PLoS ONE (Jan 2022)

Expanding the utility of the ROX index among patients with acute hypoxemic respiratory failure

  • Andrew Li,
  • Matthew Edward Cove,
  • Jason Phua,
  • Ser Hon Puah,
  • Vicky Ng,
  • Amit Kansal,
  • Qiao Li Tan,
  • Juliet Tolentino Sahagun,
  • Juvel Taculod,
  • Addy Yong-Hui Tan,
  • Amartya Mukhopadhyay,
  • Chee Kiang Tay,
  • Kollengode Ramanathan,
  • Yew Woon Chia,
  • Duu Wen Sewa,
  • Meiying Chew,
  • Sennen J. W. Lew,
  • Shirley Goh,
  • Shekhar Dhanvijay,
  • Jonathan Jit-Ern Tan,
  • Kay Choong See FCCP,
  • on behalf of SICM-NICER Group

Journal volume & issue
Vol. 17, no. 4

Abstract

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Background Delaying intubation in patients who fail high-flow nasal cannula (HFNC) may result in increased mortality. The ROX index has been validated to predict HFNC failure among pneumonia patients with acute hypoxemic respiratory failure (AHRF), but little information is available for non-pneumonia causes. In this study, we validate the ROX index among AHRF patients due to both pneumonia or non-pneumonia causes, focusing on early prediction. Methods This was a retrospective observational study in eight Singapore intensive care units from 1 January 2015 to 30 September 2017. All patients >18 years who were treated with HFNC for AHRF were eligible and recruited. Clinical parameters and arterial blood gas values at HFNC initiation and one hour were recorded. HFNC failure was defined as requiring intubation post-HFNC initiation. Results HFNC was used in 483 patients with 185 (38.3%) failing HFNC. Among pneumonia patients, the ROX index was most discriminatory in pneumonia patients one hour after HFNC initiation [AUC 0.71 (95% CI 0.64–0.79)], with a threshold value of Conclusion The ROX index demonstrated moderate discriminatory power among patients with either pneumonia or non-pneumonia-related AHRF at HFNC initiation and one hour later.