Effectiveness of the use of a high-flow nasal cannula to treat COVID-19 patients and risk factors for failure: a meta-analysis

Abstract

Background: Coronavirus disease 2019 (COVID-19) has spread globally, and many patients with severe cases have received oxygen therapy through a high-flow nasal cannula (HFNC). Objectives: We assessed the efficacy of HFNC for treating patients with COVID-19 and risk factors for HFNC failure. Methods: We searched PubMed, Embase, and the Cochrane Central Register of randomized controlled trials (RCTs) and observational studies of HFNC in patients with COVID-19 published in English from January 1st, 2020 to August 15th, 2021. The primary aim was to assess intubation, mortality, and failure rates in COVID-19 patients supported by HFNC. Secondary aims were to compare HFNC success and failure groups and to describe the risk factors for HFNC failure. Results: A total of 25 studies fulfilled selection criteria and included 2851 patients. The intubation, mortality, and failure rates were 0.44 (95% confidence interval (CI): 0.38–0.51, I2 = 84%), 0.23 (95% CI: 0.19–0.29, I2 = 88%), and 0.47 (95% CI: 0.42–0.51, I2 = 56%), respectively. Compared to the success group, age, body mass index (BMI), Sequential Organ Failure Assessment (SOFA) score, Acute Physiology and Chronic Health Evaluation (APACHE) II score, D-dimer, lactate, heart rate, and respiratory rate were higher and PaO2, PaO2/FiO2, ROX index (the ratio of SpO2/FiO2 to respiratory rate), ROX index after the initiation of HFNC, and duration of HFNC were lower in the failure group (all Ps < 0.05). There were also more smokers and more comorbidities in the failure group (all Ps < 0.05). Pooled odds ratios (ORs) revealed that older age (OR: 1.04, 95% CI: 1.01–1.07, P = 0.02, I2 = 88%), a higher white blood cell (WBC) count (OR: 1.06, 95% CI: 1.01–1.12, P = 0.02, I2 = 0%), a higher heart rate (OR: 1.42, 95% CI: 1.15–1.76, P < 0.01, I2 = 0%), and a lower ROX index(OR: 0.61, 95% CI: 0.39–0.95, P = 0.03, I2 = 93%) after the initiation of HFNC were all significant risk factors for HFNC failure. Conclusions: HFNC is an effective way of providing respiratory support in the treatment of COVID-19 patients. Older age, a higher WBC count, a higher heart rate, and a lower ROX index after the initiation of HFNC are associated with an increased risk of HFNC failure.

High flow nasal oxygen (HFNO) in the treatment of COVID-19 infection of adult patients from – An emergency perspective: A systematic review and meta-analysis

“…These results are supported by previous studies which show that ROX index is a good predictor for HFNO failure. For example, Xu et al [ 23 ] after evaluating HFNC treatment in 2851 patients with COVID-19 found that patients in the HFNC failure group showed a significantly lower ROX index than those in the success group (4.9 ± 2.5 vs. 6.1 ± 2.7 (P < 0.01), respectively). This study also suggested that the high sensitivity observed in the ROX index was sufficient to detect HFNO failure in COVID-19 patients.…”

“…Similar results were reported in a previous meta-analysis which revealed that HFNC usage in COVID-19 patients was associated with reduced intubation and mortality rates. The results of that meta-analysis showed that the mortality rate after HFNC treatment was 0.23 (95% CI; 0.19, 0.29) while the intubation rates were 0.44 (95% CI; 0.38, 0.51) [ 23 ]. Similarly, a previous literature review evaluating the use of HFNC in COVID-19 reported that HFNC treatment could reduce the need for intubation and decrease the length of hospital stay [ 28 ].…”

Relationship between different levels of ROX index and the prognosis of patients receiving high-flow nasal oxygen therapy in ICU

“…In addition, ROX index can also well predict spontaneous heart failure (aHRF) associated with pneumonia in patients, so it is necessary to dynamically monitor ROX index in the early stage of HFNC application [10]. Four other meta-analyses also showed that the ROX index could guide the treatment of acute hypoxic intubation caused by COVID-19 or other causes [11][12][13][14]. However, relevant studies suggested that ROX index can be used as a new potential marker to identify patients at high risk of HFNC failure.…”

Silent Hypoxemia in the Emergency Department: A Retrospective Cohort of Two Clinical Phenotypes in Critical COVID-19

“…At the time, patients were mainly managed following the current guidelines; there was no alternative to prolonged mechanical ventilation and patient treatment relied on typical ARDS therapeutic strategies since the potential clinical benefits of combined therapy using non-invasive ventilation were not yet validated due to the potential aerosolization of the then emerging, and unknown, viral particles [ 27 ]. As elaborated in our analysis, when comparing different ED and ICU organ support strategies, no significant differences were found between the two subgroups other than the timing of endotracheal intubation, which was further performed earlier in the ED for Phenotype II.…”