Abstract Body: Introduction: We evaluated delivery of the American Heart Association (AHA) ventilation guidelines by emergency medical services (EMS) providers delivering cardiac arrest care using the ZOLL Real BVM Help technology. Methods: A prospective, before/after, convenience sample of adult patients (≥ 18 years old) treated for any type of out-of-hospital cardiac arrest by Milwaukee County EMS and Kenosha Fire in Wisconsin. Real BVM Help was used but blinded during the before phase when providers used ETCO2 to guide ventilation. This was followed by unblinding during a 3-month interim phase when providers learned and adapted to providing care using the real-time feedback, followed by the unblinded after phase. The primary endpoint was the within-person average proportion (%) of ventilations in target for rate, volume, and both rate and volume assessed on a per-breath basis during continuous chest compressions with an advanced airway. The secondary endpoint was the within-person average proportion of manual chest compressions in target for rate, depth, and both rate and depth during the identical period. Target for ventilation rate and volume was 8-12 breaths/minute and 500-600 mL/breath, respectively. Target for compression rate and depth was 100-120 compressions/minute and 2-2.4 inches/compression, respectively. Results: From 9/29/22 to 12/22/23, 278 patients were entered in the study (148 before and 130 after). The average age was 62.3±16.7 years and 185 (67%) were male. Of the 278 patients, 171 (62%) were White, 80 (29%) Black, 2 (1%) Asian, 1 (0.5%) American Indian/Alaska Native, 1 (0.5%) Native Hawaiian/Pacific Islander, 5 (2%) Other, and 18 (6%) Unknown. Ethnicity included 250 (90%) Not Hispanic or Latinx, 20 (7%) Hispanic or Latinx, and 8 (3%) Unknown. There were no significant differences in the before and after groups with respect to age, gender, race, ethnicity, type of cardiac arrest rhythm, cardiac versus noncardiac etiology, witnessed status, type of public location, CPR prior to EMS arrival, type of advanced airway or successful endotracheal tube placement. Ventilation and manual chest compression results are shown in Table 1. Conclusion: Use of ZOLL Real BVM Help technology resulted in a statistically significant and clinically meaningful improvement in delivery of ventilation guidelines during resuscitation from out-of-hospital cardiac arrest with no change in manual chest compression quality.