Venuti, Mark

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.

Objective: The 2010 AHA Guidelines stress the need for minimally interrupted, high quality CPR. We performed a prospective, before/after trial to determine if real-time audiovisual feedback (RTAVF) along with scenario-based training (SBT) would 1) achieve the 2010 CPR targets and 2) improve survival from OHCA. Methods: Data obtained from EMS care forms and defibrillators (E Series, ZOLL) from 2 EMS agencies (population base-500,000). Phase 1 (P1, before): 18 months of baseline data with the RTAVF mode disabled (9/08-3/10). Interventions: 1) Guideline-based SBT of ~450 EMTs, 2) RTAVF enabled, 3) EMT post-code debriefings. Phase 2 (P2, after): 8 months following implementation of interventions (5/10-12/10). For univariate analyses we used Fisher's exact test (proportions), t-test (means) or Kruskal-Wallis test (medians). To estimate odds ratios for survival to hospital discharge we used multivariable logistic regression and assessed final model diagnostics, fit, and discrimination. Results: The final analysis included 284 adult OHCAs (P1-176, P2-108). Mean age 65.4 years (SD ± 15.3) with 66.6% males. Quality measures improved significantly from P1 to P2: Median (Interquartile range) chest compression (CC) rate-121 CC/min (109-135) to 101 CC/min (100-106), p <0.001; CC depth-1.73 in. (1.42-1.97) to 2.09 in. (1.92-2.3), p <0.001; CC fraction-66.5% (59.3-75.9%) to 84.0% (77.8-88.7%), p <0.001. All-rhythms survival increased significantly (p=0.034) from P1 to P2 (18/176, 10.2% vs. 23/108, 19.4%), an absolute survival increase of 9.2% (95% CI: 0.5%-17.9%). Crude odds ratio for survival for P2 vs. P1 was 2.1 (95% CI: 1.1-4.2) and adjusted odds ratio was 5.8 (95% CI: 1.8-18.9), after controlling for confounders including age, sex, location, witnessed arrest, initial rhythm, and therapeutic hypothermia. Survival for arrests with a shockable rhythm was 27.7% (18/65) for P1 and 53.9% (14/26) for P2 (p=0.028). Conclusion: RTAVF combined with SBT was associated with a significant improvement in the proportion of compressions meeting the 2010 AHA Guidelines. This intervention was associated with a 90% relative increase in overall survival. We believe this is the first report to show an improvement in OHCA survival by achieving the 2010 AHA CPR Guidelines.