Resuscitation Outcomes Consortium Research Articles

Temporal Trends in End-Tidal Capnography and Outcomes in Out-of-Hospital Cardiac Arrest

While widely measured, the time-varying association between exhaled end-tidal carbon dioxide (EtCO2) and out-of-hospital cardiac arrest (OHCA) outcomes is unclear. To evaluate temporal associations between EtCO2 and return of spontaneous circulation (ROSC) in the Pragmatic Airway Resuscitation Trial (PART). This study was a secondary analysis of a cluster randomized trial performed at multicenter emergency medical services agencies from the Resuscitation Outcomes Consortium. PART enrolled 3004 adults (aged ≥18 years) with nontraumatic OHCA from December 1, 2015, to November 4, 2017. EtCO2 was available in 1172 cases for this analysis performed in June 2023. PART evaluated the effect of laryngeal tube vs endotracheal intubation on 72-hour survival. Emergency medical services agencies collected continuous EtCO2 recordings using standard monitors, and this secondary analysis identified maximal EtCO2 values per ventilation and determined mean EtCO2 in 1-minute epochs using previously validated automated signal processing. All advanced airway cases with greater than 50% interpretable EtCO2 signal were included, and the slope of EtCO2 change over resuscitation was calculated. The primary outcome was ROSC determined by prehospital or emergency department palpable pulses. EtCO2 values were compared at discrete time points using Mann-Whitney test, and temporal trends in EtCO2 were compared using Cochran-Armitage test of trend. Multivariable logistic regression was performed, adjusting for Utstein criteria and EtCO2 slope. Among 1113 patients included in the study, 694 (62.4%) were male; 285 (25.6%) were Black or African American, 592 (53.2%) were White, and 236 (21.2%) were another race; and the median (IQR) age was 64 (52-75) years. Cardiac arrest was most commonly unwitnessed (n = 579 [52.0%]), nonshockable (n = 941 [84.6%]), and nonpublic (n = 999 [89.8%]). There were 198 patients (17.8%) with ROSC and 915 (82.2%) without ROSC. Median EtCO2 values between ROSC and non-ROSC cases were significantly different at 10 minutes (39.8 [IQR, 27.1-56.4] mm Hg vs 26.1 [IQR, 14.9-39.0] mm Hg; P < .001) and 5 minutes (43.0 [IQR, 28.1-55.8] mm Hg vs 25.0 [IQR, 13.3-37.4] mm Hg; P < .001) prior to end of resuscitation. In ROSC cases, median EtCO2 increased from 30.5 (IQR, 22.4-54.2) mm HG to 43.0 (IQR, 28.1-55.8) mm Hg (P for trend < .001). In non-ROSC cases, EtCO2 declined from 30.8 (IQR, 18.2-43.8) mm Hg to 22.5 (IQR, 12.8-35.4) mm Hg (P for trend < .001). Using adjusted multivariable logistic regression with slope of EtCO2, the temporal change in EtCO2 was associated with ROSC (odds ratio, 1.45 [95% CI, 1.31-1.61]). In this secondary analysis of the PART trial, temporal increases in EtCO2 were associated with increased odds of ROSC. These results suggest value in leveraging continuous waveform capnography during OHCA resuscitation. ClinicalTrials.gov Identifier: NCT02419573.

Survival After Intra-Arrest Transport vs On-Scene Cardiopulmonary Resuscitation in Children

For pediatric out-of-hospital cardiac arrest (OHCA), emergency medical services (EMS) may elect to transport to the hospital during active cardiopulmonary resuscitation (CPR) (ie, intra-arrest transport) or to continue on-scene CPR for the entirety of the resuscitative effort. The comparative effectiveness of these strategies is unclear. To evaluate the association between intra-arrest transport compared with continued on-scene CPR and survival after pediatric OHCA, and to determine whether this association differs based on the timing of intra-arrest transport. This cohort study included pediatric patients aged younger than 18 years with EMS-treated OHCA between December 1, 2005 and June 30, 2015. Data were collected from the Resuscitation Outcomes Consortium Epidemiologic Registry, a prospective 10-site OHCA registry in the US and Canada. Data analysis was performed from May 2022 to February 2024. Intra-arrest transport, defined as an initiation of transport prior to the return of spontaneous circulation, and the interval between EMS arrival and intra-arrest transport. The primary outcome was survival to hospital discharge. Patients who underwent intra-arrest transport at any given minute after EMS arrival were compared with patients who were at risk of undergoing intra-arrest transport within the same minute using time-dependent propensity scores calculated from patient demographics, arrest characteristics, and EMS interventions. We examined subgroups based on age (<1 year vs ≥1 year). Of 2854 eligible pediatric patients (median [IQR] age, 1 [0-9] years); 1691 males [59.3%]) who experienced OHCA between December 2005 and June 2015, 1892 children (66.3%) were treated with intra-arrest transport and 962 children (33.7%) received continued on-scene CPR. The median (IQR) time between EMS arrival and intra-arrest transport was 15 (9-22) minutes. In the propensity score-matched cohort (3680 matched cases), there was no significant difference in survival to hospital discharge between the intra-arrest transport group and the continued on-scene CPR group (87 of 1840 patients [4.7%] vs 95 of 1840 patients [5.2%]; risk ratio [RR], 0.81 [95% CI, 0.59-1.10]). Survival to hospital discharge was not modified by the timing of intra-arrest transport (P value for the interaction between intra-arrest transport and time to matching = .10). Among patients aged younger than 1 year, intra-arrest transport was associated with lower survival to hospital discharge (RR, 0.52; 95% CI, 0.33-0.83) but there was no association for children aged 1 year or older (RR, 1.22; 95% CI, 0.77-1.93). In this cohort study of a North American OHCA registry, intra-arrest transport compared with continued on-scene CPR was not associated with survival to hospital discharge among children with OHCA. However, intra-arrest transport was associated with a lower likelihood of survival to hospital discharge among children aged younger than 1 year.

Changes in neurologic status after traumatic brain injury in the Resuscitation Outcomes Consortium Hypertonic Saline trial.

Traumatic brain injury (TBI) is an important public health problem resulting in significant death and disability. Emergency medical services (EMS) personnel often provide initial treatment for TBI, but only limited data describe the long-term course and outcomes of this care. We sought to characterize changes in neurologic status among adults with TBI patients enrolled in the Resuscitation Outcomes Consortium Hypertonic Saline (ROC-HS) trial. We used data from the TBI cohort of the ROC-HS trial. The trial included adults with TBI, with Glasgow Coma Scale (GCS) ≤8, and excluded those with shock (systolic blood pressure [SBP] ≤70 or SBP 71-90 with a heart rate [HR] ≥108). The primary outcome was Glasgow Outcome Scale-Extended (GOS-E; 1=dead, 8=no disability) determined at (a) hospital discharge and (b) 6-month follow-up. We assessed changes in GOS-E between hospital discharge and 6-month follow-up using descriptive statistics and Sankey graphs. Among 1279 TBI included in the analysis, GOS-E categories at hospital discharge were as follows: favorable (GOS-E 5-8) 220 (17.2%), unfavorable (GOS-E 2-4) 664 (51.9%), dead (GOS-E 1) 321 (25.1%), and missing 74 (5.8%). GOS-E categories at 6-month follow-up were as follows: favorable 459 (35.9%), unfavorable 279 (21.8%), dead 346 (27.1%), and missing 195 (15.2%). Among initial TBI survivors with complete GOS-E,>96% followed one of three neurologic recovery patterns: (1) favorable to favorable (20.0%), (2) unfavorable to favorable (40.3%), and (3) unfavorable to unfavorable (36.0%). Few patients deteriorated from favorable to unfavorable neurologic status, and there were few additional deaths. Among TBI receiving initial prehospital care in the ROC-HS trial, changes in 6-month neurologic status followed distinct patterns. Among TBI with unfavorable neurologic status at hospital discharge, almost half improved to favorable neurologic status at 6 months. Among those with favorable neurologic status at discharge, very few worsened or died at 6 months. These findings have important implications for TBI clinical care, research, and trial design.

Association between prehospital time and in-hospital outcomes in out-of-hospital cardiac arrests according to resuscitation outcomes consortium epidemiologic registry

IntroductionFor out-of-hospital cardiac arrests (OHCAs), time is of the essence. While the relationship between EMS response time (ERT) and OHCA outcomes is well studied, a more comprehensive assessment of the effects of other intervention time is needed, which is essential to guide clinical practice. ObjectivesEvaluating how a longer total pre-hospital time (TPT), ERT, advance life support response time (ART) and EMS cardiopulmonary resuscitation time (ECT) increase the mortality rates, unfavorable neurological outcomes, and severe complications at discharge of OHCAs. Methods31,926 OHCAs from the USA and Canada were identified in Resuscitation Outcomes Consortium Epidemiologic Registry. Twelve adjusted models were used to analyze the relationship between the prehospital time (TPT, ERT, ART and ECT) and three outcomes (in hospital mortality, unfavorable neurological outcomes, and severe complications for surviving OHCAs). ResultsEvery 10-min increase in TPT was associated with a 0.14-fold increase in the risk of death (adjusted odds ratio [OR] = 1.14, 95 % confidence interval [CI] = 1.10–1.17) and a 0.13-fold increase of adverse neurological outcomes (OR = 1.13, CI =1.08–1.18). The risk of patient mortality markedly increased with every 5 min increase in ERT (OR = 1.36, CI = 1.26–1.47), ART (OR =1.10, CI = 1.06–1.15), and ECT (OR = 1.46, CI = 1.37–1.56). Adverse neurological outcome was associated with ERT and ECT, and severe complications with ERT and ART. ConclusionProlonged prehospital time, particularly ERT and ECT, are closely associated with in-hospital mortality, unfavorable neurological functions, and severe complications at discharge in OHCAs.

Racial and ethnic disparities in bystander resuscitation for out-of-hospital cardiac arrests

IntroductionBystander-provided cardiopulmonary resuscitation (CRP) influences the survival rates of out-of-hospital cardiac arrests (OHCAs). Disparities on bystander resuscitation measures between Black, Hispanic, Asians and Non-Hispanic White OHCAs is unclear. Examining racial and ethnic differences in bystander resuscitations is essential to better target interventions. Methods15,542 witnessed OHCAs were identified between April 1, 2011, and June 30, 2015 using the Resuscitation Outcomes Consortium Epidemiologic Registry 3, a multi-center, controlled trial about OHCAs in the United States and Canada. Multivariable logistic regression model was used to analyze the differences in bystander resuscitation (bystander CRP [B-CPR], CPR plus ventilation, automated external defibrillators/defibrillator application [B-AED/D], or delivery of shocks) and clinical outcomes (death at the scene or en route, return of spontaneous circulation upon first arrival at the emergency department [ROSC-ED], survival until ED discharge [S-ED], survival until hospital discharge [S-HOS], and favorable neurological outcome at discharge) between Black, Hispanic, or Asian victims and Non-Hispanic White victims. ResultsCompared to OHCA victims in Non-Hispanic Whites, Black, Hispanic, and Asians were less likely to receive B-CPR (adjusted OR: 0.79; 95 % CI: 0.63–0.99), and B-AED/D (adjusted OR: 0.80; 95 % CI: 0.65–0.98) in public locations. And, Black, Hispanic, and Asian OHCAs were less likely to receive bystander resuscitation in street/highway locations and public buildings, and less likely to have better clinical outcomes, including ROSC-ED, S-ED and S-HOS. ConclusionBlack, Hispanic and Asian victims with witnessed OHCAs are less likely to receive bystander resuscitation and more likely to get worse outcomes than Non-Hispanic White victims.

Abstract 412: Targeted Temperature Management for Patients With Out of Hospital Cardiac Arrest: A Comparison of the TTM2 Trial Population With Real World Data

Introduction: The TTM2 trial demonstrated no improvement of the functional status in survivors of Out-of-Hospital Cardiac Arrest (OHCA). However, the external validitiy of the trial remains to be investigated. Aim: We aimed to compare the patient population of the TTM2 trial to the real world data. Methods: We obtained the data from multiple national registries including Cardiac Arrest Registry to Enhance Survival (CARES), the Australasian Resuscitation Outcomes Consortium (Aus-ROC), the Danish Cardiac Arrest Registry (DCAR), and the Swedish Cardiopulmonary Resuscitation Registry (SCRR). We pooled the data from these registries and compared them to the data from the TTM2 trial. Results: We identified a total of 262,482 encounters from all the databases and 1,861 encounters from the TTM2 trial. The average age was comparable between both groups (64 years), females gender (registries 35% vs trial 20%), arrest event happened at the place of residence (registries 72% vs trial 53%), Bystander-witnessed arrest (registries 57% vs trial 91%), Bystander-performed CPR (registries 38% vs trial 80%), initial shockable rhythm (registries 25% vs trial 74%), non-shockable rhythm (registries 75% vs trial 26%). Conclusion: Large discrepancies were identified between the data from the TTM2 and the pooled data obtained from multiple registries. This needs to be further investigated.

The development of a risk-adjustment strategy to benchmark emergency medical service (EMS) performance in relation to out-of-hospital cardiac arrest in Australia and New Zealand

IntroductionThe aim of this study was to develop a risk adjustment strategy, including effect modifiers, for benchmarking emergency medical service (EMS) performance for out-of-hospital cardiac arrest (OHCA) in Australia and New Zealand. MethodUsing 2017–2019 data from the Australasian Resuscitation Outcomes Consortium (Aus-ROC) OHCA Epistry, we included adults who received an EMS attempted resuscitation for a presumed medical OHCA. Logistic regression was applied to develop risk adjustment models for event survival (return of spontaneous circulation at hospital handover) and survival to hospital discharge/30 days. We examined potential effect modifiers, and assessed model discrimination and validity. ResultsBoth OHCA survival outcome models included EMS agency and the Utstein variables (age, sex, location of arrest, witnessed arrest, initial rhythm, bystander cardiopulmonary resuscitation, defibrillation prior to EMS arrival, and EMS response time). The model for event survival had good discrimination according to the concordance statistic (0.77) and explained 28% of the variation in survival. The corresponding figures for survival to hospital discharge/30 days were 0.87 and 49%. The addition of effect modifiers did little to improve the performance of either model. ConclusionThe development of risk adjustment models with good discrimination is an important step in benchmarking EMS performance for OHCA. The Utstein variables are important in risk-adjustment, but only explain a small proportion of the variation in survival. Further research is required to understand what factors contribute to the variation in survival between EMS.

The Effect of Time to Treatment With Antiarrhythmic Drugs on Survival and Neurological Outcomes in Shock Refractory Out-of-Hospital Cardiac Arrest.

Examining the association of time to treatment (drug or placebo) with survival to hospital discharge and neurologic outcome. Post hoc analysis of the Resuscitation Outcomes Consortium Amiodarone, Lidocaine, Placebo randomized controlled trial. Emergency medical services enrolled patients with out-of-hospital cardiac arrest (OHCA) at multiple North American sites. Adults with nontraumatic OHCA and an initial rhythm of ventricular fibrillation or pulseless ventricular tachycardia refractory to at least one defibrillation attempt were included. None. We used logistic regression to examine the association of time to treatment with survival to hospital discharge and favorable neurologic status at discharge (modified Rankin Scale ≤ 3) for the three treatment groups including an interaction term between treatment and time to treatment to determine the effect of time on treatment effects. Time to treatment data were available for 2,994 out of 3,026 patients (99%). The proportion of patients who survived to hospital discharge decreased as time to drug administration increased, in amiodarone (odds ratio [OR], 0.91; 95% CI, 0.90-0.93 per min), lidocaine (OR, 0.93; 95% CI, 0.91-0.96), and placebo (OR, 0.91; 95% CI, 0.90-0.93). Comparing amiodarone to placebo, there was improved survival at all times of drug administration (OR, 1.32; 95% CI, 1.05-1.65). Comparing lidocaine to placebo, survival was not different with shorter times to drug administration (< 11 min), whereas survival was higher with lidocaine at longer times to drug administration with an interaction between treatment effect and time to treatment (p = 0.048). Survival with good neurologic outcome showed similar results for all analyses. Survival and favorable neurologic outcomes decreased with longer times to drug administration. Amiodarone improved survival at all time points whereas lidocaine improved survival only at later time points, compared with placebo.

Evaluation of Use of Epinephrine and Time to First Dose and Outcomes in Pediatric Patients With Out-of-Hospital Cardiac Arrest

While epinephrine has been widely used in prehospital resuscitation for pediatric patients with out-of-hospital cardiac arrest (OHCA), the benefit and optimal timing of epinephrine administration have not been fully investigated. To evaluate the association between epinephrine administration and patient outcomes and to ascertain whether the timing of epinephrine administration was associated with patient outcomes after pediatric OHCA. This cohort study included pediatric patients (<18 years) with OHCA treated by emergency medical services (EMS) from April 2011 to June 2015. Eligible patients were identified from the Resuscitation Outcomes Consortium Epidemiologic Registry, a prospective OHCA registry at 10 sites in the US and Canada. Data analysis was performed from May 2021 to January 2023. The main exposures were prehospital intravenous or intraosseous epinephrine administration and the interval between arrival of an advanced life support (ALS)-capable EMS clinician (ALS arrival) and the first administration of epinephrine. The primary outcome was survival to hospital discharge. Patients who received epinephrine at any given minute after ALS arrival were matched with patients who were at risk of receiving epinephrine within the same minute using time-dependent propensity scores calculated from patient demographics, arrest characteristics, and EMS interventions. Of 1032 eligible individuals (median [IQR] age, 1 [0-10] years), 625 (60.6%) were male. 765 patients (74.1%) received epinephrine and 267 (25.9%) did not. The median (IQR) time interval between ALS arrival and epinephrine administration was 9 (6.2-12.1) minutes. In the propensity score-matched cohort (1432 patients), survival to hospital discharge was higher in the epinephrine group compared with the at-risk group (epinephrine: 45 of 716 [6.3%] vs at-risk: 29 of 716 [4.1%]; risk ratio, 2.09; 95% CI, 1.29-3.40). The timing of epinephrine administration was also not associated with survival to hospital discharge after ALS arrival (P for the interaction between epinephrine administration and time to matching = .34). In this study of pediatric patients with OHCA in the US and Canada, epinephrine administration was associated with survival to hospital discharge, while timing of the administration was not associated with survival.

Effect of Different Early Oxygenation Levels on Clinical Outcomes of Patients Presenting in the Emergency Department With Severe Traumatic Brain Injury.

Despite the almost universal administration of supplemental oxygen in patients presenting in the emergency department (ED) with severe traumatic brain injury, optimal early oxygenation levels are unknown. Therefore, we aimed to examine the effect of different early oxygenation levels on the clinical outcomes of patients presenting in the emergency department with severe traumatic brain injury. We performed a secondary analysis of the Resuscitation Outcomes Consortium Traumatic Brain Injury Hypertonic Saline randomized controlled trial by including patients with Glasgow Coma Scale ≤8. Early oxygenation levels were assessed by the worst value of arterial partial pressure of oxygen (PaO2) during the first 4 hours of presentation in the emergency department. The primary outcome was 6-month neurologic status, as assessed by the Extended Glasgow Outcome Scale. A binary logistic regression was utilized, and an odds ratio (OR) with 95% (95% confidence intervals) was calculated. A total of 910 patients were included. In unadjusted (crude) analysis, a PaO2 of 101 to 250 mmHg (OR, 0.59 [0.38 to 0.91]), or 251 to 400 mmHg (OR, 0.53 [0.34 to 0.83]) or ≥401 mmHg (OR, 0.31 [0.20 to 0.49]) was less likely to be associated with poor neurologic status when compared with a PaO2 of ≤100 mmHg. This was also the case for adjusted analyses (including age, pupillary reactivity, and Revised Trauma Score). High oxygenation levels as early as the first 4 hours of presentation in the emergency department may not be adversely associated with the long-term neurologic status of patients with severe traumatic brain injury. Therefore, during the early phase of trauma, clinicians may focus on stabilizing patients while giving low priority to the titration of oxygenation levels.

Clinical outcomes following out-of-hospital cardiac arrest: The minute-by-minute impact of bystander cardiopulmonary resuscitation

AimsThe time-dependent prognostic role of bystander cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrest (OHCA) patients has not been described with great precision, especially for neurologic outcomes. Our objective was to assess the association between bystander CPR, emergency medical service (EMS) response time, and OHCA patients’ outcomes. MethodsThis cohort study used the Resuscitation Outcomes Consortium Cardiac Epidemiologic Registries. Bystander-witnessed adult OHCA treated by EMS were included. The primary outcome was survival to hospital discharge and secondary outcome was survival with a good neurologic outcome (modified Rankin scale 0–2). Multivariable logistic regression models were used to assess the associations and interactions between bystander CPR, EMS response time and clinical outcomes. ResultsOut of 229,637 patients, 41,012 were included (18,867 [46.0%] without bystander CPR and 22,145 [54.0%] with bystander CPR). Bystander CPR was independently associated with higher survival (adjusted odds ratio [AOR] = 1.70 [95%CI 1.61–1.80]) and survival with a good neurologic outcome (AOR = 1.87 [95%CI 1.70–2.06]), while longer EMS response times were independently associated with lower survival to hospital discharge (each additional minute of EMS response time: AOR = 0.92 [95%CI 0.91–0.93], p < 0.001) and lower survival with a good neurologic outcome (AOR = 0.88 [95%CI 0.86–0.89], p < 0.001). There was no interaction between bystander CPR and EMS response time’s association with survival (p = 0.12) and neurologic outcomes (p = 0.65). ConclusionsAlthough bystander CPR is associated with an immediate increase in odds of survival and of good neurologic outcome for OHCA patients, it does not influence the negative association between longer EMS response time and survival and good neurologic outcome.

Association between rate of change in PaCO2 and functional outcome for patients with hypercapnia after out-of-hospital cardiac arrest: Secondary analysis of a randomized clinical trial

BackgroundNormocapnia is suggested for post resuscitation care. For patients with hypercapnia after cardiac arrest, the relationship between rate of change in partial pressure of carbon dioxide (PaCO2) and functional outcome was unknown. MethodsThis was the secondary analysis of Resuscitation Outcomes Consortium (ROC) amiodarone, lidocaine, and placebo (ALPS) trial. Patients with at least 2 PaCO2 recorded and the first indicating hypercapnia (PaCO2 > 45 mmHg) after return of spontaneous circulation (ROSC) were included. The rate of change in PaCO2 was calculated as the ratio of the difference between the second and first PaCO2 to the time interval. The primary outcome was modified Rankin Score (mRS), dichotomized to good (mRS 0–3) and poor (mRS 4–6) outcomes at hospital discharge. The independent relationship between rate of change in PaCO2 and outcome was investigated with multivariable logistic regression model. ResultsA total of 746 patients with hypercapnia were included for analysis, of which 264 (35.4%) patients had good functional outcome. The median rate of change in PaCO2 was 4.7 (interquartile range [IQR] 1.7–12) mmHg per hour. After adjusting for confounders, the rate of change in PaCO2 (odds ratio [OR] 0.994, confidence interval [CI] 0.985–1.004, p = 0.230) was not associated the functional outcome. However, rate of change in PaCO2 (OR 1.010, CI 1.001–1.019, p = 0.029) was independently associated with hospital mortality. ConclusionsFor OHCA patients with hypercapnia on admission, the rate of change in PaCO2 was not independently associated with functional outcome; however, there was a significant trend that higher decreased rate was associated with increased hospital mortality.

Higher Oxygenation Is Associated with Improved Survival in Severe Traumatic Brain Injury but Not Traumatic Shock.

Pre-hospital resuscitation of critically injured patients traditionally includes supplemental oxygen therapy to address potential hypoxemia. The objective of this study was to explore the association between pre-hospital hypoxemia, hyperoxemia, and mortality in patients with traumatic brain injury (TBI) and traumatic shock. We hypothesized that both hypoxemia and hyperoxemia would be associated with increased mortality. We used the Resuscitation Outcomes Consortium Prospective Observational Prehospital and Hospital Registry for Trauma (ROC PROPHET) database of critically injured patients to identify a severe TBI cohort (pre-hospital Glasgow Coma Scale [GCS] 3-8) and a traumatic shock cohort (systolic blood pressure ≤90 mm Hg and pre-hospital GCS >8). Arterial blood gas (ABG) obtained within 30 min of hospital arrival was required for inclusion. Patients with hypoxemia (PaO2 <80 mm Hg) and hyperoxemia (PaO2 >400 mm Hg) were compared to those with normoxemia (PaO2 80-400 mm Hg) with regard to the primary outcome measure of in-hospital mortality in both the TBI and traumatic shock cohorts. Multiple logistic regression was used to calculate odds ratios (ORs) after adjustment for multiple covariables. In addition, regression spline curves were generated to estimate the risk of death as a continuous function of PaO2 levels. A total of 1248 TBI patients were included, of whom 396 (32%) died before hospital discharge. Associations between hypoxemia and increased mortality (OR, 1.8; 95% confidence interval [CI], 1.2-2.8; p = 0.008) and between hyperoxemia and decreased mortality (OR, 0.6; 95% CI, 0.4-0.9; p = 0.018) were observed. A total of 582 traumatic shock patients were included, of whom 52 (9%) died before hospital discharge. No statistically significant associations were observed between in-hospital mortality and either hypoxemia (OR, 1.0; 95% CI, 0.4-2.4; p = 0.987) or hyperoxemia (OR, 1.9; 95% CI, 0.6-5.7; p = 0.269). Among patients with severe TBI but not traumatic shock, hypoxemia was associated with an increase of in-hospital mortality and hyperoxemia was associated with a decrease of in-hospital mortality.

Early Hyperchloremia and Outcomes After Severe Traumatic Brain Injury: Analysis of Resuscitation Outcomes Consortium Hypertonic Saline Trial.

Post hoc analysis of Resuscitation Outcomes Consortium Hypertonic Saline (ROC HS)-TBI trial. A total of 114 North American emergency medical services agencies in the ROC. A total of 991 patients with severe TBI and Glasgow Coma Scale score of less than or equal to 8. Prehospital resuscitation with single IV dose (250 cc) of 7.5% saline in 6% dextran-70, 7.5% saline (no dextran), or crystalloid. Patients with increased serum chloride concentrations (110 mmol/L or greater) 24 hours after randomization were identified. Hyperchloremia was graded into one or greater than or equal to 2 occurrences in the first 24 hours. Logistic regression analyses were performed to determine the effects of hyperchloremia on: 1) death or severe disability at 180 days and 2) death within 180 days after adjusting for confounders. Compared with patients without hyperchloremia, patients with greater than or equal to 2 occurrences of hyperchloremia had significantly higher odds of death or severe disability at 180 days (odds ratio [OR], 1.81; 95% CI, 1.19-2.75) and death within 180 days (OR, 1.89; 95% CI, 1.14-3.08) after adjustment for confounders. However, the total volume of fluids administered during the first 24 hours was an independent predictor of death within 180 days; therefore, after adding an interaction term between the total volume of fluids administered during the first 24 hours and greater than or equal to 2 occurrences of hyperchloremia, patients with greater than or equal to 2 occurrences of hyperchloremia had significantly higher odds of death within 180 days (OR, 2.35; 95% CI, 1.21-4.61 d) but not of composite outcome of death or severe disability at 180 days. After modifying for the effect of the total volume of fluids administered during the first 24 hours, multiple occurrences of hyperchloremia in the first 24 hours were associated with higher odds of death within 180 days in patients with severe TBI.

Abstract 234: Increased Likelihood Of Survival For Patients Presenting With Non-shockable Cardiac Arrest And Treated With A Device-assisted Head-up CPR Bundle

Introduction: Despite receiving conventional (C) CPR and other standard treatments, almost all out-of-hospital cardiac arrest (OHCA) patients with non-shockable presentations will still die. As non-shockable presentations comprise nearly 80% of all OHCA cases, alternative treatment strategies are clearly indicated. Hypothesis: Compared to C-CPR controls, treatment with AHUP CPR (defined as the combination of an automated head up positioning [AHUP] device, an impedance threshold device [ITD], and manual and/or automated suction cup-based CPR), increases the probability of survival (SURV) to hospital discharge as well as neurologically favorable survival (N-SURV) for OHCA patients with (first recorded) non-shockable presentations. Methods: Prospectively collected data were obtained from a national AHUP CPR registry from 5 early adopting first responder EMS agencies that routinely initiated immediate AHUP CPR and tracked OHCA outcomes. Comparisons were made to C-CPR controls using individual patient data from high-performing prehospital systems participating in the NIH-funded Resuscitation Outcomes Consortium ROC-PRIMED and ResQTrial studies. AHUP and C-CPR patients presenting with a non-shockable rhythm were matched for the same discrete time interval from the 9-1-1 call to EMS CPR start time and propensity score for the key baseline covariables associated with outcome (e.g., age, sex, bystander-witnessed, bystander CPR) with a 1:1 ratio. Neuro-intact survival was defined as a modified Rankin Scale &lt; 3 or Cerebral Performance Category 1 or 2. Results: AHUP CPR treatment in non-shockable rhythm cases (n=380) was associated with increased unadjusted SURV rates of 7.4% vs 3.1% for C-CPR controls (1,852): Odds ratios (OR) and 95% confidence intervals [CI] = 2.46 [1.33-3.92]. After propensity matching, AHUP CPR was associated with increased SURV and N-SURV vs C-CPR controls: OR[CI] were 2.84[1.35-5.96] and 3.87[1.27-11.78], respectively. Also, the faster AHUP was initiated, the greater the benefit. Conclusions: This analysis provides strong clinical evidence of higher likelihood of survival, including favorable neurological function, for the vast majority of OHCA patients who present with a non-shockable rhythm by using AHUP CPR.

Abstract 226: Long-term Trajectory Of Neurologic Outcome After Severe Traumatic Brain Injury

Objective : Little is known about the time-based trajectories of neurologic recovery after traumatic brain injury (TBI). We sought to determine long-term changes in neurologic status after TBI. Methods: Data source: Resuscitation Outcomes Consortium Hypertonic Saline TBI Trial. Included: adult TBI, GCS≤8; Excluded: shock (SBP≤70, or SBP 71-90 with HR≥108). Primary outcome: Glasgow Outcome Scale-Extended (GOS-E; 1=dead, 8=no disability) determined at: a) hospital discharge and b) 6-months. We analyzed changes in GOS-E between hospital discharge and 6-months using Sankey graphs and the Wilcoxon signed-rank test. We repeated the analysis for the high acuity subset of patients undergoing EMS advanced airway insertion. Results: Among 1,282 TBI, GOS-E at discharge was: dead (GOS-E 1) n=321 (25.0%), unfavorable (2-4) n=664 (51.8%), favorable (5-8) n=220 (17.2%), missing n=77 (6.0%; Figure). GOS-E at 6-months was: dead n=346 (27.0%), unfavorable n=282 (22.0%), favorable n=459 (35.8%), missing n=195 (15.2%). While 7 of 220 (3.2%) with favorable GOS-E at discharge worsened at 6 months (unfavorable or died), 300 of 664 (45.2%) with unfavorable GOS-E improved to favorable at 6 months (Wilcoxon signed-rank for GOS-E change p&lt;0.0001). In the EMS advanced airway subset (n=774), 2 of 96 (7.1%) with favorable GOS-E at discharge worsened to unfavorable (or were dead) at 6 months, while 208 of 433 (48.0%) with unfavorable GOS-E improved to favorable at 6 months (Wilcoxon signed-rank for GOS-E change p&lt;0.0001). Conclusion: Among patients with TBI and unfavorable neurologic status at hospital discharge, almost half will progress to favorable neurologic status at 6 months. Very few TBI victims die or worsen to unfavorable neurologic status by the time of 6-month follow-up. Thus, assessment of long-term neurologic outcome should be considered for studies of TBI.

Abstract 163: Lung Inflation Occurs Infrequently In Most Patients During 30:2 CPR With Bag-Valve-Mask Ventilation

Background: Few studies have measured ventilation early in cardiopulmonary resuscitation (CPR) before advanced airway placement. In 30:2 CPR, there is a pause to give two ventilations after each round of 30 chest compressions. Recently, we developed a method to identify lung inflation (ventilation) waveforms from thoracic bioimpedance defibrillator recordings measured through defibrillator pads. Early work showed that in 75% of patients receiving bag-valve-mask (BVM) ventilation, lung inflation waveforms occurred in less than half of pauses in chest compressions during 30:2 CPR. Objective: To determine the incidence of lung inflation with BVM during 30:2 CPR in a multi-center study. Methods: Our study included adult out-of-hospital cardiac arrest patients from five sites of the Resuscitation Outcomes Consortium Trial of Continuous or Interrupted Chest Compressions during CPR. Patients had 30:2 CPR with ≥ two minutes of thoracic bioimpedance signal recorded with a defibrillator (Lifepak, Physio-control, Redmond, WA or MRx, Philips, Andover, MA). Previously, we defined a ventilation waveform as having a bioimpedance amplitude ≥0.5 Ohm (corresponding to ≥ 250 ml Vt) with a duration ≥1 sec. A valid pause was 3 sec to 15 sec. An automated program analyzed the recordings. We describe groups with ventilation waveforms in &lt;50% or ≥50% of pauses. Results: We included 1,552 patients; mean age was 66 years, 67% were male, mean (±SD) duration of 30:2 CPR was 9.9 ±5.8 min from the start of chest compressions until advanced airway placement. During this period there was a total of 21,705 pauses in chest compressions, a median of 12 pauses in chest compressions, and a median of 5 ventilations; 56% of patients had ventilation waveforms in &lt;50% of pauses (Group 1, N=868), and 44% had waveforms in &gt; 50% of pauses (Group 2, N=678). The median (IQR) number of pauses in Group 1 vs. Group 2, was 12 (8, 20) vs. 12 (7, 17) and the median number of ventilations was 3 (1, 6) vs. 13 (7, 21), respectively, during 30:2 CPR. The median duration of pauses for Group 1 vs. Group 2, was 5.8s (5.0, 6.5) vs. 5.7s (5.0, 6.7). Conclusion: For most patients, this multi-center study showed that ventilation waveforms were present in less than 50% of pauses in chest compressions during 30:2 CPR with BVM ventilation.

Variation in coronary angiography use in Out-of-Hospital cardiac arrest

IntroductionMultiple studies have examined the association of early coronary angiography (CAG) among out-of-hospital cardiac arrest (OHCA) patients with conflicting results. However, patterns of use of CAG among OHCA patients in real-world settings are not well-described. MethodsUtilizing data from the Resuscitation Outcomes Consortium’s Continuous Chest Compressions trial for our analysis, we stratified patients based on initial arrest rhythm and ST-elevation on initial post-resuscitation electrocardiogram (ECG) and examined the rates of CAG in resuscitated patients. We also examined the rates of CAG across different trial clusters in the overall study population as well as in pre-specified patient subgroups ResultsOf 26,148 patients in the CCC trial, 5,608 survived to hospital admission and were enrolled in the study. Among them, 26 % underwent CAG. Patients with ST-elevation underwent CAG at a significantly higher rate than patients presenting without ST-elevation (70 % vs 31 %, p < 0.001). Similarly, patients presenting with shockable rhythms underwent CAG more frequently compared with patients with non-shockable rhythms (28 % vs 5 %, p < 0.001). There was marked variation in CAG frequency across different trial clusters with the proportion of patients within a trial cluster receiving CAG ranging from 4 % − 41 %. The proportion varied more among patients with ST-elevation (16 % − 82 %) or initial shockable rhythm (11 % − 75 %) compared with no ST-elevation (2 % − 28 %) or initial non-shockable rhythm (0 % − 19 %). ConclusionAmong a national cohort of OHCA patients, large variation in the use of CAG exists, highlighting the existing uncertainty regarding perceived benefit from early CAG in OHCA.

Differential Effect of Targeted Temperature Management Between 32 °C and 36 °C Following Cardiac Arrest According to Initial Severity of Illness: Insights From Two International Data Sets

Recent guidelines have emphasized actively avoiding fever to improve outcomes in patients who are comatose following resuscitation from cardiac arrest (ie, out-of-hospital cardiac arrest). However, whether targeted temperature management between 32 °C and 36 °C (TTM32-36) can improve neurologic outcome in some patients remains debated. Is there an association between the use of TTM32-36 and outcome according to severity assessed at ICU admission using a previously derived risk score? Data prospectively collected in the Sudden Death Expertise Center (SDEC) registry (France) between May 2011 and December 2017 and in the Resuscitation Outcomes Consortium Continuous Chest Compressions (ROC-CCC) trial (United States and Canada) between June 2011 and May 2015 were used for this study. Severity at ICU admission was assessed through a modified version of the Cardiac Arrest Hospital Prognosis (mCAHP) score, divided into tertiles of severity. The study explored associations between TTM32-36 and favorable neurologic status at hospital discharge by using multiple logistic regression as well as in tertiles of severity for each data set. A total of 2,723 patients were analyzed in the SDEC data set and 4,202 patients in the ROC-CCC data set. A favorable neurologic status at hospital discharge occurred in 728 (27%) patients in the French data set and in 1,239 (29%) patients in the North American data set. Among the French data set, TTM32-36 was independently associated with better neurologic outcome in the tertile of patients with low (adjusted OR, 1.63; 95%CI, 1.15-2.30; P= .006) and high (adjusted OR, 1.94; 95%CI, 1.06-3.54; P= .030) severity according to mCAHP at ICU admission. Similar results were observed in the North American data set (adjusted ORs of 1.36 [95%CI, 1.05-1.75; P= .020] and 2.42 [95%CI, 1.38-4.24; P= .002], respectively). No association was observed between TTM32-36 and outcome in the moderate groups of the two data sets. TTM32-36 was significantly associated with a better outcome in patients with low and high severity at ICU admission assessed according to the mCAHP score. Further studies are needed to evaluate individualized temperature control following out-of-hospital cardiac arrest.

Development of a clinical decision rule for the early prediction of Shock-Refractory Out-of-Hospital cardiac arrest

BackgroundNearly half of ventricular fibrillation or ventricular tachycardia (VF/VT) out-of-hospital cardiac arrest (OHCA) patients receive three or more shocks, often referred to as refractory VF/VT. Our objective was to derive a clinical decision rule (CDR) for the early stratification of patients into risk categories for refractory VF/VT. MethodsWe included adults with non-traumatic OHCA in the Resuscitation Outcomes Consortium Epistry (2011–2015) with ≥ 1 EMS shock. We used Classification and Regression Tree analysis for CDR building using variables known at initial EMS rhythm analysis including age, sex, witness, location, bystander interventions, initial EMS rhythm, obvious non-cardiac etiology, and dispatch to arrival times. The outcome was refractory VF/VT (≥3 shocks). We calculated sensitivity, specificity, area under the receiver operating curve (AUROC), and odds ratios (OR). The rule was validated using the Portland Cardiac Arrest Epidemiologic Registry (2018–2020). ResultsThere were 17,140 eligible patients and 8,146 (47.5%) had refractory VF/VT. The optimal CDR (AUROC = 0.671) defined three groups: high-risk were any patients requiring an EMS shock after a bystander AED shock; moderate-risk were any non-EMS witnessed arrests with shockable initial EMS rhythms; and the remainder were low-risk. Refractory VF/VT increased across the low (30.7%), moderate (58.5%) and high-risk (84.8%) groups. Compared to low-risk, being moderate-risk or higher (OR [95% CI]:3.37 [3.16–3.59]; sensitivity 72.7%; specificity 55.9%) or high-risk (OR:12.63 [9.89–16.13]; sensitivity 5.4%; specificity 99.1%) had higher odds of refractory VF/VT. Results was similar in the validation cohort (n = 765, AUROC = 0.672). ConclusionsPatients at higher risk for refractory VF/VT can be identified early in EMS care.