Michael C. Kurz

Part 4: Systems of Care and Continuous Quality Improvement 2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

The science and recommendations discussed in the other Parts of the 2015 American Heart Association (AHA) Guidelines Update for Cardiopulmonary Resuscitation (CPR) and Emergency Cardiovascular Care (ECC) form the backbone of resuscitation. They answer the “why”, “what,” and “when” of performing resuscitation steps. In a perfectly controlled and predictable environment, such as a laboratory setting, those answers often suffice, but the “how” of actual implementation depends on knowing the “who” and “where” as well. The ideal work flow to accomplish resuscitation successfully is highly dependent on the system of care as a whole. Healthcare delivery requires structure (eg, people, equipment, education, prospective registry data collection) and process (eg, policies, protocols, procedures), which, when integrated, produce a system (eg, programs, organizations, cultures) leading to outcomes (eg, patient safety, quality, satisfaction). An effective system of care (Figure 1) comprises all of these elements—structure, process, system, and patient outcomes—in a framework of continuous quality improvement (CQI). Figure 1. Taxonomy of systems of care. In this Part, we will focus on 2 distinct systems of care: the system for patients who arrest inside the hospital and the one for those who arrest outside it. We will set into context the building blocks for a system of care for cardiac arrest, with consideration of the setting, team, and available resources, as well as CQI from the moment the patient becomes unstable until after the patient is discharged. The chain of survival metaphor, first used almost 25 years ago,1 is still very relevant. However, it may be helpful to create 2 separate chains (Figure 2) to reflect the differences in the steps needed for response to cardiac arrest in the hospital (in-hospital cardiac arrest [IHCA]) and out of the hospital (out of hospital cardiac arrest [OHCA]). Regardless of where an arrest occurs, the care following resuscitation converges …

An evaluation of the accuracy of emergency physician activation of the cardiac catheterization laboratory for patients with suspected ST-segment elevation myocardial infarction.

STUDY OBJECTIVE Current recommendations indicate that emergency physicians should activate cardiac catheterization laboratory personnel by a single page for ST-segment elevation myocardial infarction (STEMI) patients. We assessed the accuracy of emergency physician cardiac catheterization laboratory activations, angiographic findings, outcomes, and treatment times among patients with and without STEMI. METHODS We classified the appropriateness and outcomes of consecutive emergency physician STEMI pages between June 2006 and September 2008. Emergency physician activations of the cardiac catheterization laboratory were classified according to the findings of the initial ECG compared with cardiology interpretation for the presence of STEMI and presence of coronary disease. RESULTS During a 27-month period, emergency physician activation of the cardiac catheterization laboratory occurred 249 times. There were 188 (76%) patients with a true STEMI, of whom 13 did not receive emergency angiography. Of the 37 (15%) patients who had ECG findings meeting STEMI criteria and who ultimately did not have myocardial necrosis and underwent emergency angiography, 12 had significant disease and 5 had revascularization performed. Eleven patients had ECGs concerning for but not meeting STEMI criteria; all had emergency angiography (n=11) or received a diagnosis of non-STEMI (n=6). Only 13 patients were considered as having received unnecessary cardiac catheterization laboratory activations (5.2%) in which emergency angiography was not performed and myocardial infarction was excluded. CONCLUSION A significant number of emergency physician STEMI cardiac catheterization laboratory activations are for patients who did not meet standard STEMI criteria. However, most had ECG findings and symptoms that lead to emergency angiography, had significant disease, or were diagnosed with non-STEMI. Only a small percentage of patients received unnecessary cardiac catheterization laboratory activations. Our findings support current recommendations for emergency physician cardiac catheterization laboratory activation for potential STEMI patients.

Association Between Duration of Resuscitation and Favorable Outcome After Out-of-Hospital Cardiac Arrest: Implications for Prolonging or Terminating Resuscitation.

Background: Little evidence guides the appropriate duration of resuscitation in out-of-hospital cardiac arrest, and case features justifying longer or shorter durations are ill defined. We estimated the impact of resuscitation duration on the probability of favorable functional outcome in out-of-hospital cardiac arrest using a large, multicenter cohort. Methods: This was a secondary analysis of a North American, single-blind, multicenter, cluster-randomized, clinical trial (ROC-PRIMED [Resuscitation Outcomes Consortium Prehospital Resuscitation Using an Impedance Valve and Early Versus Delayed]) of consecutive adults with nontraumatic, emergency medical services–treated out-of-hospital cardiac arrest. Primary exposure was duration of resuscitation in minutes (onset of professional resuscitation to return of spontaneous circulation [ROSC] or termination of resuscitation). Primary outcome was survival to hospital discharge with favorable outcome (modified Rankin scale [mRS] score of 0–3). Subjects were additionally classified as survival with unfavorable outcome (mRS score of 4–5), ROSC without survival (mRS score of 6), or without ROSC. Subject accrual was plotted as a function of resuscitation duration, and the dynamic probability of favorable outcome at discharge was estimated for the whole cohort and subgroups. Adjusted logistic regression models tested the association between resuscitation duration and survival with favorable outcome. Results: The primary cohort included 11 368 subjects (median age, 69 years [interquartile range, 56–81 years]; 7121 men [62.6%]). Of these, 4023 (35.4%) achieved ROSC, 1232 (10.8%) survived to hospital discharge, and 905 (8.0%) had an mRS score of 0 to 3 at discharge. Distribution of cardiopulmonary resuscitation duration differed by outcome (P<0.00001). For cardiopulmonary resuscitation duration up to 37.0 minutes (95% confidence interval, 34.9–40.9 minutes), 99% with an eventual mRS score of 0 to 3 at discharge achieved ROSC. The dynamic probability of an mRS score of 0 to 3 at discharge declined over elapsed resuscitation duration, but subjects with initial shockable cardiac rhythm, witnessed cardiac arrest, and bystander cardiopulmonary resuscitation were more likely to survive with favorable outcome after prolonged efforts (30–40 minutes). After adjustment for prehospital (odds ratio, 0.93; 95% confidence interval, 0.92–0.95) and inpatient (odds ratio, 0.97; 95% confidence interval, 0.95–0.99) covariates, resuscitation duration was associated with survival to discharge with an mRS score of 0 to 3. Conclusions: Shorter resuscitation duration was associated with likelihood of favorable outcome at hospital discharge. Subjects with favorable case features were more likely to survive prolonged resuscitation up to 47 minutes. Clinical Trial Registration: URL: http://clinicaltrials.gov. Unique identifier: NCT00394706.

Emergency physician-initiated cath lab activation reduces door to balloon times in ST-segment elevation myocardial infarction patients

OBJECTIVES We evaluated the impact of emergency physician (EP)-initiated primary percutaneous coronary intervention (PCI) via a single-group page on door to balloon (D2B) interval times in patients with ST-segment elevation myocardial infarction. METHODS Consecutive ST-segment elevation myocardial infarction patients presenting to the emergency department between February 2004 and September 2008 were divided into 4 groups: group 1, PCI performed on an ad hoc basis after cardiology consultation; group 2, primary PCI activated via a single-group page only on-call cardiology consultation; group 3, primary PCI with EP cardiac catheterization laboratory (CCL) activation via the same page strategy; group 4, prehospital CCL activation based on prehospital diagnostic electrocardiogram. Composite D2B and relevant time intervals were measured for each time group. RESULTS A total of 295 consecutive patients undergoing emergent angiography were included. Times decreased for most time intervals from groups 1 to 4. Although there was no significant change in composite D2B or any measured interval time with the introduction of PCI after emergent cardiology consultation, each decreased significantly after implementing an EP-initiated PCI strategy except CCL2B (D2B 95 to 77 minutes, D2E 14 to 10 minutes, D2CCL 71 to 50 minutes). Further significant reductions in D2B time were achieved among all patients after the institution of emergency medicine services activation of the CCL (D2B 77 to 64 minutes, D2CCL 50 to 38 minutes, CCL2B 28 to 22 minutes). CONCLUSIONS A systematic process of initiating D2B recommendations, including EP-initiated CCL activation via a single-group page, significantly reduces D2CCL and D2B times.

Non-linear dynamical signal characterization for prediction of defibrillation success through machine learning

BackgroundVentricular Fibrillation (VF) is a common presenting dysrhythmia in the setting of cardiac arrest whose main treatment is defibrillation through direct current countershock to achieve return of spontaneous circulation. However, often defibrillation is unsuccessful and may even lead to the transition of VF to more nefarious rhythms such as asystole or pulseless electrical activity. Multiple methods have been proposed for predicting defibrillation success based on examination of the VF waveform. To date, however, no analytical technique has been widely accepted. We developed a unique approach of computational VF waveform analysis, with and without addition of the signal of end-tidal carbon dioxide (PetCO2), using advanced machine learning algorithms. We compare these results with those obtained using the Amplitude Spectral Area (AMSA) technique.MethodsA total of 90 pre-countershock ECG signals were analyzed form an accessible preshosptial cardiac arrest database. A unified predictive model, based on signal processing and machine learning, was developed with time-series and dual-tree complex wavelet transform features. Upon selection of correlated variables, a parametrically optimized support vector machine (SVM) model was trained for predicting outcomes on the test sets. Training and testing was performed with nested 10-fold cross validation and 6–10 features for each test fold.ResultsThe integrative model performs real-time, short-term (7.8 second) analysis of the Electrocardiogram (ECG). For a total of 90 signals, 34 successful and 56 unsuccessful defibrillations were classified with an average Accuracy and Receiver Operator Characteristic (ROC) Area Under the Curve (AUC) of 82.2% and 85%, respectively. Incorporation of the end-tidal carbon dioxide signal boosted Accuracy and ROC AUC to 83.3% and 93.8%, respectively, for a smaller dataset containing 48 signals. VF analysis using AMSA resulted in accuracy and ROC AUC of 64.6% and 60.9%, respectively.ConclusionWe report the development and first-use of a nontraditional non-linear method of analyzing the VF ECG signal, yielding high predictive accuracies of defibrillation success. Furthermore, incorporation of features from the PetCO2 signal noticeably increased model robustness. These predictive capabilities should further improve with the availability of a larger database.

Association of advanced airway device with chest compression fraction during out-of-hospital cardiopulmonary arrest

BACKGROUND Select Emergency Medical Services (EMS) practitioners substitute endotracheal intubation (ETI) with supraglottic airway (SGA) insertion to minimize CPR chest compression interruptions, but the resulting effects upon chest compression fraction (CCF) are unknown. We sought to determine the differences in CCF between adult out-of-hospital cardiac arrest (OHCA) receiving ETI and those receiving SGA. METHODS We studied adult, non-traumatic OHCA patients enrolled in the Resuscitation Outcomes Consortium (ROC) Prehospital Resuscitation using an Impedance valve and an Early vs. Delayed analysis (PRIMED) trial. Chest compressions were measured using compression or thoracic impedance sensors. We limited the analysis to those receiving ETI or SGA (Combitube, King Laryngeal Tube, or Laryngeal Mask Airway) and >2min of chest compression data before and after airway insertion. We compared CCF between ETI and SGA before and after airway insertion, adjusting for age, sex, witnessed arrest, bystander CPR, shockable initial rhythm, public location, PRIMED trial arm, and regional ROC center. We also compared the change in CCF for each airway technique. RESULTS Of 14,955 patients enrolled in the ROC PRIMED trial, we analyzed 2767 cases, including 2051 ETI, 671 SGA, and 45 both. Among subjects in this investigation the mean age was 66.4 years with a male predominace, 46% with witnessed event, 37% receiving bystander CPR, and 22% presenting with an initially shockable rhythm. Pre- and post-airway CCF was higher for SGA than ETI (SGA pre-airway CCF 73.2% [95%CI: 71.6-74.7%] vs. ETI 70.6% [95%CI: 69.7-71.5%]; post-airway 76.7% [95%CI: 75.2-78.1%] vs. 72.4% [95%CI: 71.5-73.3%]). After adjusting for potential confounders, these significant changes persisted (pre-airway difference 2.2% favoring SGA, p-value=0.046; post-airway 3.4% favoring SGA, p=0.001). CONCLUSION In patients with OHCA, we detected a slightly higher rate of CCF in patients for whom a SGA was inserted, both before and after insertion. However, the actual differences were so small, that in the context of this observational, secondary analysis, it is unclear if this represents a clinically significant difference.

External validation of termination of resuscitation guidelines in the setting of intra-arrest cold saline, mechanical CPR, and comprehensive post resuscitation care

BACKGROUND The development of advanced life support (ALS) termination of resuscitation (TOR) guidelines for out-of-hospital cardiac arrest (OHCA) seeks to improve the efficiency of scarce pre-hospital resources. However, as pre-hospital treatment for OHCA evolves and survival improves, these TOR guidelines must be reevaluated in the contemporary context of emergency medical services (EMS) providing access to advanced resuscitation care. METHODS Retrospective review of all adult (>18 years old), non-traumatic, OHCA patients (defined as patients with absence of pulse who received either CPR and/or defibrillation) treated by EMS in Richmond, VA, from January 1, 2009 to December 31, 2010. In addition to standard ALS, intra-arrest cold saline, mechanical CPR, and transportation to a comprehensive post-resuscitation center (CPRC) was provided. Patient treatment and outcomes were recorded via prehospital patient care reports and data were evaluated against previously established criteria for termination of resuscitation in an ALS EMS system. According to the aforementioned previously described criteria for TOR, patients meeting a single criterion for transport are recommended to be transported emergently to a comprehensive post-resuscitation care facility. Conversely, patients failing to meet any of the TOR criteria can be presumed to be expired without exception. Survival at 180 days was presumed when death could not be verified from publically reportable sources. RESULTS Of the 322 OHCA patients enrolled, the majority were male (59%), unwitnessed (52%), received no bystander CPR (67%), and presented in a non-shockable initial rhythm (79%), with an average age of 62.5 years. Overall survival was 17%, 14%, 12%, and 11% at 7, 14, 30, and 180 days, respectively. Of the 75 patients for which TOR guidelines recommended termination, none survived yielding both 100% specificity (95% CI 100-92.8%) and positive predictive value (95% CI 100-94.1%). However, TOR guidelines recommended transport of 208 of the 283 patients who died within 30 days, resulting in a sensitivity of 26.5% (95% CI 34.5-23.4%). CONCLUSION The TOR guidelines continue to have a reliable positive predictive value for death even in the setting of advanced EMS resuscitation methods and access to a CPRC. However, as the potential for survival from OHCA improves, the efficiency gained from their use is impacted greatly.

An observational study of patient selection criteria for post-cardiac arrest therapeutic hypothermia.

BACKGROUND To date, there is no comprehensive assessment of how therapeutic hypothermia and post-arrest care are being implemented clinically. At this stage in the translation of post-arrest science to clinical practice, this analysis is overdue. This study examines the first step of post-arrest care--the selection of patients for TH and post-arrest care. METHODS We conducted a systematic review to search for all publicly available TH and post-arrest protocols. Observational data was reported and no statistical inferences were made. RESULTS Notable variation was observed in the following selection criteria: total ischemic time and hemodynamic requirements. Additionally, only some of the criteria were evidence based. CONCLUSION This study demonstrates the wide range and variety of patient selection criteria that are being used for implementation of post-cardiac arrest care. The consequences of this selection criteria variability are currently unmeasured and likely underestimated. Variability is likely to breed inefficiency. Some patients who could benefit do not get treated. Other patients get cooled, yet will never regain consciousness. This variability may be important when considering inter-hospital variation in post-arrest care and outcomes.

Post-resuscitation arterial oxygen and carbon dioxide and outcomes after out-of-hospital cardiac arrest

OBJECTIVE To determine if arterial oxygen and carbon dioxide abnormalities in the first 24h after return of spontaneous circulation (ROSC) are associated with increased mortality in adult out-of-hospital cardiac arrest (OHCA). METHODS We used data from the Resuscitation Outcomes Consortium (ROC), including adult OHCA with sustained ROSC ≥1h after Emergency Department arrival and at least one arterial blood gas (ABG) measurement. Among ABGs measured during the first 24h of hospitalization, we identified the presence of hyperoxemia (PaO2≥300mmHg), hypoxemia (PaO2<60mmHg), hypercarbia (PaCO2>50mmHg) and hypocarbia (PaCO2<30mmHg). We evaluated the associations between oxygen and carbon dioxide abnormalities and hospital mortality, adjusting for confounders. RESULTS Among 9186 OHCA included in the analysis, hospital mortality was 67.3%. Hyperoxemia, hypoxemia, hypercarbia, and hypocarbia occurred in 26.5%, 19.0%, 51.0% and 30.6%, respectively. Initial hyperoxemia only was not associated with hospital mortality (adjusted OR 1.10; 95% CI: 0.97-1.26). However, final and any hyperoxemia (1.25; 1.11-1.41) were associated with increased hospital mortality. Initial (1.58; 1.30-1.92), final (3.06; 2.42-3.86) and any (1.76; 1.54-2.02) hypoxemia (PaO2<60mmHg) were associated with increased hospital mortality. Initial (1.89; 1.70-2.10); final (2.57; 2.18-3.04) and any (1.85; 1.67-2.05) hypercarbia (PaCO2>50mmHg) were associated with increased hospital mortality. Initial (1.13; 0.90-1.41), final (1.19; 1.04-1.37) and any (1.01; 0.91-1.12) hypocarbia (PaCO2<30mmHg) were not associated with hospital mortality. CONCLUSIONS In the first 24h after ROSC, abnormal post-arrest oxygen and carbon dioxide tensions are associated with increased out of-hospital cardiac arrest mortality.

PNFLBA-04 RANDOMIZED CLINICAL TRIAL OF TREATMENT WITH TAMSULOSIN BEGUN IN THE EMERGENCY DEPARTMENT TO PROMOTE PASSAGE OF URINARY STONES

BPH. Gilling et al. reported a prospective single-arm multicenter trial at 3 centers in Australia and New Zealand with 1-year follow-up on 21 men with a similar profile as WATER. Prostate volume dropped from 57 ml at baseline to 35 ml (P<0.0001). Mean IPSS score improved from 23.0 at baseline to 6.8 at 12 months (P<0.0001) and maximum urinary flow increased from 8.7 mL/sec to 18.3 mL/sec (P<0.0001). There were no important perioperative adverse events. No subject developed urinary incontinence and sexual function was preserved postoperatively. In this report, we compared the safety and efficacy of prostate resection using a high-pressure waterjet vs. electrocautery from the WATER study. METHODS: In this randomized, double-blind, multicenter phase III trial, patients with moderate-to-severe lower urinary tract symptoms related to benign prostatic hyperplasia were assigned to transurethral resection of the prostate using either standard electrosurgery (TURP) or robotic waterjet (Aquablation). The trial has a co-primary safety and efficacy endpoint designed to show non-inferiority. With a minimum enrollment of 177, the estimated power for safety was 99% and efficacy was 80%. The primary safety endpoint is the occurrence of ClavienDindo persistent grade 1 or Grade 2 or higher operative complications at 3 months. The primary efficacy endpoint is the reduction at 6 months in IPSS score. RESULTS: The geographic enrollment from the OUS (Australia, New Zealand, United Kingdom) sites and US sites was 91 and 93 subjects, respectively. The baseline IPSS score (TURP 22.2, Aquablation 22.9, p1⁄40.47), demographic profile (Table 1), and prostate volume (TURP 52.0 mL, Aquablation 54.3 mL, p1⁄40.31) were similar in both arms. Operative time was equivalent between the two groups, but resection time was lower in the Aquablation group (28 vs. 4 minutes, p<.0001). The length of stay and length of stay by geography was similar for both arms that averaged 1.4 days. CONCLUSIONS: The first report of the primary safety and efficacy endpoints will be available and ready for presentation at AUA in May 2017.