Active decompression during automated head-up cardiopulmonary resuscitation.

Background: The combination of active compression-decompression cardiopulmonary resuscitation (ACD-CPR) with an impedance threshold device (ITD) and controlled head-up positioning (AHUP-CPR) is associated with improved outcomes compared with conventional CPR (C-CPR). This study focused on the role of active decompression (AD) during AHUP-CPR.
Methods: Farm pigs (n = 10, ∼40 kg) were anesthetized, intubated and ventilated. Physiological parameters and right ventricular pressure-volume loops were recorded continuously. Ventricular fibrillation was induced and left untreated for 10 mins, followed by automated C-CPR (2 min), ACD + ITD CPR in the flat position (2 min), and then AHUP-CPR with 3 cm of lift above the neutral chest position. After 15 min of CPR, AD was discontinued and then restarted incrementally to 4 cm. Data were analyzed with a linear mixed-effects model, using random intercepts for individual pigs.
Results: Upon cessation of AD during AHUP-CPR, decompression right atrial pressure (+59%) increased (p < 0.01), whereas multiple hemodynamic parameters positively associated with perfusion, including coronary (-25%) and cerebral perfusion pressures (-11%), end-tidal CO2 (-13%), stroke volume and cardiac output (-26%), decreased immediately and significantly with p < 0.05. Restoration of AD reduced right atrial pressure and increased positive perfusion parameters in an incremental manner. Only with ≥ 3 cm of AD were all hemodynamic parameters restored to ≥ 90% of pre-AD discontinuation levels.
Conclusion: Full chest wall lift, achieved with ≥ 3 cm of AD, was needed to maintain and optimize hemodynamics during AHUP-CPR in pigs. These findings should be considered when optimizing care with this new approach.
Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: We confirm that this work is original and has not been submitted, nor is it under consideration for publication elsewhere. Lastly, the source of funding and conflicts of interest have been declared, and all authors have read and agreed to the final version of the manuscript. Two co-authors, Drs. Keith Lurie and Anja Metzger work, in part, for AdvancedCPR Solutions, the company that makes a human patient positioning system for Head Up CPR. While the device used for this porcine research is not one that can be used in humans, the relationship with AdvancedCPR Solutions is a potential conflict of interest. No other co-authors have any financial conflicts of interest.
(Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)