Beneficial Effects of Norepinephrine Alone on Cardiovascular Function and Tissue Oxygenation in a Pig Model of Cardiogenic Shock

International audienceINTRODUCTION:The present study was developed to investigate the effects of norepinephrine alone on hemodynamics and intrinsic cardiac function in a pig model of cardiogenic shock mimicking the clinical setting.METHODS:Cardiogenic shock was induced by 1-h ligation of the left anterior descending (LAD) artery followed by reperfusion. Pigs were monitored with a Swan-Ganz catheter, a transpulmonary thermodilution catheter, and a conductance catheter placed in the left ventricle for pressure-loop measurements. Measurements were performed before LAD occlusion, 1 h after LAD occlusion, and 4 h after myocardial reperfusion.RESULTS:Myocardial infarction and reperfusion was followed by cardiogenic shock characterized by a significant increase in heart rate and significant decreases in mean arterial pressure (MAP), mixed venous oxygen saturation (SVO2), left ventricular end-diastolic pressure (LVEDP), prerecruitable stroke work (PRSW), and cardiac power index (CPI). Lactate levels were significantly increased. The systemic vascular resistance index (SVRI) and global end-diastolic volume index (GEDVI) remained unchanged. When compared with the control group (n = 6), norepinephrine infusion (n = 6) was associated with no changes in heart rate, a significant increase in MAP, SVO2, left ventricular ejection fraction, pressure development during isovolumic contraction, SVRI, and CPI and a decrease in lactate level. Cardiac index tended to increase (P = 0.059), whereas PRSW did not change in the norepinephrine group. LVEDP and GEDVI remained unchanged.CONCLUSIONS:Norepinephrine alone is able to improve hemodynamics, cardiac function, and tissue oxygenation in a pig model of ischemic cardiogenic shock

Moderate Hypothermia Improves Cardiac and Vascular Function in a Pig Model of Ischemic Cardiogenic Shock Treated With Veno-Arterial ECMO

International audienceCardiogenic shock (CS) patients treated with extracorporeal membrane oxygenation (ECMO) have severe cardiac failure, associated with ischemia-reperfusion. The use of moderate hypothermia during ischemia-reperfusion syndrome is supported by experimental data. We therefore studied the effects of moderate hypothermia on cardiac and vascular function in pig ischemic CS treated with veno-arterial extracorporeal membrane oxygenation (VA-ECMO). CS was induced in 12 anesthetized pigs by coronary ligation. After 1 h of CS, VA-ECMO was initiated and pigs were randomized to normothermia (38°C) or moderate hypothermia (34°C) during 8 h. Intrinsic cardiac function was measured using a left ventricular conductance catheter. At the end of the experiment, tissues were harvested for Western blotting. ECMO associated with norepinephrine infusion and volume resuscitation increased mean arterial pressure, mixed venous oxygen saturation as well as carotid, renal, and coronary blood flow without any differences between normothermia and hypothermia. Hypothermia was associated with less fluid and less norepinephrine infusion, lower lactate level, and higher urinary output. Vascular reactivity was superior in hypothermia comparatively to normothermia as expressed using norepinephrine dose-response curves. Pressure development during isovolumic contraction, left ventricular ejection fraction, and prerecruitable stroke work index were higher in the hypothermia group. There were no differences between normothermia and hypothermia with regard to carotid and mesenteric protein expression for iNOs, eNOS, and phospho AKt/AKt measured at the end of the experimentation. The incidence of surgical bleeding and coagulation disorders was the same in both groups. In conclusion, moderate and rapid hypothermia improves hemodynamics and cardiac and vascular function in a pig model of ischemic CS treated with ECMO