The value of ROX index in predicting the outcome of high flow nasal cannula: a systematic review and meta-analysis

Abstract

Background High flow nasal cannula (HFNC) therapy is widely employed in acute hypoxemic respiratory failure (AHRF) patients. However, the techniques for predicting HFNC outcome remain scarce. Methods PubMed, EMBASE, and Cochrane Library were searched until April 20, 2021. We included the studies that evaluated the potential predictive value of ROX (respiratory rate-oxygenation) index for HFNC outcome. This meta-analysis determined sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic score, diagnostic odds ratio (DOR), and pooled area under the summary receiver operating characteristic (SROC) curve. Results We assessed nine studies with 1933 patients, of which 745 patients experienced HFNC failure. This meta-analysis found that sensitivity, specificity, PLR, NLR, diagnostic score, and DOR of ROX index in predicting HFNC failure were 0.67 (95% CI 0.57–0.76), 0.72 (95% CI 0.65–0.78), 2.4 (95% CI 2.0–2.8), 0.46 (95% CI 0.37–0.58), 1.65(95% CI 1.37–1.93), and 5.0 (95% CI 4.0–7.0), respectively. In addition, SROC was 0.75 (95% CI 0.71–0.79). Besides, our subgroup analyses revealed that ROX index had higher sensitivity and specificity for predicting HFNC failure in COVID-19 patients, use the cut-off value > 5, and the acquisition time of other times after receiving HFNC had a greater sensitivity and specificity when compared to 6 h. Conclusions This study demonstrated that ROX index could function as a novel potential marker to identify patients with a higher risk of HFNC failure. However, the prediction efficiency was moderate, and additional research is required to determine the optimal cut-off value and propel acquisition time of ROX index in the future. PROSPERO registration number: CRD42021240607.

Prediction of noninvasive ventilation failure using the ROX index in patients with de novo acute respiratory failure

“…The index has also been used to predict HFNC failure in patients with COVID-19 pneumonia [ 13 , 14 ]. Because measurement of the ROX index is feasible, effective, and reproducible, it is widely used to predict HFNC failure [ 15 , 16 ]. To the best of our knowledge, the value of the prediction of NIV failure obtained using the ROX index is unclear.…”

Greater In-Hospital Care and Early Rehabilitation Needs in People with COVID-19 Compared with Those without COVID-19

“…Approximately 15% of symptomatic COVID-19 cases develop severe disease requiring oxygen support [16]. Simple bedside markers of respiratory compromise in COVID-19 can predict critical care needs and mortality [17][18][19]. Those hospitalised with severe COVID-19 often have a prolonged length of stay (LOS) and may require long periods of mechanical ventilation; thus, they are at high risk for developing ICU-AW [20][21][22][23].…”

The ROX index: “Propelled” by high-flow nasal cannula therapy during the COVID-19 pandemic into greater applicability in respiratory support

“…The ROX index has been closely used in conjunction with the HFNC, serving as a guiding parameter to help monitor this therapy’s success or failure. Since the start of the COVID-19 pandemic, there has been a number of studies corroborating the ROX index as a valuable predictor of the success or failure of the HFNC therapy among COVID-19 patients [ 18 ], as well as non–COVID-19 patients [ 19 ]. Its predictive validity in detecting respiratory-related adverse events has surpassed other instruments, such as the National Early Warning Score, in COVID-19 patients [ 20 ], partly due to the use of FiO 2 as a continuous variable.…”

“…Although an ideal cut-off value for therapy success has not been reached, systematic reviews have provided a narrower range of values with adequate predictive capacity for successful HFNC weaning. Junhai et al [ 19 ] have found acceptable specificity (0.72 (95% CI 0.65–0.78)) but low sensitivity (0.67 (95% CI 0.57–0.76)). In a subgroup analysis of COVID-19 patients only, the predictive value was moderate (pooled sensitivity and specificity of 0.71 (95% CI 0.56–0.82) and 0.73 (95% CI 0.63–0.81), respectively), and a cut-off value of > 5 in predicting HFNC failure was reported (sensitivity and specificity 0.59 (95% CI 0.54–0.65) and 0.83 (95% CI 0.79–0.86), respectively).…”