Reducing ventilation frequency combined with an inspiratory impedance device improves CPR efficiency in swine model of cardiac arrest

Demetris Yannopoulos, Gardar Sigurdsson, Scott McKnite, David Benditt, Keith G. Lurie

Research output: Contribution to journalArticlepeer-review

49 Scopus citations


Background: The basic premise that frequent ventilations during cardiopulmonary resuscitation (CPR) are a necessity for tissue oxygenation has recently been challenged. An inspiratory impedance threshold device (ITD) recently has also been shown to increase CPR efficiency, principally by augmenting circulation with little impact on ventilation. The optimal compression to ventilation (C/V) is not known for this new device. The purpose of this study was to compare the currently recommended C/V ratio of 5:1 with a 10:1 ratio, ± the ITD, to optimize circulation and oxygenation during CPR. Methods: Thirty-two adult pigs weighing 26-31kg were randomized to CPR with varying C/V ratios ± the ITD as follows: A=5:1, B=5:1+ITD, C=10:1, D=10:1+ITD. After 6min of untreated ventricular fibrillation (VF), closed-chest standard CPR was performed with an automatic piston device that does not impede passive chest wall recoil, at a continuous compression rate of 100min -1. Synchronous breaths were given every 5 or 10 compressions during the decompression phase depending on the group. CPR was performed for 6min and physiological variables were measured throughout the experimental protocol. Results: A reduction in the frequency of ventilation from 5:1 to 10:1 resulted in significantly improved arterial and coronary perfusion pressure in a pig model of cardiac arrest. Addition of an ITD resulted in further increases in arterial and coronary perfusion pressures with both 5:1 and 10:1 C/V ratios, without compromising oxygenation. Conclusion: CPR efficiency can be optimized by changing the compression: ventilation ratio from 5:1 to 10:1 and with concurrent use of the inspiratory threshold device.

Original languageEnglish (US)
Pages (from-to)75-82
Number of pages8
Issue number1
StatePublished - Apr 2004

Bibliographical note

Copyright 2008 Elsevier B.V., All rights reserved.


  • Cardiac arrest
  • Cardiopulmonary resuscitation (CPR)
  • Coronary perfusion pressure
  • Paragem cardíaca
  • Pressão de perfusão coronária
  • Reanimação cardio-pulmonar (CPR)
  • Ventilation
  • Ventilação


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