Debaty, Guillaume P.

Background: Pre-clinical animal studies have demonstrated improved cerebral blood flow and neurological survival with Automated Head Up Position (AHUP) cardiopulmonary resuscitation (CPR) as compared to flat conventional (C) CPR. AHUP CPR consists of 1) automated head and thorax elevation 2) active compression decompression CPR and 3) an impedance threshold device. Subsequently, observational propensity-matched studies of out-of-hospital cardiac arrest (OHCA) patients demonstrated a time-dependent association between survival with intact neurological function (SNF) and application of AHUP CPR. However, comparison of AHUP CPR outcomes with contemporaneous C-CPR controls is lacking. Hypothesis: Use of AHUP CPR for OHCA by first responder agencies will demonstrate a higher incidence of SNF compared to C-CPR outcomes from a national registry Methods: Data from the previous 5 years (2020-2024) from an AHUP-CPR Registry comprised of OHCA patients routinely treated by first responders with AHUP CPR were compared with data from the Cardiac Arrest Registry to Enhance Survival (CARES). Patient demographics, arrest characteristics, ROSC, SHD, and SNF were recorded. SNF was defined as a Cerebral Performance Category 1 or 2 at hospital discharge. A two-sample test of proportions was used for outcome comparisons. Results: Nine AHUP registry sites (MN, FL, TN, IL, OK, VA, AL, IA, MI) were included. Summary 5-year demographics (Table 1) and clinical outcomes (Table 2) are presented. For 2020-2024 AHUP sites, the average time (mm:ss, SD) from 9-1-1 call to start of CPR was 9:09 (4:37) and time to start of AHUP CPR was 12:46 (5:57). The AHUP registry had a higher 5-yr incidence of SNF versus the CARES registry (difference 2.8%, 95% CI 1.8-3.8, p < 0.00001). This difference was consistent year over year (Figure 1). Secondary outcomes of sustained return of spontaneous circulation and survival to hospital discharge in the AHUP registry were also significantly higher than CARES registry data (Table 2). Conclusions: Over a 5-year period, an unadjusted analysis of aggregate data from two OHCA patient registries demonstrated that the incidence of survival with intact neurological function was higher in patients treated with AHUP CPR as part of first responder care versus patients treated with more conventional CPR methods.

Background: Addition of resuscitative endovascular balloon occlusion of the aorta (REBOA) to automated head-up position (AHUP) cardiopulmonary resuscitation (CPR), the combination of active compression decompression CPR, an impedance threshold device, and controlled gradual elevation of the head and thorax, increases cerebral perfusion pressure. Optimal management of REBOA deflation after prolonged AHUP-CPR and ROSC is unknown. Hypothesis: We hypothesized that partial deflation of REBOA, rather than full deflation after ROSC, would result in better hemodynamic parameters. Aims: To compare hemodynamic parameters 1 minute before and 1 minute after complete (100%) versus partial (50%) REBOA deflation after prolonged AHUP-CPR and ROSC. Methods: Yorkshire pigs weighing ∼40 kg were anesthetized and ventilated. After 10 minutes of untreated ventricular fibrillation, AHUP-CPR was started and continued for a median time of 44 minutes. After ROSC, REBOA deflation was initiated in two ways: complete (100%) or partial (50%) deflation over 5 seconds. The following hemodynamic parameters were measured 1 minute before and 1 minute after deflation: mean aortic pressure (MAP), cerebral perfusion pressure (CerPP), and coronary perfusion pressure (CorPP). Data, in mmHg, are presented as mean ± SD, and compared using a paired t-test. Results: 13 pigs were included, with 8 pigs in the 100% deflation group and 5 in the 50% deflation group. After ROSC in the 100% deflation group, MAP was 81.5±36.0 before deflation vs. 43.0±14.4 after (p=0.01), whereas in the 50% deflation group, MAP was 90.5±33.0 vs. 83.4±33.3 (p=0.02). CerPP was 72.3±34.4 before deflation vs. 35.9±14.6 (p=0.01) in the 100% deflation group, and 84.6±31.2 vs. 77.6±31.8 (p=0.02) with 50% deflation. Similarly, CorPP was 74.1±37.3 before deflation vs. 36.1±15.8 (p=0.01) after in the 100% deflation group, and 83.0±32.7 vs. 76.1±33.0 (p=0.02) in the 50% deflation group. The differences from before to after deflation were markedly less in the 50% deflation group versus the 100% deflation group: MAP (7.0±4.3 vs. 38.5±25.7, p=0.02), CerPP (7.1±4.4 vs. 36.3±24.4, p=0.02), and CorPP (6.0±4.2 vs. 39.8±25.2, p=0.02), respectively. Conclusion: In this porcine model of prolonged cardiac arrest, partial deflation of the REBOA balloon post ROSC resulted in strikingly higher hemodynamics compared with complete deflation. These findings highlight the need to develop a post-ROSC REBOA deflation strategy when used during AHUP-CPR.

OBJECTIVES: Cardiac arrests remain a leading cause of death worldwide. Most patients have nonshockable electrocardiographic presentations (asystole/pulseless electrical activity). Despite well-performed basic and advanced cardiopulmonary resuscitation (CPR) interventions, patients with these presentations have always faced unlikely chances of survival. The primary objective was to determine if, in addition to conventional CPR (C-CPR), expeditious application of noninvasive circulation-enhancing adjuncts, and then gradual elevation of head and thorax, would be associated with higher likelihoods of survival following out-of-hospital cardiac arrest (OHCA) with nonshockable presentations. DESIGN: Using a prospective observational study design (ClinicalTrials.gov NCT05588024), patient data from the national registry of emergency medical services (EMS) agencies deploying the CPR-enhancing adjuncts and automated head/thorax-up positioning (AHUP-CPR) were compared with counterpart reference control patient data derived from the two National Institutes of Health clinical trials that closely monitored quality CPR performance. Beyond unadjusted comparisons, propensity score matching and matching of time to EMS-initiated CPR (TCPR) were used to assemble cohorts with corresponding best-fit distributions of the well-established characteristics associated with OHCA outcomes. SETTING: North American 9-1-1 EMS agencies. PATIENTS: Adult nontraumatic OHCA patients receiving 9-1-1 responses. INTERVENTIONS: In addition to C-CPR, study patients received the CPR adjuncts and AHUP (all U.S. Food and Drug Administration-cleared). MEASUREMENTS AND MAIN RESULTS: The median TCPR for both AHUP-CPR and C-CPR groups was 8 minutes. Median time to AHUP initiation was 11 minutes. Combining all patients irrespective of lengthier response intervals, the collective unadjusted likelihood of AHUP-CPR group survival to hospital discharge was 7.4% (28/380) vs. 3.1% (58/1,852) for C-CPR (odds ratio [OR], 2.46 [95% CI, 1.55–3.92]) and, after propensity score matching, 7.6% (27/353) vs. 2.8% (10/353) (OR, 2.84 [95% CI, 1.35–5.96]). Faster AHUP-CPR application markedly amplified odds of survival and neurologically favorable survival. CONCLUSIONS: These findings indicate that, compared with C-CPR, there are strong associations between rapid AHUP-CPR treatment and greater likelihood of patient survival, as well as survival with good neurological function, in cases of nonshockable OHCA.