Derivation and Validation of Vasoactive Inotrope Score Trajectory Groups in Critically Ill Children With Shock

Abstract

Objectives: To determine whether there are clinically relevant and reproducible Vasoactive Inotrope Score (VIS) trajectories in children with shock during the acute phase of critical illness.

Design: Retrospective, observational cohort study.

Setting: Two tertiary, academic PICUs.

Patients: Children (< 18 yr old) who required vasoactive infusions within 24 hours of admission to the PICU. Those admitted post cardiac surgery were excluded.

Interventions: None.

Measurements and main results: An hourly VIS was calculated for the first 72 hours after initiation of vasoactives. Group-based trajectory modeling (GBTM) was applied to a derivation set (75% of encounters) and compared with the trajectories in a validation set (25% of encounters) using the same variables. The primary outcome was in-hospital mortality, and the secondary outcome was multiple organ dysfunction syndrome (MODS) on day 7. A total of 1,828 patients met inclusion criteria, and 309 (16.9%) died. GBTM identified four subgroups that were reproducible in the validation set: "Mild, fast resolving shock" ( n = 853 [47%]; mortality 9%), "Moderate, slow resolving shock" ( n = 422 [23%]; mortality 15%), "Moderate, prolonged shock" ( n = 312 [17%]; mortality 21%), and "Severe, prolonged shock" ( n = 241 [13%]; mortality 40%). There was a significant difference in mortality, MODS on day 7, and suspected infection ( p < 0.001) across groups. The "Mild, fast resolving shock" and "Severe, prolonged shock" groups were identifiable within the first 24 hours. The "Moderate, slow resolving" and "Moderate, prolonged shock" groups were indistinguishable in the first 24 hours after initiation of vasoactives but differed in in-hospital mortality and MODS on day 7. Hydrocortisone administration was independently associated with poor outcomes in the "Mild, fast resolving shock" group.

Conclusions: We uncovered four distinct and reproducible VIS trajectory groups that were associated with different risk factors, response to therapy, and outcomes in children with shock. Characterizing VIS trajectory groups in the acute phase of critical illness may enable better prognostication and more targeted management.