S/F and ROX indices in predicting failure of high‐flow nasal cannula in children

Abstract

Background A high‐flow nasal cannula (HFNC) is a useful respiratory support for children with respiratory distress; however, it elevates the risk of belated intubation. Recently, indices based on percutaneous oxygen saturation, a fraction of inspired oxygen, and respiratory rate (RR) have been suggested for the prediction of HFNC failure. We aimed to evaluate various indices predicting HFNC failure in children who started receiving HFNC at a tertiary center for 27 months. Methods Cases of HFNC failure were classified as hypoxic respiratory failure (HRF) or non‐HRF (NHRF) depending on the cause of intubation. The ratio of percutaneous oxygen saturation to the fraction of inspired oxygen (S/F), the ratio of S/F to RR (ROX), the ratio of S/F to RR/median RR (ROX‐M), and the ratio of S/F to z‐score of RR (ROX‐Z) were calculated and compared between groups. Results Of the 152 cases, 45 (29.6%) failed to wean from the HFNC support, of which 21 (46.7%) were HRFs and 24 (53.3%) were NHRFs. The S/F and ROX‐M at 6 h and 3 h, respectively, predicted HRF well with a high area under the curve. Initial hypercapnia and low weight were good predictors for NHRF. Conclusions For the management of children with HFNC, these risk factors and indicators should be monitored to make an early decision regarding intubation.

Can the ROX index predict high‐flow nasal cannula failure in children under 2 with lower respiratory tract infection?

“…This study aimed to evaluate the effectiveness of the ROX index in Several studies, including those by Choi S.H., 15 Kim J.H. 16 in various age groups and diagnoses, have explored the potential of the ROX index and its variations as predictors of HFNC failure in pediatric patients. However, they consistently revealed limited predictive capacity, with AUC-ROC values often in the range of 0.5 to 0.6.…”

“…Several studies, including those by Choi S.H., 15 Kim J.H 16 . in various age groups and diagnoses, have explored the potential of the ROX index and its variations as predictors of HFNC failure in pediatric patients.…”

“…[8][9][10][11] Additionally, the existing studies on its use in pediatrics are limited in scope, often involving small and diverse patient samples, which complicates drawing definitive conclusions. [12][13][14][15][16][17] This study evaluates the ROX index's accuracy in predicting the success or failure of HFNC therapy in children under 2 years of age with ARF from lower respiratory tract infections (LRTI).…”

ROX index as a predictor of failure of high-flow nasal cannula in infants with bronchiolitis

“…During the course of our study, 3 studies were published using the ROX for the pediatric population 16 , 17 , 28 . Yildizdas et al 28 and Kim et al 16 were the first authors to publish the ROX for the pediatric population; however, these studies included patients aged 0–18 years, and due to the great variability of RR in this age range, it was necessary to modulate RR with the Z score, thus changing the index value. Yildizdas et al showed that the p-ROXI (pediatric respiratory rate-oxygenation index) can be used as a good marker for predicting the risk of HFNC failure in patients with acute respiratory failure.…”

“…In the pediatric population, Yildizdas et al defined pediatric ROX to identify HFNC failure in children with different etiologies of respiratory diseases; however, they used the respiratory z score, which is relatively complicated to apply at the bedside. Subsequently, two other studies used the ROX index in the pediatric population, but only one of them was specific to infants with bronchiolitis 16 , 17 . Our hypothesis is that the ROX index is a promising predictor of the need to escalate ventilatory support from HFNC to NIV/IMV.…”