Temporal Trends in End-Tidal Capnography and Outcomes in Out-of-Hospital Cardiac Arrest: A Secondary Analysis of a Randomized Clinical Trial.

Importance: While widely measured, the time-varying association between exhaled end-tidal carbon dioxide (EtCO2) and out-of-hospital cardiac arrest (OHCA) outcomes is unclear. Objective: To evaluate temporal associations between EtCO2 and return of spontaneous circulation (ROSC) in the Pragmatic Airway Resuscitation Trial (PART). Design, Setting, and Participants: 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. Interventions: 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. Main Outcomes and Measures: 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. Results: 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]). Conclusions and Relevance: 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. Trial Registration: ClinicalTrials.gov Identifier: NCT02419573.

The association between serum free fatty acid levels and neurological outcomes in out-of-hospital cardiac arrest patients: A prospective observational study.

Free fatty acids (FFA) are a known risk factor in the development of sudden cardiac death. However, the relationship between FFA and the outcome of out-of-hospital cardiac arrest (OHCA) patients remains unclear. We aimed to examine the association between FFA and neurological outcomes in OHCA patients. This prospective observational study included adult (≥18 years) OHCA patients between February 2016 and December 2022. We measured serial FFA levels within 1 hour after ROSC and at 6, 12, 24, 48, and 72 hours after the return of spontaneous circulation (ROSC). The primary outcome was neurological outcome at 6 months. A poor neurological outcome was defined by cerebral performance categories 3, 4, and 5. A total of 147 patients were included. Of them, 104 (70.7%) had poor neurological outcomes, whereby the median FFA levels within 1 hour after ROSC (0.72 vs 1.01 mol/L), at 6 hours (1.19 vs 1.90 mol/L), 12 hours (1.20 vs 1.66 mol/L), and 24 hours (1.20 vs 1.95 mol/L) after ROSC were significantly lower than in good outcome group. The FFA levels at 6 hours (odds ratio, 0.583; 95% confidence interval, 0.370-0.919; P = .020), and 12 hours (odds ratio, 0.509; 95% confidence interval, 0.303-0.854; P = .011) after ROSC were independently associated with poor neurological outcomes. The lower FFA levels at 6 hours and 12 hours after ROSC were associated with poor neurological outcomes in patients with OHCA. FFA may reflect oxidative metabolism as well as oxidative stress.

Neurological prognosis prediction upon arrival at the hospital after out-of-hospital cardiac arrest: R-EDByUS score.

AIM: To develop a new scoring model for patients with cardiogenic out-of-hospital cardiac arrest (OHCA) to facilitate neurological prognosis prediction upon hospital arrival by using prehospital resuscitation features alone. METHODS: Between 2005 and 2019, we enrolled 942,891 adult patients with OHCA of presumed cardiac aetiology from the All-Japan Utstein Registry. Scoring models applied prehospital resuscitation features a priori from the variables the American College of Cardiology algorithm including age, duration to return of spontaneous circulation (ROSC) or hospital arrival, no bystander cardiopulmonary resuscitation (CPR), unwitnessed arrest, and nonshockable rhythm (R-EDByUS score) to predict unfavorable neurological outcomes defined as Cerebral Performance Category 3, 4, or 5 at 1 month. We created nomograms as a "Regression-based model," and created a "Simplified model" in which points were assigned by category for predicting unfavorable neurological outcomes for both the prehospital ROSC cohort (67,064 patients) and the ongoing CPR cohort (875,827 patients). For internal validation, bootstrap optimism-corrected estimates of predictive performance were calculated. RESULTS: A total of 46,971 (70.0%) and 870,991 (99.4%) patients in the prehospital ROSC and ongoing CPR cohorts, respectively, had unfavorable neurological outcomes. In the prehospital ROSC cohort, the C-statistics of the Regression-based and Simplified models were 0.851 and 0.842, and the bootstrap-validated C-statistics were 0.852 and 0.841, respectively. In the ongoing CPR cohort, the C-statistics of the Regression-based and Simplified models were 0.872 and 0.865, and the bootstrap-validated C-statistics were 0.852 and 0.841, respectively. CONCLUSIONS: The R-EDByUS score accurately predicted the neurological prognosis of cardiogenic OHCA upon hospital arrival.

External Validation of Updated Prediction Models for Neurological Outcomes at 90 Days in Patients With Out-of-Hospital Cardiac Arrest.

BACKGROUND: Few prediction models for individuals with early-stage out-of-hospital cardiac arrest (OHCA) have undergone external validation. This study aimed to externally validate updated prediction models for OHCA outcomes using a large nationwide dataset. METHODS AND RESULTS: We performed a secondary analysis of the JAAM-OHCA (Comprehensive Registry of In-Hospital Intensive Care for Out-of-Hospital Cardiac Arrest Survival and the Japanese Association for Acute Medicine Out-of-Hospital Cardiac Arrest) registry. Previously developed prediction models for patients with cardiac arrest who achieved the return of spontaneous circulation were updated. External validation was conducted using data from 56 institutions from the JAAM-OHCA registry. The primary outcome was a dichotomized 90-day cerebral performance category score. Two models were updated using the derivation set (n=3337). Model 1 included patient demographics, prehospital information, and the initial rhythm upon hospital admission; Model 2 included information obtained in the hospital immediately after the return of spontaneous circulation. In the validation set (n=4250), Models 1 and 2 exhibited a C-statistic of 0.945 (95% CI, 0.935-0.955) and 0.958 (95% CI, 0.951-0.960), respectively. Both models were well-calibrated to the observed outcomes. The decision curve analysis showed that Model 2 demonstrated higher net benefits at all risk thresholds than Model 1. A web-based calculator was developed to estimate the probability of poor outcomes (https://pcas-prediction.shinyapps.io/90d_lasso/). CONCLUSIONS: The updated models offer valuable information to medical professionals in the prediction of long-term neurological outcomes for patients with OHCA, potentially playing a vital role in clinical decision-making processes.

Impact of the COVID-19 pandemic on pediatric out-of-hospital cardiac arrest outcomes in Japan.

This study investigates the impact of the COVID-19 pandemic on pediatric out-of-hospital cardiac arrest (OHCA) outcomes in Japan, aiming to address a critical research gap. Analyzing data from the All-Japan Utstein registry covering pediatric OHCA cases from 2018 to 2021, the study observed no significant changes in one-month survival, neurological outcomes, or overall performance when comparing the pre-pandemic (2018-2019) and pandemic (2020-2021) periods among 6765 cases. However, a notable reduction in pre-hospital return of spontaneous circulation (ROSC) during the pandemic (15.1-13.1%, p = .020) was identified. Bystander-initiated chest compressions and rescue breaths declined (71.1-65.8%, 22.3-13.0%, respectively; both p < .001), while bystander-initiated automated external defibrillator (AED) use increased (3.7-4.9%, p = .029). Multivariate logistic regression analyses identified factors associated with reduced pre-hospital ROSC during the pandemic. Post-pandemic, there was no noticeable change in the one-month survival rate. The lack of significant change in survival may be attributed to the negative effects of reduced chest compressions and ventilation being offset by the positive impact of widespread AED availability in Japan. These findings underscore the importance of innovative tools and systems for safe bystander cardiopulmonary resuscitation during a pandemic, providing insights to optimize pediatric OHCA care.

Mortality, morbidity & clinical outcome with different types of vasopressors in out of hospital cardiac arrest patients- a systematic review and meta-analysis.

BACKGROUND & OBJECTIVE: Despite their continued use, the effectiveness and safety of vasopressors in post-cardiac arrest patients remain controversial. This study examined the efficacy of various vasopressors in cardiac arrest patients in terms of clinical, morbidity, and mortality outcomes. METHODS: A comprehensive literature search was performed using online databases (MeSH terms: MEDLINE (Ovid), CENTRAL (Cochrane Library), Embase (Ovid), CINAHL, Scopus, and Google Scholar) from 1997 to 2023 for relevant English language studies. The primary outcomes of interest for this study included short-term survival leading to death, return of spontaneous circulation (ROSC), survival to hospital discharge, neurological outcomes, survival to hospital admission, myocardial infarction, and incidence of arrhythmias. RESULTS: In this meta-analysis, 26 studies, including 16 RCTs and ten non-RCTs, were evaluated. The focus was on the efficacy of epinephrine, vasopressin, methylprednisolone, dopamine, and their combinations in medical emergencies. Epinephrine treatment was associated with better odds of survival to hospital discharge (OR = 1.52, 95%CI [1.20, 1.94]; p < 0.001) and achieving ROSC (OR = 3.60, 95% CI [3.45, 3.76], P < 0.00001)) over placebo but not in other outcomes of interest such as short-term survival/ death at 28-30 days, survival to hospital admission, or neurological function. In addition, our analysis indicates non-superiority of vasopressin or epinephrine vasopressin-plus-epinephrine therapy over epinephrine monotherapy except for survival to hospital admission where the combinatorial therapy was associated with better outcome (0.76, 95%CI [0.64, 0.92]; p = 0.004). Similarly, we noted the non-superiority of vasopressin-plus-methylprednisolone versus placebo. Finally, while higher odds of survival to hospital discharge (OR = 3.35, 95%CI [1.81, 6.2]; p < 0.001) and ROSC (OR = 2.87, 95%CI [1.97, 4.19]; p < 0.001) favoring placebo over VSE therapy were observed, the risk of lethal arrhythmia was not statistically significant. There was insufficient literature to assess the effects of dopamine versus other treatment modalities meta-analytically. CONCLUSION: This meta-analysis indicated that only epinephrine yielded superior outcomes among vasopressors than placebo, albeit limited to survival to hospital discharge and ROSC. Additionally, we demonstrate the non-superiority of vasopressin over epinephrine, although vasopressin could not be compared to placebo due to the paucity of data. The addition of vasopressin to epinephrine treatment only improved survival to hospital admission.

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.

BACKGROUND: The 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. METHODS: MBV 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. RESULTS: Between 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). CONCLUSIONS: Compared 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.

Endotracheal epinephrine at standard versus high dose for resuscitation of asystolic newborn lambs.

INTRODUCTION: Endotracheal (ET) epinephrine administration is an option during neonatal resuscitation, if the preferred intravenous (IV) route is unavailable. OBJECTIVES: We assessed whether endotracheal epinephrine achieved return of spontaneous circulation (ROSC), and maintained physiological stability after ROSC, at standard and higher dose, in severely asphyxiated newborn lambs. METHODS: Near-term fetal lambs were asphyxiated until asystole. Resuscitation was commenced with ventilation and chest compressions. Lambs were randomly allocated to: IV Saline placebo (5 ml/kg), IV Epinephrine (20 micrograms/kg), Standard-dose ET Epinephrine (100 micrograms/kg), and High-dose ET Epinephrine (1 mg/kg). After three allocated treatment doses, rescue IV Epinephrine was administered if ROSC had not occurred. Lambs achieving ROSC were monitored for 60 minutes. Brain histology was assessed for microbleeds. RESULTS: ROSC in response to allocated treatment (without rescue IV Epinephrine) occurred in 1/6 Saline, 9/9 IV Epinephrine, 0/9 Standard-dose ET Epinephrine, and 7/9 High-dose ET Epinephrine lambs respectively. Blood pressure during CPR increased after treatment with IV Epinephrine and High-dose ET Epinephrine, but not Saline or Standard-dose ET Epinephrine. After ROSC, both ET Epinephrine groups had lower pH, higher lactate, and higher blood pressure than the IV Epinephrine group. Cortex microbleeds were more frequent in High-dose ET Epinephrine lambs (8/8 lambs examined, versus 3/8 in IV Epinephrine lambs). CONCLUSIONS: The currently recommended dose of ET Epinephrine was ineffective in achieving ROSC. Without convincing clinical or preclinical evidence of efficacy, use of ET Epinephrine at this dose may not be appropriate. High-dose ET Epinephrine requires further evaluation before clinical translation.

[Analysis of factors affecting the return of spontaneous circulation in elderly patients with out-of-hospital cardiac arrest].

OBJECTIVE: To investigate the factors that influence the return of spontaneous circulation (ROSC) in elderly patients suffering from out-of-hospital cardiac arrest (OHCA). METHODS: A retrospective study was used to collect the clinical data of OHCA patients admitted to the emergency center of Zhengzhou People's Hospital from July 2016 to July 2019 based on the pre-hospital emergency database of Utstein model. Patients' gender, age, cardiac arrest (CA) etiology, presence or absence of bystander cardiopulmonary resuscitation (CPR), emergency response time, initial cardiac rhythm, ventilation method, use of epinephrine, defibrillation and ROSC were included. The patients were divided into elderly and young groups according to whether age ≥ 60 years old, and the differences in various indicators between the two groups were compared. Univariate Logistic regression analysis was used to analyze the relationship between emergency response time and ROSC in elderly patients and multivariate Logistic regression analysis was used to identify factors influencing ROSC in elderly patients. RESULTS: A total of 3 429 adult OHCA patients were enrolled in this study, including 2 105 elderly patients (61.39%), and 1 324 young and middle-aged patients (38.61%). Compared to the young group, the proportion of females, non-cardiac causes and asystole as the initial rhythm was higher in the elderly group, the emergency response time was shorter, the rate of defibrillation and tracheal intubation, and the success rate of ROSC were lower (all P < 0.05). Among them, the proportion of cardiac arrest as the initial rhythm in elderly male patients was significantly higher than that of young male patients (P < 0.05); the proportion of non-cardiac causes in elderly female patients was significantly higher than that of young female patients, and the proportion of defibrillation was significantly lower than that of young female patients (all P < 0.05). Multivariate Logistic regression analysis showed that cardiac arrest as the initial rhythm was strongly associated with ROSC in elderly male patients [odds ratio (OR) = 0.126, 95% confidence interval (95%CI) was 0.045-0.352, P < 0.05]. Univariate Logistic regression analysis of the relationship between emergency response time and ROSC in elderly patients showed that although there was no significant difference in the ROSC success rate among elderly patients with various emergency response times, an emergency response time within 10 minutes was beneficial for ROSC in elderly patients. CONCLUSIONS: The success rate of ROSC is very low in elderly OHCA patients aged ≥60 years. Although the CPR-related indicators of elderly patients are significantly different from those of young patients, there are gender differences. The association between the elderly male patients and cardiac arrest as the initial rhythm is stronger, while OHCA caused by non-cardiac diseases is more common and defibrillable rhythm is less common in elderly female patients. It may be more beneficial for elderly patients to shorten the emergency response time and increase bystander CPR.

Blood-brain barrier permeability for the first 24 hours in hypoxic-ischemic brain injury following cardiac arrest.

BACKGROUND: This study aimed to explore the changes in blood-brain barrier (BBB) permeability and intracranial pressure (ICP) for the first 24 h after the return of spontaneous circulation (ROSC) and their association with injury severity of cardiac arrest. METHODS: This prospective study analysed the BBB permeability assessed using the albumin quotient (Qa) and ICP every 2 h for the first 24 h after ROSC. The injury severity of cardiac arrest was assessed using Pittsburgh Cardiac Arrest Category (PCAC) scores. The primary outcome was the time course of changes in the BBB permeability and ICP for the first 24 h after ROSC and their association with injury severity (PCAC scores of 1-4). RESULTS: Qa and ICP were measured 274 and 197 times, respectively, in 32 enrolled patients. Overall, the BBB permeability increased progressively over time after ROSC, and then it increased significantly at 18 h after ROSC compared with the baseline. In contrast, the ICP revealed non-significant changes for the first 24 h after ROSC. The Qa in the PCAC 2 group was < 0.01, indicating normal or mild BBB disruption at all time points, whereas the PCAC 3 and 4 groups showed a significant increase in BBB permeability at 14 and 22 h, and 12 and 14 h after ROSC, respectively. CONCLUSION: BBB permeability increased progressively over time for the first 24 h after ROSC despite post-resuscitation care, whereas ICP did not change over time. BBB permeability has an individual pattern when stratified by injury severity.

Is the lactate value predictive of the return of spontaneous circulation during CPR in nontraumatic OHCA?

AIM OF THE STUDY: Cardiac arrest is a major public health issue, in which emergency medical services (EMS) initiating or continuing resuscitation in about 50% to 60% of cases. The aim of this study was to determine whether blood lactate levels and their course during cardiopulmonary resuscitation are prognostic indicators of the return of spontaneous cardiac activity (ROSC) in non-traumatic out-of-hospital cardiac arrest (OHCA). METHODS: This was a prospective, interventional, multi-center study between 2017 and 2020. Patients above the age of 18 years (>50 years for women) who had non-traumatic OHCA and did not achieve ROSC before the arrival of the EMS, and for whom the medical team decided to initiate or continue cardiopulmonary resuscitation have been included. The primary endpoint was the return of spontaneous cardiac activity during out-of-hospital cardiopulmonary resuscitation, and secondary endpoint was survival at day 28. The lactate was initially measured simultaneously on a venous and capillary sample and then in capillary samples throughout the CPR, using POC device. RESULTS: A total 60 patients were included. Median age was 71 [IQR: 62-84] and 21.3% were female. Among them, 25% underwent ROSC in out-of-hospital setting, and 13,3% were alive at D-28. The median venous lactate value in all patients at T0 (time at which the EMS set up the peripheral venous line) was 6.2 mmol/L [IQR: 4.6-8.1], with no difference between patients with or without ROSC: 6.4 mmol/L [IQR:4.7-7.9] for patients with ROSC and 6.2 mmol/L [IQR: 4.7-8] for patients without ROSC (p = 0.87). The variables independently associated with ROSC were initial EtCo2 value (aOR = 1.12; 95% CI 1.01-1.25); the initial shockable rhythm (aOR = 10.2; 95% CI 1.18-88.2); and the pre-ROSC adrenaline dose (aOR = 0.54; 95% CI 0.35-0.82). CONCLUSION: In this prospective multi-center study, there was no independent association between lactate values during cardiopulmonary resuscitation and ROSC in non-traumatic OHCA. However, the post-ROSC pre-hospital kinetics of lactate (i.e., during the first 30 min) seem to be associated with survival.

The design of the PRINCESS 2 trial: A randomized trial to study the impact of ultrafast hypothermia on complete neurologic recovery after out-of-hospital cardiac arrest with initial shockable rhythm.

BACKGROUND: Delayed hypothermia, initiated after hospital arrival, several hours after cardiac arrest with 8-10 hours to reach the target temperature, is likely to have limited impact on overall survival. However, the effect of ultrafast hypothermia, i.e., delivered intra-arrest or immediately after return of spontaneous circulation (ROSC), on functional neurologic outcome after out-of-hospital cardiac arrest (OHCA) is unclear. In two prior trials, prehospital trans-nasal evaporative intra-arrest cooling was safe, feasible and reduced time to target temperature compared to delayed cooling. Both studies showed trends towards improved neurologic recovery in patients with shockable rhythms. The aim of the PRINCESS2-study is to assess whether cooling, initiated either intra-arrest or immediately after ROSC, followed by in-hospital hypothermia, significantly increases survival with complete neurologic recovery as compared to standard normothermia care, in OHCA patients with shockable rhythms. METHODS/DESIGN: In this investigator-initiated, randomized, controlled trial, the emergency medical services (EMS) will randomize patients at the scene of cardiac arrest to either trans-nasal cooling within 20 minutes from EMS arrival with subsequent hypothermia at 33°C for 24 hours after hospital admission (intervention), or to standard of care with no prehospital or in-hospital cooling (control). Fever (>37,7°C) will be avoided for the first 72 hours in both groups. All patients will receive post resuscitation care and withdrawal of life support procedures according to current guidelines. Primary outcome is survival with complete neurologic recovery at 90 days, defined as modified Rankin scale (mRS) 0-1. Key secondary outcomes include survival to hospital discharge, survival at 90 days and mRS 0-3 at 90 days. In total, 1022 patients are required to detect an absolute difference of 9% (from 45 to 54%) in survival with neurologic recovery (80% power and one-sided α=0,025, ß=0,2) and assuming 2,5% lost to follow-up. Recruitment starts in Q1 2024 and we expect maximum enrolment to be achieved during Q4 2024 at 20-25 European and US sites. DISCUSSION: This trial will assess the impact of ultrafast hypothermia applied on the scene of cardiac arrest, as compared to normothermia, on 90-day survival with complete neurologic recovery in OHCA patients with initial shockable rhythm. TRIAL REGISTRATION: NCT06025123.

Validation of Utstein-Based score to predict return of spontaneous circulation (UB-ROSC) in patients with out-of-hospital cardiac arrest.

BACKGROUND AND AIMS: The Utstein Based-ROSC (UB-ROSC) score has been developed to predict ROSC in OHCA victims. Aim of the study was to validate the UB-ROSC score using two Utstein-based OHCA registries: the SWiss REgistry of Cardiac Arrest (SWISSRECA) and the Lombardia Cardiac Arrest Registry (Lombardia CARe), northern Italy. METHODS: Consecutive patients with OHCA of any etiology occurring between January 1st, 2019 and December 31st 2021 were included in this retrospective validation study. UB-ROSC score was computed for each patient and categorized in one of three subgroups: low, medium or high likelihood of ROSC according to the UB-ROSC cut-offs (≤-19; -18 to 12; ≥13). To assess the performance of the UB-ROSC score in this new cohort, we assessed both discrimination and calibration. The score was plotted against the survival to hospital admission. RESULTS: A total of 12.577 patients were included in the study. A sustained ROSC was obtained in 2.719 patients (22%). The UB-ROSC model resulted well calibrated and showed a good discrimination (AUC 0.71, 95% CI 0.70-0.72). In the low likelihood subgroup of UB-ROSC, only 10% of patients achieved ROSC, whereas the proportion raised to 36% for a score between -18 and 12 (OR 5.0, 95% CI 2.9-8.6, p < 0.001) and to 85% for a score ≥13 (OR 49.4, 95% CI 14.3-170.6, p < 0.001). CONCLUSIONS: UB-ROSC score represents a reliable tool to predict ROSC probability in OHCA patients. Its application may help the medical decision-making process, providing a realistic stratification of the probability for ROSC.

Supraglottic Airway Versus Tracheal Intubation for Airway Management in Out-of-Hospital Cardiac Arrest: A Systematic Review, Meta-Analysis, and Trial Sequential Analysis of Randomized Controlled Trials.

OBJECTIVES: Given the uncertainty regarding the optimal approach for airway management for adult patients with out-of-hospital cardiac arrest (OHCA), we conducted a systematic review and meta-analysis to compare the use of supraglottic airways (SGAs) with tracheal intubation for initial airway management in OHCA. DATA SOURCES: We searched MEDLINE, PubMed, Embase, Cochrane Library, as well as unpublished sources, from inception to February 7, 2023. STUDY SELECTION: We included randomized controlled trials (RCTs) of adult OHCA patients randomized to SGA compared with tracheal intubation for initial prehospital airway management. DATA EXTRACTION: Reviewers screened abstracts, full texts, and extracted data independently and in duplicate. We pooled data using a random-effects model. We used the modified Cochrane risk of bias 2 tool and assessed certainty of evidence using the Grading Recommendations Assessment, Development, and Evaluation approach. We preregistered the protocol on PROSPERO (CRD42022342935). DATA SYNTHESIS: We included four RCTs ( n = 13,412 patients). Compared with tracheal intubation , SGA use probably increases return of spontaneous circulation (ROSC) (relative risk [RR] 1.09; 95% CI, 1.02-1.15; moderate certainty) and leads to a faster time to airway placement (mean difference 2.5 min less; 95% CI, 1.6-3.4 min less; high certainty). SGA use may have no effect on survival at longest follow-up (RR 1.06; 95% CI, 0.84-1.34; low certainty), has an uncertain effect on survival with good functional outcome (RR 1.11; 95% CI, 0.82-1.50; very low certainty), and may have no effect on risk of aspiration (RR 1.04; 95% CI, 0.94 to 1.16; low certainty). CONCLUSIONS: In adult patients with OHCA, compared with tracheal intubation, the use of SGA for initial airway management probably leads to more ROSC, and faster time to airway placement, but may have no effect on longer-term survival outcomes or aspiration events.

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.

Assessing the influence of abdominal compression on time to return of circulation during resuscitation of asphyxiated newborn lambs: a randomised preclinical study.

OBJECTIVE: During neonatal resuscitation, the return of spontaneous circulation (ROSC) can be achieved using epinephrine which optimises coronary perfusion by increasing diastolic pressure. Abdominal compression (AC) applied during resuscitation could potentially increase diastolic pressure and therefore help achieve ROSC. We assessed the use of AC during resuscitation of asystolic newborn lambs, with and without epinephrine. METHODS: Near-term fetal lambs were instrumented for physiological monitoring and after delivery, asphyxiated until asystole. Resuscitation was commenced with ventilation followed by chest compressions. Lambs were randomly allocated to: intravenous epinephrine (20 µg/kg, n=9), intravenous epinephrine+continuous AC (n=8), intravenous saline placebo (5 mL/kg, n=6) and intravenous saline+AC (n=9). After three allocated treatment doses, rescue intravenous epinephrine was administered if ROSC had not occurred. Time to achieve ROSC was the primary outcome. Lambs achieving ROSC were ventilated and monitored for 60 min before euthanasia. Brain histology was assessed for micro-haemorrhage. RESULTS: Use of AC did not influence mean time to achieve ROSC (epinephrine lambs 177 s vs epinephrine+AC lambs 179 s, saline lambs 602 s vs saline+AC lambs 585 s) or rate of ROSC (nine of nine lambs, eight of eight lambs, one of six lambs and two of eight lambs, respectively). Application of AC was associated with higher diastolic blood pressure (mean value >10 mm Hg), mean and systolic blood pressure and carotid blood flow during resuscitation. Cortex and deep grey matter micro-haemorrhage was more frequent in AC lambs. CONCLUSION: Use of AC during resuscitation increased diastolic blood pressure, but did not impact time to ROSC.