Lower-dose epinephrine administration and out-of-hospital cardiac arrest outcomes

Optimal weight-based epinephrine dosing for patients with a low likelihood of survival following out-of-hospital cardiac arrest

INTRODUCTION

Cardiac arrest patients presenting with non-shockable rhythms have a low probability of survival, and epinephrine is one of the few pharmaceutical options for this group. The recommended 1.0 mg adult dose is extrapolated from early animal studies and lacks adjustment for patient weight. Although several prior studies have investigated "low-" and "high-" dose epinephrine, none have identified a benefit to either strategy.

AIMS

To identify an optimal weight-based epinephrine dose for return-of-spontaneous-circulation (ROSC) after a single bolus among patients with low likelihood of survival.

METHODS

Included were adult patients who experienced a witnessed, non-traumatic out-of-hospital cardiac arrest prior to EMS arrival. Patients with shockable presenting rhythms or receiving bystander CPR were excluded. The AUROC was used to assess the predictive value of epinephrine dose (mg/kg) for ROSC following a single bolus. From the ROC curve, the optimal threshold dosage (OTD) was determined using the Youden Index. A logistic regression model calculated the adjusted odds ratio of OTD on ROSC.

RESULTS

A total of 2,463 patients met inclusion criteria, of which 190 (7.7%) attained ROSC after the first epinephrine administration. The dosage AUROC for ROSC was 0.603 (p < 0.01). As calculated by the Youden index, the OTD was 0.013 mg/kg. Patients receiving ≥ OTD were more likely to attain ROSC after a single epinephrine bolus (OR = 2.25,p < 0.001).

CONCLUSIONS

Among patients with a low likelihood of survival, the optimal dose of epinephrine for attaining ROSC with a single bolus of epinephrine was 0.013 mg/kg. These findings should inspire further investigation into optimal dosing strategies for epinephrine.

Prehospital Administration of Norepinephrine and Epinephrine for Shock after Resuscitation from Cardiac Arrest

INTRODUCTION

Shock after resuscitation from out-of-hospital cardiac arrest (OHCA) is often treated with vasopressors. We examined whether infusion of epinephrine versus norepinephrine was associated with prehospital rearrest and neurologically favorable survival among OHCA patients.

METHODS

This retrospective study included OHCA cases in Seattle, Washington from 2014-2021 who had return of spontaneous circulation (ROSC) followed by vasopressor infusion. Our primary exposure was infusion of epinephrine or norepinephrine. Our primary outcome was prehospital rearrest. Secondary outcomes included survival and neurologically favorable outcome (Cerebral Performance Category score of 1 or 2). We used multivariable logistic regression to test associations between exposures and outcomes adjusting for key covariates.

RESULTS

Of 451 OHCA patients with ROSC followed by vasopressor infusion, 253 (56%) received norepinephrine and 198 (44%) received epinephrine infusions. Those who received epinephrine were older (median 66 [interquartile ranges {IQR} 53-79] vs 63 [IQR 47-75] years), but otherwise had similar baseline characteristics. Patients who received epinephrine were twice as likely to rearrest (55% vs 25%). After adjustment, the difference in rearrest rates between epinephrine and norepinephrine persisted (OR 3.28, 95%CI 2.25-5.08), and the odds of pulses at hospital arrival were lower in the epinephrine group (OR 0.52 95%CI 0.32-0.83). After adjustment, there was no difference in neurologically favorable survival, survival to hospital admission, or survival to discharge.

CONCLUSION

Patients who received epinephrine infusions after ROSC suffered prehospital rearrest more frequently than those who received norepinephrine. Survival and neurological status at hospital discharge were similar. Future trials should examine the optimal approach to hemodynamic management for post-OHCA shock.

One and Done Epinephrine in Out-of-Hospital Cardiac Arrest? Outcomes in a Multiagency United States Study

BACKGROUND

Cardiac arrest guidelines recommend epinephrine every 3-5 minutes during cardiac arrest resuscitation. However, it is unclear if multiple epinephrine doses are associated with improved outcomes. The objective of this study was to determine if a single-dose epinephrine protocol was associated with improved survival compared to traditional multidose protocols.

METHODS

We conducted a pre-post study across five North Carolina EMS agencies from 11/1/2016 to 10/29/2019. Patients ≥18 years old with attempted resuscitation for non-traumatic prehospital cardiac arrest were included. Data were collected 1 year before and after implementation of the single-dose epinephrine protocol. Prior to implementation, all agencies used a multidose epinephrine protocol. The Cardiac Arrest Registry to Enhance Survival (CARES) was used to obtain patient outcomes. Study outcomes were survival to hospital discharge (primary) and return of spontaneous circulation (ROSC). Analysis was by intention to treat. Outcomes were compared pre- vs. post-implementation using generalized estimating equations to account for clustering within EMS agencies. Adjusted analyses included age, sex, race, shockable vs. non-shockable rhythm, witnessed arrest, automatic external defibrillator availability, EMS response interval, and bystander cardiopulmonary resuscitation.

RESULTS

During the study period there were 1,690 encounters (899 pre- and 791 post-implementation). The population was 74.7% white, 61.1% male, and had a median age of 65 (IQR 53-76) years. Survival to hospital discharge was similar pre- vs. post-implementation [13.6% (122/899) vs. 15.4% (122/791); OR 1.19, 95%CI 0.89-1.59]. However, ROSC was more common post-implementation [42.3% (380/899) vs. 32.5% (257/791); OR 0.66, 95%CI 0.54-0.81]. After adjusting for covariates, the single-dose protocol was associated with similar survival to discharge rates (aOR 0.88, 95%CI 0.77-1.29), but with decreased ROSC rates (aOR 0.58, 95%CI 0.47-0.72).

CONCLUSION

A prehospital single-dose epinephrine protocol was associated with similar survival to hospital discharge, but decreased ROSC rates compared to the traditional multidose epinephrine protocol.

Adrénaline au cours de la réanimation de l’arrêt cardiaque

À ce jour, l’adrénaline est fortement recommandée dans le traitement de l’arrêt cardiaque. Son utilisation est bien ancrée dans les pratiques, et elle est présente dans les recommandations et les algorithmes de prise en charge depuis des décennies. Cependant, ces mêmes recommandations reposent sur un niveau de preuve faible dans cette indication. Les propriétés pharmacologiques de l’adrénaline et ses effets secondaires et indirects peuvent expliquer en partie la controverse actuelle qui anime les experts dans ce domaine. Plusieurs études cliniques récentes, majoritairement observationnelles, ont renforcé les incertitudes concernant le devenir des patients exposés à ce traitement lors d’un arrêt cardiaque, en termes de survie et d’évolution neurologique. Ces observations ont encouragé la réalisation d’essais cliniques susceptibles de clarifier le rapport bénéfice/risque de ce traitement. Un large essai randomisé a récemment évalué l’adrénaline comparée à un placebo, et a montré l’efficacité de ce médicament concernant le succès de la réanimation initiale. Toutefois, le questionnement demeure entier concernant l’effet de ce traitement sur le devenir neurologique à distance. Actuellement, plusieurs études cliniques explorent d’autres modalités d’administration afin d’optimiser au mieux son effet sur les différents critères de jugement incluant le devenir à long terme. Globalement, même si l’adrénaline permet d’améliorer la survie immédiate après un arrêt cardiaque, son rôle reste donc incertain concernant le devenir neurologique des patients à moyen et long termes. Cependant, en l’absence d’alternative et dans l’attente de données supplémentaires, ce médicament reste recommandé dans tous les protocoles de réanimation spécialisée de l’arrêt cardiaque.

Drug use during adult advanced cardiac life support: An overview of reviews

AIM

To conduct an overview of systematic reviews and meta-analyses to summarize the ever-growing evidence on drug use during advanced life support.

METHODS

We searched Embase, Medline, Cochrane central register of controlled trials and Web of science for systematic reviews and meta-analyses reporting on drug use during advanced life support from inception to March, 2020. Two reviewers independently assessed all abstracts for eligibility, extracted data and assessed risk of bias using the AMSTAR-2 tool. Corrected covered areas were calculated from publication citation matrices to account for potential risk of bias. Data were graphically represented using forest plots.

RESULTS

Twenty-two head-to-head drug comparisons from 47 included articles were analysed. Adrenaline significantly increases the incidence of return of spontaneous circulation and survival to hospital discharge, but not the incidence of neurological intact survival. Vasopressin alone or in combination with adrenaline is not superior to adrenaline alone. There is a trend favouring lidocaine over amiodarone in shockable cardiac arrest. The risk of bias assessment of included studies ranged from very low to very high and the overlap between articles was moderate to high.

CONCLUSIONS

In line with the guidelines, we currently suggest that a standard dose of adrenaline should be administered during resuscitation, however, studies assessing lower doses of adrenaline are pressing. There is no rationale for the combination of vasopressin and adrenaline or vasopressin alone instead of adrenaline. In addition, lidocaine is a valuable alternative for amiodarone and maybe even preferable for shockable cardiac arrest. However more research is necessary.

Severe Myocardial Dysfunction after Non-Ischemic Cardiac Arrest: Effectiveness of Percutaneous Assist Devices

Introduction: Despite the improvements in standardized cardiopulmonary resuscitation, survival remains low, mainly due to initial myocardial dysfunction and hemodynamic instability. Our goal was to compare the efficacy of two left ventricular assist devices on resuscitation and hemodynamic supply in a porcine model of ventricular fibrillation (VF) cardiac arrest. Methods: Seventeen anaesthetized pigs had 12 min of untreated VF followed by 6 min of chest compression and boluses of epinephrine. Next, a first defibrillation was attempted and pigs were randomized to any of the three groups: control (n = 5), implantation of an percutaneous left ventricular assist device (Impella, n = 5) or extracorporeal membrane oxygenation (ECMO, n = 7). Hemodynamic and myocardial functions were evaluated invasively at baseline, at return of spontaneous circulation (ROSC), after 10–30–60–120–240 min post-resuscitation. The primary endpoint was the rate of ROSC. Results: Only one of 5 pigs in the control group, 5 of 5 pigs in the Impella group, and 5 of 7 pigs in the ECMO group had ROSC (p < 0.05). Left ventricular ejection fraction at 240 min post-resuscitation was 37.5 ± 6.2% in the ECMO group vs. 23 ± 3% in the Impella group (p = 0.06). No significant difference in hemodynamic parameters was observed between the two ventricular assist devices. Conclusion: Early mechanical circulatory support appeared to improve resuscitation rates in a shockable rhythm model of cardiac arrest. This approach appears promising and should be further evaluated.

Fewer tracheal intubation attempts are associated with improved neurologically intact survival following out-of-hospital cardiac arrest

BACKGROUND

International guidelines emphasize advanced airway management during out-of-hospital cardiac arrest (OHCA). We hypothesized that increasing endotracheal intubation attempts during OHCA were associated with a lower likelihood of favorable neurologic survival at discharge.

METHODS

This retrospective, observational cohort evaluated the relationship between number of intubation attempts and favorable neurologic survival among non-traumatic OHCA patients receiving cardiopulmonary resuscitation (CPR) from January 1, 2015-June 30, 2019 in a large urban emergency medical services (EMS) system. Favorable neurologic status at hospital discharge was defined as a Cerebral Performance Category score of 1 or 2. Multivariable logistic regression, adjusted for age, sex, witness status, bystander CPR, initial rhythm, and time of EMS arrival, was performed using the number of attempts as a continuous variable.

RESULTS

Over 54 months, 1205 patients were included. Intubation attempts per case were 1 = 757(63%), 2 = 279(23%), 3 = 116(10%), ≥4 = 49(4%), and missing/unknown in 4(<1%). The mean (SD) time interval from paramedic arrival to intubation increased with the number of attempts: 1 = 4.9(2.4) min, 2 = 8.0(2.9) min, 3 = 10.9(3.3) min, and ≥4 = 15.5(4.4) min. Final advanced airway techniques employed were endotracheal intubation (97%), supraglottic devices (3%), and cricothyrotomy (<1%). Favorable neurologic outcome declined with each additional attempt: 11% with 1 attempt, 4% with 2 attempts, 3% with 3 attempts, and 2% with 4 or more attempts (AOR = 0.41, 95% CI 0.25-0.68).

CONCLUSIONS

Increasing number of intubation attempts during OHCA resuscitation was associated with lower likelihood of favorable neurologic outcome.

Impact of Total Epinephrine Dose on Long Term Neurological Outcome for Cardiac Arrest Patients: A Cohort Study

Introduction: Although epinephrine is universally acknowledged to increase return of spontaneous circulation (ROSC) after cardiac arrest, its balanced effects on later outcomes remain uncertain, causing potential harm during post-resuscitation phase. Recent studies have questioned the efficacy and potential deleterious effects of epinephrine on long-term survival and neurological outcomes, despite that the adverse relationship between epinephrine dose and outcome can be partially biased by longer CPR duration and underlying comorbidities. This study explored the long-term effect of epinephrine when used in a cohort of patients that underwent cardiac arrest during cardiopulmonary resuscitation.

Methods: The data were originally collected from a retrospective institutional database from January 2007 to December 2015 and are now available on Dryad (via: https://doi.org/10.5061/dryad.qv6fp83). Use of epinephrine was coded by dose (<2 mg, 2 mg, 3–4 mg, ≥5 mg). A favorable neurological outcome was defined using a Cerebral Performance Category (CPC) 1 or 2. The association between epinephrine dosing and 3-months neurological outcome was analyzed by univariate analysis and multivariate logistic regression.

Results: Univariate and multivariate analysis demonstrated a negative association between total epinephrine dose and neurological outcome. Of the 373 eligible patients, 92 received less than 2 mg of epinephrine, 60 received 2 mg, 97 received 3–4 mg and 124 received more than 5 mg. Compared to patients who received less than 2 mg of epinephrine, the adjusted odds ratio (OR) of a favorable neurological outcome was 0.8 (95% confidence interval [CI]: 0.38–1.68) for 2 mg of epinephrine, 0.43 (95% confidence interval [CI]: 0.21–0.89) for 3–4 mg of epinephrine and 0.40 (95% confidence interval [CI]: 0.17–0.96) for more than 5 mg of epinephrine.

Conclusion: In this cohort of patients who achieved ROSC, total epinephrine dosing during resuscitation was associated with a worse neurological outcome three months after cardiac arrest, after adjusting other confounding factors. Further researches are needed to investigate the long-term effect of epinephrine on cardiac arrest patients.

Adrenaline to improve survival in out-of-hospital cardiac arrest: the PARAMEDIC2 RCT

BACKGROUND

Adrenaline has been used as a treatment for cardiac arrest for many years, despite uncertainty about its effects on long-term outcomes and concerns that it may cause worse neurological outcomes.

OBJECTIVES

The objectives were to evaluate the effects of adrenaline on survival and neurological outcomes, and to assess the cost-effectiveness of adrenaline use.

DESIGN

This was a pragmatic, randomised, allocation-concealed, placebo-controlled, parallel-group superiority trial and economic evaluation. Costs are expressed in Great British pounds and reported in 2016/17 prices.

SETTING

This trial was set in five NHS ambulance services in England and Wales.

PARTICIPANTS

Adults treated for an out-of-hospital cardiac arrest were included. Patients were ineligible if they were pregnant, if they were aged < 16 years, if the cardiac arrest had been caused by anaphylaxis or life-threatening asthma, or if adrenaline had already been given.

INTERVENTIONS

Participants were randomised to either adrenaline (1 mg) or placebo in a 1 : 1 allocation ratio by the opening of allocation-concealed treatment packs.

MAIN OUTCOME MEASURES

The primary outcome was survival to 30 days. The secondary outcomes were survival to hospital admission, survival to hospital discharge, survival at 3, 6 and 12 months, neurological outcomes and health-related quality of life through to 6 months. The economic evaluation assessed the incremental cost per quality-adjusted life-year gained from the perspective of the NHS and Personal Social Services. Participants, clinical teams and those assessing patient outcomes were masked to the treatment allocation.

RESULTS

From December 2014 to October 2017, 8014 participants were assigned to the adrenaline (n = 4015) or to the placebo (n = 3999) arm. At 30 days, 130 out of 4012 participants (3.2%) in the adrenaline arm and 94 out of 3995 (2.4%) in the placebo arm were alive (adjusted odds ratio for survival 1.47, 95% confidence interval 1.09 to 1.97). For secondary outcomes, survival to hospital admission was higher for those receiving adrenaline than for those receiving placebo (23.6% vs. 8.0%; adjusted odds ratio 3.83, 95% confidence interval 3.30 to 4.43). The rate of favourable neurological outcome at hospital discharge was not significantly different between the arms (2.2% vs. 1.9%; adjusted odds ratio 1.19, 95% confidence interval 0.85 to 1.68). The pattern of improved survival but no significant improvement in neurological outcomes continued through to 6 months. By 12 months, survival in the adrenaline arm was 2.7%, compared with 2.0% in the placebo arm (adjusted odds ratio 1.38, 95% confidence interval 1.00 to 1.92). An adjusted subgroup analysis did not identify significant interactions. The incremental cost-effectiveness ratio for adrenaline was estimated at £1,693,003 per quality-adjusted life-year gained over the first 6 months after the cardiac arrest event and £81,070 per quality-adjusted life-year gained over the lifetime of survivors. Additional economic analyses estimated incremental cost-effectiveness ratios for adrenaline at £982,880 per percentage point increase in overall survival and £377,232 per percentage point increase in neurological outcomes over the first 6 months after the cardiac arrest.

LIMITATIONS

The estimate for survival with a favourable neurological outcome is imprecise because of the small numbers of patients surviving with a good outcome.

CONCLUSIONS

Adrenaline improved long-term survival, but there was no evidence that it significantly improved neurological outcomes. The incremental cost-effectiveness ratio per quality-adjusted life-year exceeds the threshold of £20,000-30,000 per quality-adjusted life-year usually supported by the NHS.

FUTURE WORK

Further research is required to better understand patients' preferences in relation to survival and neurological outcomes after out-of-hospital cardiac arrest and to aid interpretation of the trial findings from a patient and public perspective.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN73485024 and EudraCT 2014-000792-11.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 25. See the NIHR Journals Library website for further project information.

Early Administration of Adrenaline for Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-Analysis

Background

The use of adrenaline in out‐of‐hospital cardiac arrest (OHCA) patients is still controversial. This study aimed to determine the effects of early pre‐hospital adrenaline administration in OHCA patients.

Methods and Results

PubMed, EMBASE, Google Scholar, and the Cochrane Library database were searched from study inception to February 2019 to identify studies that reported OHCA patients who received adrenaline. The primary outcome was survival to discharge, and the secondary outcomes were return of spontaneous circulation, favorable neurological outcome, and survival to hospital admission. A total of 574 392 patients were included from 24 studies. The use of early pre‐hospital adrenaline administration in OHCA patients was associated with a significant increase in survival to discharge (risk ratio [RR], 1.62; 95% CI, 1.45–1.83; P<0.001) and return of spontaneous circulation (RR, 1.50; 95% CI, 1.36–1.67; P<0.001), as well as a favorable neurological outcome (RR, 2.09; 95% CI, 1.73–2.52; P<0.001). Patients with shockable rhythm cardiac arrest had a significantly higher rate of survival to discharge (RR, 5.86; 95% CI, 4.25–8.07; P<0.001) and more favorable neurological outcomes (RR, 5.10; 95% CI, 2.90–8.97; P<0.001) than non‐shockable rhythm cardiac arrest patients.

Conclusions

Early pre‐hospital administration of adrenaline to OHCA patients might increase the survival to discharge, return of spontaneous circulation, and favorable neurological outcomes.

Registration

URL: https://www.crd.york.ac.uk/PROSPERO; Unique identifier: CRD42019130542.

Improved outcomes for out-of-hospital cardiac arrest patients treated by emergency life-saving technicians compared with basic emergency medical technicians: A JCS-ReSS study report

BACKGROUND

Emergency life-saving technicians (ELSTs) are specially trained prehospital medical providers believed to provide better care than basic emergency medical technicians (BEMTs). ELSTs are certified to perform techniques such as administration of advanced airways or adrenaline and are considered to have more knowledge; nevertheless, ELSTs' effectiveness over BEMTs regarding out-of-hospital cardiac arrest (OHCA) remains unclear. We investigated whether the presence of an ELST improves OHCA patient outcomes.

METHODS

In a retrospective study of adult OHCA patients treated in Japan from 2011 to 2015, we compared two OHCA patient groups: patients transported with at least one ELST and patients transported by only BEMTs. The primary outcome measure was one-month favorable neurological outcomes, defined as Cerebral Performance Category ≤ 2. A multivariable logistic regression model was used to calculate odds ratios (ORs) and their confidence intervals (CIs) to evaluate the effect of ELSTs.

RESULTS

Included were 552,337 OHCA patients, with 538,222 patients in the ELST group and 14,115 in the BEMT group. The ELST group had a significantly higher odds of favorable neurological outcomes (2.5% vs. 2.1%, adjusted OR 1.39, 95% CI 1.17-1.66), one-month survival (4.9% vs. 4.1%, adjusted OR 1.37, 95% CI 1.22-1.54), and return of spontaneous circulation (8.1% vs. 5.1%, adjusted OR 1.90, 95% CI 1.72-2.11) compared with the BEMT group. However, ELSTs' limited procedure range (adrenaline administration or advanced airway management) did not promote favorable neurological outcomes.

CONCLUSIONS

Compared with the BEMT group, transport by the ELST group was associated with better neurological outcomes in OHCA.

Causes of Chest Compression Interruptions During Out-of-Hospital Cardiac Arrest Resuscitation

Background

Interruptions in chest compressions contribute to poor outcomes in out‐of‐hospital cardiac arrest. The objective of this retrospective observational cohort study was to characterize the frequency, reasons, and duration of interruptions in chest compressions and to determine if interruptions changed over time.

Methods and Results

All out‐of‐hospital cardiac arrests treated by the Seattle Fire Department (Seattle, WA, United States) from 2007 to 2016 with capture of recordings from automated external defibrillators and manual defibrillators were included. Compression interruptions >1 second were classified into categories using audio recordings. Among the 3601 eligible out‐of‐hospital cardiac arrests, we analyzed 74 584 minutes, identifying 30 043 pauses that accounted for 6621 minutes (8.9% of total resuscitation duration). The median total interruption duration per case decreased from 115 seconds in 2007 to 72 seconds in 2016 (P<0.0001). Median individual interruption duration decreased from 14 seconds in 2007 to 7 seconds in 2016 (P<0.0001). Among interruptions >10 seconds, median interruption duration decreased from 20 seconds in 2007 to 16 seconds in 2016 (P<0.0001). Cardiac rhythm analysis accounted for most compression interruptions. Manual ECG rhythm analysis and pulse checks accounted for 41.6% of all interruption time (median individual interruption, 8 seconds), automated external defibrillator rhythm analysis for 13.7% (median, 17 seconds), and manual rhythm analysis and shock delivery for 8.0% (median, 9 seconds).

Conclusions

Median duration of chest compression interruptions decreased by half from 2007 to 2016, indicating that care teams can significantly improve performance. Reducing compression interruptions is an evidence‐based benchmark that provides a modifiable process quality improvement goal.

Predictors of In-Hospital Mortality after Recovered Out-of-Hospital Cardiac Arrest in Patients with Proven Significant Coronary Artery Disease: A Retrospective Study

INTRODUCTION

Recovered Out-of-Hospital Cardiac Arrest (rOHCA) population is heterogenous. Few studies focused on outcomes in the rOHCA subgroup with proven significant coronary artery disease (SigCAD). We aimed to characterize this subgroup and study the determinants of in-hospital mortality.

METHODS

Retrospective study of consecutive rOHCA patients submitted to coronary angiography. Only patients with SigCAD were included.

RESULTS

60 patients were studied, 85% were male, mean age was 62.6 ± 12.1 years. In-hospital mortality rate was 43.3%. Patients with diabetes and history of stroke were less likely to survive. Significant univariate predictors of in-hospital mortality were further analysed separately, according to whether they were present at hospital admission or developed during hospital evolution. At hospital admission, initial non-shockable rhythm, low-flow time>12min, pH<7.25mmol/L and lactates >4.75mmol/L were the most relevant predictors and therefore included in a score tested by Kaplan-Meyer. Patients who had 0/4 criteria had 100% chance of survival till hospital discharge, 1/4 had 77%, 2/4 had 50%, 3/4 had 25%. Patients with all 4 criteria had 0% survival. During in-hospital evolution, a pH<7.35 at 24h, lactates>2mmol/L at 24h, anoxic brain injury and persistent hemodynamic instability proved significant. Patients who had 0/4 of these in-hospital criteria had 100% chance of survival till hospital discharge, 1/4 had 94%, 2/4 had 47%, 3/4 had 25%. Patients with all 4 criteria had 0% survival. Contrarily, CAD severity and ventricular dysfunction didn't significantly correlate to the outcome.

CONCLUSION

Classic prehospital variables retain their value in predicting mortality in the specific group of OHCA with SigCAD. In-hospital evolution variables proved to add value in mortality prediction. Combining these simple variables in risk scores might help refining prognostic prediction in these patients's subset.

Impact of epinephrine administration frequency in out-of-hospital cardiac arrest patients: a retrospective analysis in a tertiary hospital setting

Introduction

Epinephrine is recommended for patients with out-of-hospital cardiac arrest (OHCA). However, whether epinephrine improves or adversely affects OHCA outcomes is controversial.

Objectives

This study aims to determine whether the frequency of epinephrine administration impacts OHCA patient survival.

Methods

We conducted a retrospective analysis of OHCA cases registered in the Emergency Department at King Fahd University Hospital, Saudi Arabia between 2005 and 2015. The primary outcomes were mortality and survival rates until discharge. The impact of epinephrine administration timing and frequency on patient survival was analyzed.

Results

Data from 300 OHCA cases were analyzed. Among them, 66.3% were men, and the overall mean age of 50.4 ± 20.6 years. The overall survival rate until hospital discharge was 12%. There was no statistically significant difference between in gender, age, or time interval to the first epinephrine dose in the survival and non-survival groups. Only the number of epinephrine doses was related to the survival outcome.

Conclusion

Non-survivors received significantly more epinephrine doses compared with survivors. However, a causal relationship between OHCA patient survival and epinephrine dose and time cannot be confirmed. Further studies are needed to investigate whether the long-term outcomes in OHCA patients are influenced by the timing and frequency of epinephrine administration.

Effect of initial airway strategy on time to epinephrine administration in patients with out-of-hospital cardiac arrest

INTRODUCTION

Epinephrine and advanced airway management are commonly used during treatment of out-of-hospital cardiac arrest (OHCA). Recent studies suggest that early but not late administration of epinephrine is associated with improved survival. The purpose of this study was to evaluate the effect of initial airway strategy on timing to the first epinephrine dose in OHCA.

METHODS

This is a secondary analysis of patients enrolled in the Pragmatic Airway Resuscitation Trial who had an advanced airway attempted. We examined differences in time to epinephrine administration by randomly assigned airway strategy, laryngeal tube (LT) or endotracheal tube (ETI); by the duration of airway attempt; and by number of attempts. We used survival methods to account for interval censoring due to unknown administration time. We also examined the association of epinephrine administration timing with survival to hospital discharge.

RESULTS

Among 2652 subjects (1299 ETI and 1353 LT), 2579 received epinephrine.There were no significant differences between ETI and LT in median time to initial epinephrine administration (min) (ETI - 9.0 vs. LT - 8.6, p = 0.55). There was no significant association between the duration of airway attempt or number of attempts and time to initial epinephrine administration (p = 0.12 and 0.66, respectively). Early administration of epinephrine (<10 min from EMS arrival) was significantly associated with survival compared to administration ≥10 min (OR 1.36, 95% CI: 1.05, 1.77).

CONCLUSIONS

There was no significant association between airway strategy and time to initial epinephrine administration. Earlier administration of epinephrine (< 10 min from EMS arrival) was associated with improved survival.

Repeated adrenaline doses and survival from an out-of-hospital cardiac arrest

BACKGROUND

Adrenaline is the primary drug of choice for resuscitation from out-of-hospital cardiac arrest (OHCA). Although adrenaline may increase the chance of achieving return of spontaneous circulation (ROSC), there is limited evidence that repeated doses of adrenaline improves overall survival, and increasing evidence of a detrimental effect on neurological function in survivors. This paper reports the relationship between repeated doses of adrenaline and survival in a cohort of patients attended by the London Ambulance Service in the United Kingdom.

METHODS

A retrospective review of OHCA treated by the London Ambulance Service over a one year period. Patients aged ≥18 years who received one or more doses of adrenaline (1 mg bolus) during resuscitation were included in the analyses. Outcomes described are survival to hospital discharge and survival to one year post-arrest.

RESULTS

Over the one year study period, 3151 patients received adrenaline during OHCA. A significant inverse relationship was found between increasing cumulative doses of adrenaline and survival both to hospital discharge and one year post-arrest. No patients survived after receiving more than ten adrenaline doses.

CONCLUSION

Our study indicates that repeated doses of adrenaline are associated with decreasing odds of survival. There were no survivors amongst patients requiring more than 10 doses of adrenaline.

The role of adrenaline in cardiopulmonary resuscitation

Adrenaline has been used in the treatment of cardiac arrest for many years. It increases the likelihood of return of spontaneous circulation (ROSC), but some studies have shown that it impairs cerebral microcirculatory flow. It is possible that better short-term survival comes at the cost of worse long-term outcomes. This narrative review summarises the rationale for using adrenaline, significant studies to date, and ongoing research.