Abstract 16154: Head and Shoulder Elevation Improves Cerebral Perfusion Pressure During Active Compression-decompression CPR and Conventional CPR in a Porcine Cardiac Arrest Model

Abstract

Background: Chest compressions during conventional cardiopulmonary resuscitation (C-CPR) increase arterial and venous pressures simultaneously, delivering bidirectional high pressure compression waves to the brain. It is possible that this may be detrimental neurologically and could be partially overcome by elevating the head during CPR. Previous animal study work using a tilt table has shown that a 30° head up position for the entire body during CPR significantly increases cerebral blood flow and cerebral perfusion pressure (CerPP) over a period of 5 minutes. We hypothesize that elevating the head and shoulders only will increase CerPP over a prolonged period of time with two different CPR techniques. Methods: Female farm pigs were sedated, intubated, anesthetized, and placed on a table designed to elevate the head and shoulders to 30°. After 8 min of untreated ventricular fibrillation and 2 min of automated C-CPR in the supine position, pigs were randomized to head up (HUP) or supine (SUP) CPR for 20 more min. In Group A, pigs were treated after 2 min of C-CPR with automated active compression decompression (ACD) CPR at 100 cycles/min plus an impedance threshold device (ITD), randomized to HUP (n=8) or SUP (n=8). In Group B, pigs were randomized after 2 min of C-CPR to treatment with HUP (n=7) or SUP (n=7) automated C-CPR. After 22 total min of CPR, defibrillation was performed. The primary outcome of the study was the comparison of CerPP at 22 min between HUP and SUP positions within each group. Results: After 22 min of CPR, CerPP (mmHg) was 39±7 with HUP versus 14±4 with SUP CPR (p=0.013) in Group A and 3.4±2.2 with HUP versus -6.3±2.6 with SUP CPR (p = 0.014) in Group B. There was no significant difference within groups for coronary perfusion pressure (CPP) after 22 min, but CPP trended higher with HUP in Group A (32.0 ± 4.9) versus SUP (18.8 ± 4.7)(p=0.072). The CPPs in Group B were 5.8 ± 1.1 with HUP versus 3.3±1.8 with SUP CPR, p=0.26). In Group A, 6/8 pigs were resuscitated in both positions where no pigs could be resuscitated in Group B. Conclusions: The HUP position using two different CPR techniques significantly improved CerPP over a prolonged period of time. This simple maneuver has the potential to improve neurological outcomes after cardiac arrest.