The Study of ROX Index to Predict Clinical Outcomes in COVID-19 Patients with Hypoxemic Respiratory Failure Treated with High Flow Nasal Cannula

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Kritsada Chumvanichaya
Weeraroj Nithithariyasophon
Sorapop Phakdewong
Kanoklekha Suwannapong


            This retrospective cross-sectional observational study aimed to determine the ROX index to predict clinical outcomes (success and failure) after receiving HFNC treatment at 2, 6, 12, and 24 hours. We collected data using medical records of 113 COVID-19 patients with acute hypoxemic respiratory failure who received HFNC treatment and were admitted in Somdech Phra Pinklao hospital between 1st February 2021 to 31st July 2021. Data were analyzed using descriptive statistic, receiver operating characteristic (ROC), and Areas under the ROC curve (AUROC). The result showed that 51.3% of sample improved oxygenation and were successfully withdrawn from HFNC. The ROX index at 6, 12, and 24 hours of HFNC initiation were closely related to the prognosis. The ROX index after 6h of HFNC initiation (AUROC, 0.549) had correlated with HFNC failure. The healthcare provider can use this as a guideline for HFNC therapy termination in patients with COVID-19 infection related acute hypoxic respiratory failure.


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