Improving neurologic outcomes after out-of-hospital cardiac arrest

Abstract

Objectives. 1) To compare the outcomes of adult trauma patients transported to a level I trauma center by helicopter vs. ground ambulance. 2) To determine whether using a unique “natural experiment” design to obtain the ground comparison group will reduce potential confounders. Methods. Outcomes in adult trauma patients transported to a tertiary care trauma center by air were compared with outcomes in a group of patients who were accepted by the online medical control physician for air transport, but whose air missions were aborted for aviation reasons (weather, maintenance, out on a mission); these patients were subsequently transported by ground ambulance instead. Outcomes were also analyzed for a third ground control group composed of all other adult trauma patients transported by ground during this time period. Data were collected by retrospective database review of trauma patients transferred between July 1, 1997, and June 30, 2003. Outcomes were measured by Trauma Injury Severity Score (TRISS) analysis. Z and W scores were calculated. Results. Three hundred ninety-seven missions were flown by LifeFlight during the study period vs. 57 in the clinical accept–aviation abort ground transport group. The mean ages, gender distributions, mechanisms of injury, and Injury Severity Scores (ISSs) were similar in the two groups. Per 100 patients transported, 5.61 more lives were saved in the air group vs. the clinical accept–aviation abort ground transport group (Z = 3.37). As per TRISS analysis, this is relative to the expected mortality seen with a similar group in the Major Trauma Outcomes Study (MTOS). The Z score for the clinical accept–aviation abort ground transport group was 0.4. The 1,195 patients in the third all-other ground control group had a higher mean age, lower mean ISS, and worse outcomes according to TRISS analysis (W = –2.02). Conclusions. This unique natural experiment led to better matched air vs. ground cohorts for comparison. As per TRISS analysis, air transport of the adult major trauma patient is associated with significantly improved survival as compared with ground transport.     

Epidemiology and outcomes of poisoning-induced out-of-hospital cardiac arrest

Objectives

We aimed to describe and compare the epidemiologic features and outcomes among patients with poisoning-induced out-of-hospital cardiac arrests (POHCAs) according to causative agent groups.

Methods

We identified emergency medical service (EMS)-treated POHCA patients from a nationwide OHCA registry between 2006 and 2008, which was derived from EMS run sheets and followed by hospital record review. Utstein elements were collected and hospital outcomes (survival to admission and to discharge) were measured. We compared risk factors and outcomes according to the main poisons. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated from a multivariate logistic regression model for hospital outcomes.

Results

The total number of non-cardiac aetiology OHCAs was 20,536. Of these, the number of EMS-assessed and EMS-treated POHCAs was 900 (4.4%). For EMS-treated POHCAs, insecticides (n = 111, 15.5%) including organophosphate and carbamates; herbicides (n = 94, 13.2%); unknown pesticides (n = 142, 19.9%); non-pesticide drugs (n = 120, 16.8%); and unknown poisons (n = 247, 6%) were identified. The survival to admission rate was 22.5% for insecticides, 3.2% for herbicides, 16.2% for unknown pesticides, 16.7% for non-pesticides and 11.3% for the unknown group. The survival to discharge rates were 9.9% for insecticides, 0.0% for herbicides, 2.1% for unknown pesticides, 3.3% for non-pesticides and 3.2% for the unknown group. The adjusted OR for each group for survival to admission was significantly lower when compared with insecticides: herbicides (OR = 0.11, 95% CI = 0.03-0.44), non-pesticide drugs (OR = 0.28, 95% CI = 0.13-0.61) and unknown group (OR = 0.40, 95% CI = 0.21-0.76). The adjusted OR for each group for survival to discharge was significantly lower when compared with insecticides: herbicides (OR < 0.01, 95% CI < 0.01 or >99.9), unknown pesticides (OR = 0.23, 95% CI = 0.0.06-0.87), non-pesticide drugs (OR = 0.14, 95% CI = 0.04-0.54) and unknown group (OR = 0.30, 95% CI = 0.11-0.83).

Conclusion

Using a nationwide OHCA registry, we found that poisonings were responsible for 4.4% of OHCAs of a non-cardiac aetiology. Ingestion of insecticides including organophosphate and carbamate was associated with more favourable outcomes.     

Incidence and outcomes of rearrest following out-of-hospital cardiac arrest

IntroductionRearrest occurs when a patient experiences cardiac arrest after successful resuscitation. The incidence and outcomes of rearrest following out-of-hospital cardiac arrest have been estimated in limited local studies. We sought provide a large-scale estimate of rearrest incidence and its effect on survival.MethodsWe obtained case data from emergency medical services-treated, out-of-hospital cardiac arrest from the Resuscitation Outcomes Consortium, a multi-site clinical research network with clinical centers in 11 regions in the US and Canada. The cohort comprised all cases captured between 2006 and 2008 at 10 of 11 regions with prehospital return of spontaneous circulation. We used three methods to ascertain rearrest via direct signal analysis, indirect signal analysis, and emergency department arrival vital status. Rearrest incidence was estimated as the proportion of cases with return of spontaneous circulation that experience rearrest. Regional rearrest incidence estimates were compared with the χ²-squared test. Multivariable logistic regression was used to assess the relationship between rearrest and survival to hospital discharge.ResultsOut of 18,937 emergency medical services-assessed cases captured between 2006 and 2008, 11,456 (60.5%) cases were treated by emergency medical services and 4396 (38.4%) had prehospital return of spontaneous circulation. Of these, rearrest ascertainment data was available in 3253 cases, with 568 (17.5%) experiencing rearrest. Rearrest differed by region (10.2% to 21.2%, p < 0.001). Rearrest was inversely associated with survival (OR: 0.19, 95% CI: 0.14–0.26).ConclusionsRearrest was found to occur frequently after resuscitation and was inversely related to survival.     

Rapid epinephrine administration improves early outcomes in out-of-hospital cardiac arrest

Introduction

Early administration of epinephrine (Epi) improves outcomes in animal models of cardiac arrest, but there is limited time-dependent clinical data regarding its benefit.

Objective

Our objective was to assess whether timing of Epi administration was associated with improved outcomes after out of hospital cardiac arrest (OHCA).

Methods

We performed a retrospective analysis of a cardiac arrest database from a suburban EMS system from November 2005 to April 2011. Data was abstracted from EMS run sheets, including drug treatment, route and timing of drug administration, and other Utstein variables. Our primary outcome was return of spontaneous circulation (ROSC). Secondary outcomes measured were survival to hospital admission and discharge. For analysis, data were dichotomized according to timing of Epi administration: early Epi group (defined as 911 call to Epi administration of ≤10 min) and late Epi group (>10 min). Further, exploratory analyses were conducted looking at subgroups sorted by initial rhythm and whether the arrest was witnessed. Wilcoxon rank sum tests, chi-square tests, 95% confidence intervals, and multi-variable regression were used for statistical analysis.

Results

We reviewed 809 patients from study communities: 123 patients were excluded, leaving a sample size of 686 for study analysis. The mean time from 911-Epi was 14.3 ± 5.5 min, with 155 (22.6%) receiving early Epi. Key arrest and treatment characteristics were similar between groups. Patients who received early Epi were more likely to have ROSC (32.9% vs. 23.4%, OR 1.59 (1.07, 2.38)), however, no significant increase in survival to admission or discharge was observed. Patients with an initial rhythm of PEA had an increased rate of ROSC (48.6% vs. 21.5%, OR 3.45 (1.56, 7.62)) but not survival to discharge (5.9% vs. 2.6%), OR 2.35 (0.38, 14.7) with early Epi. In a multivariable analysis of bystander witnessed arrests, early Epi was associated with a higher rate of ROSC (OR 3.20 (1.75, 5.88) but not survival to discharge (OR 1.48 (0.50, 4.36)). No improvement in ROSC or secondary outcomes was noted in patients with other arrest rhythms or un-witnessed arrest with Early Epi.

Conclusions

Within the limitations of our study, this data suggests improved rates of ROSC with early Epi administration during OHCA resuscitation, but this study lacks adequate sample size to demonstrate impact on survival to discharge. Large prospective trials are needed to further delineate the benefit of early Epi administration in OHCA.     

Resuscitation characteristics and outcomes in suspected drug overdose-related out-of-hospital cardiac arrest

Introduction

We sought to compare characteristics of emergency medical services-treated out-of-hospital cardiac arrests resulting from suspected drug overdose with non-overdose cases and test the relationship between suspected overdose and survival to hospital discharge.

Methods

Data from emergency medical services-treated, non-traumatic out-of-hospital cardiac arrests from 2006 to 2008 and late 2009 to 2011 were obtained from four EMS agencies in the Pittsburgh, Pennsylvania metropolitan area. Case definition for suspected drug overdose was naloxone administration, indication on the patient care report and/or indication by a review of hospital records. Resuscitation parameters included chest compression fraction, rate, and depth and the administration of resuscitation drugs. Demographic and outcome variables compared by suspected overdose status included age, sex, and survival to hospital discharge.

Results

From 2342 treated out-of-hospital cardiac arrests, 180 were suspected overdose cases (7.7%) and were compared to 2162 non-overdose cases. Suspected overdose cases were significantly younger (45 vs. 65, p < 0.001), less likely to be witnessed by a bystander (29% vs. 41%, p < 0.005), and had a higher rate of survival to hospital discharge (19% vs. 12%, p = 0.014) than non-overdoses. Suspected overdose cases had a higher overall chest compression fraction (0.69 vs. 0.67, p = 0.018) and higher probability of adrenaline, sodium bicarbonate, and atropine administration (p < 0.001). Suspected overdose status was predictive of survival to hospital discharge when controlling for other variables (p < 0.001).

Conclusion

Patients with suspected overdose-related out-of-hospital cardiac arrest were younger, received different resuscitative care, and survived more often than non-overdose cases.     

Sex disparity in resuscitation efforts and outcomes in out-of-hospital cardiac arrest

Objectives

The aim of this study was to investigate the association between sex, cardiopulmonary resuscitation efforts, and outcomes of out-of-hospital cardiac arrests in Korea.

Methods

We used a nationwide, out-of-hospital cardiac arrest cohort database in 2008. We extracted cases involving patients older than 20 years with symptoms of presumed cardiac etiology. Potential predictors were collected using the Utstein style. The primary outcome was the resuscitation effort: basic life support and application of an automatic external defibrillator by emergency medical service providers, and advanced cardiac life support by emergency department physicians. Secondary outcomes were survival to admission and survival to discharge. Univariate and multivariate logistic regression models were applied by sex to calculate odds ratios and 95% confidence intervals adjusting for potential predictors.

Results

The total number of eligible patients was 13?922. Of these, 5158 patients (37.0%) were female. Females were also less likely than males to receive basic life support (70.8% vs 77.5%, P < .001) or an automatic external defibrillator (9.6% vs 14.3%, P < .001), or receive advanced cardiac life support (42.2% vs 49.2%, P < .001). When compared with males, rates of survival to admission and discharge for females were 11.8% (vs 12.3%, P = .43) and 3.1% (vs 1.8%, P < .001), respectively. Adjusted odds ratios for survival to admission and survival to discharge for females, when compared with males, were 1.32 (1.17-1.48) and 0.82 (0.63-1.05), respectively.

Conclusions

Females were less likely than males to receive resuscitation. Female sex was associated with a higher rate of survival at admission rate, whereas it was not associated with survival at discharge.     

Quick epinephrine administration induces favorable neurological outcomes in out-of-hospital cardiac arrest patients

Objective

This research is to study if quick administration of adrenaline on OHCA prior to hospitalization has an effect on improving CPC1-2 at one month.

Dynamics and state transitions during resuscitation in out-of-hospital cardiac arrest

BACKGROUND: The state or rhythm during resuscitation, i.e. ventricular fibrillation/tachycardia (VF/VT), asystole (ASY), pulseless electrical activity (PEA), or return of spontaneous circulation (ROSC) determines management. The state is unstable and will change either spontaneously (e.g. PEA-->ASY) or by intervention (e.g. VF-->ASY after DC shock); temporary ROSC may also occur. To gain insight into the dynamics of this process, we analyzed the state transitions over time using real-life data. METHODS: Detailed recordings from 304 episodes of attempted resuscitation from out-of-hospital cardiac arrests of presumed cardiac etiology were obtained from modified Heartstart 4000 defibrillators. State transitions were visualized and described, and analyzed in terms of a Markov probability model. RESULTS: The median number of state transitions was 5 (range 1-39), and more transitions were observed with VF than PEA or asystole as the initial rhythm. Of 105 patients (35%) who regained ROSC at some point during CPR, only 65 (21%) achieved sustained ROSC; suggesting an unrealized survival potential. A 3-min transition probability matrix was estimated: for example, a patient early in VF has a probability of 31% to be in ASY, 32% of still being in VF, 5% to have temporary ROSC, and 2% to have sustained ROSC after 3 min. CONCLUSION: The dynamics of resuscitation can be described in terms of state transitions and a Markov probability model. This framework enables prediction of short-term clinical development, supports informed decisions during CPR, and suggests a novel area for research.     

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.     

Epidemiology and outcomes of out-of-hospital cardiac arrest in Rochester, New York

OBJECTIVE: To characterize out-of-hospital cardiac arrest (OHCA) and factors that affect survival in a medium sized city that uses system status management for dispatch. METHODS: A retrospective cohort study of all adult OHCA patients treated by EMS between 1998 and 2001 was conducted using Utstein definitions. The primary endpoint was 1-year survival. RESULTS: Of the 1177 patients who experienced OHCA during the study period, 539 (46%) met inclusion criteria. Age ranged from 18 to 98 years (median 67). The median call-response interval was 5 min (range 0-21), and 93% were 9 min or less. There was no significant difference in the median call-response intervals between call location zip (Post) codes (p=0.07). Twenty percent of experienced ROSC (95% CI 17-23), 7% survived more than 30 days (95% CI 5-9%), and 5% survived to 1 year (95% CI 3-7%). In bivariate analysis, first rhythm and bystander CPR affected survival to 1 year. There was no significant difference in survival between male (4%) and female (7%), black (4%) and white (6%), or witnessed (7%) and unwitnessed arrest (4%). Logistic regression identified younger age, CPR initiated by bystander (19%) or first responder (41%), and presenting rhythm of VF/VT (32%) as factors associated with survival to 1 year. CONCLUSIONS: This study finds a 5% survival to 1 year among OHCA patients in Rochester, NY. A presenting rhythm of VF/VT and bystander CPR were associated with increased survival.     

Sympathetic responses in out-of-hospital cardiac arrest

To determine the clinical relevance of the sympathetic response to out-of-hospital cardiac arrest, we measured plasma concentrations of catecholamine and cortisol in ten such arrested patients on their arrival. The duration of cardiac arrest was estimated from 9 to 200 min before basic life support was initiated by ambulance personnel. Two of the patients developed spontaneous pulses in response to ALS and were resuscitated, and the others were not, although the length and the extent of ALS were not different between the two groups. Plasma concentrations of epinephrine (EN), norepinephrine (NE) and cortisol prior to ALS in both groups were markedly elevated. In particular, the patients who never regained spontaneous pulses showed 58-fold and 12-fold increase in the plasma EN and NE levels, respectively, which were much higher than those in the resuscitated cases; 8- and 1.7-fold increase, respectively. These massive EN and NE discharges correlated well with the arrest time (r = 0.96 and 0.94, respectively) and the degree of acidosis (r = -0.82 and -0.82, respectively).     

Long-term survival after out-of-hospital cardiac arrest

OBJECTIVE: The purpose of this study was to assess the long-term survival after OHCA. METHODS: All OHCA-calls where the Copenhagen Mobile Emergency Care Unit (MECU) was involved from 1994 to1998 are included in this study. Data were collected prospectively. Data on long-term survival was obtained from the Danish Causes of Death Registry and the Danish Civil Registration System. We conducted a search to find out whether patients were still alive on 31 January 2005. RESULTS: Resuscitation was indicated and attempted in 1095 cases and 95 patients (8.7%) survived to discharge. Of these 75% had an initial rhythm of VF, 13% had asystole, 10% had PEA and 2% were unknown. Survival was 87% after one year and survival after 10 years was 46% with a significantly lower survival for patients over 60 years. CONCLUSION: Long-term survival after out-of-hospital cardiac arrest in a physician-staffed emergency system was comparable to survival after myocardial infarction with 46% being alive after ten years.     

External noninvasive cardiac pacing in out-of-hospital cardiac arrest

External noninvasive cardiac pacing was applied outside the hospital to 19 patients who had experienced cardiopulmonary arrest and 1 patient with life-threatening bradycardia. Seven patients developed electrocardiographic evidence of pacemaker capture, although only 2 had palpable pulses. The patient with bradycardia was successfully paced. This study demonstrates the feasibility of cardiac pacing in out-of-hospital cardiac arrest but confirms the poor prognosis of asystolic cardiac arrest even with the application of pacing.     

Long-term prognosis after out-of-hospital cardiac arrest

OBJECTIVE: In this study we aimed to report survival beyond 6 months, including quality of life, for patients after out-of-hospital cardiac arrest (OHCA) with a physician-based EMS in an urban area. METHODS: We collected data related to OHCA prospectively during a 2-year period. Long-term survival was determined by cross-referencing our database with two Danish national registries. Patients older than 18 years who had survived for more than 6 months after OHCA were contacted, and after informed written consent was obtained, an interview was conducted in their home and a questionnaire on quality of life (SF-36) and the mini mental state examination (MMSE) were administered. RESULTS: We had data on 984 cases of OHCA. In 512 cases CPR was attempted and at 6 months, a total of 63 patients were alive corresponding to 12.3% [95% CI: 9.7-15.5%] of all who were treated. Of the 33 patients examined, the median MMSE was 29 (16-30) and two patients, corresponding to 6%, [95% CI: 0.7-20.6%] had an MMSE below 24. Two out of eight aspects of the SF-36 were significantly worse than national norms at the same age, but none of the summary scores differed significantly. CONCLUSION: Survival beyond 6 months was found in 12.3% OHCA in a physician-based EMS. Summary scores of quality of life were not significantly different from the national norm but 2 out of 8 subscores were lower. Signs of dementia were uncommon as only 6% had an MMSE score below 24.     

Post-discharge outcomes after resuscitation from out-of-hospital cardiac arrest: A ROC PRIMED substudy

ImportanceAssessment of morbidity is an important component of evaluating interventions for patients with out-of-hospital cardiac arrest (OHCA).ObjectiveWe evaluated among survivors of OHCA cognition, functional status, health-related quality of life and depression as functions of patient and emergency medical services (EMS) factors.DesignProspective cohort sub-study of a randomized trial.SettingThe parent trial studied two comparisons in persons with non-traumatic OHCA treated by EMS personnel participating in the Resuscitation Outcomes Consortium.ParticipantsConsenting survivors to discharge.Main outcome measuresTelephone assessments up to 6 months after discharge included neurologic function (modified Rankin score, MRS), cognitive impairment (Adult Lifestyle and Function Mini Mental Status Examination, ALFI-MMSE), health-related quality of life (Health Utilities Index Mark 3, HUI3) and depression (Telephone Geriatric Depression Scale, T-GDS).ResultsOf 15,794 patients enrolled in the parent trial, 729 (56% of survivors) consented. About 644 respondents (88% of consented) completed ≥ 1 assessment. Likelihood of assessment was associated with baseline characteristics and study site. Most respondents had MRS ≤ 3 (82.7%), no cognitive impairment (82.7% ALFI-MMSE ≥ 17), no severe impairment in health (71.6%, HUI3 ≥ 0.7) and no depression (90.1% T-GDS ≤ 10). Outcomes did not differ by trial intervention or time from hospital discharge.Conclusions and relevanceThe majority of patients in this large cohort who survived cardiac arrest and were interviewed had no, mild or moderate health impairment. Concern about poor quality of life is not a valid reason to abandon efforts to improve an EMS system's response to cardiac arrest.