Introduction: Hemodynamic management of patients with hypotension and reduced left ventricular ejection fraction (LVEF) can be challenging. Mixed shock states such as sepsis can also introduce an vasodilation for these patients. Pulmonary artery catheters (PAC) may be helpful in mixed shock states to quantify the relative benefits of therapies by providing additional hemodynamic parameters compared to alternative monitoring. Vasopressin (AVP) is an adjunctive vasopressor agent commonly used in septic and mixed shock, with hemodynamic response documented to be around 50% of patients. This study seeks to compare the effects of AVP initiation in patients with reduced LVEF that did and did not have sepsis. Methods: This study included patients admitted to either a cardiac or cardiothoracic intensive care unit (ICU) with a measured LVEF under 30% that were receiving PAC monitoring while initiated on an AVP infusion. Hemodynamic parameters were assessed prior to and following the initiation of AVP. Patients were classified as being a hemodynamic responder to AVP if they had a mean arterial pressure ≥ 65 and a decrease in vasopressor dose at 6 hours following AVP initiation. Results: This analysis included 53 patients, 22 of which had sepsis and 31 which did not. Median vasopressin rate was 0.03 units/minute in both groups. There were no differences in baseline age, weight, or systemic vascular resistance. Patients with sepsis were had similar sequential organ failure assessment (SOFA) scores (13 vs. 10, p=0.08), and similar incidence of mechanical ventilation (81% vs. 93.5%, p=0.22). Hemodynamic response to AVP was found in 39.6% (21/53) of patients. Patients with sepsis were more likely to demonstrate hemodynamic response compared to patients without sepsis (54.5% vs. 29%, p=0.08), though this difference failed to reach statistical significance. Patients with sepsis were not more likely to see a positive response in systemic vascular resistance (68% vs. 58%, p=0.65) and cardiac index (50% vs. 38.7%, p=0.57). Conclusions: Addition of AVP may be more likely to improve hemodynamics if patients with reduced LVEF have sepsis compared to when they do not. Response to AVP initiation remains unpredictable. Alternate definitions of hemodynamic response may be useful to better quantify effects of clinical interventions.
Farina et al. (Sun,) studied this question.