Comparison of respiratory rate oxygenation (ROX) and pediatric respiratory rate oxygenation (PROX) indices for predicting high-flow nasal cannula failure in children: A single-centre prospective observational study
Year: 2026
Type: article
Study design: Observational Study
Abstract: Background: High-flow nasal cannula (HFNC) is increasingly used to manage pediatric respiratory distress, but delayed recognition of HFNC failure can worsen outcomes. The respiratory rate-oxygenation (ROX) index predicts HFNC response but is limited by age-related variability in respiratory rate. The pediatric respiratory rate-oxygenation (PROX) index standardizes respiratory rate and may improve early prediction. This study aimed to compare the diagnostic accuracy of ROX and PROX for predicting HFNC failure in children. Subjects and Methods: This prospective observational study included children aged 1 month–18 years who were initiated on HFNC. ROX and PROX were calculated at initiation, 2 h, and 6 h. HFNC failure was defined as escalation of respiratory support within 48 h. Discrimination was assessed by receiver operating characteristic analysis; optimal cutoffs were derived using the Youden index. Results: Ninety children were enrolled; 19 (21.1%) required escalation. Both indices differed significantly between failure and success groups at all-time points ( P < 0.001). At initiation, PROX showed superior discrimination (area under the curve [AUC]: 0.852) versus ROX (AUC: 0.725). At 2 h, PROX outperformed ROX (AUC: 0.971 vs. 0.848), with higher specificity (91.5%) and accuracy (90.8%). By 6 h, both indices demonstrated excellent predictive performance. Conclusions: Both ROX and PROX predict HFNC failure in children. PROX provides superior early diagnostic accuracy, supporting its use for early bedside risk stratification and timely escalation of respiratory support.
Authors: Sana Gupta, Nitika Agrawal, Ashish Simalti
Institution: Swami Rama Himalayan University
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W7202397969