Objectives: To describe the hemodynamic patterns associated with starting vasopressin in children with septic shock and to compare the early patterns based on subsequent progression of shock. Design: Retrospective cohort (2020–2023) study. Setting: Single-center, tertiary PICU in Australia. Patients: Children younger than 18 years with septic shock. Interventions: None. Measurements and Main Results: Hemodynamic variables collected at 1-minute intervals during a 1-hour observation period after starting vasopressin infusion were reviewed and collated according to whether shock subsequently progressed in the following 5 hours. In a cohort of 30 children (median age, 9 yr [interquartile range, 2–14 yr]), eight had shock progression, which was defined by echocardiography, lactate, and use of extracorporeal support. Cases with subsequent shock progression, as opposedto not, had an associated higher Phoenix score (7 [7–8] vs. 6 [5–6]; p = 0.01). The vasopressin starting dose in the shock vs. nonshock progression groups was 0.03 U/kg/hr (0.02–0.06 U/kg/hr) vs. 0.02 U/kg/hr (0.02–0.04 U/kg/hr; p = 0.72). We failed to find an association between ventricular dysfunction at baseline and the shock progression group vs. no shock progression (4/6 vs. 7/18; mean difference, 28%; 95% CI, –16% to 71%; p = 0.36). In the shock progression group, earlier pulse pressure continued on a decreasing trajectory following vasopressin initiation, despite increasing systolic and diastolic blood pressures. In those without shock progression, pulse pressure increased marginally. The difference between groups in the median pulse pressures during the observation period was 7.5 mm Hg. Conclusions: In this hypothesis-generating, retrospective study of children with septic shock treated with vasopressin, subsequent shock progression was associated with early decreasing pulse pressure. Further studies are needed to test whether early changes in pulse pressure after starting vasopressin can be used as a potential marker of subsequent shock progression.
