Abstract 141: Automated Head-Up Cardiopulmonary Resuscitation Increased End Tidal Co2 in Patients With Out-of-Hospital Cardiac Arrest Compared With Conventional CPR: A Prospective Before-After Interventional Study

Abstract

Background: Little is known in humans about the physiological effects of the combination of automated Head-Up cardiopulmonary resuscitation CPR, active compression-decompression CPR and an impedance threshold device (ITD). This new approach, termed AHUP-CPR, improves perfusion of vital organs and lowers intracranial pressure compared with conventional (C)CPR in animal models of cardiac arrest. This study tested the hypothesis that AHUP-CPR treatment would increase end tidal CO2 (ETCO2), a circulation surrogate, more than C-CPR in out-of-hospital cardiac arrest (OHCA) patients. Method: Prospective before-after interventional study of witnessed OHCA patients. C-CPR and AHUP-CPR were performed by firefighters who measured ETCO2. AHUP-CPR was delivered using a LUCAS AD (5 cm of compression and 3 cm active decompression) (Stryker Medical, USA), an EleGARD Patient Positioning System (AdvancedCPR Solutions, USA), and an ITD (ResQPOD-16, Zoll, USA). The study was performed in the greater Grenoble France region in four different fire stations. The primary endpoint was the measurement of maximum EtCO2 during CPR. Results are presented as mean ± standard deviation. Results: Baseline characteristics (age, sex, arrest location, initial rhythm, bystander CPR, witnessed) were not statistically different between groups.EtCO2 was higher for patients treated with AHUP-CPR (n=63) compared to the C-CPR (n=59) (41±18 vs. 30.2 mmHg, p<0.001). This difference was significant for shockable (45±13 vs. 34±12 mmHg, p=0.03) and non-shockable (40±19 vs. 28±13 mmHg, p=0.004) rhythms, respectively. The calculated difference between the maximum and first recorded ETCO2 values was 6.3 ± 20.4 in the C-CPR arm versus 21.1 ± 20.6 in the AHUP-CPR group (P<0.001). A total of 29% (n=18) of the AHUP patients vs. 22 % (n=13) were admitted alive to the hospital (P=0.34). Conclusion: Results from this first prospective clinical trial on AHUP-CPR demonstrated that ETCO2 values were significantly higher after AHUP-CPR versus C-CPR, regardless of the presenting rhythm. Using ETCO2 as a surrogate for circulation, these findings confirm animal studies showing AHUP-CPR provides significantly more vital organ blood flow to patients in OHCA compared with C-CPR.