The association between emergency medical services staffing patterns and out-of-hospital cardiac arrest survival

An exploratory study on the effect of rescuer team size on basic and advanced life support technical skills in a high-fidelity simulation of canine cardiopulmonary arrest

OBJECTIVE

To evaluate the effect of rescuer team size on objective skill measures of basic life support (BLS) and advanced life support (ALS) using high-fidelity canine CPR simulation.

DESIGN

Prospective, experimental study.

SETTING

Veterinary clinical simulation center.

SUBJECTS

Forty-eight Reassessment Campaign on Veterinary Resuscitation CPR-certified veterinary students.

MEASUREMENTS AND MAIN RESULTS

Five groups of participants each conducted 3 CPR simulations in configurations of 4, 6, and 8 rescuers. Simulations represented a shock patient declining into asystole, followed by ventricular fibrillation and return of spontaneous circulation. Resuscitation efforts were video-recorded to evaluate BLS and ALS tasks. Mean (±SD) was derived and data were compared among team sizes using ANOVA and Tukey's post hoc analysis. Significance was set at P < 0.05. Among teams of 4, 6, and 8 rescuers, time to first chest compression (13 s [±6], 9 s [±2], 8 s [±4]; P = 0.24) and positive-pressure breath (101 s [±37], 56 s [±15], 67 s [±24]; P = 0.05) were not significantly different. Chest compression (100/min [±5], 108/min [±6], 107/min [±6]; P = 0.12) and ventilatory rates (9/min [±1], respectively, P = 0.52) were not significantly different. Time without chest compressions/total length of CPR was not significantly different (72 s [±16], 61 s [±16], 54 s [±8]; P = 0.15). Capnography and ECG monitoring were used by all teams. Time to first vasopressor administration was significantly different among team sizes (268 s [±70], 164 s [±65], 174 s [±34]; P = 0.04), with vasopressors being most quickly administered by teams of 6 rescuers. Time to electrical defibrillation was not significantly different (486 s [±45], 424 s [±22], 488 s [±181]; P = 0.57). Incorrect ALS interventions occurred in 60%, 0%, and 40% of CPR events in 4, 6, and 8 rescuer teams, respectively.

CONCLUSIONS

Although the achievement of BLS tasks was comparable in teams of 4 rescuers, teams of 6 rescuers may be preferable based on differences in the rate of guideline-incompliant treatments and ALS task efficiency. Teams of 8 rescuers were neither more efficient nor more accurate at conducting BLS and ALS tasks.

Efficiency of two-member crews in delivering prehospital advanced life support cardiopulmonary resuscitation: A scoping review

BACKGROUND

Advanced Life Support (ALS) during cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrest (OHCA) is frequently administered by two-member crews. However, ALS CPR is mostly designed for larger crews, and the feasibility and efficacy of implementing ALS guidelines for only two rescuers remain unclear.

OBJECTIVE

This scoping review aims to examine the existing evidence and identify knowledge gaps in the efficiency of pre-hospital ALS CPR performed by two-member teams.

DESIGN

A comprehensive search was undertaken across the following databases: PubMed, Web of Science, SCOPUS, Cochrane Library Trials, and ClinicalTrials.gov. The search covered publications in English or German from January 1, 2005, to November 30, 2023. The review included studies that focused on ALS CPR procedures carried out by two-member teams in adult patients in either simulated or clinical settings.

RESULTS

A total of 22 articles were included in the qualitative synthesis. Seven topics in two-person prehospital ALS/CPR delivery were identified: 1) effect of team configuration on clinical outcome and CPR quality, 2) early airway management and ventilation techniques, 3) mechanical chest compressions, 4) prefilled syringes, 5) additional equipment, 6) adaptation of recommended ALS/CPR protocols, and 7) human factors.

CONCLUSION

There is a lack of comprehensive data regarding the adaptation of the recommended ALS algorithm in CPR for two-member crews. Although simulation studies indicate potential benefits arising from the employment of mechanical chest compression devices, prefilled syringes, and automation-assisted protocols, the current evidence is too limited to support specific modifications to existing guidelines.

Out-of-Hospital Cardiac Arrest

Survival from out-of-hospital cardiac arrest (OHCA) is predicated on a community and system-wide approach that includes rapid recognition of cardiac arrest, capable bystander CPR, effective basic and advanced life support (BLS and ALS) by EMS providers, and coordinated postresuscitation care. Management of these critically ill patients continues to evolve. This article focuses on the management of OHCA by EMS providers.

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.

Prehospital emergency medicine research by additional teams on scene - Concepts and lessons learned

While the initial minutes of acute emergencies significantly influence clinical outcomes, prehospital research often receives inadequate attention due to several challenges. Retrospective chart reviews carry the risk of incomplete and inaccurate data. Furthermore, prehospital intervention trials frequently encounter difficulties related to extensive training requirements, even during the planning phase. Consequently, we have implemented prospective research concepts involving additional paramedics and physicians directly at the scene during major emergency calls. Three concepts were used: (I) Paramedic field supervisor units, (II) a paramedic + physician field supervisor unit, (III) a special physician-based research car. This paper provides insights into our historical perspective, the current situation, and the lessons learned while overcoming certain barriers and using existing and novel facilitators. Our objective is to support other research groups with our experiences in their planning of upcoming prehospital trials.

Out-of-Hospital Cardiac Arrest

Survival from out-of-hospital cardiac arrest (OHCA) is predicated on a community and system-wide approach that includes rapid recognition of cardiac arrest, capable bystander CPR, effective basic and advanced life support (BLS and ALS) by EMS providers, and coordinated postresuscitation care. Management of these critically ill patients continues to evolve. This article focuses on the management of OHCA by EMS providers.

Urban-suburb disparities in pre-hospital emergency medical resources and response time among patients with out-of-hospital cardiac arrest: A mixed-method cross-sectional study

Aim

To investigate (1) the association between pre-hospital emergency medical resources and pre-hospital emergency medical system (EMS) response time among patients with Out-of-hospital cardiac arrest (OHCA); (2) whether the association differs between urban and suburbs.

Methods

Densities of ambulances and physicians were independent variables, respectively. Pre-hospital emergency medical system response time was dependent variable. Multivariate linear regression was used to investigate the roles of ambulance density and physician density in pre-hospital EMS response time. Qualitative data were collected and analyzed to explore reasons for the disparities in pre-hospital resources between urban areas and suburbs.

Results

Ambulance density and physician density were both negatively associated with call to ambulance dispatch time, with odds ratios (ORs) 0.98 (95% confidence interval [CI] 0.96-0.99; P = 0.001) and 0.97 (95% CI; 0.93-0.99; P < 0.001), respectively. ORs of ambulance density and physician density in association with total response time were 0.99 (95% CI: 0.97-0.99; P = 0.013) and 0.90 (95% CI: 0.86-0.99; P = 0.048). The effect of ambulance density on call to ambulance dispatch time in urban areas was 14% smaller than that in suburb areas and that on total response time in urban areas was 3% smaller than the effect in suburbs. Similar effects were identified for physician density on urban-suburb disparities in call to ambulance dispatch time and total response time. The main reasons summarized from stakeholders for a lack of physicians and ambulances in suburbs included low income, poor personal incentive mechanisms, and inequality in financial distribution of the healthcare system.

Conclusion

Improving pre-hospital emergency medical resources allocation can reduce system delay and narrow urban-suburb disparity in EMS response time for OHCA patients.

The number and level of first-contact emergency medical services crew and clinical outcomes in out-of-hospital cardiac arrest with dual dispatch response

OBJECTIVE

This study aimed to evaluate the association between the number and level of emergency medical technicians (EMTs) in the first-contact emergency medical services (EMS) unit and the clinical outcomes of out-of-hospital cardiac arrest (OHCA) with a dual dispatch response.

METHODS

Adult nontraumatic EMS-treated OHCAs between 2015 and 2018 in a nationwide database, were enrolled. The main exposure was the number and certification level of first-contact EMS crew: three versus two members, proportion of EMT intermediate level (EMT-I) over 50% versus under or equal to 50%. Good neurologic recovery was selected as the primary outcome. Multilevel multivariable logistic regression analysis was conducted to calculate adjusted odds ratios and confidence intervals.

RESULTS

A total of 26,867 patients were enrolled and analyzed. Good neurologic recovery was different across the study groups: 5.4% in the two-member crews, 7.2% in the three-member crews, 5.9% in the low EMT-I proportion crews, and 6.8% in the high EMT-I proportion crews. In the main analysis, statistically significant differences for favorable outcomes were found between the three-member and two-member crews, and the high EMT-I proportion and low EMT-I proportion crews; for good neurologic recovery, adjusted odds ratios (95% confidence interval) were 1.23 (1.06-1.43) for three-member crews, and 1.28 (1.17-1.40) for a high EMT-I proportion.

CONCLUSION

The higher number and level of first-contact EMS crew was associated with better neurologic recovery in adult nontraumatic OHCA with a dual-dispatched EMS response.

Association between Paramedic Workforce and Survival Rate in Prehospital Advanced Life Support in Out-of-Hospital Cardiac Arrest Patients

The low survival rate of out-of-hospital cardiac arrest (OHCA) patients is a global public health challenge. We analyzed the relationship between the number of prehospital EMS personnel and survival admission, survival discharge, and good neurologic outcomes in OHCA patients. This was a retrospective observational study. Adult nontraumatic OHCA patients from January 1, 2015, to December 31, 2018, were included from 12 cities in the Gyeonggi province, a metropolitan area located in the suburbs of the capital of the Republic of Korea. By comparing the insufficient EMS team (four or five EMS personnel) and the sufficient EMS team (six EMS personnel), we showed the survival rate of each group. Using propensity score matching, we reduced the bias of the confounding variables. A total of 3,632 OHCA patients were included. After propensity score matching, survival to admission was higher in the sufficient EMS team than in the insufficient EMS team (odds ratio (OR): 1.38, 95% confidence interval (CI): 1.04–1.84, P=0.03). Survival-to-discharge was similar (OR: 1.70, CI: 1.20–2.40, P=0.03), but there was no significant outcome in good neurologic outcomes (OR: 0.88, CI: 0.57–1.36, P=0.58). Our findings suggest that a sufficient EMS team (six EMS personnel) could improve the survival admission and discharge of OHCA patients compared to an insufficient EMS team (four or five EMS personnel). However, there was no significant difference in neurologic outcomes according to the number of EMS personnel.

The Association Between the Number of Prehospital Providers On-Scene and Out-of-Hospital Cardiac Arrest Outcomes

Objective: The ideal number of emergency medical services (EMS) providers needed on-scene during an out-of-hospital cardiac arrest (OHCA) resuscitation is unknown. Our objective was to evaluate the association between the number of providers on-scene and OHCA outcomes. Methods: This was a secondary analysis of adults (≥18 years old) with non-traumatic OHCA from a 10-site North American prospective cardiac arrest registry (Resuscitation Outcomes Consortium) including a 2005-2011 cohort and a 2011-2015 cohort. The primary outcome was survival to hospital discharge. We calculated the median number of EMS providers on-scene during the first 10 minutes of the resuscitation and used multivariable logistic regression adjusting for age, sex, witness status, bystander CPR, arrest location, initial rhythm, and dispatch to EMS arrival time. Results: There were 30,613 and 41,946 patients with necessary variables in the 2005-2011 and 2011-2015 cohorts, respectively. Survival to hospital discharge (95% CI) was higher with 9 or more providers on-scene (17.2% [15.8-18.5] and 14.0% [12.6-15.4]) compared to 7-8 (14.1% [13.4-14.8] and 10.5% [9.9-11.1]), 5-6 (10.0% [9.5-10.5] and 8.5% [8.1-8.9]), 3-4 (10.5% [9.3-11.6] and 9.3% [8.5-10.1]), and 1-2 (8.6% [7.2-10.0] and 8.0% [7.1-9.0]) providers for the 2005-2011 and 2011-2015 cohorts, respectively. In multivariable logistic regressions, compared to 5-6 providers, there were no significant differences in survival to hospital discharge for 1-2 or 3-4 providers, while having 7-8 (adjusted odds ratios (aORs) 1.53 [1.39-1.67] and 1.31 [1.20-1.44]) and 9 or more (aORs 1.76 [1.56-1.98] and 1.63 [1.41-1.89]) providers were associated with improved survival in both the 2005-2011 and 2011-2015 cohorts, respectively. Conclusions: The presence of seven or more prehospital providers on-scene was associated with significantly greater adjusted odds of survival to hospital discharge after OHCA compared to fewer on-scene providers.

Can We Predict Good Survival Outcomes by Classifying Initial and Re-Arrest Rhythm Change Patterns in Out-of-Hospital Cardiac Arrest Settings?

Objective

The purpose of this study was to investigate whether a change in prehospital arrest rhythms could allow medical personnel to predict survival outcomes in patients who achieved a return of spontaneous circulation (ROSC) in the setting of out-of-hospital cardiac arrest (OHCA).

Methods

The design of this study was retrospective, multi-regional, observational, and cross-sectional with a determining period between August 2015 and July 2016. Cardiac arrest rhythms were defined as a shockable rhythm (S), which refers to ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT), and non-shockable rhythm (NS), which refers to pulseless electrical activity or asystole. Survival to admission, survival to discharge, and good cerebral performance category (CPC) (CPC 1 or 2) were defined as good survival outcomes.

Results

A total of 163 subjects were classified into four groups according to the rhythm change pattern: NS→NS (98), S→S (27), S→NS (23), and NS→S (15). NS→NS pattern was used as the reference in logistic regression analysis. In the case of survival to hospital admission, the odds ratio (OR) (95% CI) of the S→S pattern was the highest [12.63 (3.56-44.85), p: <0.001 by no correction] and [7.29 (1.96-27.10), p = 0.003 with adjusting]. In the case of survival to hospital discharge, the OR (95% CI) of the S→S pattern was the highest [37.14 (11.71-117.78), p: <0.001 by no correction] and [13.85 (3.69-51.97), p: <0.001 with adjusting]. In the case of good CPC (CPC 1 or 2) at discharge, the OR (95% CI) of the S→S pattern was the highest [96 (19.14-481.60), p: <0.001 by no correction] and [149.69 (19.51-1148.48), p: <0.001 with adjusting].

Conclusions

The S→S group showed the highest correlation with survival to hospital admission, survival to hospital discharge, and good CPC (CPC 1 or 2) at discharge compared to the NS→NS group. Verifying changes in initial cardiac arrest rhythm and prehospital re-arrest (RA) rhythm patterns after prehospital ROSC can help us predict good survival outcomes in the OHCA setting.

Healthcare costs and resource utilization associated with treatment of out-of-hospital cardiac arrest

BACKGROUND

The management of out-of-hospital cardiac arrest (OHCA) patients requires the coordination of prehospital, in-hospital and post-discharge teams. Data reporting a comprehensive analysis of all costs associated with treating OHCA are scarce. We aimed to describe the total costs (and their components) related to the management of OHCA patients.

PATIENT AND METHODS

We performed an analysis on a merged database of the Toronto Regional RescuNet Epistry database (prehospital data) and administrative population-based databases in Ontario. All non-traumatic OHCA patients over 18 years of age treated by the EMS between January 1, 2006, and March 31, 2014, were included in this study. The primary outcome was per patient longitudinal cumulative healthcare costs, from time of collapse to a maximum follow-up until death or 30 days after the event. We included all available cost sectors, from the perspective of the health system payer. We used multivariable generalized linear models with a logarithmic link and a gamma distribution to determine predictors of healthcare costs.

RESULTS

25,826/44,637 patients were treated by EMS services for an OHCA (mostly male 64.4%, mean age 70.1). 11,727 (45%) were pronounced dead on scene, 8359 (32%) died in the emergency department, 3640 (14%) were admitted to hospital but died before day-30, and 2100 (8.1%) were still alive at day-30. Total cost was $690 [interquartile range (IQR) $308, $1742] per patient; ranging from $290 [IQR $188, $390] for patients who were pronounced on scene to $39,216 [IQR 21,802, 62,093] for patients who were still alive at day-30. In-hospital costs accounted for 93% of total costs. After adjustment for age and gender, rate of patient survival was the main driver of total costs: the rate ratio was 3.88 (95% confidence interval 3.80, 3.95), 49.46 and 148.89 for patients who died in the ED, patients who died after the ED but within 30 days, and patients who were still alive at day-30 compared to patients who were pronounced dead on scene, respectively. Factors independently associated with costs were the number of prehospital teams (rate ratio (RR) 5.50 [5.32, 5.67] for being treated by 4 teams vs. 1), the need for hospital transfer (RR 2.38 [2.01, 2.82]), coronary angiography (RR 1.43 [1.27, 1.62]) and targeted temperature management (RR 1.25 [1.09, 1.44]).

CONCLUSION

Survival is the main driver of total costs of treating OHCA patients in a large Canadian health system. Inpatient costs accounted for the majority of the total costs; potentially modifiable factors include the number of prehospital teams that arrive to the scene of the arrest and the need for between-hospital transfers after successful resuscitation.

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.

Impacts of Emergency Medical Technician Configurations on Outcomes of Patients with Out-of-Hospital Cardiac Arrest

Paramedics can provide advanced life support (ALS) for patients with out-of-hospital cardiac arrest (OHCA). However, the impact of emergency medical technician (EMT) configuration on their outcomes remains debated. A three-year cohort study consisted of non-traumatic OHCA adults transported by ALS teams was retrospectively conducted in Tainan City using an Utstein-style population database. The EMT-paramedic (EMT-P) ratio was defined as the EMT-P proportion out of all on-scene EMTs. Among the 1357 eligible cases, the median (interquartile range) number of on-scene EMTs and the EMT-P ratio were 2 (2–2) persons and 50% (50–100%), respectively. The multivariate analysis identified five independent predictors of sustained return of spontaneous circulation (ROSC): younger adults, witnessed cardiac arrest, prehospital ROSC, prehospital defibrillation, and comorbid diabetes mellitus. After adjustment, every 10% increase in the EMT-P ratio was on average associated with an 8% increased chance (adjusted odds ratio [aOR], 1.08; p < 0.01) of sustained ROSC and a 12% increase change (aOR, 1.12; p = 0.048) of favorable neurologic status at discharge. However, increased number of on-scene EMTs was not linked to better outcomes. For nontraumatic OHCA adults, an increase in the on-scene EMT-P ratio resulted in a higher proportion of improved patient outcomes.

Prospective Evaluation of Cardiopulmonary Resuscitation Performed in Dogs and Cats According to the RECOVER Guidelines. Part 1: Prognostic Factors According to Utstein-Style Reporting

Factors associated with positive cardiopulmonary resuscitation (CPR) outcomes defined according to the veterinary Utstein-style CPR reporting guidelines have not been described since implementation of the Reassessment Campaign on Veterinary Resuscitation (RECOVER) CPR clinical guidelines in 2012. The aims of this study were to assess factors associated with positive CPR outcomes at a U.S. veterinary teaching hospital, to re-evaluate these factors since implementation of the RECOVER guidelines compared to reported factors prior to their publication, and to identify potential additional factors since guideline publication. One-hundred and seventy-two dogs and 47 cats that experienced cardiopulmonary arrest (CPA) and had CPR performed were prospectively included in this observational study. Supervising clinicians were asked to complete a data form on CPR events immediately following completion of CPR efforts. Multivariable logistic regression was used to evaluate the effect of twenty hospital, animal, and arrest variables on the three patient outcomes “any return of spontaneous circulation (ROSC),” “sustained ROSC,” and survival to hospital discharge. Cats had significantly higher odds to achieve any ROSC [OR (95%CI) 2.72 (1.12–6.61), p = 0.028] and survive to hospital discharge than dogs [OR (95%CI) 4.87 (1.52–15.58), p = 0.008]. Patients had significantly lower odds of achieving any ROSC if CPA occurred during nighttime hours [OR (95%CI) nighttime = 0.52 (0.27–0.98), p = 0.043], and higher odds if CPA was witnessed [OR (95%CI) 3.45 (1.57–7.55), p = 0.002], if less people were involved in CPR efforts [OR (95%CI) 0.8 (0.66–0.96), p = 0.016], if pulses were palpable during CPR [OR (95%CI) 9.27 (4.16–20.63), p < 0.0005], and if an IV catheter was already in place at the time of CPA [OR (95%CI) 5.07 (2.12–12.07), p = 0.0003]. Odds for survival to hospital discharge were significantly higher if less people were involved in CPR efforts [OR (95%CI) 0.65 (0.46–0.91), p = 0.013] and for patients of the anesthesia service [OR (95%CI) 14.82 (3.91–56.17), p = 0.00007]. Overall, factors associated with improved CPR outcomes have remained similar since incorporation of RECOVER guidelines into daily practice. Witnessed CPA events and high-quality CPR interventions were associated with positive patient outcomes, emphasizing the importance of timely recognition and initiation of CPR efforts. An optimal CPR team size has yet to be determined.

Application of a Dual-Dispatch System for Out-of-Hospital Cardiac Arrest Patients: Will More Hands Save More Lives?

BACKGROUND

Recovery after out-of-hospital cardiac arrest (OHCA) is difficult, and emergency medical services (EMS) systems apply various strategies to improve outcomes. Multi-dispatch is one means of providing high-quality cardiopulmonary resuscitation (CPR), but no definitive best-operation guidelines are available. We assessed the effects of a basic life support (BLS)-based dual-dispatch system for OHCA.

METHODS

This prospective observational study of 898 enrolled OHCA patients, conducted in Daegu, Korea from March 1, 2015 to June 30, 2016, involved patients > 18 years old with suspected cardiac etiology OHCA. In Daegu, EMS started a BLS-based dual-dispatch system in March 2015, for cases of cardiac arrest recognition by a dispatch center. We assessed the association between dual-dispatch and OHCA outcomes using multivariate logistic regressions. We also analyzed the effect of dual-dispatch according to the stratified on-scene time.

RESULTS

Of 898 OHCA patients (median, 69.0 years; 65.5% men), dual-dispatch was applied in 480 (53.5%) patients. There was no difference between the single-dispatch group (SDG) and the dual-dispatch group (DDG) in survival at discharge and neurological outcomes (survival discharge, P = 0.176; neurological outcomes, P = 0.345). In the case of less than 10 minutes of on-scene time, the adjusted odds ratio was 1.749 (95% confidence interval [CI], 0.490-6.246) for survival discharge and 6.058 (95% CI, 1.346-27.277) for favorable neurological outcomes in the DDG compared with the SDG.

CONCLUSION

Dual-dispatch was not associated with better OHCA outcomes for the entire study population, but showed favorable neurological outcomes when the on-scene time was less than 10 minutes.

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.

Effects of designated leadership and team-size on cardiopulmonary resuscitation: The Basel-Washington SIMulation (BaWaSim) trial

OBJECTIVE

During cardiopulmonary resuscitation (CPR), it remains unclear whether designating an individual person as team leader compared with emergent leadership results in better team performance. Also, the effect of CPR team size on team performance remains understudied.

METHODS

This randomized-controlled trial compared designated versus emergent leadership and size of rescue team (3 vs 6 rescuers) on resuscitation performance.

RESULTS

We included 90 teams with a total of 408 students. No difference in mean (±SD) hands-on time (seconds) were observed between emergent leadership (106 ± 30) compared to designated leadership (103 ± 27) groups (adjusted difference - 2.97 (95%CI -15.75 to 9.80, p = 0.645), or between smaller (103 ± 30) and larger teams (106 ± 26, adjusted difference 3.53, 95%CI -8.47 to 15.53, p = 0.56). Emergent leadership groups had a shorter time to circulation check and first defibrillation, but the quality of CPR based on arm and shoulder position was lower. No differences in CPR quality measures were observed between smaller and larger teams.

CONCLUSIONS

Within this international US/Swiss trial, leadership designation and larger team size did not improve hands-on time, but emergent leadership teams initiated defibrillation earlier. Improvements in performance may be more likely to be achieved by optimization of emergent leadership than increasing the size of cardiac arrest teams.

Review of 14 drowning publications based on the Utstein style for drowning

BACKGROUND

The Utstein style for drowning (USFD) was published in 2003 with the aim of improving drowning research. To support a revision of the USFD, the current study aimed to generate an inventory of the use of the USFD parameters and compare the findings of the publications that have used the USFD.

METHODS

A search in Pubmed, Embase, the Cochrane Library, Web of Science and Scopus was performed to identify studies that used the USFD and were published between 01-10-2003 and 22-03-2015. We also searched in Pubmed, Embase, the Cochrane Library, Web of Science, and Scopus for all publications that cited the two publications containing the original ILCOR advisory statement introducing and recommending the USFD. In total we identified 14 publications by groups that explicitly used elements of the USFD for collecting and reporting their data.

RESULTS

Of the 22 core and 19 supplemental USFD parameters, 6-19 core (27-86%) and 1-12 (5-63%) supplemental parameters were used; two parameters (5%) have not been used in any publication. Associations with outcome were reported for nine core (41%) and five supplemental (26%) USFD parameters. The USFD publications also identified non-USFD parameters related to outcome: initial cardiac rhythm, time points and intervals during resuscitation, intubation at the drowning scene, first hospital core temperature, serum glucose and potassium, the use of inotropic/vasoactive agents and the Paediatric Index of Mortality 2-score.

CONCLUSIONS

Fourteen USFD based drowning publications have been identified. These publications provide valuable information about the process and quality of drowning resuscitation and confirm that the USFD is helpful for a structured comparison of the outcome of drowning resuscitation.

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.

The Effect of Ambulance Staffing Models in a Metropolitan, Fire-Based EMS System

Introduction The staffing of ambulances with different levels of Emergency Medical Service (EMS) providers is a difficult decision with evidence being mixed on the benefit of each model. Hypothesis/Problem The objective of this study was to describe a pilot program evaluating alternative staffing on two ambulances utilizing the paramedic-basic (PB) model (staffed with one paramedic and one emergency medical technician[EMT]).

METHODS

This was a retrospective study conducted from September 17, 2013 through December 31, 2013. The PB ambulances were compared to geographically matched ambulances staffed with paramedic-paramedic (PP ambulances). One PP and one PB ambulance were based at Station A; one PP and one PB ambulance were based at Station B. The primary outcome was total on-scene time. Secondary outcomes included time-to-electrocardiogram (EKG), time-to-intravenous (IV) line insertion, IV-line success rate, and percentage of protocol violations. Inclusion criteria were all patients requesting prehospital services that were attended to by these teams. Patients were excluded if they were not attended to by the study ambulance vehicles. Descriptive statistics were reported as medians and interquartile ranges (IQR). Proportions were reported with 95% confidence intervals (CI). The Mann-Whitley U test was used for significance testing (P<.05).

RESULTS

Median on-scene times at Station A for the PP ambulance were shorter than the PB ambulance team (PP: 10.1 minutes, IQR 6.0-15; PB: 13.0 minutes, IQR 8.1-18; P=.01). This finding also was noted at Station B (PP: 13.5 minutes, IQR 8.5-19; PB: 14.3 minutes, IQR 9.9-20; P=.01). There were no differences between PP and PB ambulance teams at Station A or Station B in time-to-EKG, time-to-IV insertion, IV success rate, and protocol violation rates.

CONCLUSION

In the setting of a well-developed EMS system utilizing an all-Advanced Life Support (ALS) response, this study suggests that PB ambulance teams may function well when compared to PP ambulances. Though longer scene times were observed, differences in time to ALS interventions and protocol violation rates were not different. Hybrid ambulance teams may be an effective staffing alternative, but decisions to use this model must address clinical and operational concerns. Cortez EJ , Panchal AR , Davis JE , Keseg DP . The effect of ambulance staffing models in a metropolitan, fire-based EMS system. Prehosp Disaster Med. 2017;32(2):175-179.

Volume versus outcome: More emergency medical services personnel on-scene and increased survival after out-of-hospital cardiac arrest

BACKGROUND AND AIM

The large regional variation in survival after treatment of out-of-hospital cardiac arrest (OHCA) is incompletely explained. Communities respond to OHCA with differing number of emergency medical services (EMS) personnel who respond to the scene. The effect of different numbers of EMS personnel on-scene upon outcomes is unclear. We sought to evaluate the association between number of EMS personnel on-scene and survival after OHCA.

METHODS

We performed a retrospective review of prospectively collected data on 16,122 EMS-treated OHCA events from December 1, 2005 to May 31, 2007 from a combined population over 21 million people residing in an area of over 33,000 square miles in Canada and the United States. Number of EMS personnel on-scene was defined as the number of EMS personnel who responded to the scene of OHCA within 15 min after 9-1-1 call receipt and prior to patient death or transport away from the scene. Associations with survival to hospital discharge were assessed by using generalized estimating equations to construct multivariable logistic regression models.

RESULTS

Compared to a reference number of EMS personnel on-scene of 5 or 6, 7 or 8 EMS personnel on-scene was associated with a higher rate of survival to hospital discharge, adjusted odds ratio [OR], 1.35 (95% CI: 1.05, 1.73). There was no significant difference in survival between 5 or 6 personnel on-scene versus fewer.

CONCLUSION

More EMS personnel on-scene within 15 min of 9-1-1 call was associated with improved survival of out-of-hospital cardiac arrest. It is unlikely that this finding was mediated solely by earlier CPR or earlier defibrillation.

Inaccuracy of patient care reports for identification of critical resuscitation events during out-of-hospital cardiac arrest

OBJECTIVE

Out-of-hospital cardiac arrest (OHCA) is a leading cause of mortality in the United States. We sought to evaluate the accuracy of the patient care report (PCR) for detection of 2 clinically important events: return of spontaneous circulation (ROSC) and rearrest (RA).

METHODS

We used defibrillator recordings and PCRs for Emergency Medical Services-treated OHCA collected by the Resuscitation Outcomes Consortium's Pittsburgh site from 2006 to 2008 and 2011 to 2012. Defibrillator data included electrocardiogram rhythm tracing, chest compression measurement, and audio voice recording. Sensitivity analysis was performed by comparing the accuracy of the PCR to detect the presence and number of ROSC and RA events to integrated defibrillator data.

RESULTS

In the 158 OHCA cases, there were 163 ROSC events and 53 RA events. The sensitivity of PCRs to identify all ROSC events was 85% (confidence interval [CI], .795-.905); to identify primary ROSC events, it was 85% (CI, .793-.907); and to identify secondary ROSC events, it was 78% (CI, .565-.995). The sensitivity of PCRs to identify the presence of all RA events was .60 (CI, .469-.731); to identify primary RA events, it was 71% (CI, .578-.842); and to identify secondary RA events, it was 0. Of the 32 RA incidents captured by the PCR, only 15 (47%) correctly identified the correct lethal arrhythmia.

CONCLUSIONS

We found that PCRs are not a reliable source of information for assessing the presence of ROSC and post-RA electrocardiogram rhythm. For quality control and research purposes, medical providers should consider augmenting data collection with continuous defibrillator recordings before making any conclusions about the occurrence of critical resuscitation events.

Physician and nonphysician health-care provider perspectives on resuscitation of suspected drug-related out-of-hospital cardiac arrest

INTRODUCTION

In the United States, out-of-hospital cardiac arrest from drug overdose (OD-OHCA) caused over 38,000 deaths in 2010. A study in Pittsburgh found that OD-OHCA patients differed demographically and in the resuscitation treatments they received, despite identical AHA resuscitation guidelines. We hypothesized that health-care provider perceptions affect decision-making in the treatment of OD-OHCA versus non-OD OHCA.

METHODS

We conducted this survey at the National Association of EMS Physicians 2013 Scientific Assembly. Physicians and non-physician health-care providers were given one of two surveys containing 19 questions pertaining to the respondents' affiliated EMS agencies, the estimated proportion of OD-OHCA as well as the drugs involved, and the respondents' belief about the treatments for OD versus non-OD OHCA.

RESULTS

One hundred ninety-three respondents participated in this survey. Of the 193, 144 (75%) were physicians and 49 (25%) were nonphysicians. Seventy-nine percent of physicians identified current status as a medical director and 76% of nonphysicians identified as a paramedic. Participants estimated the average monthly proportion of all OHCA due to OD to be 9.4%. Participants ranked opioids, alcohol, antidepressants, and benzodiazepines as the most commonly utilized agents in OD-OHCA. The majority of physicians (42%) felt that the incidence of OD-OHCA was not changing while the majority of nonphysicians (53%) felt the incidence was increasing. Eighty-four percent of all respondents reported the use of naloxone during OD-OHCA resuscitation, while 13% reported administering naloxone during non-OD OHCA resuscitation. Eighty-nine percent of physicians and 67% of nonphysicians indicated that OD-OHCA patients had different demographics than non-OD OHCA, with primary reported differences being age, comorbidities, and socioeconomic status. Sixty-three percent of physicians and 71% of nonphysicians felt that OD-OHCA patients should be treated differently, with primary differences being the incorporation of etiology-specific treatments, performing different CPR with a focus on airway support, and transporting earlier.

CONCLUSIONS

When surveyed, physicians and nonphysician providers report perceiving OD-OHCA treatment, outcomes, and patient demographics differently than non-OD OHCA and making different treatment decisions based on these perceptions. This may result in etiology-oriented resuscitation in the out-of-hospital setting, despite the lack of OD-specific resuscitation guidelines.

Recommendations on ambulance cardiopulmonary resuscitation in basic life support systems

AIM

Cardiopulmonary resuscitation (CPR) during ambulance transport can be a safety risk for providers and can affect CPR quality. In many Asian countries with basic life support (BLS) systems, patients experiencing out-of-hospital cardiac arrest (OHCA) are routinely transported in ambulances in which CPR is performed. This paper aims to make recommendations on best practices for CPR during ambulance transport in BLS systems.

METHODS

A panel consisting of 20 experts (including 4 North Americans) in emergency medical services (EMS) and resuscitation science was selected, and met over two days. We performed a literature review and selected 33 candidate issues in five core areas. Using Delphi methodology, the issues were classified into dichotomous (yes/no), multiple choice, and ranking questions. Primary consensus between experts was reached when there was more than 70% agreement. Questions with 60-69% agreement were made more specific and were submitted for a second round of voting.

RESULTS

The panel agreed upon 24 consensus statements with more than 70% agreement (2 rounds of voting). The recommendations cover the following: length of time on the scene; advanced airway at the scene; CPR prior to transport; rhythm analysis and defibrillation during transport; prehospital interventions; field termination of resuscitation (TOR); consent for TOR; destination hospital; transport protocol; number of staff members; restraint systems; mechanical CPR; turning off of the engine for rhythm analysis; alternative CPR; and feedback for CPR quality.

CONCLUSION

Recommendations for CPR during ambulance transport were developed using the Delphi method. These recommendations should be validated in clinical settings.

Impact of the number of on-scene emergency life-saving technicians and outcomes from out-of-hospital cardiac arrest in Osaka City

BACKGROUNDS

In Japan, ambulance staffing for cardiac arrest responses consists of a 3-person unit with at least one emergency life-saving technician (ELST). Recently, the number of ELSTs on ambulances has increased since it is believed that this improves the quality of on-scene care leading to better outcomes from out-of-hospital cardiac arrest (OHCA). The objective of this study was to evaluate the association between the number of on-scene ELSTs and OHCA outcome.

METHODS

This was a prospective cohort study of all bystander-witnessed OHCA patients aged ≥ 18 years in Osaka City from January 2005 to December 2007 using on an Utstein-style database. The primary outcome measure was one-month survival with favorable neurological outcome defined as a cerebral performance category ≤ 2. Multivariable logistic regression model were used to assess the contribution of the number of on-scene ELSTs to the outcome after adjusting for confounders.

RESULTS

Of the 2408 bystander-witnessed OHCA patients, one ELST group was present in 639 (26.5%), two ELST were present in 1357 (56.4%), and three ELST group in 412 (17.1%). The three ELST group had a significantly higher rate of one-month survival with favorable neurological outcome compared with the one ELST group (8.0% versus 4.5%, adjusted OR 2.26, 95% CI 1.27-4.04), while the two ELST group did not (5.4% versus 4.5%, adjusted OR 1.34, 95% CI 0.82-2.19).

CONCLUSIONS

Compared with the one on-scene ELST group, the three on-scene ELST group was associated with the improved one-month survival with favorable neurological outcome from OHCA in Osaka City.

Cardiopulmonary resuscitation quality: [corrected] improving cardiac resuscitation outcomes both inside and outside the hospital: a consensus statement from the American Heart Association

The "2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care" increased the focus on methods to ensure that high-quality cardiopulmonary resuscitation (CPR) is performed in all resuscitation attempts. There are 5 critical components of high-quality CPR: minimize interruptions in chest compressions, provide compressions of adequate rate and depth, avoid leaning between compressions, and avoid excessive ventilation. Although it is clear that high-quality CPR is the primary component in influencing survival from cardiac arrest, there is considerable variation in monitoring, implementation, and quality improvement. As such, CPR quality varies widely between systems and locations. Victims often do not receive high-quality CPR because of provider ambiguity in prioritization of resuscitative efforts during an arrest. This ambiguity also impedes the development of optimal systems of care to increase survival from cardiac arrest. This consensus statement addresses the following key areas of CPR quality for the trained rescuer: metrics of CPR performance; monitoring, feedback, and integration of the patient's response to CPR; team-level logistics to ensure performance of high-quality CPR; and continuous quality improvement on provider, team, and systems levels. Clear definitions of metrics and methods to consistently deliver and improve the quality of CPR will narrow the gap between resuscitation science and the victims, both in and out of the hospital, and lay the foundation for further improvements in the future.

Variation in emergency medical technician partner familiarity

OBJECTIVE

To characterize patterns of Emergency Medical Technician (EMT) partner familiarity in three Emergency Medical Services (EMS) agencies. STUDY DESIGN/DATA SOURCES: We utilized a case study design and retrospective review of administrative data from three EMS agencies and 182 EMTs over 12 months. We used the Kruskal-Wallis test and Bonferroni corrected p-values to compare measures of partner familiarity. Measures included the annual mean number of partners, rate of partners per 10 shifts, mean shifts per EMT, and proportion of shifts worked with same partner. We standardized select measures by size of agency to account for a greater number of possible partnerships in larger agencies.

PRINCIPAL FINDINGS

Across all agencies, the mean number of shifts worked annually by EMTs was (mean [SD]) 77.3 (59.8). The unstandardized mean number of EMT partnerships was 19.3 (12.4) and did not vary across EMS agencies after standardizing by agency size (p=.328). The unstandardized mean rate of EMT partnerships for every 10 shifts worked was 4.0 (2.7) and varied across agencies after standardizing (p<.001). The mean proportion of shifts worked with the same partner was 34.8 percent and varied across agencies (p<.001).

CONCLUSIONS

There was wide variation in select measures of EMT partner familiarity.

The frequency and consequences of cardiopulmonary resuscitation performed by bystanders on patients who are not in cardiac arrest

BACKGROUND

The American Heart Association encourages trained and untrained bystanders to perform, at a minimum, chest compressions on anyone who suddenly collapses. It is possible that people who are not in cardiac arrest may receive bystander cardiopulmonary resuscitation (CPR), from which the potential for injury is unknown.

OBJECTIVES

To determine the number of victims who received bystander CPR but were not in cardiac arrest and to identify any injuries resulting from receiving bystander CPR.

METHODS

Retrospective review of patient care records from a countywide emergency medical services (EMS) database. All patients treated by EMS between March 2003 and February 2009 who received bystander CPR were queried. Victims who were determined not to be in cardiac arrest upon EMS personnel assessment were identified as likely not in cardiac arrest. Hospital medical records for transported patients were reviewed for injuries possibly related to CPR. Patient demographics were collected and descriptive statistics were used for analysis.

RESULTS

Six hundred seventy-two incidents of bystander CPR occurred, with 77 (11.5%) cases not being identified as cardiac arrests by EMS. Twenty-three percent of the patients were less than 19 years of age. Emergency medical services arrived in less than 6 minutes for 68% of patients. Seventy-two patients were evaluable for injury; of those, 53% were admitted to the intensive care unit. One patient (1.4%) had an injury that was documented in the medical record as possibly CPR-related: rhabdomyolysis.

CONCLUSIONS

Bystanders provide CPR for patients who are not in cardiac arrest at a relatively low frequency. Short-duration bystander CPR caused injury in less than 2% of victims. Our results suggest that the benefits of bystander CPR for adults who suddenly collapse outweigh the risk of injury for those not in cardiac arrest.

Incidence of rearrest after return of spontaneous circulation in out-of-hospital cardiac arrest

BACKGROUND

Return of spontaneous circulation (ROSC) occurs in 35.0 to 61.0% of emergency medical services (EMS)-treated out-of-hospital cardiac arrests (OHCAs); however, not all patients achieving ROSC survive to hospital arrival or discharge. Previous studies have estimated the incidence of some types of rearrest(RA) at 61.0 to 79.0%, and the electrocardiogram (ECG) waveform characteristics of prehospital RA rhythms have not been previously described.

OBJECTIVES

We sought to determine the incidence of RA in OHCA, to classify RA events by type, and to measure the time from ROSC to RA. We also conducted a preliminary analysis of the relationship between first EMS-detected rhythms and RA, as well as the effect of RA on survival.

METHODS

The Pittsburgh Regional Clinical Center of the National Heart, Lung, and Blood Institute (NHLBI) -sponsored Resuscitation Outcomes Consortium (ROC) provided cases from a population-based cardiac arrest surveillance program, ROC Epistry. Only OHCA cases of nontraumatic etiology with available and adequate ECG files were included. We analyzed defibrillator-monitor ECG tracings (Philips MRX), patient care reports (PCRs), and defibrillator audio recordings from EMS-treated cases of OHCA spanning the period from October 2006 to December 2008. We identified ROSC and RA through interpretation of ECG tracings and audio recordings. Rearrest events were categorized as ventricular fibrillation (VF), pulseless ventricular tachycardia (VT), asystole, and pulseless electrical activity (PEA) based on ECG waveform characteristics. Proportions of RA rhythms were stratified by first EMS rhythm and compared using Pearson's chi-square test. Logistic regression was used to test the predictive relationship between RA and survival to hospital discharge.

RESULTS

Return of spontaneous circulation occurred in 329 of 1,199 patients (27.4% [95.0% confidence interval (CI): 25.0-30.0%]) treated for cardiac arrest. Of these, 113 had ECG tracings that were available and adequate for analysis. Rearrest occurred in 41 patients (36.0% [95.0% CI: 26.0-46.0%]), with a total of 69 RA events. Survival to hospital discharge in RA cases was 23.1% (95.0% CI: 11.1-39.3%), compared with 27.8% (95.0% CI: 17.9-39.6%) in cases without RA. Counts of RA events by type were as follows: 17 VF (24.6% [95% CI: 15.2-36.5%]), 20 pulseless VT (29.0% [95.0% CI: 18.7-41.2%]), 26 PEA (37.0% [95.0% CI: 26.3-50.2%]), and six asystole (8.8% [95.0% CI: 3.3-18.0%]). Rearrest was not predictive of survival to hospital discharge; however, initial EMS rhythm was predictive of RA shockability. The overall median (interquartile range) time from ROSC to RA among all events was 3.1 (1.6-6.3) minutes.

CONCLUSION

In this sample, the incidence of RA was 38.0%. The most common type of RA was PEA. Shockability of first EMS rhythm was found to predict subsequent RA rhythm shockability.

Effect of crew size on objective measures of resuscitation for out-of-hospital cardiac arrest

BACKGROUND

There is no consensus among emergency medical services (EMS) systems as to the optimal numbers and training of EMS providers who respond to the scene of prehospital cardiac arrests. Increased numbers of providers may improve the performance of cardiopulmonary resuscitation (CPR), but this has not been studied as part of a comprehensive resuscitation scenario.

OBJECTIVE

To compare different all-paramedic crew size configurations on objective measures of patient resuscitation using a high-fidelity human simulator.

METHODS

We compared two-, three-, and four-person all-paramedic crew configurations in the effectiveness and timeliness of performing basic life support (BLS) and advanced life support (ALS) skills during the first 8 minutes of a simulated cardiac arrest scenario. Crews were compared to determine differences in no-flow fraction (NFF) as a measure of effectiveness of CPR and time to defibrillation, endotracheal intubation, establishment of intravenous access, and medication administration.

RESULTS

There was no significant difference in mean NFF among the two-, three-, and four-provider crew configurations (0.32, 0.26, and 0.27, respectively; p = 0.105). More three- and four-person groups completed ALS procedures during the scenario, but there was no significant difference in time to performance of BLS or ALS procedures among the crew size configurations for completed procedures. There was a trend toward lower time to intubation with increasing group size, though this was not significant using a Bonferroni-corrected p-value of 0.01 (379, 316, and 263 seconds, respectively; p = 0.018).

CONCLUSION

This study found no significant difference in effectiveness of CPR or in time to performance of BLS or ALS procedures among crew size configurations, though there was a trend toward decreased time to intubation with increased crew size. Effectiveness of CPR may be hindered by distractions related to the performance of ALS procedures with increasing group size, particularly with an all-paramedic provider model. We suggest a renewed emphasis on the provision of effective CPR by designated providers independent of any ALS interventions being performed.