Comparison of out-of-hospital cardiac arrest occurring before and after paramedic arrival: Epidemiology,survival to hospital discharge and 12-month functional recovery

BackgroundDespite immediate resuscitation, survival rates following out-of-hospital cardiac arrests (OHCA) witnessed by emergency medical service (EMS) are reportedly low. We sought to compare survival and 12-month functional recovery outcomes for OHCA occurring before and after EMS arrival.MethodsBetween 1st July 2008 and 30th June 2013, we included 8648 adult OHCA cases receiving an EMS attempted resuscitation from the Victorian Ambulance Cardiac Arrest Registry, and categorised them into five groups: bystander witnessed cases ± bystander CPR, unwitnessed cases ± bystander CPR, and EMS witnessed cases. The main outcomes were survival to hospital and survival to hospital discharge. Twelve-month survival with good functional recovery was measured in a sub-group of patients using the Extended Glasgow Outcome Scale (GOSE).ResultsBaseline and arrest characteristics differed significantly across groups. Unadjusted survival outcomes were highest among bystander witnessed cases receiving bystander CPR and EMS witnessed cases, however outcomes differed significantly between these groups: survival to hospital (46.0% vs. 53.4% respectively, p < 0.001); survival to hospital discharge (21.1% vs. 34.9% respectively, p < 0.001). When compared to bystander witnessed cases receiving bystander CPR, EMS witnessed cases were associated with a significant improvement in the risk adjusted odds of survival to hospital (OR 2.02, 95% CI: 1.75–2.35), survival to hospital discharge (OR 6.16, 95% CI: 5.04–7.52) and survival to 12 months with good functional recovery (OR 5.56, 95% CI: 4.18–7.40).ConclusionWhen compared to OHCA occurring prior to EMS arrival, EMS witnessed arrests were associated with significantly higher survival to hospital discharge rates and favourable neurological recovery at 12-month post-arrest.     

The association between chest compression release velocity and outcomes from out-of-hospital cardiac arrest

BackgroundPrevious studies have demonstrated significant relationships between cardiopulmonary resuscitation (CPR) quality metrics and survival to hospital discharge from out-of-hospital cardiac arrest (OHCA). Recently, it has been suggested that a new metric, chest compression release velocity (CCRV), may be associated with improved survival from OHCA.Methods and resultsWe performed a retrospective review of all treated adult OHCA occurring over a two year period beginning January 1, 2012. CPR metrics were abstracted from accelerometer measurements during each resuscitation. Multivariable regression analysis was used to examine the impact of CCRV on survival to hospital discharge. Secondary outcome measures were the impact of CCRV on return of spontaneous circulation (ROSC) and neurologically intact survival (MRS ≤ 3). Among 1800 treated OHCA, 1137 met inclusion criteria. The median (IQR) age was 71.6 (60.6, 82.3) with 724 (64%) being male. The median (IQR) CCRV (mm/s) amongst 96 survivors was 334.5 (300.0, 383.2) compared to 304.0 (262.6, 354.1) in 1041 non survivors (p < 0.001). When adjusted for Utstein variables, the odds of survival to hospital discharge for each 10 mm/s increase in CCRV was 1.02 (95% CI: 0.98, 1.06). Similarly the odds of ROSC and neurologically intact survival were 1.01 (95% CI: 0.99, 1.03) and 1.02 (95% CI: 0.98, 1.06), respectively.ConclusionsWhen adjusted for Utstein variables, CCRV was not significantly associated with outcomes from OHCA. Further research in other EMS systems is required to clarify the potential impact of this variable on OHCA survival.     

The time dependent association of adrenaline administration and survival from out-of-hospital cardiac arrest

BackgroundRecommended for decades, the therapeutic value of adrenaline (epinephrine) in the resuscitation of patients with out-of-hospital cardiac arrest (OHCA) is controversial.PurposeTo investigate the possible time-dependent outcomes associated with adrenaline administration by Emergency Medical Services personnel (EMS).MethodsA retrospective analysis of prospectively collected data from a near statewide cardiac resuscitation database between 1 January 2005 and 30 November 2013. Multivariable logistic regression was used to analyze the effect of the time interval between EMS dispatch and the initial dose of adrenaline on survival. The primary endpoints were survival to hospital discharge and favourable neurologic outcome.ResultsData from 3469 patients with witnessed OHCA were analyzed. Their mean age was 66.3 years and 69% were male. An initially shockable rhythm was present in 41.8% of patients. Based on a multivariable logistic regression model with initial adrenaline administration time interval (AATI) from EMS dispatch as the covariate, survival was greatest when adrenaline was administered very early but decreased rapidly with increasing (AATI); odds ratio 0.94 (95% Confidence Interval (CI) 0.92–0.97). The AATI had no significant effect on good neurological outcome (OR = 0.96, 95% CI = 0.90–1.02).ConclusionsIn patients with OHCA, survival to hospital discharge was greater in those treated early with adrenaline by EMS especially in the subset of patients with a shockable rhythm. However survival rapidly decreased with increasing adrenaline administration time intervals (AATI).     

Urban and rural differences in out-of-hospital cardiac arrest in Ireland

BackgroundMore than a third of Ireland's population lives in a rural area, defined as the population residing in all areas outside clusters of 1500 or more inhabitants. This presents a challenge for the provision of effective pre-hospital resuscitation services. In 2012, Ireland became one of three European countries with nationwide Out-of-Hospital Cardiac Arrest (OHCA) register coverage. An OHCA register provides an ability to monitor quality and equity of access to life-saving services in Irish communities.AimTo use the first year of national OHCAR data to assess differences in the occurrence, incidence and outcomes of OHCA where resuscitation is attempted and the incident is attended by statutory Emergency Medical Services between rural and urban settings.MethodsThe geographical coordinates of incident locations were identified and co-ordinates were then classified as ‘urban’ or ‘rural’ according to the Irish Central Statistics Office (CSO) definition.Results1798 OHCA incidents were recorded which were attended by statutory Emergency Medical Services (EMS) and where resuscitation was attempted. There was a higher percentage of male patients in rural settings (71% vs. 65%; p = 0.009) but the incidence of male patients did not differ significantly between urban and rural settings (26 vs. 25 males/100,000 population/year p = 0.353). A higher proportion of rural patients received bystander cardiopulmonary resuscitation (B-CPR) 70% vs. 55% (p ≤ 0.001), and had defibrillation attempted before statutory EMS arrival (7% vs. 4% (p = 0.019), respectively). Urban patients were more likely to receive a statutory EMS response in 8 min or less (33% vs. 9%; p ≤ 0.001). Urban patients were also more likely to be discharged alive from hospital (6% vs. 3%; p = 0.006) (incidence 2.5 vs. 1.1/100,000 population/year; p ≤ 0.001).Multivariable analysis of survival showed that the main variable of interest i.e. urban vs. rural setting was also independently associated with discharge from hospital alive (OR 3.23 (95% CI 1.43–7.31)).ConclusionThere are significant disparities in the incidence of resuscitation attempts in urban and rural areas. There are challenges in the provision of services and subsequent outcomes from OHCA that occur outside of urban areas requiring novel and innovative solutions. An integrated community response system is necessary to improve metrics around OHCA response and outcomes in rural areas.     

Interventional strategies associated with improvements in survival for out-of-hospital cardiac arrests in Singapore over 10 years

AimWe aim to study if there has been an improvement in survival for Out-of-Hospital Cardiac Arrest (OHCA) in Singapore, the effects of various interventional strategies over the past 10 years, and identify strategies that contributed to improved survival.MethodsRates of OHCA survival were compared between 2001–2004 and 2010–2012, using nationwide data for all OHCA presenting to EMS and public hospitals. A multivariate logistic regression model for survival to discharge was constructed to identify strategies with significant impact.ResultsA total of 5453 cases were included, 2428 cases from 2001 to 2004 and 3025 cases from 2010 to 2012. There was significant improvement in Utstein (witnessed, shockable) survival to discharge from 2001–2004 (2.5%) to 2010–2012 (11.0%), adjusted odds ratio (OR) 9.6 [95% CI: 2.2–41.9]). Overall survival to discharge increased from 1.6% to 3.2% (adjusted OR 2.2 [1.5–3.3]). Bystander CPR rates increased from 19.7% to 22.4% (p = 0.02). The multivariate regression model (adjusted for important non-modifiable risk factors) showed that response time <8 min (OR 1.5 [1.0–2.3]), bystander AED (OR 5.8 [2.0–16.2]), and post-resuscitation hypothermia (OR 30.0 [11.5–78.0]) were significantly associated with survival to hospital discharge. Conversely, pre-hospital epinephrine (OR 0.6 [0.4–0.9]) was associated negatively with survival.ConclusionsOHCA survival has improved in Singapore over the past 10 years. Improvement in response time, public AEDs and post-resuscitation hypothermia appear to have contributed to the increase in survival. Singapore's experience might suggest that developing EMS systems should focus on reducing times to basic life support, including bystander defibrillation and post-resuscitation care.     

Interaction effects between hypothermia and diabetes mellitus on survival outcomes after out-of-hospital cardiac arrest

ObjectivesMild therapeutic hypothermia (MTH) is the core hospital intervention to enhance neurological outcome after out-of-hospital cardiac arrest (OHCA). Diabetes mellitus (DM) has been known to be a harmful risk factor on survival after OHCA. This study aimed to investigate whether the effect of MTH on brain recovery after OHCA differed between patients with or without DM.MethodsWe used a Korean national OHCA database composed of hospital and ambulance data. We included adult OHCA patients who survived to admission with presumed cardiac etiology during the study period from 2009 to 2013. We excluded cases without hospital outcome data. The primary exposure was MTH, which included all kinds of cooling methods that had been initiated within 6 h after return of spontaneous circulation. DM was coded positive when the patient had a clinical history diagnosed by a physician before an OHCA event. The endpoints were discharge with good neurological recovery (cerebral performance category 1 or 2) and survival to discharge. We compared outcomes between MTH vs. non-MTH groups using multivariable logistic regression with an interaction term between MTH and DM for calculating adjusted odds ratios (AORs) and 95% confidence intervals (CIs) after adjusting for potential confounders.ResultsAmong 9735 patients following OHCA survived to hospital admission with cardiac etiology, MTH was performed in 16.5%. History of DM was observed in 25.4% among MTH group and 27.4% in non-MTH group (p = 0.09). MTH group showed better outcomes than non-MTH group; 23.6% vs. 15.7% for good neurological recovery (p < 0.01). AOR (95% CI) of MTH for good neurological recovery for all study groups was 1.23 (1.03–1.47). In the interaction model, AOR (95% CI) of MTH for good neurological recovery was 1.40 (1.16–1.70) in patients without DM vs. 0.69 (0.46–1.04) in patients with DM. For survival to discharge, the effects of MTH were different in patients without DM (1.97 (1.70–2.29)) and patients with DM (1.23 (0.96–1.57)).ConclusionDM modified the effect of MTH on survival and neurological outcomes for OHCA survivors. MTH is significantly associated with good neurological recovery in patients without DM, but not in patients with DM.     

The duration of cardiopulmonary resuscitation in emergency departments after out-of-hospital cardiac arrest is associated with the outcome: A nationwide observational study

Aim of the studyThe appropriate duration of cardiopulmonary resuscitation (CPR) for patients who experience out-of-hospital cardiac arrest (OHCA) remains unknown. This study aimed to evaluate the duration of CPR in emergency departments (EDs) and to determine whether the institutions’ median duration of CPR was associated with survival-to-discharge rate.MethodsA cohort of adult patients from a nationwide OHCA registry was retrospectively evaluated. The main variable was the median duration of CPR for each ED (institutional duration), and the main outcome was survival to discharge. Multivariable logistic regression analysis was performed to adjust for individual and aggregated confounders.ResultsAmong the 107,736 patients who experienced OHCA between 2006 and 2010, 30,716 (28.5%) were selected for analysis. The median age was 65 years, and 67.1% were men. The median duration of CPR for all EDs was 28 min, ranging from 11 to 45 min. EDs were categorized into 3 groups according to their institutional duration of CPR: groups A (<20 min), B (20–29 min), C (≥30 min). The observed survival rates of the 3 groups were 2.11%, 5.20%, and 5.62%, respectively. Compared with group B, the adjusted difference (95% confidence interval) for survival to discharge was 3.01% (1.90–4.11, P < 0.001) for group A, and 0.33% (−0.64 to 1.30, P = 0.51) for group C.ConclusionThe duration of CPR varied widely among hospitals. The institutional duration of CPR less than 20 min was significantly associated with lower survival-to-discharge rate.     

Correlation between initial serum levels of lactate after return of spontaneous circulation and survival and neurological outcomes in patients who undergo therapeutic hypothermia after cardiac arrest

ObjectivesWe analysed the relationship between serum levels of lactate within 1 h of return of spontaneous circulation (ROSC) and survival and neurological outcomes in patients who underwent therapeutic hypothermia (TH).MethodsThis was a multi-centre retrospective and observational study that examined data from the first Korean Hypothermia Network (KORHN) registry from 2007 to 2012. The inclusion criteria were out-of-hospital cardiac arrest (OHCA) and examination of serum levels of lactate within 1 h after ROSC, taken from KORHN registry data. The primary endpoint was survival outcome at hospital discharge, and the secondary endpoint was poor neurological outcome (Cerebral Performance Category, CPC, 3–5) at hospital discharge. Initial lactate levels and other variables collected within 1 h of ROSC were analysed via multivariable logistic regression.ResultsData from 930 cardiac arrest patients who underwent TH were collected from the KORHN registry. In a total of 443 patients, serum levels of lactate were examined within 1 h of ROSC. In-hospital mortality was 289/443 (65.24%), and 347/443 (78.33%) of the patients had CPCs of 3–5 upon hospital discharge. The odds ratios of lactate levels for CPC and in-hospital mortality were 1.072 (95% confidence interval (CI) 1.026–1.121) and 1.087 (95% CI = 1.031–1.147), respectively, based on multivariate ordinal logistic regression analyses.ConclusionHigh levels of lactate in serum measured within 1 h of ROSC are associated with hospital mortality and high CPC scores in cardiac arrest patients treated with TH.     

Out-of-hospital cardiac arrest survival improving over time: Results from the Resuscitation Outcomes Consortium (ROC)

BackgroundOut-of-hospital cardiac arrest (OHCA) remains a leading cause of death and a 2010 meta-analysis concluded that outcomes have not improved over several decades. However, guidelines have changed to emphasize CPR quality, minimization of interruptions, and standardized post-resuscitation care. We sought to evaluate whether OHCA outcomes have improved over time among agencies participating in the Resuscitation Outcomes Consortium (ROC) cardiac arrest registry (Epistry) and randomized clinical trials (RCTs).MethodsObservational cohort study of 47,148 EMS-treated OHCA cases in Epistry from 139 EMS agencies at 10 ROC sites that participated in at least one RCT between 1/1/2006 and 12/31/2010. We reviewed patient, scene, event characteristics, and outcomes of EMS-treated OHCA over time, including subgroups with initial rhythm of pulseless ventricular tachycardia or ventricular fibrillation (VT/VF).ResultsMean response interval, median age and male proportion remained similar over time. Unadjusted survival to discharge increased between 2006 and 2010 for treated OHCA (from 8.2% to 10.4%), as well as for subgroups of VT/VF (21.4% to 29.3%) and bystander witnessed VT/VF (23.5% to 30.3%). Compared with 2006, adjusted survival to discharge was significantly higher in 2010 for treated cases (OR = 1.72; 95% CI 1.53, 1.94), VT/VF cases (OR = 1.69; 95% CI 1.45, 1.98) and bystander witnessed VT/VF cases (OR = 1.65; 95% CI 1.36, 2.00). Tests for trend in each subgroup were significant (p < 0.001).ConclusionsROC-wide survival increased significantly between 2006 and 2010. Additional research efforts are warranted to identify specific factors associated with this improvement.     

Recurrent ventricular fibrillation: Experience with first responders prior to advanced life support interventions

AimFollowing defibrillation, ventricular fibrillation (VF) frequently recurs during out-of-hospital cardiac arrest (OHCA). Prior studies have reported conflicting results regarding its association with survival. The aim of this study was to examine the impact of recurrent VF in the presence of first responders before advanced life support (ALS) interventions.MethodsElectrocardiographic data from first responder automated external defibrillators (AEDs) were analyzed. A successful shock was defined as termination of VF for 5 s or longer. Recurrent VF was defined as any VF that occurred after a successful shock. The primary outcome was neurologically intact survival to hospital discharge (CPC 1–2).Results108 patients within our emergency system experienced a witnessed VF arrest. Of these, 73 (68%) had at least one recurrence of VF. Median time to recurrence of VF was 25 s [interquartile range (IQR) 11–66 s]. Median time in recurrent VF was 180 s (IQR 105–266 s). Survival was observed in 25 (71%) of patients with no recurrent VF and in 36 (49%) who had recurrence. Recurrent VF was associated with a lower odds of survival on univariate analysis (OR 0.39, 95% CI 0.16–0.92, p = 0.0325). After adjusting for bystander CPR, gender and age, recurrent VF had a similar direction of effect but was no longer significantly associated with neurologically intact survival (OR 0.44, 95% CI 0.17–1.11, p = 0.081).ConclusionsIn the presence of first responders, VF recurred in 68% of patients. Recurrent VF was associated with a lower odds of survival, though its prognostic significance appeared to be blunted when considered in light of confounding variables. Recurrent VF may have significant survival implications, and further studies to assess its prognostic significance should be performed.     

Association between prehospital prognostic factors and out-of-hospital cardiac arrest: Effect of rural–urban disparities

BackgroundOut-of-hospital cardiac arrest (OHCA) is associated with a poor prognosis and a highly variable survival rate. Few studies have focused on outcomes in rural and urban groups while also evaluating underlying diseases and prehospital factors for OHCAs.ObjectiveTo investigate the relationship between the patient's underlying disease and outcomes of OHCAs in urban areas versus those in rural areas.MethodsWe reviewed the emergency medical service (EMS) database for information on OHCA patients treated between January 2015 and December 2019, and collected data on pre-hospital factors, underlying diseases, and outcomes of OHCAs. Univariate and multivariate logistic regression analyses were used to evaluate the prognostic factors for OHCA.ResultsData from 4225 OHCAs were analysed. EMS response time was shorter and the rate of attendance by EMS paramedics was higher in urban areas (p < 0.001 for both). Urban area was a prognostic factor for >24-h survival (odds ratio [OR] = 1.437, 95% confidence interval [CI]: 1.179–1.761). Age (OR = 0.986, 95% CI: 0.979–0.993). EMS response time (OR = 0.854, 95% CI: 0.811–0.898), cardiac arrest location (OR = 2.187, 95% CI: 1.707–2.795), attendance by paramedics (OR = 1.867, 95% CI: 1.483–2.347), and prehospital defibrillation (OR = 2.771, 95% CI: 2.154–3.556) were independent risk factors for survival to hospital discharge, although the influence of an urban area was not significant (OR = 1.211, 95% CI: 0.918–1.584).ConclusionsCompared with rural areas, OHCA in urban areas are associated with a higher 24-h survival rate. Shorter EMS response time and a higher probability of being attended by paramedics were noted in urban areas. Although shorter EMS response time, younger age, public location, defibrillation by an automated external defibrillator, and attendance by Emergency Medical Technician-paramedics were associated with a higher rate of survival to hospital discharge, urban area was not an independent prognostic factor for survival to hospital discharge in OHCA patients.     

Effect of implementation of new resuscitation guidelines on quality of cardiopulmonary resuscitation and survival

BackgroundDuring cardiopulmonary resuscitation (CPR), advanced life support (ALS) providers have been shown to deliver inadequate CPR with long intervals without chest compressions. Several changes made to the 2005 CPR Guidelines were intended to reduce unnecessary interruptions. We have evaluated if quality of CPR performed by the Oslo Emergency Medical System (EMS) improved after implementation of the modified 2005 CPR Guidelines, and if any such improvement would result in increased survival.Materials and methodsRetrospective, observational study of all consecutive adult cardiac arrest patients treated during a 2-year period before (May 2003–April 2005), and after (January 2006–December 2007) implementation of the modified 2005 CPR Guidelines. CPR quality was assessed from continuous electronic recordings from LIFEPACK 12 defibrillators where ventilations and chest compressions were identified from transthoracic impedance changes. Ambulance run sheets, Utstein forms and hospital records were collected and outcome evaluated.ResultsResuscitation was attempted in 435 patients before and 481 patients after implementation of the modified 2005 CPR Guidelines. ECGs usable for CPR quality evaluation were obtained in 64% and 76% of the cases, respectively. Pre-shock pauses decreased from median (interquartile range) 17 s (11, 22) to 5 s (2, 17) (p = 0.000), overall hands-off ratios from 0.23 ± 0.13 to 0.14 ± 0.09 (p = 0.000), compression rates from 120 ± 9 to 115 ± 10 (p = 0.000) and ventilation rates from 12 ± 4 to 10 ± 4 (p = 0.000). Overall survival to hospital discharge was 11% and 13% (p = 0.287), respectively.ConclusionQuality of CPR improved after implementation of the modified 2005 Guidelines with only a weak trend towards improved survival to hospital discharge.     

Association of presence and timing of invasive airway placement with outcomes after pediatric in-hospital cardiac arrest

BackgroundLittle data exist regarding the association of presence of an invasive airway before cardiac arrest or early placement of an invasive airway after cardiac arrest with outcomes in children who experience in-hospital cardiac arrest.MethodsWe conducted a retrospective review of patients aged 1 day to 18 years who received cardiopulmonary resuscitation (CPR) for ≥1 min in any of the three intensive care units (ICUs) at a tertiary care, academic children's hospital between 2002 and 2010. Specific outcomes evaluated included survival to hospital discharge, return of spontaneous circulation (ROSC), 24-h survival, and good neurological status at hospital discharge. We fitted multivariable logistic regression models to evaluate the association between the presence of an invasive airway prior to cardiac arrest and timing of placement of an invasive airway with these outcomes.ResultsThree hundred and ninety-one patients were included. Of these, 197 (51%) patients were already tracheally intubated before the occurrence of cardiac arrest. Median time to intubation was 6 min [interquartile range (IQR): 2, 12] among the 194 patients tracheally intubated following cardiac arrest. We found lower survival to hospital discharge among patients intubated prior to cardiac arrest (intubated vs. non-intubated group, 43% vs. 61%, p < 0.001). After adjusting for patient and event characteristics, presence of an invasive airway prior to cardiac arrest was not associated with a significant improvement in survival to hospital discharge [odds ratio (OR): 0.70, 95% confidence interval (CI): 0.42–1.16, p = 0.17], or good neurological outcomes (OR: 0.60, 95% CI: 0.34–1.05, p = 0.07). Similarly, early placement of an invasive airway after cardiac arrest was also not associated with an improvement in survival to hospital discharge (OR: 1.05, 95% CI: 0.78–1.42, p = 0.73), or good neurological outcomes (OR: 1.08, 95% CI: 0.77–1.53, p = 0.65).ConclusionsOur study demonstrates that presence of an invasive airway prior to cardiac arrest or early placement of an invasive airway after cardiac arrest is not associated with an improvement in survival to hospital discharge or good neurological outcomes. Further study of the relationship between invasive airway management and survival following cardiac arrest is warranted.     

Association between hospital post-resuscitative performance and clinical outcomes after out-of-hospital cardiac arrest

BackgroundSurvival varies among those resuscitated from out-of-hospital cardiac arrest (OHCA). Evidence-based performance measures have been used to describe hospital quality of care in conditions such as acute coronary syndrome and major trauma. It remains unclear if adherence to performance measures is associated with better outcome in patients hospitalized after OHCA.ObjectivesTo assess whether a composite performance score based on evidence-based guidelines for care of patients resuscitated from OHCA was independently associated with clinical outcomes.MethodsIncluded were 3252 patients with OHCA who received care at 111 U.S. and Canadian hospitals participating in the Resuscitation Outcomes Consortium (ROC-PRIMED) study between June 2007 and October 2009. We calculated composite performance scores for all patients, aggregated these at the hospital level, then associated them with patient mortality and favorable neurological status at discharge.ResultsComposite performance scores varied widely (median [IQR] scores from lowest to highest hospital quartiles, 21% [20%, 25%] vs. 59% [55%, 64%]. Adjusted survival to discharge increased with each quartile of performance score (from lowest to highest: 16.2%, 20.8%, 28.5%, 34.8%, P < 0.01), with similar findings for adjusted rates of good neurologic status. Hospital score was significantly associated with outcome after risk adjustment for established baseline factors (highest vs. lowest adherence quartile: adjusted OR of survival 1.64; 95% CI 1.13, 2.38).ConclusionsGreater survival and favorable neurologic status at discharge were associated with greater adherence to recommended hospital based post-resuscitative care guidelines. Consideration should be given to measuring, reporting and improving hospital adherence to guideline-based performance measures, which could improve outcomes following OHCA.     

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.MethodsWe 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.ResultsCompared 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.ConclusionMore 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.     

Outcomes after extracorporeal cardiopulmonary resuscitation (ECPR) following refractory pediatric cardiac arrest in the intensive care unit

AimTo describe our experience using extracorporeal cardiopulmonary resuscitation (ECPR) in resuscitating children with refractory cardiac arrest in the intensive care unit (ICU) and to describe hospital survival and neurologic outcomes after ECPR.MethodsA retrospective chart review of a consecutive case series of patients requiring ECPR from 2001 to 2006 at Arkansas Children's Hospital. Data from medical records was abstracted and reviewed. Primary study outcomes were survival to hospital discharge and neurological outcome at hospital discharge.ResultsDuring the 6-year study period, ECPR was deployed 34 times in 32 patients. 24 deployments (73%) resulted in survival to hospital discharge. Twenty-eight deployments (82%) were for underlying cardiac disease, 3 for neonatal non-cardiac (NICU) patients and 3 for paediatric non-cardiac (PICU) patients. On multivariate logistic regression analysis, only serum ALT (p-value = 0.043; OR, 1.6; 95% confidence interval, 1.014–2.527) was significantly associated with risk of death prior to hospital discharge. Blood lactate at 24 h post-ECPR showed a trend towards significance (p-value = 0.059; OR, 1.27; 95% confidence interval, 0.991–1.627). The Hosmer–Lemeshow tests (p-value = 0.178) suggested a good fit for the model. Neurological evaluation of the survivors revealed that there was no change in PCPC scores from a baseline of 1–2 in 18/24 (75%) survivors.ConclusionsECPR can be used successfully to resuscitate children following refractory cardiac arrest in the ICU, and grossly intact neurologic outcomes can be achieved in a majority of cases.     

The influence of age and chronic medical conditions on neurological outcomes in out of hospital cardiac arrest

AimIt is unknown whether older patients with out of hospital cardiac arrest (OHCA) have worse outcomes because of aging itself, or because age can be a marker for overall health status. We aimed to study the prognostic utility of age and pre-arrest comorbidities.MethodsWe conducted a retrospective cohort study, reviewing electronic health records of all adults treated for non-traumatic OHCA in the University of Michigan Emergency Department (N = 588). Primary covariates included age, Charlson Comorbidity Index (CCI), and a combined Charlson-age index. The primary dichotomized outcome was favorable neurological outcome (cerebral performance category, 1–2), evaluated by logistic regressions.ResultsDementia (p = 0.01), witnessed arrest (p = 0.03), bystander CPR (p < 0.001), presenting rhythm (p < 0.001), and mild therapeutic hypothermia (p < 0.001) were associated with the primary outcome. Increasing age (unadjusted OR for each decade of life, 95% CI: 0.78, 0.70–0.88; adjusted 0.79, 0.67–0.94) was negatively associated with likelihood of a favorable neurological outcome. CCI and combined Charlson-age index significantly predicted outcome in the unadjusted, but not adjusted analysis. Composite variables were stronger predictors in patients with shockable than non-shockable presenting rhythms (interaction terms: age and rhythm [p = 0.004], CCI and rhythm [p = 0.01]).ConclusionAge, but not CCI, was significantly associated with less favorable neurological outcomes in patients with OHCA after adjusting important covariates. Age appears to be an independent predictor of prognosis rather than a marker for comorbidity.     

Public Access Defibrillation: Great benefit and potential but infrequently used

BackgroundIn Copenhagen, a volunteer-based Automated External Defibrillator (AED) network provides a unique opportunity to assess AED use.We aimed to determine the proportion of Out-of-Hospital Cardiac Arrest (OHCA) where an AED was applied before arrival of the ambulance, and the proportion of OHCA-cases where an accessible AED was located within 100 m. In addition, we assessed 30-day survival.MethodsUsing data from the Mobile Emergency Care Unit and the Danish Cardiac Arrest Registry, we identified 521 patients with OHCA between October 1, 2011 and September 31, 2013 in Copenhagen, Denmark.ResultsAn AED was applied in 20 cases (3.8%, 95% CI [2.4 to 5.9]). Irrespective of AED accessibility, an AED was located within 100 m of a cardiac arrest in 23.4% (n = 102, 95% CI [19.5 to 27.7]) of all OHCAs. However, at the time of OHCA, an AED was located within 100 m and accessible in only 15.1% (n = 66, 95% CI [11.9 to 18.9]) of all cases.The 30-day survival for OHCA with an initial shockable rhythm was 64% for patients where an AED was applied prior to ambulance arrival and 47% for patients where an AED was not applied.ConclusionsWe found that 3.8% of all OHCAs had an AED applied prior to ambulance arrival, but 15.1% of all OHCAs occurred within 100 m of an accessible AED. This indicates the potential of utilising AED networks by improving strategies for AED accessibility and referring bystanders of OHCA to existing AEDs.     

Prognostic implication of out-of-hospital cardiac arrest in patients with cardiogenic shock and acute myocardial infarction

ObjectivesTo compare outcome in patients with acute myocardial infarction (MI) and cardiogenic shock (CS) presenting with and without out-of-hospital cardiac arrest (OHCA).BackgroundDespite general improvement in outcome after acute MI, CS remains a leading cause of death in acute MI patients with a high 30-day mortality rate. OHCA on top of cardiogenic shock may further increase mortality in these patients resulting in premature withdrawal of supportive therapy, but this is not known.Methods and resultsIn a retrospective study from 2008 to 2013, 248 consecutive patients admitted alive to a tertiary centre with the diagnosis of CS and acute MI were enrolled, 118 (48%) presented with OHCA and 130 (52%) without (non-OHCA patients). Mean lactate level at admission was significantly higher in OHCA patients compared with non-OCHA patients (9 mmol/l (SD 6) vs. 6 mmol/l (SD 4) p < 0.0001). Co-morbidities were more prevalent in the non-OHCA group. By univariate analysis age (Hazard ratio (HR) = 1.02 [CI 1.00–1.03], p = 0.01) and lactate at admission (HR = 1.06 [CI 1.03–1.09], p < 0.001), but not OHCA (HR = 1.1 [CI 0.8–1.4], p = NS) was associated with mortality. In multivariate analysis, only age (HR = 1.02 [CI 1.01–1.04], p = 0.003) and lactate level at admission (HR = 1.06 [1.03–1.09], p < 0.001) were independent predictors of mortality. One-week mortality was 63% in the OHCA group and 56% in the non-OHCA group, p = NS.ConclusionOHCA is not an independent predictor of mortality in patients with acute MI complicated by cardiogenic shock. This should encourage active intensive treatment of CS patients regardless of OHCA.     

Outcome of out-of-hospital cardiac arrest over a period of 15 years in comparison to the RACA score in a physician staffed urban emergency medical service in Germany

BackgroundPatient outcome after out of hospital cardiac arrest (OHCA) depends on the cardiopulmonary resuscitation (CPR) performance and might also be influenced by organisation of the emergency medical service (EMS) and implementation of guidelines.AimTo assess the rate of return of spontaneous circulation (ROSC) after cardiac arrest to the predicted rate by the ROSC after cardiac arrest (RACA) score over a 15-year period reflecting three different implemented ALS-guidelines in a physician-staffed EMS.MethodsAll adult patients with non-traumatic OHCA in the EMS of Bonn from 1996 to 2011 were included. Utstein data from three 5-years time periods (1996–2001, 2001–2006, 2006–2011) representing different ALS-guideline implementations were collected. Group comparisons were made in terms of incidence, epidemiology and short-term outcome of CPR with emphasis on changes over time and factors of importance. In each group observed ROSC rate were compared to the predicted ROSC rates (the RACA score).ResultsCPR by the ALS unit was attempted in a total of 1989 patients (735, 666, and 588 patients in the first, second and third period, respectively). Average crude incidence of CPR per 100,000 person-years decreased over time (61.3; 55.5; 49.0/100,000/years) while patients treated were significantly older (65.5 ± 16.5; 67.9 ± 15; 68.9 ± 15.7 (p < 0.001)). Observed ROSC rates were higher than predicted by the RACA score in all time periods, however, admittance to ICU decreased significantly from 50% in the first five-year period to 38% last five-year period (p < 0.001). From first to third period the proportion of arrests with first observed rhythm of VT/VF arrests did not change (29% vs. 27%, p = 0.323) nor there were changes in bystander CPR rates (17% vs. 17%, p = 0.520).ConclusionsIn a 15-years period and in the setting of a physician-staffed EMS the ROSC rates remain higher than predicted by the RACA score but the admittance to the ICU after OHCA declined significantly. This finding was accompanied by a decrease in CPR incidence and an increase in age of patients.