable neurological outcome after stabilized IPW adjustment.