Pleth Variability Index to Assess Course of Illness in Children with Asthma

Background: Status asthmaticus (SA) is a common reason for admission to the pediatric emergency department (ED). Assessing asthma severity efficiently in the ED can be challenging for clinicians. Adjunctive tools for the clinician have demonstrated inconsistent results. Studies have shown that pulsus paradoxus (PP) correlates with asthma severity. Pleth Variability Index (PVI) is a surrogate measure of PP. Objective: We investigated whether PVI at triage correlates with disposition from the ED. Methods: We recruited children aged 2–18 years old who presented to the pediatric ED of a tertiary care children's hospital with SA. PVI, Respiratory Severity Score, and vital signs were documented at triage and 2 hours into each patient's ED stay. PVI was measured using the Masimo Radical-7^® monitor (Masimo Corp., Irvine, CA). Results: Thirty-eight patients were recruited. Twenty-seven patients were discharged home, 10 patients were admitted to the general pediatrics floor and 1 patient was admitted to the intensive care unit. PVI values at triage did not correlate with disposition from the ED (p = 0.63). Additionally, when trending the change in PVI after 2 hours of therapy in the ED, no statistically significant patterns were demonstrated. Conclusions: Our study did not demonstrate a correlation between PVI and clinical course for asthmatics. PVI may be more clinically relevant in sicker children. Furthermore, it is possible that continuous monitoring of PVI may demonstrate more unique trends in relation to asthma severity versus single values of PVI. Additional studies are necessary to help clarify the relationship between PVI and the clinical course of children with SA.