ROX index as a good predictor of high flow nasal cannula failure in COVID-19 patients with acute hypoxemic respiratory failure: A systematic review and meta-analysis

Abstract

Purpose Prediction of high flow nasal cannula (HFNC) failure in COVID-19 patients with acute hypoxemic respiratory failure (AHRF) may improve clinical management and stratification of patients for optimal treatment. We performed a systematic review and meta-analysis to determine performance of ROX index as a predictor of HFNC failure. Materials and methods Systematic search was performed in electronic databases (PubMed, Google Scholar, Web of Science and Cochrane Library) for articles published till 15 June 2021 investigating ROX index as a predictor for HFNC failure. Quality In Prognosis Studies (QUIPS) tool was used to analyze risk of bias for prognostic factors, by two independent authors. Results Eight retrospective or prospective cohort studies involving 1301 patients showed a good discriminatory value, summary area under the curve (sAUC) 0.81 (95% CI, 0.77–0.84) with sensitivity of 0.70 (95% CI, 0.59–0.80) and specificity of 0.79 (95% CI, 0.67–0.88) for predicting HNFC failure. The positive and negative likelihood ratio were 3.0 (95% CI, 2.2–5.3) and 0.37 (95% CI, 0.28–0.50) respectively, and was strongly associated with a promising predictive accuracy (Diagnostic odds ratio (DOR) 9, 95% CI, 5–16). Conclusion This meta-analysis suggests ROX index has good discriminating power for prediction of HFNC failure in COVID-19 patients with AHRF.

Respiratory rate index utility in high-flow nasal cannula oxygen therapy in COVID-19 pneumonia; what are the perfect boundaries?

“…We have read with interest the article by Takeshita et al [ 1 ] on the use of the respiratory rate index as a predictor of high-flow nasal cannula (HFNC) treatment efficacy in patients with coronavirus disease 2019 (COVID-19). This study confirms the complexity of the prediction of HFNC failure [ 2 ]. However, there are some issues, in our opinion, that need to be clarified.…”

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

“…Suliman et al, 30 in a prospective study that included 69 patients with moderate and severe COVID found that ROX index measured on the first day of admission was independent predictor factor of intubation with a cut-off point <25.26; a very high cut-off point is striking in this study, 30 fact for which it was not included in a recent meta-analysis. 32 Finally, Gianstefani et al, 31 enrolled 554 patients admitted to emergency department with SARS-Cov-2 infection and found that ROX index at admission was associated with hospitalization and 30 days mortality; again, the cut-off points of this study were very high (25.7 and 22.3 respectively), included patients with mild upper respiratory tract illness and pneumonia and the authors do not mention the use of HFNC.…”

Early Measurement of ROX Index in Intermediary Care Unit Is Associated with Mortality in Intubated COVID-19 Patients: A Retrospective Study

“…Before ICU admission, the median ROX H0-H8 value under non-invasive procedures was 6.26 [5.04-8.18]. After ICU admission, the median (IQR) duration of invasive mechanical ventilation was 12 (7-21) days, with a median (IQR) ICU length of stay of 13.5 (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23) days, a median (IQR) IMCU length of stay of 4 (2-7) days, and a median (IQR) total hospital stay of 27 days. ICU mortality was 40% (32/82).…”

“…For this purpose, available SpO2, respiratory rate, and FiO2 data with their related time records were extracted for each patient from the electronic patient system to an excel sheet. The ROX index was calculated according to the following formula: ([SpO2/FIO2]/RR) [12]. Only values under HFNO were selected and the median of these values was calculated (Excel ® ) for this period of time.…”

“…The ROX index is defined as the ratio of oxygen saturation (SpO2), as measured by pulse oximetry/FIO2, to respiratory rate (RR), and was described by Roca et al as a predictive factor of mechanical ventilation in patients under HFNO, with a value lower than 4.88 measured 12 h after admission being an indicator that a patient may be at higher risk of orotracheal intubation (OTI) [11]. In a recent systematic review and metaanalysis of eight observational studies, Prakash et al showed that the ROX index might be an interesting predictor of HFNO failure in COVID-19 patients with acute hypoxemic respiratory failure [12]. The pooled sensitivity and specificity were 0.7 (95% CI, 0.59-0.8) and 0.79 (95% CI, 0.67-0.88), respectively.…”