Introduction: Myocardial and cerebral perfusion generated by conventional chest compression during cardiopulmonary resuscitation (CPR) rarely exceeds 30% and 10% of normal. The effectiveness of chest compression decreases with the prolongation of cardiac arrest. In this study, we investigated the effects of chest compression in combination with physical increases in peripheral vascular resistance (PIPVR) on myocardial and cerebral perfusion during CPR. Methods: Ventricular fibrillation was induced and untreated for 7 mins in ten male domestic pigs weighing between 33 - 37 kg. The animals were then randomized to receive chest compression alone or combined with PIPVR. Chest compression was performed by a miniaturized mechanical chest compressor. Coincident with the start of resuscitation, PIPVR was performed by thin elastic tourniquets around the four limbs from distal end to proximal part. Defibrillation was attempted after 5 mins of CPR. If spontaneous circulation was not returned, CPR was resumed for 2 mins prior to the next defibrillation until either successful resuscitation or for a total of 15 mins. Coronary perfusion pressure and carotid blood flow were continuously recorded during CPR. Results: During CPR, significantly greater coronary perfusion pressure and carotid blood flow were observed by the combination of chest compression and PIPVR when compared with chest compression alone [(45 ± 15) mmHg vs. (34 ± 12) mmHg; (52 ± 11) ml/min vs. (39 ± 10) ml/min, all p<0.05]. However, there was no significant difference in intrathoracic positive and negative pressure [(26 ± 6) mmHg vs. (24 ± 7) mmHg, p=0.63; (-5 ± 2) mmHg vs. (-6 ± 2) mmHg, p=0.51]. Conclusions: The combination of chest compression and PIPVR significantly improved myocardial and cerebral perfusion during CPR.
1Weil Institute of Critical Care Medicine, Rancho Mirage, CA, 2Eisenhower Medical Center, Rancho Mirage, CA, 3Keck School of Medicine of the University of Southern California, Los Angeles, CA