Enhanced Cerebral Blood Flow and Hemodynamic Status with an Alternative Left Ventricle Chest Compression Position during Cardiopulmonary Resuscitation in Swine

INTRODUCTION: The standard chest compression (SCC) position for cardiopulmonary resuscitation (CPR) is the centre of the chest and typically central to the aortic root. An alternative left ventricle chest compression (LVCC) position may facilitate superior global blood flow. We tested the hypothesis that, consistent with improved ETCO2 (indicative of cardiac output) and blood pressure (BP), LVCC would promote greater cerebral blood flow (CBF) than SCC. METHODS: Female pigs (N=32; 35±2kg) were rotated systematically to receive either SCC (n=14) or LVCC (n=18). Transthoracic echocardiography was used to identify and externally mark: (1) the SCC position, the midline at the level of the aortic route, or (2) the LVCC position, the midpoint of the left ventricle. After 2 minutes of untreated asphyxiated cardiac arrest (CA), swine were treated with three 2-minute cycles of mechanical chest compressions (LUCAS III). ETCO2 (in-line sampling), BP (arterial catheter line), and CBF velocity (CBFv, transcranial Doppler, primary outcome) were measured during the pre-CA, untreated-CA, and CPR-treated phases. Between-group outcomes were compared using a mixed model ANOVA with significant differences considered at P<0.05 and data are presented as mean±standard deviation. RESULTS: Pre- and untreated-CA ETCO2 , BP and CBFv were similar between the SCC and LVCC groups (P>0.100). During CPR, ETCO2 (36±6 mmHg versus 24±10 mmHg; P<0.001), Mean Arterial Pressure (MAP; 49±9 mmHg versus 37±9 mmHg; P=0.002), and Mean CBFv (11±5 cm/s versus 5±2 cm/s; P<0.001) were significantly higher in the LVCC, versus SCC, group. CONCLUSION: In comparison to SCC,LVCC resulted in higher ETCO2 , MAP, and Mean CBFv values throughout CPR in a swine model of CA. NEW AND NOTEWORTHY: We provide novel evidence that compared with mechanical compressions performed over the centre of the chest, compressions performed over the left ventricle promote greater CBF during BLS CPR. Clinical validation of these results may improve survival rates and attenuate neurological deficits following CA. © FASEB.