“…4 On the other hand, vasopressin could increase mean circulatory filling pressure during the hyperdynamic phase of sepsis without affecting heart rate, resistance to venous return or arterial resistance. 5 Feldheiser et al 1 are correct that a focus on the arterial pressure neglects the vasopressor effects on the microcirculation, venous return, splanchnic perfusion, right ventricular performance and the pulmonary circulation, which together account for most of the volume of the circulatory system. Although the study by Laterre et al 6 failed to show beneficial effects of a selective V1a receptor agonist on ventilator-free and vasopressor-free days or on secondary outcome measures, the selepressin group had higher mean arterial pressure and lower norepinephrine requirement, significantly less cardiovascular dysfunction, significantly higher urine output, significantly lower net fluid balance in the first 24 h, and was significantly less likely to receive steroids than the placebo group.…”