The effect of resuscitation position on cerebral and coronary perfusion pressure during mechanical cardiopulmonary resuscitation in porcine cardiac arrest model

Objective It is unknown whether patient position is associated with the optimal cerebral (CePP) and coronary (CoPP) perfusion pressure. Methods This study utilized a randomized experimental design and anesthetized, intubated and paralyzed female pigs (n = 12) (mean 42, SD 3 kg). After 6 min of untreated ventricular fibrillation, mechanical CPR with was performed for 3 min in 0° supine position. The CPR was then performed for 5 min in a position randomly assigned to either 1) head-up tilt (HUT) by three angles (30°, 45°, or 60°) or 2) head-down tilt (HDT) by three angles (30°, 45°, or 60°) and at 3) supine position between HUT and HDT positions. 4 Pigs were assigned to each angle of HUT or HDT position and 12 pigs were assigned to supine position. CePPs and CoPPs were measured and compared using MIXED procedure with pig as a random effect among angles and compared between angles with Tukey post-hoc analysis. Results With 60°, 45°, 30° head-down, 0° (supine), and 30°, 45°, 60° head-up positioning, mean(SD) CePPs increased consistently as follows: 2.4(0.4), 9.3(1.6), 16.5(1.6), 27.0(1.5), 35.1(0.4), 39.4(0.6), and 39.9(0.3) mmHg, respectively. CoPPs were followings according to same angle: 12.9(2.5), 13.3(2.5), 12.8(0.4), 18.1(0.7), 30.3(0.4), 24.1(0.6), and 26.5(0.9) mmHg, respectively. The CePPs were peak at HUT(45°) and HUT(60°), but CoPP was peak in HUT(30°) and higher than HUT(45°) and HUT(60°). Conclusion Cerebral perfusion pressure during mechanical CPR were similar and highest in the HUT(45° and 60°) positions whereas the peak coronary perfusion pressure was observed with HUT(30°).