Oximetry-detected pulsus paradoxus predicts for severity in paediatric asthma.

OBJECTIVE: To evaluate if qualitative visual detection of pulsus paradoxus (PP) on the pulse oximeter plethysmograph can predict outcomes for children with moderate to severe respiratory distress in a paediatric emergency department (ED). DESIGN: Prospective cohort study. SETTING: Paediatric ED of a tertiary paediatrics hospital in Singapore. PATIENTS: Children managed for moderate to severe wheezing in the resuscitation bay of the ED. INTERVENTIONS: Patients were assessed for the presence of PP based on visual detection of oximeter plethysmograph before and after initial inhaled bronchodilator therapy. MAIN OUTCOME MEASURES: These include the need for adjunct medications such as aminophylline or magnesium sulfate, the need for supplementary ventilation and the need for admission to the high dependency unit (HDU) or intensive care unit (ICU). RESULTS: There were 285 patients included in the study, of whom 78 (27.4%) had PP at ED presentation. There were 40 (14.0%) who had PP after initial management. Children who had PP after initial management had significantly relative risks (RR) of requiring adjunct medications (RR 12.5, 95% CI 4.0 to 38.6), need for supplementary ventilation (RR 5.6, 95% CI 1.2 to 26.5) and admission to the HDU/ICU (RR 5.6, 95% CI 3.0 to 10.4). CONCLUSION: Qualitative detection of PP on pulse oximetry can be used as a potential point-of-care tool to help in the assessment of response to initial treatment in paediatric patients with acute moderate to severe asthma exacerbations. Future studies are needed to assess and validate its role in guiding ED management of acute paediatric asthma.