ABDOMINAL COMPRESSIONS INCREASE VITAL ORGAN PERFUSION DURING CPR IN DOGS - RELATION WITH EFFICACY OF THORACIC COMPRESSIONS

Study objective: Abdominal compressions can be interposed between the thoracic compressions of standard CPR (SCPR). The resulting interposed abdominal compression CPR(IAC-CPR) may increase blood pressures and p atient survival, particularly if applied as a primary technique after in-hospital cardiac arrest. We used a predominant cardiac compression canine model to study the effects of IAC-CPR on blood pressures and to tal and vital organ perfusion as a function of time after cardiac arre st and efficacy of SCPR. Design: In a crossover design, we measured bl ood pressures and total and regional blood flow (radioactive microsphe res) during 6-minute episodes of mechanical SCPR and IAC-CPR, both ear ly (4 to 16 minutes) and late (18 to 30 minutes) after induction of ve ntricular fibrillation in eight dogs (weight, 25 to 33 kg) under neuro leptanalgesia/anesthesia. Results: During IAC-CPR, the ascending aorti c-right atrial pressure gradient increased (P<.05), and retrograde pre ssure pulses contributed to the rise of ascending aortic pressure. Wit hin 2 minutes after the start of IAC-CPR, end-tidal CO2 fraction incre ased by 0.6+/-0.4 vol% (P<.05), suggesting ehanced venous return. IAC- CPR enhanced (P<.05) total forward blood flow (574+/-406 versus 394+/- 266 mL/minute during SCPR for the early phase) and vital organ perfusi on (including myocardium), in both early and late phases. The IAC-CPR- induced augmentation of blood flow was greater if perfusion was relati vely high during SCPR. Conclusion: Compared with predominant cardiac c ompressions alone (SCPR), the addition of interposed abdominal compres sions (IAC-CPR) improves total and vital organ oxygen delivery through enhanced venous return and perfusion pressures.