High-flow nasal cannula for Acute Respiratory Distress Syndrome (ARDS) due to COVID-19

Abstract

Background: High-flow nasal cannula oxygen therapy (HFNC) has been shown to be a useful therapy in the treatment of patients with Acute Respiratory Distress Syndrome (ARDS), but its efficacy is still unknown in patients with COVID-19. Our objective is to describe its utility as therapy for the treatment of ARDS caused by SARS-CoV-2. Methods: A retrospective, observational study was performed at a single centre, evaluating patients with ARDS secondary to COVID-19 treated with HFNC. The main outcome was the intubation rate at day 30, which defined failure of therapy. We also analysed the role of the ROX index to predict the need for intubation.Results: In the study period, 196 patients with bilateral pneumonia were admitted to our pulmonology unit, 40 of whom were treated with HFNC due to the presence of ARDS. The intubation rate at day 30 was 52.5%, and overall mortality was 22.5%. After initiating HFNC, the SpO2/FiO2 ratio was significantly better in the group that did not require intubation (113.4±6.6 vs 93.7±6.7, p=0.020), as was the ROX index (5.0±1.6 vs 4.0±1.0, p=0.018). A ROX index less than 4.94 measured 2 to 6 h after the start of therapy was associated with increased risk of intubation (HR 4.03 [95% CI 1.18 – 13.7]; p=0.026).Conclusion: High-flow therapy is a useful treatment in ARDS in order to avoid intubation or as a bridge therapy, and no increased mortality was observed secondary to the delay in intubation. After initiating HFNC, a ROX index below 4.94 predicts the need for intubation.

Non-invasive respiratory support paths in hospitalized patients with COVID-19: proposal of an algorithm

“…Three recent studies applying the ROX index in COVID-19 patients, suggest different cut-off points like slightly higher values ≥4,94 at 2 and 6 h 38 and ≥5,37 at 4 h 39 and lower values ≥3,7 at 6 h. 23 Moreover other authors point to a daily significant decrease in the ROX index as a predictor failure within the first 3 days of HFNC treatment. 25 …”

Severe covid-19 pneumonia: pathogenesis and clinical management

“…rr=respiratory rate, PeeP=positive end expiratory pressure, r/i=recruitment/inflation ratio, CoPD=chronic obstructive pulmonary disease, CHF=congestive heart failure, HFnC=high flow nasal cannula, Wob=work of breathing, P/F=Pao2/Fio2 ratio, MaP=mean arterial pressure, niv=non-invasive ventilation doi: 10.1136/bmj.n436 | BMJ 2021;372:n436 | the bmj series. [93][94][95][96][97][98][99][100][101][102] It attests to the feasibility of utilizing HFNC in this setting; however, firm conclusions regarding efficacy are difficult to draw because of the lack of control groups. Table 1 shows large case series in the English language and provides detailed patient information and outcomes.…”

“…Evidence on the use of HFNC for covid-19 pneumonia consists of case reports and case series 93949596979899100101102. It attests to the feasibility of utilizing HFNC in this setting; however, firm conclusions regarding efficacy are difficult to draw because of the lack of control groups.…”

“…HFNC was associated with successful outcomes (ie, no escalation of care) in 34% to 70% of cases. ROX index determined after 4-6 hours of treatment predicted escalation of care 939597. Patients with P a O 2 / F i O 2 >200 before commencing HFNC and who had a reduction in respiratory rate within the first several hours had the best outcomes 101.…”

High-Flow Nasal Cannula Therapy in COVID-19: Using the ROX Index to Predict Success

“…7 The score has been subsequently applied to the use of HFNC in the treatment of COVID-19, and investigators have proposed values that correlate with subsequent failure of HFNC and need for endotracheal intubation. [8][9][10][11] Most prior research related to HFNC use in patients with COVID-19 has focused efforts on utilizing the ROX index to identify patients at risk of subsequent endotracheal intubation, and data regarding the use of the index to select patients who may ultimately be weaned from HFNC are lacking.…”