High Versus Low Blood-Pressure Target in Experimental Ischemic Prolonged Cardiac Arrest Treated with Extra Corporeal Life Support

BACKGROUND:There is currently no recommendation for the mean arterial pressure target in the particular setting of Extracorporeal Cardiopulmonary Resuscitation (ECPR) in the first hours following cardiogenic shock complicated by cardiac arrest. This study aimed to assess the effects of two different levels of mean arterial pressure on macrocirculatory, microcirculatory, and metabolic functions. DESIGN:Randomized animal study. SETTING:University research laboratory. INTERVENTION:Ventricular fibrillation was induced in 14 male pigs by surgical ligature of the interventricular coronary artery. After 20 min of cardiopulmonary resuscitation, Extracorporeal Life Support (ECLS) was initiated to restore circulatory flow. Thereafter, animals were randomly allocated to a high mean arterial pressure group (High-MAP, 80–85 mm Hg) or to a standard mean arterial pressure group (Standard-MAP, 65–70 mm Hg). Assessments conducted at baseline, immediately following and 6 h after ECLS initiation were focused on lactate evolution, amount of infused fluid, and microcirculatory parameters. RESULTS:There was no significant difference between the two groups at the time of ECLS initiation and at 6 h with regard to lactate levels (High-MAP vs. Standard-MAP8.8 [6.7–12.9] vs. 9.6 [9.1–9.8] mmol·l, P = 0.779 and 8.9 [4.3–11.1] vs. 3.3 [2.4–11] mmol·l, P = 0.603). Infused fluid volume did not significantly differ between the two groups (4,000 [3,500–12,000] vs. 5,000 [2,500–18,000] mL, P = 0.977). There was also no significant difference between the two groups regarding renal and liver functions, and sublingual capillary microvascular flow index assessed by Sidestream Dark Field imaging. CONCLUSION:Compared with a standard mean arterial pressure regimen, targeting a high mean arterial pressure in the first hours of an experimental ECPR model did not result in any hemodynamic improvement nor in a decrease in the amount of infused fluid.