Compared to catecholamine infusions which are routinely titrated, there’s a polarized practice with vasopressin – those who titrate and those who don’t. As a resident, I worked with intensivists who strongly believed in “0.04 U/min or nothing at all.” They believed that similar to electrolyte repletion, vasopressin at this fixed dose (used in many studies) addressed a deficiency in the critically ill population beyond which there was no additional benefit. Torbic et al. showed that even adjusting vasopressin for weight/BMI in septic shock did not change MAP or concurrent catecholamine infusion doses. So maybe a fixed dose is enough?
Transitioning to a different medical center, I saw more cardiac anesthesiologists and intensivists titrating vasopressin anywhere from 0.01 to 0.10 units/minute. There are plenty of vasopressin titration protocols one can look up online and which have also been used in studies to achieve a mean arterial pressure goal. I’ve also bolused vasopressin after coming off cardiopulmonary bypass and in trauma with associated acidosis with very good results. But are higher doses safe?
I can’t find any studies that directly address the question of fixed dose versus titrated vasopressin. Intuitively, one would think that a higher dose (0.10 U/min) would activate more V1 receptors causing more vasoconstriction. But could this, in turn, cause more ill effects like digital ischemia?