Abstract 19230: The CPR “Sweet Spot”: A Target Combination of Optimal Chest Compression Rate and Depth to Achieve Survival With Favorable Neurological Function After Out of Hospital Cardiac Arrest
Introduction: Collectively, recent studies of out of hospital cardiac arrest (OOHCA) not only confirm that both the CPR chest compression rate (CCR) and depth (CCD) each impact survival, but they also interact and may, in turn, be affected by CPR adjuncts.
Hypothesis: An ideal combination of CCR and CCD can be identified that optimizes chances of surviving OOHCA with neuro-intact function. It also was hypothesized that such an ideal target might differ by use of an impedance threshold device (ITD).
Methods: Using the NIH “ROC” PRIMED (ITD clinical trial) database, we analyzed the control and ITD-treated subjects with CCR and CCD data available (n=3,749). Response surface modeling and numerical optimization techniques were used to calculate the optimal CCR/CCD combination that maximized survival with a modified Rankin Score (mRS) ≤3. Contour plots identified the combined CCR/CCD values with the greatest density of survivors. The interaction among the range of optimal values, ITD use and neuro-intact survival (mRS≤3) was modeled using multivariable logistic regression analyses, adjusted for the presenting ECG rhythm, age and sex.
Results: Among 96 neuro-intact survivors in the “sham” ITD (control) group (n=1,888), the identified optimal CCR/CCD target was 108/min and 4.6 cm (Fig., left) vs. 106/min and 4.8 cm for 95 neuro-intact ITD-treated survivors (n=1,861; Fig., right). Overall, identified values for sham and ITD groups were not statistically or clinically different, but, when CPR was performed within ±20% of these optimal CCR/CCD values, the interaction became significant (p=0.012) with the ITD conferring better survival. Multivariable modeling did not alter this result (interaction p=0.016).
Conclusions: During CPR, an optimal CCR/CCD combination can improve outcome after OOHCA, particularly with use of an ITD. Using NIH clinical trial data, that target “sweet spot” for CCR/CCD is a combination of 108/min and 4.6 cm; 106/min and 4.8 cm with ITD use.
- Cardiopulmonary resuscitation
- Cardiac arrest
- Chest compression
- Emergency medical services (EMS)
Author Disclosures: S. Duval: None. P.E. Pepe: None. J.M. Goodloe: None. A. Sugiyama: None. D. Yannopoulos: Research Grant; Significant; NIH resuscitation grants.
- © 2016 by American Heart Association, Inc.