Tilting for perfusion: Head-up position during cardiopulmonary resuscitation improves brain flow in a porcine model of cardiac arrest

Introduction: Cerebral perfusion is compromised during cardiopulmonary resuscitation (CPR). We hypothesized that beneficial effects of gravity on the venous circulation during CPR performed in the head-up tilt (HUT) position would improve cerebral perfusion compared with supine or head-down tilt (HDT). Methods: Twenty-two pigs were sedated, intubated, anesthetized, paralyzed and placed on a tilt table. After 6 min of untreated ventricular fibrillation (VF) CPR was performed on 14 pigs for 3 min with an automated CPR device called LUCAS (L) plus an impedance threshold device (ITD), followed by 5 min of L-CPR + ITD at 0 degrees supine, 5 min at 30 degrees HUT, and then 5 min at 30 degrees HDT. Microspheres were used to measure organ blood flow in 8 pigs. L-CPR + ITD was performed on 8 additional pigs at 0 degrees, 20 degrees, 30 degrees, 40 degrees, and 50 degrees HUT. Results: Coronary perfusion pressure was 19 +/- 2 mmHg at 0 degrees vs. 30 +/- 3 at 30 degrees HUT (p < 0.001) and 10 +/- 3 at 30 degrees HDT (p < 0.001). Cerebral perfusion pressure was 19 perpendicular to 3 at 0 degrees vs. 35 perpendicular to 3 at 30 degrees HUT (p < 0.001) and 4 +/- 4 at 30 degrees HDT (p < 0.001). Brain-blood flow was 0.19 +/- 0.04 ml min(-1) g(-1) at 0 degrees vs. 0.27 +/- 0.04 at 30 degrees. HUT (p = 0.01) and 0.14 +/- 0.06 at 30 degrees. HDT (p = 0.16). Heart blood flow was not significantly different between interventions. With 0, 10, 20, 30, 40 and 50 degrees HUT, ICP values were 21 +/- 2, 16 +/- 2, 10 +/- 2, 5 +/- 2, 0 +/- 2, -5 +/- 2 respectively, (p < 0.001), CerPP increased linearly (p = 0.001), and CPP remained constant. Conclusion: During CPR, HDT decreased brain flow whereas HUT significantly lowered ICP and improved cerebral perfusion. Further studies are warranted to explore this new resuscitation concept. (C) 2014 Elsevier Ireland Ltd. All rights reserved.