Olver, T. Dylan2021-08-122023-08-122021-072021-08-12July 2021https://hdl.handle.net/10388/13518Introduction: Cardiopulmonary resuscitation (CPR) is a standard treatment for cardiac arrest. A major goal of CPR is to maintain blood flow to the brain. Compared with standard chest compression (SCC), performed in the centre of the chest, left ventricle chest compression (LVCC) has been shown to improve end-tidal CO2 (ETCO2) and arterial blood pressure (BP). Using a porcine model, we hypothesized that, consistent with improved ETCO2 and BP, LVCC will promote greater cerebral blood flow (CBF) than SCC. Methods: Female pigs (N=32; 35±2 kg) were systematically assigned to receive either SCC (n=14) or LVCC (n=18) following 2 minutes of untreated asphyxiated cardiac arrest. Transthoracic echocardiography was used to identify and externally mark the midline at the level of the aortic root (SCC) or the intersection of the long and short axis of the left ventricle (LVCC) for mechanical chest compressions (LUCAS III). ETCO2, BP (arterial catheter line), and CBF velocity (CBFv; transcranial Doppler) were measured pre-cardiac arrest, during cardiac arrest, and through three rounds of basic life support (BLS) CPR. Data were analyzed using a mixed model RM ANOVA. Results: ETCO2, BP, and CBFv were similar between the SCC and LVCC groups at baseline (P≥0.224) and during untreated cardiac arrest (P≥0.216). ETCO2 (SCC=24±10 versus LVCC=36±6 mmHg; P<0.001) was significantly elevated throughout CPR in the LVCC versus SCC group. Systolic BP (SCC=45±10 versus LVCC=61±10 mmHg; P<0.001), Diastolic BP (SCC=33±10 versus LVCC=41±8 mmHg; P<0.001), and Mean BP (SCC=33±9 versus LVCC=49±9 mmHg; P<0.001) were significantly elevated throughout CPR in the LVCC versus SCC group. Peak CBFv (SCC=19±6 versus LVCC=37±6 cm/s; P<0.001) and Mean CBFv (SCC=5±2 versus LVCC=11±5 cm/s; P<0.001), but not Minimum CBFv (P≥0.249), were significantly elevated throughout CPR in the LVCC versus SCC group. Conclusion: LVCC improved ETCO2, BP, and CBFv throughout BLS in a porcine model of cardiac arrest. New and Noteworthy: This is the first study to provide evidence that compared with mechanical compressions performed over the middle 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 cardiac arrest.application/pdfCardiac ArrestCardiopulmonary ResuscitationCPRCerebral Blood FlowThesis2021-08-12