Association of the Emergency Medical Services-Related Time Interval with Survival Outcomes of Out-of-Hospital Cardiac Arrest Cases in Four Asian Metropolitan Cities Using the Scoop-and-Run Emergency Medical Services Model

Prehospital stroke care in Singapore

ABSTRACT

Due to the narrow window of opportunity for stroke therapeutics to be employed, effectiveness of stroke care systems is predicated on the efficiency of prehospital stroke systems. A robust prehospital stroke system of care that provides a rapid and well-coordinated response maximises favourable poststroke outcomes, but achieving this presents a unique set of challenges dependent on demographic and geographical circumstances. Set in the context of a highly urbanised first-world nation with a rising burden of stroke, Singapore's prehospital stroke system has evolved to reflect the environment in which it operates. This review aims to characterise the current state of prehospital stroke care in Singapore, covering prehospital aspects of the stroke survival chain from symptom onset till arrival at the emergency department. We identify areas for improvement and innovation, as well as provide insights into the possible future of prehospital stroke care in Singapore.

Association between institutional volume of out-of-hospital cardiac arrest cases and short term outcomes

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is a serious condition. The volume-outcome relationship and various post-cardiac arrest care elements are believed to be associated with improved neurological outcomes. Although previous studies have investigated the volume-outcome relationship, adjusting for post-cardiac arrest care, intra-class correlation for each institution, and other covariates may have been insufficient.

OBJECTIVE

To investigate the volume-outcome relationships and favorable neurological outcomes among OHCA cases in each institution.

METHODS

We conducted a prospective observational study of adult patients with non-traumatic OHCA using the OHCA registry in Japan. The primary outcome was 30-day favorable neurological outcomes, and the secondary outcome was 30-day survival. We set the cutoff values to trisect the number of patients as equally as possible and classified institutions into high-, middle-, and low-volume. Generalized estimating equations (GEE) were performed to adjust for covariates and within-hospital clustering.

RESULTS

Among the 9909 registry patients, 7857 were included. These patients were transported to either low- (2679), middle- (2657), or high- (2521) volume institutions. The median number of eligible patients per institution in 19 months of study periods was 82 (range, 1-207), 252 (range, 210-353), and 463 (range, 390-701), respectively. After multivariable GEE using the low-volume institution as a reference, no significant difference in odds ratios and 95% confidence intervals were noted for 30-day favorable neurological outcomes for middle volume [1.22 (0.69-2.17)] and high volume [0.80 (0.47-1.37)] institutions. Moreover, there was no significant difference for 30-day survival for middle volume [1.02 (0.51-2.02)] and high volume [1.09 (0.53-2.23)] institutions.

CONCLUSION

The patient volume of each institution was not associated with 30-day favorable neurological outcomes. Although this result needs to be evaluated more comprehensively, there may be no need to set strict requirements for the type of institution when selecting a destination for OHCA cases.

Expedited transport versus continued on-scene resuscitation for refractory out-of-hospital cardiac arrest: A systematic review and meta-analysis

Background

The benefit of rapid transport from the scene to definitive in-hospital care versus extended on-scene resuscitation in out-of-Hospital Cardiac Arrest (OHCA) is uncertain.

Aim

To assess the use of expedited transport from the scene of OHCA compared with more extended on-scene resuscitation of out-of-hospital cardiac arrest in adults.

Methods

A systematic search of the literature was conducted using MEDLINE, Embase, and SCOPUS. Randomised control trials (RCTs) and observational studies were included. Studies reporting transport timing for OHCA patients with outcome data on survival were identified and reviewed. Two investigators assessed studies identified by screening for relevance and assessed bias using the ROBINS-I tool. Studies with non-dichotomous timing data or an absence of comparator group(s) were excluded. Outcomes of interest included survival and favourable neurological outcome. Survival to discharge and favourable neurological outcome were meta-analysed using a random-effects model.

Results

Nine studies (eight cohort studies, one RCT) met eligibility criteria and were considered suitable for meta-analysis. On pooled analysis, expedited (or earlier) transfer was not predictive of survival to discharge (odds ratio [OR] 1.16, 95% confidence interval [CI] 0.53 to 2.53, I2 = 99%, p = 0. 65) or favorable neurological outcome (OR 1.06, 95% CI 0.48 to 2.37, I2 = 99%, p = 0.85). The certainty of evidence across studies was assessed as very low with a moderate risk of bias. Region of publication was noted to be a major contributor to the significant heterogeneity observed amongst included studies.

Conclusions

There is inconclusive evidence to support or refute the use of expedited transport of refractory OHCA.

Evaluation of optimal scene time interval for out-of-hospital cardiac arrest using a deep neural network

AIM

This study aims to develop a cardiac arrest prediction model using deep learning (CAPD) algorithm and to validate the developed algorithm by evaluating the change in out-of-hospital cardiac arrest patient prognosis according to the increase in scene time interval (STI).

METHODS

We conducted a retrospective cohort study using smart advanced life support trial data collected by the National Emergency Center from January 2016 to December 2019. The smart advanced life support data were randomly partitioned into derivation and validation datasets. The performance of the CAPD model using the patient's age, sex, event witness, bystander cardiopulmonary resuscitation (CPR), administration of epinephrine, initial shockable rhythm, prehospital defibrillation, provision of advanced life support, response time interval, and STI as prediction variables for prediction of a patient's prognosis was compared with conventional machine learning methods. After fixing other values of the input data, the changes in prognosis of the patient with respect to the increase in STI was observed.

RESULTS

A total of 16,992 patients were included in this study. The area under the receiver operating characteristic curve values for predicting prehospital return of spontaneous circulation (ROSC) and favorable neurological outcomes were 0.828 (95% confidence interval 0.826-0.830) and 0.907 (0.914-0.910), respectively. Our algorithm significantly outperformed other artificial intelligence algorithms and conventional methods. The neurological recovery rate was predicted to decrease to 1/3 of that at the beginning of cardiopulmonary resuscitation when the STI was 28 min, and the prehospital ROSC was predicted to decrease to 1/2 of its initial level when the STI was 30 min.

CONCLUSION

The CAPD exhibits potential and effectiveness in identifying patients with ROSC and favorable neurological outcomes for prehospital resuscitation.

Prehospital Use of the Esophageal Tracheal Combitube Supraglottic Airway Device: A Retrospective Cohort Study

BACKGROUND

In the province of Quebec (Canada), paramedics use the esophageal tracheal Combitube (ETC) for prehospital airway management.

OBJECTIVES

Our main objective was to determine the proportion of patients with successful ventilation achieved after ETC use. Our secondary aim was to determine the number of ETC insertion attempts required to ventilate the patient.

METHOD

This is a retrospective cohort study. All patients who had ≥1 attempt to insert an ETC during prehospital care between January 1, 2017 and December 31, 2018 were included. Prehospital and in-hospital data were extracted. Successful ventilation was defined as thorax elevation, lung sounds on chest auscultation, or positive end-tidal capnography after ETC insertion.

RESULTS

A total of 580 emergency medical services interventions (99.3% cardiac arrests) were included. Most patients were men (62.5%) with a mean age 67.0 years (SD 17.6 years), and 35 (13.1%) of the 298 patients transported to emergency department survived to hospital discharge. Sufficient information to determine whether ventilation was successful or not was available for 515 interventions. Ventilation was achieved during 427 (82.7%) of these interventions. The number of ETC insertion attempts was available for 349 of the 427 successful ETC use. Overall, the first insertion resulted in successful ventilation during 294 interventions for an overall proportion of first-pass success ranging between 57.1% and 72.1%.

CONCLUSION

Proportions of successful ventilation and ETC first-pass success are lower than those reported in the literature with supraglottic airway devices. The reasons explaining these lower rates and their impact on patient-centered outcomes need to be studied.

Association between Scene Time Interval and Survival in EMS-Treated Major Trauma Admitted to the Intensive Care Unit: A Multinational, Multicenter Observational Study

Objective: Major trauma is a major concern in public health and a leading cause of mortality worldwide. This study aimed to evaluate the association between the prehospital scene time interval (STI) and survival in emergency medical service (EMS)-assessed major trauma patients admitted to the intensive care unit (ICU). Methods: A retrospective observational study using the Pan-Asian Trauma Outcomes Study (PATOS) database was conducted. Adult trauma patients with injury severity scores (ISSs) greater than 15 who were admitted to the ICU were selected. EMS STIs were categorized into three groups: short (0-8 minutes), intermediate (9-16 minutes), and long (over 16 minutes). The primary outcome was survival to hospital discharge, and the secondary outcome was good neurological outcome at hospital discharge. Multivariable logistic regression analysis was conducted to calculate odds ratios and confidence intervals, adjusting for age, sex, mechanism of injury, prehospital alertness, prehospital shock index, response time interval, and EMS intervention (airway, oxygen supplementation, and intravenous fluid administration). Sensitivity analysis for patients who underwent surgery or nontraumatic brain injury cases and interaction analysis by EMS intervention were performed. Results: Data from a total of 1,874 eligible patients were analyzed. Intermediate and long STIs showed significant associations with outcomes, with adjusted ORs (95% CI) of 1.21 (1.07-1.38) in the intermediate STI group and 1.74 (1.55-1.96) in the long STI group for survival and 1.37 (1.32-1.40) in the intermediate STI group and 1.31 (1.22-1.41) in the long STI group for neurological outcome. In the sensitivity analysis, the highest ORs were found in the intermediate STI group, with adjusted ORs (95% CI) of 1.40 (1.37-1.42) for survival and 1.32 (1.26-1.38) for neurological outcome. In the interaction analysis, EMS intervention showed a positive interaction effect with an intermediate STI on survival. Conclusion: In EMS-assessed adult major trauma patients admitted to the ICU, we found significant associations between STIs longer than 8 minutes and outcomes. EMS intervention has a positive interaction effect with an intermediate STI on survival. More research is needed to understand the implications of practice for major trauma in the field.

Out-of-hospital cardiac arrest patients with implantable cardioverter-defibrillators: What are their outcomes?

THE AIM OF THE STUDY

To identify the prognostic factors and effects of implantable cardioverter-defibrillators (ICDs) in out-of-hospital cardiac arrest (OHCA) patients with ICDs because the clinical characteristics and outcomes of OHCA patients with ICDs are unknown.

METHODS

The North American Resuscitation Outcomes Consortium (ROC) Cardiac Epistry Version 3 dataset was analyzed. Eligible patients were divided into OHCA patients with and without ICDs. Multivariable regressions were employed to analyze.

RESULTS

Of 51,634 eligible OHCA patients, 581 (1.13%) had implanted ICDs. Among them, 53 (9.1%) patients survived to hospital discharge, and 40 (6.9%) patients had favorable neurological outcome at hospital discharge. Multivariable regression showed ICDs were not associated with OHCA outcomes in the total OHCA patients. In the OHCA patients with ICDs, shockable initial emergency medical services (EMS)-recorded rhythms and the ICD-shock-only defibrillation pattern were independent favorable factors for survival to hospital discharge(OR = 3.3, 95%CI 1.7-6.2, P < 0.001; OR = 2.4, 95%CI 1.1-5.5, P = 0.035, respectively) and neurological outcome at hospital discharge (OR = 6.5, 95%CI 2.9-14.4, P < 0.001; OR = 3.6, 95%CI 1.4-9.1, P = 0.006, respectively). During field resuscitation in OHCA patients with ICDs, at least 34.9% of total patients and 64.6% of patients with initial EMS-recorded VT/VF rhythms needed additional external shocks.

CONCLUSIONS

Shockable initial EMS-recorded rhythms and ICD-shock-only defibrillation pattern were independent factors for the favorable outcomes of OHCA patients with ICDs. ICDs were not associated with the outcomes of OHCA, and additional external shocks were needed in a substantial number of OHCA patients with ICDs during field resuscitation.

Management of EMS on-scene time during advanced life support in out-of-hospital cardiac arrest: a retrospective observational trial

Objective

Most western emergency medical services provide advanced life support in out-of-hospital cardiac arrest aiming for a return of spontaneous circulation at the scene. Little attention is given to prehospital time management in the case of out-of-hospital cardiac arrest with regard to early coronary angiography or to the start of extracorporeal cardiopulmonary resuscitation treatment within 60 minutes after out-of-hospital cardiac arrest onset. We investigated the emergency medical services on-scene time, defined as emergency medical services arrival at the scene until departure to the hospital, and its association with 30-day survival with favourable neurological outcome after out-of-hospital cardiac arrest.

Methods

All patients of over 18 years of age with non-traumatic, non-emergency medical services witnessed out-of-hospital cardiac arrest between July 2013 and August 2015 from the Vienna Cardiac Arrest Registry were included in this retrospective observational study.

Results

Out of 2149 out-of-hospital cardiac arrest patients, a total of 1687 (79%) patients were eligible for analyses. These patients were stratified into groups according to the on-scene time (&lt;35 minutes, 35–45 minutes, 45–60 minutes, &gt;60 minutes). Within short on-scene time groups, out-of-hospital cardiac arrest occurred more often in public and bystander cardiopulmonary resuscitation was more common (both P&lt;0.001). Patients who did not achieve return of spontaneous circulation at the scene showed higher rates of 30-day survival with favourable neurological outcome with an on-scene time of less than 35 minutes (adjusted odds ratio 5.00, 95% confidence interval 1.39–17.96).

Conclusion

An emergency medical services on-scene time of less than 35 minutes was associated with higher rates of survival and favourable outcomes. It seems to be reasonable to develop time optimised advance life support protocols to minimise the on-scene time in view of further treatments such as early coronary angiography as part of post-resuscitation care or extracorporeal cardiopulmonary resuscitation in refractory out-of-hospital cardiac arrest.

Impact of Transport Time and Cardiac Arrest Centers on the Neurological Outcome After Out-of-Hospital Cardiac Arrest: A Retrospective Cohort Study

Background

Should all out‐of‐hospital cardiac arrest (OHCA) patients be directly transported to cardiac arrest centers (CACs) remains under debate. Our study evaluated the impacts of different transport time and destination hospital on the outcomes of OHCA patients.

Methods and Results

Data were collected from 6655 OHCA patients recorded in the regional prospective OHCA registry database of Taoyuan City, Taiwan, between January 2012 and December 2016. Patients were matched on propensity score, which left 5156 patients, 2578 each in the CAC and non‐CAC groups. Transport time was dichotomized into <8 and ≥8 minutes. The relations between the transport time to CACs and good neurological outcome at discharge and survival to discharge were investigated. Of the 5156 patients, 4215 (81.7%) presented with nonshockable rhythms and 941 (18.3%) presented with shockable rhythms. Regardless of transport time, transportation to a CAC increased the likelihoods of survival to discharge (<8 minutes: adjusted odds ratio [aOR], 1.95; 95% CI, 1.11–3.41; ≥8 minutes: aOR, 1.92; 95% CI, 1.25–2.94) and good neurological outcome at discharge (<8 minutes: aOR, 2.70; 95% CI, 1.40–5.22; ≥8 minutes: aOR, 2.20; 95% CI, 1.29–3.75) in OHCA patients with shockable rhythms but not in patients with nonshockable rhythms.

Conclusions

OHCA patients with shockable rhythms transported to CACs demonstrated higher probabilities of survival to discharge and a good neurological outcome at discharge. Direct ambulance delivery to CACs should thus be considered, particularly when OHCA patients present with shockable rhythms.

Relationship Between Institutional Volume of Out-of-Hospital Cardiac Arrest Cases and 1-Month Neurologic Outcomes: A Post Hoc Analysis of a Prospective Observational Study

BACKGROUND

The influence of institutional volume of out-of-hospital cardiac arrest (OHCA) cases on outcomes remains unclear.

OBJECTIVES

This study evaluated the relationship between institutional volume of adult, nontraumatic OHCA cases and 1-month favorable neurologic outcomes.

METHODS

This study retrospectively analyzed data between January 2012 and March 2013 from a prospective observational study in the Kanto area of Japan. We analyzed adult patients with nontraumatic OHCA who underwent cardiopulmonary resuscitation by emergency medical service personnel and in whom spontaneous circulation was restored. Based on the institutional volume of OHCA cases, we divided institutions into low-, middle-, or high-volume groups. The primary and secondary outcomes were 1-month favorable neurologic outcomes and 1-month survival, respectively. A multivariate logistic regression analysis adjusted for propensity score and in-hospital variables was performed.

RESULTS

Of 2699 eligible patients, 889, 898, and 912 patients were transported to low-volume (40 institutions), middle-volume (14 institutions), and high-volume (9 institutions) centers, respectively. Using low-volume centers as the reference, transport to a middle- or high-volume center was not significantly associated with a favorable 1-month neurologic outcome (adjusted odds ratio [OR] 1.21 [95% confidence interval {CI} 0.84-1.75] and adjusted OR 0.77 [95% CI 0.53-1.12], respectively) or 1-month survival (adjusted OR 1.10 [95% CI 0.82-1.47] and adjusted OR 0.76 [95% CI 0.56-1.02], respectively).

CONCLUSIONS

Institutional volume was not significantly associated with favorable 1-month neurologic outcomes or 1-month survival in OHCA. Further investigation is needed to determine the association between hospital characteristics and outcomes in patients with OHCA.

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 endotracheal intubation and supraglottic airway device placement during cardiopulmonary resuscitation on carotid blood flow over resuscitation time: An experimental porcine cardiac arrest study

BACKGROUND

Supraglottic airway devices (SGDs) are widely used during the resuscitation of out-of-hospital cardiac arrest (OHCA). The effect of SGDs on carotid blood flow (CBF) as resuscitation time passes is controversial. We assessed the effects of endotracheal intubation (ETI) and 3 types of SGD placement on CBF over time in prolonged resuscitation through an experimental porcine cardiac arrest study.

METHODS

We conducted a randomized crossover study using 12 female pigs. After 4 min of untreated ventricular fibrillation, 3 pairs of ETI for 3 min and each type of SGD placement, including Combitube, I-gel, and laryngeal mask airway, for 3 min were conducted. The order of the 3 pairs of ETI and SGD were randomly assigned for each pig. We measured physiological parameters including CBF and mean arterial pressure (MAP). We compared CBF and MAP between the last 1 min of the insertion period for each of the 3 types of SGD and the preceding ETI period. Trends of CBF and MAP according to ETI and SGD transition were also plotted during the prolonged resuscitation duration.

RESULTS

CBF decreased after inserting I-gel and Combitube compared to ETI (mean difference (95% CI): -685 ml (-1052 to -318) for Combitube, -369 ml (-623 to -114) for I-gel). MAP subsequently decreased after transitioning airway devices as resuscitation was prolonged, regardless of the device type. The mean CBF during the transition from ETI to SGD decreased by -480 ml (95% CI: -675 to -286), but the decrease in CBF during the transition from SGD to ETI was only -4 ml (95% CI: -182 to 175).

CONCLUSION

SGD placement was associated with decreased carotid blood flow during cardiopulmonary resuscitation in an experimental porcine model. As time passed during prolonged resuscitation, reduction in CBF was aggravated after the transition to SGD placement compared to the reduction after the transition to ETI. This study was approved by the study institution IACUC 16-0140-S1A0.