Falling pulse pressure followed vasopressin initiation in children with worsening septic shock

Researchers reviewed minute-by-minute hemodynamic data from children younger than 18 years treated with vasopressin for septic shock at a tertiary pediatric intensive care unit in Australia between 2020 and 2023. The analysis compared patterns during the first hour after vasopressin initiation according to whether shock progressed in the next five hours. Progression, defined using echocardiography, lactate and extracorporeal support, occurred in eight of the 30 children; median age was 9 years.

Children with subsequent progression had a higher median Phoenix score than those without progression (7 vs. 6; p=0.01). Starting vasopressin doses did not differ significantly between groups. In the progression group, pulse pressure continued to decrease after vasopressin was started, despite rising systolic and diastolic blood pressures. It increased marginally in children without progression; the median pulse-pressure difference between groups during observation was 7.5 mm Hg.

The authors describe the findings as hypothesis-generating. The small, retrospective, single-center study identifies an association, not a validated predictor, and does not establish that pulse-pressure changes should guide treatment. Further studies are needed to determine whether this pattern can reliably identify children at risk of worsening shock.