Ventricular fibrillation waveform measures combined with prior shock outcome predict defibrillation success during cardiopulmonary resuscitation

AIM

Amplitude Spectrum Area (AMSA) and Median Slope (MS) are ventricular fibrillation (VF) waveform measures that predict defibrillation shock success. Cardiopulmonary resuscitation (CPR) obscures electrocardiograms and must be paused for analysis. Studies suggest waveform measures better predict subsequent shock success when combined with prior shock success. We determined whether this relationship applies during CPR.

METHODS

AMSA and MS were calculated from 5-second pre-shock segments with and without CPR, and compared to logistic models combining each measure with prior return of organized rhythm (ROR).

RESULTS

VF segments from 692 patients were analyzed during CPR before 1372 shocks and without CPR before 1283 shocks. Combining waveform measures with prior ROR increased areas under receiver operating characteristic curves for AMSA/MS with CPR (0.66/0.68 to 0.73/0.74, p<0.001) and without CPR (0.71/0.72 to 0.76/0.76, p<0.001).

CONCLUSIONS

Prior ROR improves prediction of shock success during CPR, and may enable waveform measure calculation without chest compression pauses.

Availability and Accuracy of EMS Information about Chronic Health and Medications in Cardiac Arrest

Introduction

Field information available to emergency medical services (EMS) about a patient’s chronic health conditions or medication therapies could help direct patient care or be used to investigate outcome disparities. However, little is known about the field availability or accuracy of information of chronic health conditions or chronic medication treatments in emergent circumstances, especially when the patient cannot serve as an information resource. We evaluated the prehospital availability and accuracy of specific chronic health conditions and medication treatments among out-of-hospital cardiac arrest (OHCA) patients.

Methods

The investigation was a retrospective cohort study of adult persons suffering ventricular fibrillation OHCA treated by EMS in a large metropolitan county from January 1, 2007, to December 31, 2013. The study was designed to determine the availability and accuracy of EMS ascertainment of selected chronic health conditions and medication treatments. We evaluated chronic health conditions of “any heart disease,” congestive heart failure (CHF), and diabetes and medication treatments of beta blockers and loop diuretics using two distinct sources: 1) EMS report, and 2) hospital record specific to the OHCA event. Because hospital information was considered the gold standard, we restricted the primary analysis to those who were admitted to hospital.

Results

Of the 1,496 initially eligible patients, 387 could not be resuscitated and were pronounced dead in the field, one patient was left alive at scene due to Physician’s Orders for Life-sustaining Treatment (POLST) orders, 125 expired in the emergency department (n=125), and 983 were admitted to hospital. A total of 832 of 1,496 (55.6%) had both sources of data for comparison and comprised the primary analytic group. Using the hospital record as the gold standard, EMS ascertainment had a sensitivity of 0.79 (304/384) and a specificity of 0.88 (218/248) for any prior heart disease; sensitivity 0.45 (47/105) and specificity 0.87 (477/516) for CHF; sensitivity 0.71 (143/201) and specificity 0.98 (416/424) for diabetes; sensitivity 0.70 (118/169) and specificity 0.94 (273/290) for beta blockers; sensitivity 0.70 (62/89) and specificity 0.97 (358/370) for loop diuretics.

Conclusion

In this cohort of OHCA, information about selected chronic health conditions and medication treatments based on EMS ascertainment was available for many patients, generally revealing moderate sensitivity and greater specificity.

Early Identification of Patients With Out-of-Hospital Cardiac Arrest With No Chance of Survival and Consideration for Organ Donation

BACKGROUND

In patients with out-of-hospital cardiac arrest (OHCA), care requirements can conflict with the need to promptly focus efforts on organ donation in patients who are pronounced dead.

OBJECTIVE

To evaluate objective criteria for identifying patients with OHCA with no chance of survival during the first minutes of cardiopulmonary resuscitation to enable prompt orientation toward organ donation.

DESIGN

Retrospective assessment using OHCA data from 2 registries and 1 trial.

SETTING

France (Paris Sudden Death Expertise Center [SDEC] prospective cohort [2011 to 2014] and PRESENCE multicenter cluster randomized trial [ClinicalTrials.gov: NCT01009606] [2009 to 2011]) and the United States (King County, Washington, prospective cohort [2006 to 2011]).

PATIENTS

1771 patients from the Paris SDEC 1-year cohort (2011 to 2012) and 5192 from the validation cohorts.

MEASUREMENTS

Evaluation of 3 objective criteria (OHCA not witnessed by emergency medical services personnel, nonshockable initial cardiac rhythm, and no return of spontaneous circulation before receipt of a third 1-mg dose of epinephrine), survival rate at hospital discharge among patients meeting these criteria, performance of the criteria, and number of patients eligible for organ donation.

RESULTS

In the Paris SDEC 1-year cohort, the survival rate among the 772 patients with OHCA who met the objective criteria was 0% (95% CI, 0.0% to 0.5%), with a specificity of 100% (CI, 97% to 100%) and a positive predictive value of 100% (CI, 99% to 100%). These results were verified in the validation cohorts. Ninety-five (12%) patients in the Paris SDEC 1-year cohort may have been eligible for organ donation.

LIMITATION

Several patients had unknown outcomes.

CONCLUSION

Three objective criteria enable the early identification of patients with OHCA with essentially no chance of survival and may help in decision making about the organ donation process.

PRIMARY FUNDING SOURCE

French Ministry of Health.

Short ECG segments predict defibrillation outcome using quantitative waveform measures

AIM

Quantitative waveform measures of the ventricular fibrillation (VF) electrocardiogram (ECG) predict defibrillation outcome. Calculation requires an ECG epoch without chest compression artifact. However, pauses in CPR can adversely affect survival. Thus the potential use of waveform measures is limited by the need to pause CPR. We sought to characterize the relationship between the length of the CPR-free epoch and the ability to predict outcome.

METHODS

We conducted a retrospective investigation using the CPR-free ECG prior to first shock among out-of-hospital VF cardiac arrest patients in a large metropolitan region (n=442). Amplitude Spectrum Area (AMSA) and Median Slope (MS) were calculated using ECG epochs ranging from 5s to 0.2s. The relative ability of the measures to predict return of organized rhythm (ROR) and neurologically-intact survival was evaluated at different epoch lengths by calculating the area under the receiver operating characteristic curve (AUC) using the 5-s epoch as the referent group.

RESULTS

Compared to the 5-s epoch, AMSA performance declined significantly only after reducing epoch length to 0.2s for ROR (AUC 0.77-0.74, p=0.03) and with epochs of ≤0.6s for neurologically-intact survival (AUC 0.72-0.70, p=0.04). MS performance declined significantly with epochs of ≤0.8s for ROR (AUC 0.78-0.77, p=0.04) and with epochs ≤1.6s for neurologically-intact survival (AUC 0.72-0.71, p=0.04).

CONCLUSION

Waveform measures predict defibrillation outcome using very brief ECG epochs, a quality that may enable their use in current resuscitation algorithms designed to limit CPR interruption.

Ethnic differences in sudden cardiac arrest resuscitation

OBJECTIVE

Ethnic differences in sudden cardiac arrest resuscitation have not been fully explored and studies have yielded inconsistent results. We examined the association of ethnicity with factors affecting sudden cardiac arrest outcomes.

METHODS

Retrospective cohort study of 3551 white, 440 black and 297 Asian sudden cardiac arrest cases in Seattle and King County, Washington, USA.

RESULTS

Compared with whites, blacks and Asians were younger, had lower socioeconomic status and were more likely to have diabetes, hypertension and end-stage renal disease (all p<0.001). Blacks and Asians were less likely to have a witnessed arrest (whites 57.6%, blacks 52.1%, Asians 46.1%, p<0.001) or receive bystander cardiopulmonary resuscitation (whites 50.9%, blacks 41.4%, Asians 47.1%, p=0.001), but had shorter average emergency medical services response time (mean in minutes: whites 5.18, blacks 4.75, Asians 4.85, p<0.001). Compared with whites, blacks were more likely to be found in pulseless electrical activity (blacks 20.9% vs whites 16.6%, p<0.001), and Asians were more likely to be found in asystole (Asians 41.1% vs whites 30.0%, p<0.001). One of the strongest predictors of resuscitation outcomes was initial cardiac rhythm with 25% of ventricular fibrillation, 4% of patients with pulseless electrical activity and 1% of patients with asystole surviving to hospital discharge (adjusted OR of resuscitation in pulseless electrical activity compared with ventricular fibrillation: 0.30, 95% CI 0.24 to 0.34, p<0.001, adjusted OR of resuscitation in asystole relative to ventricular fibrillation 0.21, 95% CI 0.17 to 0.26, p<0.001). Survival to hospital discharge was similar across all three ethnicities.

CONCLUSIONS

While there were differences in some prognostic characteristics between blacks, whites and Asians, we did not detect a significant difference in survival following sudden cardiac arrest between the three ethnic groups. There was, however, an ethnic difference in presenting rhythm, with pulseless electrical activity more prevalent in blacks and asystole more prevalent in Asians.

Socioeconomic status and survival from ventricular fibrillation out-of-hospital cardiac arrest

PURPOSE

Out-of-hospital cardiac arrest (OHCA) is a major cause of death in the United States. How individual-level socioeconomic status (SES) influences survival is uncertain.

METHODS

The investigation is a retrospective cohort study of adults who suffered OHCA and presented with a shockable rhythm in a metropolitan county from January 1, 1999-December 31, 2005. Individual-level measures of SES were obtained from vital records and surveys. SES measures included education and occupation. We used multivariable logistic regression to assess the independent association between SES measures and survival to hospital discharge.

RESULTS

Of the 1390 eligible OHCA patients, 374 (27%) survived to hospital discharge. Compared to those with less than high school diploma, the multivariable-adjusted odds ratio of survival was 1.36 (95% confidence interval [CI], 0.87-2.14) for high school graduates, 1.54 (95% CI, 0.95-2.48) for those with some college, and 1.96 (95% CI, 1.17-3.27) for those with college degrees (test for trend across the categories P < .001). We did not observe an independent association between occupation and survival.

CONCLUSIONS

Higher education was associated with greater survival after OHCA. This relationship was not explained by key demographic or clinical characteristics. A better understanding of the mechanism by which individual-level SES characteristics influence prognosis may provide opportunities to improve survival.

Assessment of Clinical Criteria for Sepsis: For the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3)

IMPORTANCE

The Third International Consensus Definitions Task Force defined sepsis as "life-threatening organ dysfunction due to a dysregulated host response to infection." The performance of clinical criteria for this sepsis definition is unknown.

OBJECTIVE

To evaluate the validity of clinical criteria to identify patients with suspected infection who are at risk of sepsis.

DESIGN, SETTINGS, AND POPULATION

Among 1.3 million electronic health record encounters from January 1, 2010, to December 31, 2012, at 12 hospitals in southwestern Pennsylvania, we identified those with suspected infection in whom to compare criteria. Confirmatory analyses were performed in 4 data sets of 706,399 out-of-hospital and hospital encounters at 165 US and non-US hospitals ranging from January 1, 2008, until December 31, 2013.

EXPOSURES

Sequential [Sepsis-related] Organ Failure Assessment (SOFA) score, systemic inflammatory response syndrome (SIRS) criteria, Logistic Organ Dysfunction System (LODS) score, and a new model derived using multivariable logistic regression in a split sample, the quick Sequential [Sepsis-related] Organ Failure Assessment (qSOFA) score (range, 0-3 points, with 1 point each for systolic hypotension [≤100 mm Hg], tachypnea [≥22/min], or altered mentation).

MAIN OUTCOMES AND MEASURES

For construct validity, pairwise agreement was assessed. For predictive validity, the discrimination for outcomes (primary: in-hospital mortality; secondary: in-hospital mortality or intensive care unit [ICU] length of stay ≥3 days) more common in sepsis than uncomplicated infection was determined. Results were expressed as the fold change in outcome over deciles of baseline risk of death and area under the receiver operating characteristic curve (AUROC).

RESULTS

In the primary cohort, 148,907 encounters had suspected infection (n = 74,453 derivation; n = 74,454 validation), of whom 6347 (4%) died. Among ICU encounters in the validation cohort (n = 7932 with suspected infection, of whom 1289 [16%] died), the predictive validity for in-hospital mortality was lower for SIRS (AUROC = 0.64; 95% CI, 0.62-0.66) and qSOFA (AUROC = 0.66; 95% CI, 0.64-0.68) vs SOFA (AUROC = 0.74; 95% CI, 0.73-0.76; P < .001 for both) or LODS (AUROC = 0.75; 95% CI, 0.73-0.76; P < .001 for both). Among non-ICU encounters in the validation cohort (n = 66 522 with suspected infection, of whom 1886 [3%] died), qSOFA had predictive validity (AUROC = 0.81; 95% CI, 0.80-0.82) that was greater than SOFA (AUROC = 0.79; 95% CI, 0.78-0.80; P < .001) and SIRS (AUROC = 0.76; 95% CI, 0.75-0.77; P < .001). Relative to qSOFA scores lower than 2, encounters with qSOFA scores of 2 or higher had a 3- to 14-fold increase in hospital mortality across baseline risk deciles. Findings were similar in external data sets and for the secondary outcome.

CONCLUSIONS AND RELEVANCE

Among ICU encounters with suspected infection, the predictive validity for in-hospital mortality of SOFA was not significantly different than the more complex LODS but was statistically greater than SIRS and qSOFA, supporting its use in clinical criteria for sepsis. Among encounters with suspected infection outside of the ICU, the predictive validity for in-hospital mortality of qSOFA was statistically greater than SOFA and SIRS, supporting its use as a prompt to consider possible sepsis.

Assessment of Clinical Criteria for Sepsis: For the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3)

IMPORTANCE

The Third International Consensus Definitions Task Force defined sepsis as "life-threatening organ dysfunction due to a dysregulated host response to infection." The performance of clinical criteria for this sepsis definition is unknown.

OBJECTIVE

To evaluate the validity of clinical criteria to identify patients with suspected infection who are at risk of sepsis.

DESIGN, SETTINGS, AND POPULATION

Among 1.3 million electronic health record encounters from January 1, 2010, to December 31, 2012, at 12 hospitals in southwestern Pennsylvania, we identified those with suspected infection in whom to compare criteria. Confirmatory analyses were performed in 4 data sets of 706,399 out-of-hospital and hospital encounters at 165 US and non-US hospitals ranging from January 1, 2008, until December 31, 2013.

EXPOSURES

Sequential [Sepsis-related] Organ Failure Assessment (SOFA) score, systemic inflammatory response syndrome (SIRS) criteria, Logistic Organ Dysfunction System (LODS) score, and a new model derived using multivariable logistic regression in a split sample, the quick Sequential [Sepsis-related] Organ Failure Assessment (qSOFA) score (range, 0-3 points, with 1 point each for systolic hypotension [≤100 mm Hg], tachypnea [≥22/min], or altered mentation).

MAIN OUTCOMES AND MEASURES

For construct validity, pairwise agreement was assessed. For predictive validity, the discrimination for outcomes (primary: in-hospital mortality; secondary: in-hospital mortality or intensive care unit [ICU] length of stay ≥3 days) more common in sepsis than uncomplicated infection was determined. Results were expressed as the fold change in outcome over deciles of baseline risk of death and area under the receiver operating characteristic curve (AUROC).

RESULTS

In the primary cohort, 148,907 encounters had suspected infection (n = 74,453 derivation; n = 74,454 validation), of whom 6347 (4%) died. Among ICU encounters in the validation cohort (n = 7932 with suspected infection, of whom 1289 [16%] died), the predictive validity for in-hospital mortality was lower for SIRS (AUROC = 0.64; 95% CI, 0.62-0.66) and qSOFA (AUROC = 0.66; 95% CI, 0.64-0.68) vs SOFA (AUROC = 0.74; 95% CI, 0.73-0.76; P < .001 for both) or LODS (AUROC = 0.75; 95% CI, 0.73-0.76; P < .001 for both). Among non-ICU encounters in the validation cohort (n = 66 522 with suspected infection, of whom 1886 [3%] died), qSOFA had predictive validity (AUROC = 0.81; 95% CI, 0.80-0.82) that was greater than SOFA (AUROC = 0.79; 95% CI, 0.78-0.80; P < .001) and SIRS (AUROC = 0.76; 95% CI, 0.75-0.77; P < .001). Relative to qSOFA scores lower than 2, encounters with qSOFA scores of 2 or higher had a 3- to 14-fold increase in hospital mortality across baseline risk deciles. Findings were similar in external data sets and for the secondary outcome.

CONCLUSIONS AND RELEVANCE

Among ICU encounters with suspected infection, the predictive validity for in-hospital mortality of SOFA was not significantly different than the more complex LODS but was statistically greater than SIRS and qSOFA, supporting its use in clinical criteria for sepsis. Among encounters with suspected infection outside of the ICU, the predictive validity for in-hospital mortality of qSOFA was statistically greater than SOFA and SIRS, supporting its use as a prompt to consider possible sepsis.

Trial of Continuous or Interrupted Chest Compressions during CPR

BACKGROUND

During cardiopulmonary resuscitation (CPR) in patients with out-of-hospital cardiac arrest, the interruption of manual chest compressions for rescue breathing reduces blood flow and possibly survival. We assessed whether outcomes after continuous compressions with positive-pressure ventilation differed from those after compressions that were interrupted for ventilations at a ratio of 30 compressions to two ventilations.

METHODS

This cluster-randomized trial with crossover included 114 emergency medical service (EMS) agencies. Adults with non-trauma-related cardiac arrest who were treated by EMS providers received continuous chest compressions (intervention group) or interrupted chest compressions (control group). The primary outcome was the rate of survival to hospital discharge. Secondary outcomes included the modified Rankin scale score (on a scale from 0 to 6, with a score of ≤3 indicating favorable neurologic function). CPR process was measured to assess compliance.

RESULTS

Of 23,711 patients included in the primary analysis, 12,653 were assigned to the intervention group and 11,058 to the control group. A total of 1129 of 12,613 patients with available data (9.0%) in the intervention group and 1072 of 11,035 with available data (9.7%) in the control group survived until discharge (difference, -0.7 percentage points; 95% confidence interval [CI], -1.5 to 0.1; P=0.07); 7.0% of the patients in the intervention group and 7.7% of those in the control group survived with favorable neurologic function at discharge (difference, -0.6 percentage points; 95% CI, -1.4 to 0.1, P=0.09). Hospital-free survival was significantly shorter in the intervention group than in the control group (mean difference, -0.2 days; 95% CI, -0.3 to -0.1; P=0.004).

CONCLUSIONS

In patients with out-of-hospital cardiac arrest, continuous chest compressions during CPR performed by EMS providers did not result in significantly higher rates of survival or favorable neurologic function than did interrupted chest compressions. (Funded by the National Heart, Lung, and Blood Institute and others; ROC CCC ClinicalTrials.gov number, NCT01372748.).

American Heart Association Response to the 2015 Institute of Medicine Report on Strategies to Improve Cardiac Arrest Survival

The American Heart Association (AHA) commends the recently released Institute of Medicine (IOM) report, Strategies to Improve Cardiac Arrest Survival: A Time to Act (2015). The AHA recognizes the unique opportunity created by the report to meaningfully advance the objectives of improving outcomes for sudden cardiac arrest. For decades, the AHA has focused on the goal of reducing morbidity and mortality from cardiovascular disease though robust support of basic, translational, clinical, and population research. The AHA also has developed a rigorous process using the best available evidence to develop scientific, advisory, and guideline documents. These core activities of development and dissemination of scientific evidence have served as the foundation for a broad range of advocacy initiatives and programs that serve as a foundation for advancing the AHA and IOM goal of improving cardiac arrest outcomes. In response to the call to action in the IOM report, the AHA is announcing 4 new commitments to increase cardiac arrest survival: (1) The AHA will provide up to $5 million in funding over 5 years to incentivize resuscitation data interoperability; (2) the AHA will actively pursue philanthropic support for local and regional implementation opportunities to increase cardiac arrest survival by improving out-of-hospital and in-hospital systems of care; (3) the AHA will actively pursue philanthropic support to launch an AHA resuscitation research network; and (4) the AHA will cosponsor a National Cardiac Arrest Summit to facilitate the creation of a national cardiac arrest collaborative that will unify the field and identify common goals to improve survival. In addition to the AHA’s historic and ongoing commitment to improving cardiac arrest care and outcomes, these new initiatives are responsive to each of the IOM recommendations and demonstrate the AHA’s leadership in the field. However, successful implementation of the IOM recommendations will require a timely response by all stakeholders identified in the report and a coordinated approach to achieve our common goal of improved cardiac arrest outcomes.

Pediatric Intubation by Paramedics in a Large Emergency Medical Services System: Process, Challenges, and Outcomes

STUDY OBJECTIVE

Pediatric intubation is a core paramedic skill in some emergency medical services (EMS) systems. The literature lacks a detailed examination of the challenges and subsequent adjustments made by paramedics when intubating children in the out-of-hospital setting. We undertake a descriptive evaluation of the process of out-of-hospital pediatric intubation, focusing on challenges, adjustments, and outcomes.

METHODS

We performed a retrospective analysis of EMS responses between 2006 and 2012 that involved attempted intubation of children younger than 13 years by paramedics in a large, metropolitan EMS system. We calculated the incidence rate of attempted pediatric intubation with EMS and county census data. To summarize the intubation process, we linked a detailed out-of-hospital airway registry with clinical records from EMS, hospital, or autopsy encounters for each child. The main outcome measures were procedural challenges, procedural success, complications, and patient disposition.

RESULTS

Paramedics attempted intubation in 299 cases during 6.3 years, with an incidence of 1 pediatric intubation per 2,198 EMS responses. Less than half of intubations (44%) were for patients in cardiac arrest. Two thirds of patients were intubated on the first attempt (66%), and overall success was 97%. The most prevalent challenge was body fluids obscuring the laryngeal view (33%). After a failed first intubation attempt, corrective actions taken by paramedics included changing equipment (33%), suctioning (32%), and repositioning the patient (27%). Six patients (2%) experienced peri-intubation cardiac arrest and 1 patient had an iatrogenic tracheal injury. No esophageal intubations were observed. Of patients transported to the hospital, 86% were admitted to intensive care and hospital mortality was 27%.

CONCLUSION

Pediatric intubation by paramedics was performed infrequently in this EMS system. Although overall intubation success was high, a detailed evaluation of the process of intubation revealed specific challenges and adjustments that can be anticipated by paramedics to improve first-pass success, potentially reduce complications, and ultimately improve clinical outcomes.

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

BACKGROUND

Out-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).

METHODS

Observational 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).

RESULTS

Mean 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).

CONCLUSIONS

ROC-wide survival increased significantly between 2006 and 2010. Additional research efforts are warranted to identify specific factors associated with this improvement.

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

IMPORTANCE

Assessment of morbidity is an important component of evaluating interventions for patients with out-of-hospital cardiac arrest (OHCA).

OBJECTIVE

We 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.

DESIGN

Prospective cohort sub-study of a randomized trial.

SETTING

The parent trial studied two comparisons in persons with non-traumatic OHCA treated by EMS personnel participating in the Resuscitation Outcomes Consortium.

PARTICIPANTS

Consenting survivors to discharge.

MAIN OUTCOME MEASURES

Telephone 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).

RESULTS

Of 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 RELEVANCE

The 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.

A quantitative analysis of out-of-hospital pediatric and adolescent resuscitation quality--A report from the ROC epistry-cardiac arrest

AIM

High-quality cardiopulmonary resuscitation (CPR) may improve survival. The quality of CPR performed during pediatric out-of-hospital cardiac arrest (p-OHCA) is largely unknown. The main objective of this study was to describe the quality of CPR performed during p-OHCA resuscitation attempts.

METHODS

Prospective observational multi-center cohort study of p-OHCA patients ≥ 1 and < 19 years of age registered in the Resuscitation Outcomes Consortium (ROC) Epistry database. The primary outcome was an a priori composite variable of compliance with American Heart Association (AHA) guidelines for both chest compression (CC) rate and CC fraction (CCF). Event compliance was defined as a case with 60% or more of its minute epochs compliant with AHA targets (rate 100-120 min(-1); depth ≥ 38 mm; and CCF ≥ 0.80). In a secondary analysis, multivariable logistic regression was used to evaluate the association between guideline compliance and return of spontaneous circulation (ROSC).

RESULTS

Between December 2005 and December 2012, 2564 pediatric events were treated by EMS providers, 390 of which were included in the final cohort. Of these events, 22% achieved AHA compliance for both rate and CCF, 36% for rate alone, 53% for CCF alone, and 58% for depth alone. Over time, there was a significant increase in CCF (p < 0.001) and depth (p = 0.03). After controlling for potential confounders, there was no significant association between AHA guideline compliance and ROSC.

CONCLUSIONS

In this multi-center study, we have established that there are opportunities for professional rescuers to improve prehospital CPR quality. Encouragingly, CCF and depth both increased significantly over time.

Is epinephrine during cardiac arrest associated with worse outcomes in resuscitated patients?

BACKGROUND

Although epinephrine is essential for successful return of spontaneous circulation (ROSC), the influence of this drug on recovery during the post-cardiac arrest phase is debatable.

OBJECTIVES

This study sought to investigate the relationship between pre-hospital use of epinephrine and functional survival among patients with out-of-hospital cardiac arrest (OHCA) who achieved successful ROSC.

METHODS

We included all patients with OHCA who achieved successful ROSC admitted to a cardiac arrest center from January 2000 to August 2012. Use of epinephrine was coded as yes/no and by dose (none, 1 mg, 2 to 5 mg, >5 mg). A favorable discharge outcome was coded using a Cerebral Performance Category 1 or 2. Analyses incorporated multivariable logistic regression, propensity scoring, and matching methods.

RESULTS

Of the 1,556 eligible patients, 1,134 (73%) received epinephrine; 194 (17%) of these patients had a good outcome versus 255 of 422 patients (63%) in the nontreated group (p < 0.001). This adverse association of epinephrine was observed regardless of length of resuscitation or in-hospital interventions performed. Compared with patients who did not receive epinephrine, the adjusted odds ratio of intact survival was 0.48 (95% confidence interval [CI]: 0.27 to 0.84) for 1 mg of epinephrine, 0.30 (95% CI: 0.20 to 0.47) for 2 to 5 mg of epinephrine, and 0.23 (95% CI: 0.14 to 0.37) for >5 mg of epinephrine. Delayed administration of epinephrine was associated with worse outcome.

CONCLUSIONS

In this large cohort of patients who achieved ROSC, pre-hospital use of epinephrine was consistently associated with a lower chance of survival, an association that showed a dose effect and persisted despite post-resuscitation interventions. These findings suggest that additional studies to determine if and how epinephrine may provide long-term functional survival benefit are needed.

Erythrocyte very long-chain saturated fatty acids associated with lower risk of incident sudden cardiac arrest

Prior studies suggest that circulating n-3 and trans-fatty acids influence the risk of sudden cardiac arrest (SCA). Yet, while other fatty acids also differ in their membrane properties and biological activities which may influence SCA, little is known about the associations of other circulating fatty acids with SCA. The aim of this study was to investigate the associations of 17 erythrocyte membrane fatty acids with SCA risk. We used data from a population-based case-control study of SCA in the greater Seattle, Washington, area. Cases, aged 25-74 years, were out-of-hospital SCA patients, attended by paramedics (n=265). Controls, matched to cases by age, sex and calendar year, were randomly identified from the community (n=415). All participants were free of prior clinically-diagnosed heart disease. Blood was obtained at the time of cardiac arrest by attending paramedics (cases) or at the time of an interview (controls). Higher levels of erythrocyte very long-chain saturated fatty acids (VLSFA) were associated with lower risk of SCA. After adjustment for risk factors and levels of n-3 and trans-fatty acids, higher levels of 20:0 corresponding to 1 SD were associated with 30% lower SCA risk (13-43%, p=0.001). Higher levels of 22:0 and 24:0 were associated with similar lower SCA risk (ORs for 1 SD-difference: 0.71 [95% CI: 0.57-0.88, p=0.002] for 22:0; and 0.79 [95% CI: 0.63-0.98, p=0.04] for 24:0). These novel findings support the need for investigation of biologic effects of circulating VLSFA and their determinants.

The dispatcher assisted resuscitation trial: indirect benefits of emergency research

OBJECTIVE

Conduct of emergency research under waiver of consent produces special challenges. Moreover, the act of performing research may have unintended effects, potentially beneficial or detrimental. The Dispatcher-Assisted Randomized Trial (DART) was designed to compare 2 types of dispatcher cardiopulmonary (CPR) instruction, but not intended to affect the proportion of arrest victims that received bystander CPR. We sought to determine whether odds of receiving bystander CPR were higher during DART than during the periods before and after.

METHODS

We conducted an observational cohort study of 8626 adults who suffered non-traumatic out-of-hospital cardiac arrest prior to emergency medical services (EMS) arrival in greater King County, Washington, between January 1, 1999, and December 31, 2011. Bystander CPR status was assessed through review of dispatch recordings and EMS reports to classify any bystander CPR (any B-CPR), and further categorized as bystander CPR with or without dispatcher assistance (DA-CPR and B-CPR, no DA). We used multivariable logistic regression to evaluate odds of B-CPR before, during, and after DART.

RESULTS

The proportions receiving any B-CPR were 52% before DART (1817/3468), 59% during DART (2093/3527), and 54% after DART (885/1631). Compared to the period before DART, odds of receiving any B-CPR were higher during DART (OR=1.35, 95% CI=1.23-1.49), but no different after (OR=1.10, 0.98-1.24). Compared to the before period, odds of DA-CPR were higher during DART (OR=1.79, 1.59-2.02) but no different after (OR=0.94, 0.80-1.10).

CONCLUSIONS

Odds of bystander CPR were higher during the trial, an increase related to higher likelihood of DA-CPR. The finding suggests a possible indirect community-wide benefit due to the interventional trial.

Physiologic field triage criteria for identifying seriously injured older adults

OBJECTIVE

To evaluate the ability of out-of-hospital physiologic measures to predict serious injury for field triage purposes among older adults and potentially reduce the undertriage of seriously injured elders to non-trauma hospitals.

METHODS

This was a retrospective cohort study involving injured adults 55 years and older transported by 94 emergency medical services (EMS) agencies to 122 hospitals (trauma and non-trauma) in 7 regions of the western United States from January 1, 2006 to December 31, 2008. We evaluated initial out-of-hospital Glasgow Coma Scale (GCS) score, systolic blood pressure (SBP), respiratory rate, heart rate, shock index (SBP ÷ heart rate), out-of-hospital procedures, mechanism of injury, and patient demographics. The primary outcome was "serious injury," defined as Injury Severity Score (ISS) ≥ 16, as a measure of trauma center need. We used multivariable regression models, fractional polynomials and binary recursive partitioning to evaluate appropriate physiologic cut-points and the value of different physiologic triage criteria.

RESULTS

A total of 44,890 injured older adults were evaluated and transported by EMS, of whom 2,328 (5.2%) had ISS ≥ 16. Nonlinear associations existed between all physiologic measures and ISS ≥ 16 (unadjusted and adjusted p ≤ 0.001 for all,), except for heart rate (adjusted p = 0.48). Revised physiologic triage criteria included GCS score ≤ 14; respiratory rate < 10 or > 24 breaths per minute or assisted ventilation; and SBP < 110 or > 200 mmHg. Compared to current triage practices, the revised criteria would increase triage sensitivity from 78.6 to 86.3% (difference 7.7%, 95% CI 6.1-9.6%), reduce specificity from 75.5 to 60.7% (difference 14.8%, 95% CI 14.3-15.3%), and increase the proportion of patients without serious injuries transported to major trauma centers by 60%.

CONCLUSIONS

Existing out-of-hospital physiologic triage criteria could be revised to better identify seriously injured older adults at the expense of increasing overtriage to major trauma centers.

Changes to DA-CPR instructions: can we reduce time to first compression and improve quality of bystander CPR?

INTRODUCTION

Dispatcher-assisted CPR (DA-CPR) can increase rates of bystander CPR, survival, and quality of life following cardiac arrest. Dispatcher protocols designed to improve rapid recognition of arrest and coach CPR may increase survival by (1) reducing preventable time delays to start of chest compressions and (2) improving the quality of bystander CPR.

METHODS

We conducted a randomized controlled trial comparing a simplified DA CPR script to a conventional DA CPR script in a manikin cardiac arrest simulation with lay participants. The primary outcomes measured were the time interval from call receipt to the first chest compression and the core metrics of chest compression (depth, rate, release, and compression fraction). CPR was measured using a recording manikin for the first 3 min of participant CPR.

RESULTS

Of the 75 participants, 39 were randomized to the simplified instructions and 36 were randomized to the conventional instructions. The interval from call receipt to first compression was 99 s using the simplified script and 124 s using the conventional script for a difference of 24s (p<0.01). Although hand position was judged to be correct more often in the conventional instruction group (88% versus 63%, p<0.01), compression depth was an average 7 mm deeper among those receiving the simplified CPR script (32 mm versus 25 mm, p<0.05). No statistically significant differences were detected between the two instruction groups for compression rate, complete release, number of hands-off periods, or compression fraction.

DISCUSSION

Simplified DA-CPR instructions to lay callers in simulated cardiac arrest settings resulted in significant reductions in time to first compression and improvements in compression depth. These results suggest an important opportunity to improve DA CPR instructions to reduce delays and improve CPR quality.