ROX index as predictor of high flow nasal cannula therapy success in acute respiratory failure due to SARS-CoV-2

• Published in: Respiratory medicine 2021-11, Vol.189, p.106638-106638, Article 106638
• Main Authors: Ferrer, Santos, Sancho, Jesús, Bocigas, Irene, Bures, Enric, Mora, Heidi, Monclou, Erik, Mulet, Alba, Quezada, Antonio, Royo, Pablo, Signes-Costa, Jaime
• Format: Article
• Language: English
• Subjects: COVID-19; COVID-19 - complications; Female; High flow nasal cannula; Humans; Male; Mechanical ventilation; Middle Aged; Noninvasive Ventilation; Oximetry; Oxygen - metabolism; Oxygen Inhalation Therapy; Prospective Studies; Respiratory failure; Respiratory Insufficiency - therapy; Respiratory Rate
• ISSN: 0954-6111; 1532-3064
• DOI: 10.1016/j.rmed.2021.106638

High-Flow Nasal Cannula (HFNC) therapy is useful treatment in patients with acute respiratory failure (ARF). The ROX index (ratio of pulse oximetry/fraction of inspired oxygen to respiratory rate) has been evaluated to predict success of HFNC in patients with pneumonia. The aim of this study was to determine whether the ROX Index could predict HFNC therapy success in patients with ARF due to SARS-CoV-2 pneumonia. An observational, prospective study was performed including patients admitted with ARF secondary to SARS-CoV-2 pneumonia who met criteria for HFNC therapy initiation. Demographic, radiological, laboratory and clinical course data were collected. The ROX index was calculated at 1 h, 6 h, 12 h and 24 h after starting HFNC. In total 85 patients were included (age, 64.51 + 11.78 years; male, 69.4%). HFNC failed in 47 (55.3%) patients, of whom 45 (97.8%) were initially managed with noninvasive ventilation (NIV). ROX index at 24 h was the best predictor of HFNC success (AUC 0.826, 95%CI 0.593–1.00, p = 0.015) with a cut-off point of 5.35 (S 0.91, Sp 0.79, PPV 0.92, NPP 0.79). In multivariate logistic regression analysis ROX index at 24 h proved the best predictor of HFNC success. ROX index at 24 h with a cut-off point of 5.35 predicts HFNC success in patients with SARS-Cov-2-induced ARF. •ROX index is the most accurate predictor for HFNC therapy success in acute respiratory failure due to COVID-19.•24h ROX index (cut-off point 5.35) predicts HFNC therapy success in patients with SARS-Cov-2- and acute respiratory failure.•HFNC and noninvasive ventilation as rescue therapy avoid endotracheal intubation or death in 59% of patients with COVID-19.