The effect of using an impedance threshold device on hemodynamic parameters during cardiopulmonary resuscitation in dogs

Objective To investigate the hemodynamic effects following the use of an impedance threshold device (ITD) in a canine model of cardiopulmonary arrest. Design Experimental, randomized crossover study. Setting Cardiovascular research laboratory at a university veterinary center. Animals Eight purpose bred beagle dogs. Interventions Dogs were anesthetized and instrumented for the measurement of right atrial pressure , systolic blood pressure, mean blood pressure, and diastolic arterial blood pressure, end‐tidal CO2, and carotid blood flow (CBF). CBF was determined via ultrasonic flow probe placed around the carotid artery. Animals were taking part in an unassociated terminal study and following subsequent euthanasia with pentobarbital, standardized cardiopulmonary resuscitation (CPR) was performed with an impedance threshold device attached (ITD‐CPR group) and without (S‐CPR group). Order of treatment was randomized. Measurements and Main Results ITD group had increased CBF, coronary perfusion pressure, and a decrease in right atrial diastolic pressure. No differences in end‐tidal CO2, diastolic arterial blood pressure, mean blood pressure, or systolic blood pressure were seen. Return of spontaneous circulation was not observed in any of the animals Conclusions Use of the ITD resulted in favorable changes in hemodynamic parameters in dogs undergoing CPR. The ITD may be a useful adjunct during CPR in dogs and warrants clinical evaluation.