Bobrow, Bentley J.

Background: Bystander CPR (BCPR) strongly influences survival from OHCA yet is provided in a minority of cases. The AHA has promulgated guidelines on provision of pre-arrival Hands-Only dispatcher-assisted telephone CPR (TCPR) instructions to increase the proportion of arrests receiving early BCPR; however, the impact of those guidelines is unknown. Objective: Evaluate the impact of implementing the TCPR guidelines on: recognition of OHCA by 911 dispatchers, time from call receipt to start of TCPR instructions, time to first chest compression (CC), prehospital ROSC, survival, and favorable neuro outcome (FNO). Methods: Dispatch audio records of OHCA in 3 large dispatch centers in Arizona (10/10-3/13) were reviewed using a standardized time-stamp methodology. Data were entered into a structured TCPR database linked to EMS and hospital outcome data. Intervention: Implementation of a 3.5-hour staff training and a guideline-based change in dispatch protocol. Results: There were 860 pre-implementation (P1) and 799 post-implementation (P2) cases. A total of 1265 cases met inclusion criteria. Outcome data collection and linkage is ongoing: ROSC, survival and neuro outcomes were available in 26%, 24% and 22% of cases, respectively. The proportion of cases receiving TCPR increased: P1 (28.7%); P2 (49.9%, p<0.001). Median time to beginning TCPR instructions decreased significantly: P1 (153 sec); P2 (129 sec, p<0.001) as did median time to first CC: P1 (198 sec); P2 (162 sec, p<0.001). Outcomes - see Table. Conclusion: The implementation of the AHA pre-arrival TCPR guidelines was associated with a significant improvement in the time-to-CPR instructions and time-to-first CCs and rate of provision of telephone-assisted bystander CPR. This small, preliminary analysis of prehospital ROSC, survival, and FNO revealed higher, but statistically non-significant, rates after the interventions.

Background: In the simulation setting, chest compression (CC) quality is reduced when out-of-hospital cardiac arrest “patients” are prepared for transport (i.e. packaged and moved to ambulance). It is unknown whether use of real-time audiovisual CPR feedback (RTAVF) affects manual CC quality when the patient is prepared for transport during actual out-of-hospital resuscitations. We tested the hypothesis that CC quality during patient transfer would be better when using RTAVF. Methods: CC quality was monitored at two EMS agencies using an E Series monitor/defibrillator with CC sensing capability (ZOLL Medical) during the treatment of consecutive out-of-hospital cardiac arrest patients who received CC on scene and were transported with ongoing CC. Data were collected during study phases; P1: RTAVF disabled, P2: RTAVF enabled following scenario-based training. Student’s t-test and Wilcoxon-Mann Whitney tests were used to compare CC quality in P1 vs. P2 during early scene and late scene treatment. Late scene was defined as the 3 minutes prior to transport (when packaging and transfer to the ambulance occurs) and early scene was all prior minutes at the scene. Results: 211 cardiac arrest cases were included: mean age 64±15 yrs, 67% male, 8% survival to hospital discharge. The Table shows that CC quality was superior during both early scene and late scene treatment in P2, when RTAVF was enabled, vs. P1, when RTAVF was disabled. Conclusion: CC quality, particularly the CC fraction, declines when a patient is packaged for transport and moved to the ambulance. While this decline is not prevented by RTAVF, CC quality during the late scene period is significantly better when using RTAVF. Further study is required to determine the impact of this improvement on outcomes.

Background and Objectives: There are a growing number of Hispanic citizens in the US and language or other barriers may impede them receiving bystander CPR (BCPR). Our aim was to determine if there are differences in BCPR provision and outcomes for out-of-hospital cardiac arrest (OHCA) occurring in mainly Hispanic neighborhoods compared to mainly White non-Hispanic neighborhoods in Arizona. Methods: We analyzed our prospectively-collected statewide Utstein-compliant OHCA database between 1/1/10 - 12/31/11. OHCA cases were geocoded according to the incident address using ArcGIS 10.1 (Esri, Redlands, CA). Census-tract data was used to determine neighborhood characteristics of ethnicity. Neighborhoods were classified as mainly Hispanic or mainly White, non-Hispanic when each population was over 60% in the census-tract. Results: There were 4531 adult OHCA victims during the study. Cases were excluded from analysis (n=1380) due to incident location, cause of arrest, or because the arrest occurred after EMS arrival. Among 3151 cases, 2839 cases (90.1%) could be geocoded using incident address. CPR performance and outcomes by neighborhood ethnicity are shown (Table). When compared with patients who arrested in mainly White, non-Hispanic neighborhoods, those in mainly Hispanic neighborhoods were less likely to receive BCPR (odds ratio, 0.67; 95% confidence interval [CI], 0.52 to 0.84). Although no statistically significant differences were identified in the rate of survival to hospital discharge by main neighborhood ethnicity, patients who arrested in mainly Hispanic neighborhoods were less likely to have favorable neurologic outcomes (Cerebral Performance Score 1 or 2) than those in White, non-Hispanic neighborhoods (odds ratio, 0.16; 95% CI, 0.05 - 0.53). Conclusion: In Arizona, OHCA victims in mainly Hispanic neighborhoods received BCPR less frequently and had worse neurologic outcomes than those in mainly White, non-Hispanic neighborhoods.

Background: CPR quality is closely linked to outcome in cardiac arrest. The AHA 2010 Guidelines recommend monitoring CPR quality performed by healthcare providers both inside and outside the hospital. However, most EDs currently do not monitor CPR quality. The goal of the present investigation was to assess the quality of CPR performed in an urban ED and determine the influence of training and real-time audiovisual feedback (RTAVF) on CPR quality and patient outcome. Methods: CPR quality was monitored using an R Series defibrillator (ZOLL Medical) during the treatment of adult cardiac resuscitation attempts. During phase 1 (P1; 11/2010-11/2012), real-time audiovisual chest compression feedback was disabled. During phase 2 (P2; 11/2012-3/2013), clinicians underwent a 60 minute didactic/hands-on CPR training session after which the RTAVF and the ECG artifact filtering feature were enabled. CPR quality data (fraction, depth, rate, release, peri-shock pause) were reviewed using Code Review software (ZOLL Medical). Student’s t-test and Wilcoxon-signed rank test were employed. Results: A total of 44 OHCA patients were treated in P1 (mean age 57±18 yrs, 59% male) and 24 in Phase 2 (mean age 63±15 yrs, 88% male). The majority of patients (89% P1; 96% P2) suffered prehospital arrest and were transported to the ED. Chest compression (CC) depth increased from 1.8±0.5 inches in P1 to 2.3±0.4 in P2 (p<0.001), with the percentage of compressions exceeding 2 inches more than doubling from 36% in P1 to 79% in P2 (p<0.001). CC release velocity increased from 1.25±0.36 inch/sec in P1 to 1.69±0.28 in P2 (p<0.001). No significant differences were identified in CC rate (125±12 cpm P1 vs. 121±15 cpm P2, p=0.3) or CC fraction (82% P1 vs. 87% P2, p=0.1). Pre-shock pause (11.5±10.4 sec P1 vs. 8.0±6.2 P2, p=0.4) and post-shock pause (5.2±3.4 sec vs. 3.8±0.6, p=0.9) were statistically similar in P1 and P2. Conclusion: The bundle of real time audiovisual CPR feedback and training were associated with an improvement in chest compression depth and recoil and closer adherence to guidelines for CPR quality in this large urban ED.

Background: Bystander cardiopulmonary resuscitation (BCPR) significantly improves survival from out-of-hospital cardiac arrest (OHCA). Telecommunicator CPR (TCPR) has been shown to increase BCPR rates, yet TCPR performance varies widely. We assess whether a bundled TCPR protocol, training, and continuous quality improvement (CQI) intervention improves TCPR performance. Methods: The intervention was implemented at a regional 9-1-1 dispatch center and had three main components: (1) the installation of the AHA-recommended 2-question TCPR protocol, (2) training to enhance telecommunicator OHCA recognition and (3) CQI with system and case-level feedback. Training included a two-hour lecture, 30 minutes of video training, and one hour of simulation training. Audio recordings of suspected OHCAs from pre (P1, 10/5/10 - 11/6/11) and post-intervention (P2, 11/7/11 - 11/4/13) periods were collected by searching center archives for calls originally processed as cardiac arrests. Recordings were analyzed according to six key TCPR metrics. Times to telecommunicator recognition of cardiac arrest, start of TCPR instructions, and initiation of chest compressions were measured using a standardized timestamp format. Results: Rates of OHCA recognition (80% to 95%, p<0.0001), TCPR instructions started (32% to 72%, p<0.0001), and bystander chest compressions initiated (18% to 70%, p<0.001) all increased significantly. Reductions in the time from call receipt to the start of TCPR instructions (176s to 133s, p<0.0001) and to the start of compressions (265s to 162s, p<0.0001) were also observed. Conclusion: This bundled protocol, training and CQI intervention was associated with a significant increase in TCPR rates and a reduction in the time to first chest compression.

Background: Bystander CPR (BCPR) and telephone CPR (TCPR) are associated with improved OHCA outcomes. It has been shown that BCPR increases the proportion of patients with an initial shockable cardiac rhythm (VF/VT) when encountered by EMS. It is unknown whether TCPR does the same. Objective: To assess whether TCPR is independently associated with an increase in initial shockable cardiac rhythms during OHCA. Methods: Data from 9-1-1 audio recordings, first care EMS reports and hospital records were linked for OHCAs of presumed cardiac origin (1/2011-12/2014). Three cohorts were analyzed: TCPR, BCPR or no CPR. Using no CPR as the reference group, we assessed whether TCPR and BCPR were independently associated with initial shockable rhythms in a logistic regression model controlling for gender, event location, witness status and EMS response interval. Results: After exclusions, 2715 adult OHCA events with linked outcome data were analyzed (median age: 63; male: 66.8%; 33.3% witnessed arrest). Median response interval was 5 min. The BCPR rate (lay rescuer CPR without telephone instructions) was 24.8% and survival in this group was 15.4%. The TCPR rate (lay rescuer CPR with telephone instructions) was 40.2% and survival in this group was 11.7%. For the no-CPR group, 20.5% had an initial shockable rhythm. For the BCPR group, 34.6 % had an initial shockable rhythm. For the TCPR group, 23.2% had an initial shockable rhythm. Provision of BCPR and of TCPR were each independently associated with shockable rhythms [aOR (BCPR) = 1.7, 95% CI: 1.33-2.17, p=0.0001; aOR (TCPR) = 1.3, 95% CI: 1.04-1.63, p=0.0001]. Conclusion: The provision of both BCPR and TCPR were independently associated with an increased rate of initial shockable cardiac rhythms and an increase in survival to hospital discharge compared to no CPR.

Introduction: Coronary angiography (CA) is recommended after out-of-hospital cardiac arrest (OHCA) when ST-elevation is present but the ideal timing and benefit of CA when ST-elevation is not present are unknown. Methods: Prospective observational study of adult (age >17) OHCA of presumed cardiac etiology from 1/01/2010-12/31/2014 who were admitted to one of 40 recognized cardiac receiving centers within a state resuscitation center network. DNR patients, those who did not achieve ROSC, and/or those who died in the ED were excluded since the likelihood of percutaneous coronary intervention (PCI) impacting outcome in these patients is low. An in-hospital database was linked with a statewide OHCA database. Results: Among 6,615 cases, 1,247 remained for analysis after exclusion [DNR (1254); failed to achieve ROSC/died in ED (4,020); missing prehospital variable (92); and missing outcome (2)]. Median age was 63 and 70% were male. There were 62% witnessed arrests, 54% received bystander CPR and the initial rhythm was VF/VT in 55%. Sixty-four percent survived to hospital discharge, 82% of which had a CPC score of 1 or 2. Of the 326 STEMI cases, 298 (91%) underwent CA with resultant PCI in 206 (63%). Of the 849 non-STEMI cases, 361 (43%) underwent CA with resultant PCI in 107 (13%). Overall survival was: 54% in cases without CA; 73% in cases with CA but without PCI; and 73% in those with PCI. Survival in non-STEMI cases was: 55% in cases without CA; 82% in cases with CA but without PCI; and 80% in those with PCI. In non-STEMI cases, the adjusted odds of survival for CA without PCI vs no CA was 2.70 (95% CI: 1.81, 4.02) and for PCI versus no CA it was 2.01 (95% CI: 1.16, 3.48). Conclusion: In this statewide analysis over 90% of OHCA cases with STEMI underwent CA. In cases that were not STEMI, CA was strongly and independently associated with survival regardless of whether PCI was performed. Since there is no reason to believe that CA without PCI confers a survival benefit, these findings suggest a component of selection bias in those without STEMI who undergo CA.

Background: During CPR in animals, chest compressions (CC) may produce passive volumes large enough to provide adequate ventilation. In humans, this mechanism may explain why continuous CCs have been associated with improved survival. We quantified the volume of passive ventilation during emergency department (ED) CCs to determine if compression-only CPR (COCPR) provides clinically significant gas exchange during resuscitation. Methods: In an urban ED, continuous flow and volume of air exhaled through an endotracheal tube were measured during the CC phase of manual CPR (between ventilations) with NICO monitors (Philip/Respironics) and recorded using LabView (National Instruments). Gas exchange with CC was quantified using Matlab (Mathworks) as the area under the flow curve (figure). CC quality was measured using accelerometer-based technology (R Series, ZOLL Medical). Results: Eight patients (6 male) aged 37-83 yrs [median age 51 yr (IQR 43-56)] who suffered out-of-hospital cardiac arrest (CA) and were transported and treated with CC in the ED were included. A total of 548 CCs [median depth 1.89 in (IQR=1.66, 2.29), median rate 128 CC/min (IQR=122-134) were analyzed over 30 min of CPR. Median tidal volume per CC was 17.3 mL (IQR=5.9-22.4). This was considerably less than measured dead space in all patients (median 118mL, IQR=93-143), regardless of CC depth. The figure illustrates a typical tracing in which ventilation volume dwarfs any passive ventilation occurring with CC. Conclusion: Late in CA, passive ventilation occurring during CCs appears to produce considerably less gas exchange than calculated dead space. The effectiveness of passive ventilation during early stages of CPR, when chest and lung compliance are greater, remains unknown. However, these findings suggest that the benefits of COCPR strategies may be related to reliably higher CC fraction and/or prevention of the negative effects of hyperventilation rather than from any passive ventilation.

Background: The 2010 AHA Guidelines state rescuers should perform chest compressions (CCs) of at least 2 inches in depth for adult cardiac arrest patients. Although the pediatric guidelines recommend adjustment of CC depth based upon anteroposterior chest dimension, there is no such recommendation for adults. Purpose: To determine 1) whether prehospital providers intuitively vary CC depth in adults according to patient size and 2) whether implementation of real-time audiovisual CPR feedback (RTAVF) impacts weight/CC depth variation. Methods: CC quality data were prospectively collected prior to (9/08-4/10; Pre-feedback) and after (5/10-12/10; Post-feedback) implementation of an RTAVF system (ZOLL Medical, Chelmsford MA) from 3 EMS agencies. The RTAVF includes a visual display of absolute CC depth and gives audio prompts when depth is outside of the Guideline-recommended range. Among 363 cases of adult, non-traumatic out-of-hospital cardiac arrest (OHCA), body weight was estimated by EMS in 249 patients (study group; 66%). CPR quality data were available for all cases via code review software. Results: 168 Pre-feedback and 81 Post-feedback study group cases (mean 64±16 years, 68% male). Mean estimated body weight was 201 lbs (quartiles 161, 231; range 70-451) and was not different between groups. CC depth increased significantly with RTAVF use (Pre-feedback = 1.77, 95% confidence interval [CI]:1.71-1.83 in.; Post-feedback = 2.10, CI: 2.04-2.15 in.; p<0.001). CC depth did not vary significantly by patient gender or age (p>0.4). Multivariate linear regression (r 2 =0.23, p<0.001 for model) revealed a significant increase in CC depth with estimated weight in both periods (0.07in/50lbs, p<0.001) after controlling for the presence of RTAVF. RTAVF was not an effect-modifier of the relationship between estimated weight and CC depth (p-value for interaction term=0.4). Conclusion: Although not specifically recommended in the 2010 AHA Guidelines for adults, rescuers may instinctively and/or intentionally adjust CC depth according to patient size. In this setting, weight/CC depth adjustments occurred both without and with real-time feedback. Follow-up studies are needed to determine the potential effect of size-adjusted CC depth on patient outcome.

BACKGROUND: For sudden collapse from out-of-hospital cardiac arrest (OHCA) in adults, bystander chest compression-only CPR (COCPR) results in equivalent or better survival compared with conventional CPR with rescue breathing. However, patients who arrest from a non-cardiac cause may also receive COCPR even though rescue breathing might benefit them. We sought to determine whether lay rescuers appropriately provided COCPR or conventional CPR depending on the suspected etiology of OHCA. METHODS: Analysis of a statewide, Utstein-style registry of adult OHCA during a large-scale campaign endorsing COCPR for adults who suddenly collapse. The relationship between bystander CPR (both COCPR and conventional CPR), presumed arrest etiology, and survival to hospital discharge were evaluated. Means and 95% confidence intervals (CI) were calculated. FINDINGS: A total of 7,652 adult OHCAs not witnessed by EMS were analyzed from 10/04 to 09/10. After exclusion of non-lay bystanders and arrests in medical facilities, presumed cardiac etiology and non-cardiac etiology OHCA totaled 4,913 and 1,202, respectively. The presumed specific non-cardiac etiologies were non-cardiopulmonary (e.g. overdose, suicide, subarachnoid hemorrhage) (57%), trauma (27%), and respiratory (16%). All-rhythm survival was 7.0% (CI: 6.3 - 7.8) for cardiac etiologies and 3.3% (CI: 2.3 - 4.3) for non-cardiac (p<0.001). Bystander CPR was provided for 33% (CI: 31.4 - 34.1) of victims with presumed cardiac causes versus 28% (CI: 25.6 - 30.7) for non-cardiac causes (p=0.002). Presumed respiratory causes of OHCA had a much lower proportion of COCPR (8.3%, CI: 4.4 - 12.2) than cardiac causes (18.0%, CI: 16.9 - 19.1, p<0.001). Survival for non-cardiac cases was: 4.4% (CI 0.9 - 7.8) for conventional CPR, 3.5% (CI: 0.9 - 6.0) for COCPR, and 3.1% (CI: 2.0 - 4.3) for no CPR (p = 0.66). CONCLUSIONS: In the setting of a large-scale, statewide public health campaign endorsing lay rescuer COCPR for adults who suddenly collapse and are not breathing normally, bystanders were much less likely to perform COCPR on OHCA victims who might benefit from rescue breathing. Furthermore, when COCPR was performed on presumed non-cardiac cause arrest victims, there was no demonstrable negative impact on survival.