Abstract
【Introduction】Septic shock is characterized by progressive vasodilation and increased vascular permeability. The current treatment consensus is administering noradrenaline (NA) and vasopressin (AVP) with appropriate fluids. However, the hemodynamic effects of these agents in septic shock are not fully understood. In this study, we examined the effects of NA and AVP on the cardiovascular properties constituting the circulatory equilibrium (CE) in a canine model of lipopolysaccharide (LPS) induced shock.
【Methods】In six beagle dogs under general anesthesia, we opened the chest and simultaneously measured arterial pressure (AP), right atrial pressure (RAP), left atrial pressure (LAP), and cardiac output (CO). We infused LPS (2 mg/kg) and examined the impact of 10-min infusion of NA (0.3 μg/kg/min), AVP (0.04 U/min), and NA (0.3 μg/kg/min) with AVP (0.04 U/min) on hemodynamics for 2-h after LPS.
【Results】LPS reduced AP with decreasing stressed blood volume (SBV). In LPS-induced shock, NA increased systemic vascular resistance (SVR), heart rate, left ventricular end-systolic elastance, and SBV. Meanwhile, AVP increased SVR, but not other parameters. As a result, the equilibrium point in the CE were significantly different between NA and AVP.
【Conclusion】NA increases CO with an inotropic effect and SBV augment effect compared to AVP. Understanding drug impacts through analysis of cardiovascular properties, which constitutes the CE, may contribute to the optimization of septic shock treatment.
