Increasing support by nasal high flow acutely modifies the ROX index in hypoxemic patients: A physiologic study

J Crit Care. 2019 Oct:53:183-185. doi: 10.1016/j.jcrc.2019.06.020. Epub 2019 Jun 21.

Abstract

The ROX (Respiratory rate-OXygenation) index is an early predictor of failure of nasal high flow (NHF), with lower values indicating higher risk of intubation. We measured the ROX index at set flow rate of 30 and 60 l/min in 57 hypoxemic patients on NHF. Patients with increased ROX index values at higher flow (n = 40) showed worse baseline oxygenation, higher respiratory rate and lower ROX index in comparison to patients with unchanged or decreased ROX index values (n = 17). The ROX index variation between flows was correlated with the change in end expiratory lung volume. Set flow rate during NHF might impact the ROX index value.

Keywords: Acute hypoxemic respiratory failure; Electrical impedance tomography; Monitoring; Nasal high flow.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Blood Gas Analysis
  • Cross-Over Studies
  • Female
  • Humans
  • Hypoxia / physiopathology*
  • Hypoxia / prevention & control*
  • Male
  • Middle Aged
  • Noninvasive Ventilation / methods*
  • Nose
  • Oxygen Inhalation Therapy
  • Prospective Studies
  • Respiratory Insufficiency / etiology
  • Respiratory Insufficiency / physiopathology*
  • Respiratory Insufficiency / therapy*
  • Respiratory Rate