Effect of regulating airway pressure on intrathoracic pressure and vital organ perfusion pressure during cardiopulmonary resuscitation: a non-randomized interventional cross-over study.

Younghoon Kwon,Jennifer Rees,Guillaume Debaty,Anja Metzger,Scott Mcknite,Demetris Yannopoulos,Keith Lurie,Laura Puertas

doi:10.1186/s13049-015-0164-5

Abstract

BackgroundThe objective of this investigation was to evaluate changes in intrathoracic pressure (Ppl), airway pressure (Paw) and vital organ perfusion pressures during standard and intrathoracic pressure regulation (IPR)-assisted cardiopulmonary resuscitation (CPR).MethodsMultiple CPR interventions were assessed, including newer ones based upon IPR, a therapy that enhances negative intrathoracic pressure after each positive pressure breath. Eight anesthetized pigs underwent 4 min of untreated ventricular fibrillation followed by 2 min each of sequential interventions: (1) conventional standard CPR (STD), (2) automated active compression decompression (ACD) CPR, (3) ACD+ an impedance threshold device (ITD) CPR or (4) ACD+ an intrathoracic pressure regulator (ITPR) CPR, the latter two representing IPR-based CPR therapies. Intrapleural (Ppl), airway (Paw), right atrial, intracranial, and aortic pressures, along with carotid blood flow and end tidal CO2, were measured and compared during each CPR intervention.ResultsThe lowest mean and decompression phase Ppl were observed with IPR-based therapies [Ppl mean (mean ± SE): STD (0.8 ± 1.1 mmHg); ACD (−1.6 ± 1.6); ACD-ITD (−3.7 ± 1.5, p < 0.05 vs. both STD and ACD); ACD-ITPR (−7.0 ± 1.9, p < 0.05 vs. both STD and ACD)] [Ppl decompression (mean ± SE): STD (−6.3 ± 2.2); ACD (−13.0 ± 3.8); ACD-ITD −16.9 ± 3.6, p < 0.05 vs. both STD and ACD); ACD-ITPR −18.7 ± 3.5, p < 0.05 vs. both STD and ACD)]. Interventions with the lower mean or decompression phase Ppl also demonstrated lower Paw and were associated with higher vital organ perfusion pressures.ConclusionsIPR-based CPR methods, specifically ACD-ITPR, yielded the most pronounced reduction in both Ppl and Paw and resulted in the most favorable augmentation of hemodynamics during CPR.Electronic supplementary materialThe online version of this article (doi:10.1186/s13049-015-0164-5) contains supplementary material, which is available to authorized users.

Highlights

The objective of this investigation was to evaluate changes in intrathoracic pressure (Ppl), airway pressure (Paw) and vital organ perfusion pressures during standard and intrathoracic pressure regulation (IPR)-assisted cardiopulmonary resuscitation (CPR)
Circulation as measured by coronary perfusion pressure (CPP), cerebral perfusion pressures (CePP), carotid blood flow (CBF), and End tidal CO2 (ETCO2) improved with the use of active compression decompression (ACD)-impedance threshold device (ITD) or ACD-intrathoracic pressure regulator (ITPR)
Data are derived from 8 animals CPR cardiopulmonary resuscitation, STD standard, ACD active compression decompression, ITD impedance threshold device, ITPR intrathoracic pressure regulator, Intrapleural pressure (Ppl) intrapleural pressure, Paw Airway pressure; max, maximum; min, minimum *denotes p < 0.05 for STD vs. (ACD, ACD ITD, ACD ITPR) **denotes p < 0.05 for ACD vs. (ACD ITD, ACD ITPR) ***denotes p < 0.05 for ACD-ITD vs. ACD-ITPR

Summary

Introduction

The objective of this investigation was to evaluate changes in intrathoracic pressure (Ppl), airway pressure (Paw) and vital organ perfusion pressures during standard and intrathoracic pressure regulation (IPR)-assisted cardiopulmonary resuscitation (CPR). Dynamic changes in intrathoracic pressure during cardiopulmonary resuscitation (CPR) play an important role in generating forward blood flow and perfusion pressure in CPR [1]. Since 1960, when closed-chest manual or standard (STD) CPR was first described, multiple new CPR methods and techniques have been developed to further enhance blood flow to the heart and brain in patients in cardiac arrest. The degree of chest wall recoil varies from patient to patient Based upon these mechanisms of action, STD-CPR only provides 10–30 % of normal blood flow to the brain and heart. This low rate of cardio-cerebral perfusion likely contributes to the persistently low neurologically-sound survival rates typically reported with the STD-CPR [10]

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Conclusion