An intrathoracic pressure regulator (ITPR) is a device that can be added to the external end of an endotracheal tube to create controlled negative airway pressure between positive pressure ventilations. The resulting downward bias of the airway pressure baseline promotes increased venous return and enhanced circulation during CPR and also during hypovolemic shock. In the present study we exercised a mathematical model of the human cardiopulmonary system, including airways, lungs, a 4 chambered heart, great vessels, peripheral vascular beds, and the biomechanics of chest compression and recoil, to determine the relationship between systemic perfusion pressure during CPR and the value of baseline negative airway pressure in an ITPR. Perfusion pressure increases approximately 50 percent as baseline airway pressure falls from zero to –10 cm H2O. Thereafter perfusion pressure plateaus. Negative bias pressures exceeding –10 cm H2O are not needed in ITPR-CPR.


This is the author accepted manuscript of C. F. Babbs and D. Yannopoulos, A dose—response curve for the negative bias pressure of an intrathoracic pressure regulator during CPR, Resuscitation, 71, 365-368, 2006. DOI: 10.1016/j.resuscitation.2006.01.022 CC-BY-NC-ND


Airway management, ACD-CPR, Cardiopulmonary resuscitation (CPR); Coronary perfusion pressure; Decompression, Device; Impedance, Mathematical model, Threshold, Valve

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