Effectiveness of Prehospital Epinephrine Administration in Improving Long-term Outcomes of Witnessed Out-of-hospital Cardiac Arrest Patients with Initial Non-shockable Rhythms

2024 RECOVER Guidelines: Advanced Life Support. Evidence and knowledge gap analysis with treatment recommendations for small animal CPR

OBJECTIVE

To systematically review the evidence and devise clinical recommendations on advanced life support (ALS) in dogs and cats and to identify critical knowledge gaps.

DESIGN

Standardized, systematic evaluation of literature pertinent to ALS following Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Prioritized questions were each reviewed by Evidence Evaluators, and findings were reconciled by ALS Domain Chairs and Reassessment Campaign on Veterinary Resuscitation (RECOVER) Co-Chairs to arrive at treatment recommendations commensurate to quality of evidence, risk:benefit relationship, and clinical feasibility. This process was implemented using an Evidence Profile Worksheet for each question that included an introduction, consensus on science, treatment recommendations, justification for these recommendations, and important knowledge gaps. A draft of these worksheets was distributed to veterinary professionals for comment for 4 weeks prior to finalization.

SETTING

Transdisciplinary, international collaboration in university, specialty, and emergency practice.

RESULTS

Seventeen questions pertaining to vascular access, vasopressors in shockable and nonshockable rhythms, anticholinergics, defibrillation, antiarrhythmics, and adjunct drug therapy as well as open-chest CPR were reviewed. Of the 33 treatment recommendations formulated, 6 recommendations addressed the management of patients with nonshockable arrest rhythms, 10 addressed shockable rhythms, and 6 provided guidance on open-chest CPR. We recommend against high-dose epinephrine even after prolonged CPR and suggest that atropine, when indicated, is used only once. In animals with a shockable rhythm in which initial defibrillation was unsuccessful, we recommend doubling the defibrillator dose once and suggest vasopressin (or epinephrine if vasopressin is not available), esmolol, lidocaine in dogs, and/or amiodarone in cats.

CONCLUSIONS

These updated RECOVER ALS guidelines clarify the approach to refractory shockable rhythms and prolonged CPR. Very low quality of evidence due to absence of clinical data in dogs and cats continues to compromise the certainty with which recommendations can be made.

Effect of crew ratio of advanced life support-trained personnel on patients with out-of-hospital cardiac arrest: A systematic review and meta-analysis

BACKGROUND/PURPOSE

This review aimed to investigate the effect of crew ratios of on-scene advanced life support (ALS)-trained personnel on patients with out-of-hospital cardiac arrest (OHCA).

METHODS

We systematically searched PubMed, Ovid EMBASE, and the Cochrane Central Register of Controlled Trials databases from the inception date until September 30, 2022, for eligible studies. Two reviewers independently screened the studies for relevance, extracted data, and quality. We compared the effect of the ratio of on-scene ALS-trained personnel >50 % to those with a ratio ≤50 % among prehospital personnel on the clinical outcomes of OHCA patients. The primary outcome was survival-to-discharge and secondary outcomes were any return of spontaneous circulation (ROSC), sustained ROSC (≥2 h), and favourable neurological outcome at discharge (cerebral performance category scores: 1 or 2). Pooled odds ratios (ORs) were calculated, and the certainty of evidence was assessed.

RESULTS

From 10,864 references, we identified four non-randomised studies, including 16,475 patients. Two studies were performed in Japan and two in Taiwan. There were significant differences in survival-to-discharge (OR: 1.24, 95 % confidence interval [CI]: 1.07-1.44, I2: 7 %), any ROSC (OR:1.22, 95 % CI: 1.04-1.43, I2: 74 %) and sustained ROSC (OR: 1.39, 95 % CI: 1.16-1.65, I2: 40 %), but insignificant differences in favourable neurological outcome at discharge. The overall certainty of evidence was rated as very low for all outcomes.

CONCLUSION

Prehospital ALS care with a ratio of on-scene ALS-trained personnel >50 % could improve OHCA patient outcomes than crew ratios ≤50 %. Further studies are required to reach a robust conclusion.

Impact of emergency medical service with advanced life support training for adults with out-of-hospital cardiac arrest in the Republic of Korea: A retrospective multicenter study

Prehospital advanced life support (ALS) has been offered in many countries for patients experiencing out-of-hospital cardiac arrest (OHCA); however, its effectiveness remains unclear. This study aimed to determine the impact of emergency medical service (EMS) with ALS training as a nationwide pilot project for adults with OHCA in the Republic of Korea. This retrospective multicenter observational study was conducted between July 2019 and December 2020 using the Korean Cardiac Arrest Research Consortium registry. The patients were categorized into an intervention group that received EMS with ALS training and a control group that did not receive EMS with ALS training. Conditional logistic regression analysis was performed using matched data to compare clinical outcomes between the two groups. Compared with the control group, the intervention group had a lower rate of supraglottic airway usage (60.5% vs. 75.6%) and a higher rate of undergoing endotracheal intubation (21.7% vs. 6.1%, P < 0.001). In addition, the intervention group was administered more intravenous epinephrine (59.8% vs. 14.2%, P < 0.001) and used mechanical chest compression devices more frequently in prehospital settings than the control group (59.0% vs. 23.8%, P < 0.001). Based on the results of multivariable conditional logistic regression analysis, survival to hospital discharge (odds ratio: 0.48, 95% confidence interval: 0.27-0.87) of the intervention group was significantly lower than that of the control group; however, good neurological outcome was not significantly different between the two groups. In this study, survival to hospital discharge was worse in patients with OHCA who received EMS with ALS training than in those who did not.

Effects of prehospital management in out-of-hospital cardiac arrest: advanced airway and adrenaline administration

Background

There is uncertainty about the best approaches for advanced airway management (AAM) and the effectiveness of adrenaline treatments in Out-of-hospital cardiac arrest (OHCA). This study aimed to evaluate whether AAM and adrenaline administration provided by Emergency Medical Service (EMS) can improve the outcomes of OHCA.

Methods

This study was a prospective analysis of collected data based on OHCA adult patients treated by the EMS in China from January 2019 to December 2020.The patients were divided into AAM group and no AAM group, and into subgroups according to whether adrenaline was used. The outcome was rate of return of spontaneous circulation (ROSC), survival to admission and hospital discharge.

Results

1533 OHCA patients were reported. The probability of ROSC outcome and survival admission in the AAM group was significantly higher, compared with no AAM group. The probability of ROSC outcome in the AAM group increased by 66% (adjusted OR: 1.66, 95%CI, 1.02–2.71). There were no significant differences in outcomes between the adrenaline and no adrenaline groups. The combined treatment of AAM and adrenaline increased the probability of ROSC outcome by 114% (adjusted OR, 2.14, 95%CI, 1.20–3.81) and the probability of survival to admission increased by 115% (adjusted OR, 2.15, 95%CI, 1.16–3.97).

Conclusions

The prehospital AAM and the combined treatment of AAM and adrenaline in OHCA patients are both associated with an increased rate of ROSC. The combined treatment of AAM and adrenaline can improve rate of survival to admission in OHCA patients.

Effect of Prehospital Epinephrine Use on Survival from Out-of-Hospital Cardiac Arrest and on Emergency Medical Services

This study was to identify the effect of epinephrine on the survival of out-of-hospital cardiac arrest (OHCA) patients and changes in prehospital emergency medical services (EMSs) after the introduction of prehospital epinephrine use by EMS providers. This was a retrospective observational study comparing two groups (epinephrine group and norepinephrine group). We used propensity score matching of the two groups and identified the association between outcome variables regarding survival and epinephrine use, controlling for confounding factors. The epinephrine group was 339 patients of a total 1943 study population. The survival-to-discharge rate and OR (95% CI) of the epinephrine group were 5.0% (p = 0.215) and 0.72 (0.43–1.21) in the total patient population and 4.7% (p = 0.699) and 1.15 (0.55–2.43) in the 1:1 propensity-matched population. The epinephrine group received more mechanical chest compression and had longer EMS response times and scene times than the norepinephrine group. Mechanical chest compression was a negative prognostic factor for survival to discharge and favorable neurological outcomes in the epinephrine group. The introduction of prehospital epinephrine use in OHCA patients yielded no evidence of improvement in survival to discharge and favorable neurological outcomes and adversely affected the practice of EMS providers, exacerbating the factors negatively associated with survival from OHCA.

A Time-Dependent Propensity Score Matching Approach to Assess Epinephrine Use on Patients Survival Within Out-of-Hospital Cardiac Arrest Care

BACKGROUND

Epinephrine effectiveness and safety are still questioned. It is well known that the effect of epinephrine varies depending on patients' rhythm and time to injection.

OBJECTIVE

We aimed to assess the association between epinephrine use during out-of-hospital cardiac arrest (OHCA) care and patient 30-day (D30) survival.

METHODS

Between 2011 and 2017, 27,008 OHCA patients were included from the French OHCA registry. We adjusted populations using a time-dependent propensity score matching. Analyses were stratified according to patient's first rhythm. After matching, 2837 pairs of patients with a shockable rhythm were created and 20,950 with a nonshockable rhythm.

RESULTS

Whatever the patient's rhythm (shockable or nonshockable), epinephrine use was associated with less D30 survival (odds ratio [OR] 0.508; 95% confidence interval [CI] 0.440-0.586] and OR 0.645; 95% CI 0.549-0.759, respectively). In shockable rhythms, on all outcomes, epinephrine use was deleterious. In nonshockable rhythms, no difference was observed regarding return of spontaneous circulation and survival at hospital admission. However, epinephrine use was associated with worse neurological prognosis (OR 0.646; 95% CI 0.549-0.759).

CONCLUSIONS

In shockable and nonshockable rhythms, epinephrine does not seem to have any benefit on D30 survival. These results underscore the need to perform further studies to define the optimal conditions for using epinephrine in patients with OHCA.

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.

Effect of Implementation of Cardiopulmonary Resuscitation-Targeted Multi-Tier Response System on Outcomes After Out-of-Hospital Cardiac Arrest: A Before-and-After Population-Based Study

Objective: A multi-tiered response (MTR) system has been controversial in terms of cost-effectiveness and outcome improvement. It remains uncertain whether a cardiopulmonary resuscitation (CPR)-targeted tiered response system is associated with better outcomes after out-of-hospital cardiac arrest (OHCA). This study aimed to investigate the effect of an MTR on OHCA outcomes. Methods: A natural experimental study was conducted for resuscitation-attempted adult OHCAs. The MTR system was implemented in Korea by the National Fire Agency in 2015 across the country where the single-tiered ambulance response system existed. The MTR program had the following 3 components: 1) detection of OHCA by dispatcher, 2) dispatch of ambulance or fire engine in addition to routine dispatch of ambulance, and 3) performance of team CPR. The study period of 2015-2016 was divided by 6 months (phases I [reference], II, III, and IV). The endpoints were prehospital defibrillation, prehospital return of spontaneous circulation (PROSC), survival to discharge and good neurological recovery. A multivariable logistic regression analysis was performed to evaluate the effect of the intervention, and adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were calculated, adjusting for potential confounders. Results: A total of 32,663 eligible OHCA cases were evaluated during the study period. As the intervention program spread, the MTR with ambulance increased (from 7.0% in phase I to 53.7% in phase IV, p for trend < 0.01). During the study period, prehospital defibrillation increased from 23.6% in phase I to 26.9% in phase IV and the study outcome was improved from 7.4 to 12.6% for PROSC, from 6.7 to 9.1% for survival to discharge, and from 4.5 to 5.8% for good neurological outcome (p for trend < 0.01 for all). Compared with phase I, the AORs (95% CI) of phase IV were 1.16 (1.08-1.25) for prehospital defibrillation, 1.82 (1.63-2.04) for PROSC, 1.37 (1.21-1.56) for survival to discharge, and 1.23 (1.06-1.43) for good neurological outcome. Conclusion: The nationwide implementation of a multi-tiered response system for OHCA was associated with increased prehospital defibrillation and improved outcomes of OHCA patients.

The effects of cardiac arrest recognition by dispatcher on Smart Advanced Life Support

Objectives:

The purpose of this study was to analyze the effect of cardiac arrest recognition by emergency medical dispatch on the pre-hospital advanced cardiac life support and to investigate the outcome of out-of-hospital cardiac arrest.

Method:

This study was conducted to evaluate the out-of-hospital cardiac arrest patients over 18 years of age, excluding trauma and poisoning patients, from 1 August 2015 to 31 July 2016. We investigated whether it was a cardiac-arrest recognition at dispatch. We compared the pre-hospital return of spontaneous circulation, the rate of survival admission and discharge, good neurological outcome, and also analyzed the time of securing vein, time of first epinephrine administration, and arrival time of paramedics.

Results:

A total of 3695 out-of-hospital cardiac arrest patients occurred during the study period, and 1468 patients were included in the study. Resuscitation rate by caller was significantly higher in the recognition group. The arrival interval between the first and second emergency service unit was shorter as 5.1 min on average, and the connection rate of paramedics and physicians before the arrival was 32.3%, which was significantly higher than that of the unrecognized group. The mean time required to first epinephrine administration was 13.1 min, which was significantly faster in the recognition group. However, there was no statistically significant difference between the two groups in patients with good neurological outcome, and rather the rate of return of spontaneous circulation and survival discharge was significantly higher in the non-recognition group.

Conclusion:

Although the recognition of cardiac arrest at dispatch does not directly affect survival rate and good neurological outcome, the activation of pre-hospital advanced cardiac life support and the shortening the time of epinephrine administration can increase pre-hospital return of spontaneous circulation. Therefore, effort to increase recognition by dispatcher is needed.

Advanced airway management during adult cardiac arrest: A systematic review

AIM

To systematically review the literature on advanced airway management during adult cardiac arrest in order to inform the International Liaison Committee of Resuscitation (ILCOR) consensus on science and treatment recommendations.

METHODS

The review was performed according to PRISMA guidelines and registered on PROSPERO (CRD42018115556). We searched Medline, Embase, and Evidence-Based Medicine Reviews for controlled trials and observational studies published before October 30, 2018. The population included adult patients with cardiac arrest. Two investigators reviewed studies for relevance, extracted data, and assessed the risk of bias of individual studies.

RESULTS

We included 78 observational studies and 11 controlled trials. Most of the observational studies and all of the controlled trials only included patients with out-of-hospital cardiac arrest. The risk of bias for individual observational studies was overall assessed as critical or serious, with confounding and selection bias being the primary sources of bias. Three of the controlled trials, all published in 2018, were powered for clinical outcomes with two comparing a supraglottic airway to tracheal intubation and one comparing bag-mask ventilation to tracheal intubation. All three trials had some concerns regarding risk of bias primarily due to lack of blinding and variable adherence to the protocol. Clinical and methodological heterogeneity across studies, for both the observational studies and the controlled trials, precluded any meaningful meta-analyses.

CONCLUSIONS

We identified a large number of studies related to advanced airway management in adult cardiac arrest. Three recently published, large randomized trials in out-of-hospital cardiac arrest will help to inform future guidelines. Trials of advanced airway management during in-hospital cardiac arrest are lacking.

Time to epinephrine treatment is associated with the risk of mortality in children who achieve sustained ROSC after traumatic out-of-hospital cardiac arrest

Background

The benefits of early epinephrine administration in pediatric with nontraumatic out-of-hospital cardiac arrest (OHCA) have been reported; however, the effects in pediatric cases of traumatic OHCA are unclear. Since the volume-related pharmacokinetics of early epinephrine may differ obviously with and without hemorrhagic shock (HS), beneficial or harmful effects of nonselective epinephrine stimulation (alpha and beta agonists) may also be enhanced with early administration. In this study, we aimed to analyze the therapeutic effect of early epinephrine administration in pediatric cases of HS and non-HS traumatic OHCA.

Methods

This was a multicenter retrospective study (2003–2014). Children (aged ≤ 19 years) who experienced traumatic OHCA and were administered epinephrine for resuscitation were included. Children were classified into the HS (blood loss > 30% of total body fluid) and non-HS groups. The demographics, outcomes, postresuscitation hemodynamics (the first hour) after the sustained return of spontaneous circulation (ROSC), and survival durations were analyzed and correlated with the time to epinephrine administration (early < 15, middle 15–30, late > 30 min) in the HS and non-HS groups. Cox regression analysis was used to adjust for risk factors of mortality.

Results

A total of 509 children were included. Most of them (n = 348, 68.4%) had HS OHCA. Early epinephrine administration was implemented in 131 (25.7%) children. In both the HS and non-HS groups, early epinephrine administration was associated with achieving sustained ROSC (both p < 0.05) but was not related to survival or good neurological outcomes (without adjusting for confounding factors). However, early epinephrine administration in the HS group increased cardiac output but induced metabolic acidosis and decreased urine output during the initial postresuscitation period (all p < 0.05). After adjusting for confounding factors, early epinephrine administration was a risk factor of mortality in the HS group (HR 4.52, 95% CI 2.73–15.91).

Conclusion

Early epinephrine was significantly associated with achieving sustained ROSC in pediatric cases of HS and non-HS traumatic OHCA. For children with HS, early epinephrine administration was associated with both beneficial (increased cardiac output) and harmful effects (decreased urine output and metabolic acidosis) during the postresuscitation period. More importantly, early epinephrine was a risk factor associated with mortality in the HS group.

Pharmacokinetic effects of endotracheal, intraosseous, and intravenous epinephrine in a swine model of traumatic cardiac arrest

INTRODUCTION

Limited prospective data exist regarding epinephrine's controversial role in managing traumatic cardiac arrest (TCA). This study compared the maximum concentration (Cmax), time to maximum concentration (Tmax), plasma concentration over time, return of spontaneous circulation (ROSC), time to ROSC, and odds of ROSC of epinephrine administered by the endotracheal (ETT), intraosseous (IO), and intravenous (IV) routes in a swine TCA model.

METHODS

Forty-nine Yorkshire-cross swine were assigned to seven groups: ETT, tibial IO (TIO), sternal IO (SIO), humeral IO (HIO), IV, CPR with defibrillation (CPRD), and CPR only. Swine were exsanguinated 31% of their blood volume and cardiac arrest induced. Chest compressions began 2 min post-arrest. At 4 min post-arrest, 1 mg epinephrine was administered, and blood specimens collected over 4 min. Resuscitation continued until ROSC or 30 min elapsed.

RESULTS

The Cmax of IV epinephrine was significantly higher than the TIO group (P = 0.049). No other differences in Cmax, Tmax, ROSC, and time to ROSC existed between the epinephrine groups (P > 0.05). Epinephrine levels were detectable in two of seven ETT swine. No significant difference in ROSC existed between the epinephrine groups and CPRD group (P > 0.05). Significant differences in ROSC existed between all groups and the CPR only group (P < 0.05). No significant differences in odds of ROSC were noted.

CONCLUSIONS

The pharmacokinetics of IV, HIO, and SIO epinephrine were comparable. Endotracheal epinephrine absorption was highly variable and unreliable compared to IV and IO epinephrine. Epinephrine appeared to have a lesser role than volume replacement in resuscitating TCA.

Early Epinephrine Improves the Stabilization of Initial Post-resuscitation Hemodynamics in Children With Non-shockable Out-of-Hospital Cardiac Arrest

Background: In children with non-shockable out-of-hospital cardiac arrest, early epinephrine (EE) might help to establish the return of spontaneous circulation (ROSC) and be associated with survival. In the present study, we aimed to analyze the effects of EE on outcomes and post-resuscitation hemodynamics in children with non-shockable OHCA. Methods: This was a retrospective analysis of data from 216 children (<19 years) who had suffered non-traumatic and non-shockable OHCA and received epinephrine for resuscitation (Jan 1, 2006-Dec 31, 2014). Demographics, pre-/in-hospital information, and the time to the first dose of epinephrine were recorded. Early post-resuscitation hemodynamics (the first hour after sustained ROSC), survival and good neurological outcomes (Pediatric Cerebral Performance Category Scales 1 or 2) were analyzed by the time to epinephrine-classified as early (EE): <15 min, intermediate (IE): 15-30 min, or late (LE): >30 min. Results: Twenty-eight (13.0%) children survived to discharge, but only 17 (7.9%) had good neurological outcomes. In all, 41 (18.9%) children received EE; in comparison to IE and LE, this was significantly associated with tachycardia (73.9%) in the post-resuscitation period (p < 0.05). Tachycardia (OR: 7.41, 95% CI: 1.96-29.31) and hypertension (OR: 6.03, 95% CI: 1.85-13.77) were significantly associated with EE after adjusting for confounding factors. EE was also significantly associated with better overall outcomes than ME and LE (any ROSC, sustained ROSC, survival to the intensive care unit, admission, survival to discharge and good neurological outcomes, all p < 0.05). Conclusions: EE helped to establish ROSC but was also associated with more tachycardia and hypertension in the early post-resuscitation period. In children with non-traumatic and non-shockable OHCA, EE was associated with a higher survival rate and better neurological outcomes than were ME and LE.

Effects of prehospital epinephrine administration on neurologically intact survival in bystander-witnessed out-of-hospital cardiac arrest patients with non-shockable rhythm depend on prehospital cardiopulmonary resuscitation duration required to hospital arrival

The effects of prehospital epinephrine administration on post-arrest neurological outcome in out-of-hospital cardiac arrest (OHCA) patients with non-shockable rhythm remain unclear. To examine the time-dependent effectiveness of prehospital epinephrine administration, we analyzed 118,396 bystander-witnessed OHCA patients with non-shockable rhythm from the prospectively recorded all-Japan OHCA registry between 2011 and 2014. Patients who achieved prehospital return of spontaneous circulation without prehospital epinephrine administration were excluded. Patients with prehospital epinephrine administration were stratified according to the time from the initiation of cardiopulmonary resuscitation (CPR) by emergency medical service (EMS) providers to the first epinephrine administration (≤ 10, 11-19, and ≥ 20 min). Patients without prehospital epinephrine administration were stratified according to the time from CPR initiation by EMS providers to hospital arrival (≤ 10, 11-19, and ≥ 20 min). The primary outcome was 1-month neurologically intact survival (cerebral performance category 1 or 2; CPC 1-2). Multivariate logistic regression analysis demonstrated that there was no significant difference in the chance of 1-month CPC 1-2 between patients who arrived at hospital in ≤ 10 min without prehospital epinephrine administration and patients with time to epinephrine administration ≤ 19 min. However, compared to patients who arrived at hospital in ≤ 10 min without prehospital epinephrine administration, patients with time to epinephrine administration ≥ 20 min and patients who arrived at hospital in 11-19, and ≥ 20 min without prehospital epinephrine administration were significantly associated with decreased chance of 1-month CPC 1-2 (p < 0.05, < 0.05, and < 0.001, respectively). In conclusion, when prehospital CPR duration from CPR initiation by EMS providers to hospital arrival estimated to be ≥ 11 min, prehospital epinephrine administered ≤ 19 min from CPR initiation by EMS providers could improve neurologically intact survival in bystander-witnessed OHCA patients with non-shockable rhythm.

The effect of the number and level of emergency medical technicians on patient outcomes following out of hospital cardiac arrest in Taipei

AIM

The effect of the number and level of on-scene emergency medical technicians (EMTs) on the outcomes of patients with out-of-hospital cardiac arrest (OHCA) remains unclear. We aimed to test the association between the number and level of EMTs and the outcomes of patients with OHCA.

METHODS

We analysed Utstein-based registry data on OHCA in Taipei from 2011 to 2015. The eligible patients were adults, aged ≥20 years, with non-traumatic OHCA who underwent resuscitation attempts. The exposures were the total number of EMTs or the EMT-Paramedic (EMT-P) ratio >50%. The outcome of interest was survival to discharge.

RESULTS

During study period, total 8262 OHCA cases were included, of which 1085 (13.1%) were approached by crews with an EMT-P ratio >50%. While an increase in the number of EMTs on-scene was not associated with better chances of survival (adjusted odds ratio [aOR] 0.98, 95% confidence interval [CI] 0.89-1.08), an EMT-P ratio >50% was significantly associated with improved outcome (aOR 1.36, 95% CI 1.06-1.76). Subgroup analyses showed that EMT-P >50% significantly benefited survival in witnessed OHCA cases with non-shockable rhythm (aOR 1.69, 95% CI 1.01-2.58). Survival was the highest among cases seen by four EMTs with an EMT-P ratio >50% (aOR 2.54, 95% CI 1.43-4.50).

CONCLUSION

An on-scene EMT-P ratio >50% was associated with improved survival to discharge of OHCA cases, especially in those with witnessed, non-shockable rhythm. The presence of four EMTs with an EMT-P ratio >50% at the scene of OHCA was associated with the best outcome.