Identifying a Refractory Shock Phenotype in Pediatric Sepsis Using a Vasoactive-Adjusted Shock Index.

Area of Science:

• Pediatric critical care medicine
• Cardiovascular physiology
• Sepsis research

Background:

• Refractory septic shock (RSS) in children is a severe condition with high mortality.
• Existing hemodynamic indices may not fully capture the complexity of pediatric septic shock.
• The role of vasoactive medications complicates the assessment of hemodynamic status.

Purpose of the Study:

• To develop a novel cardiovascular index (VASI) incorporating hemodynamic status and vasoactive medication use.
• To identify pediatric patients with refractory septic shock (RSS) using early VASI trends.
• To evaluate treatment effect heterogeneity in RSS versus non-RSS patients.

Main Methods:

• Developed the Vasoactive-Adjusted Shock Index (VASI) using heart rate and systolic pressure, adjusted for vasoactive drugs.
• Applied group-based trajectory modeling and K-means with dynamic time warping to VASI trends.
• Analyzed heterogeneity of treatment effect using inverse-probability weighted logistic regression.

Main Results:

• The VASI index effectively predicted poor outcomes in pediatric sepsis patients.
• Trajectory analysis identified a distinct RSS phenotype characterized by persistently high VASI.
• Hydrocortisone use on day one was linked to reduced mortality in RSS patients, unlike fluid or albumin.

Conclusions:

• The early VASI trajectory is a valuable tool for identifying pediatric RSS phenotypes.
• This index has prognostic relevance and aids in understanding treatment responses.
• Integrating VASI into early risk assessment can improve management of high-risk pediatric sepsis.