Table 1.
The baseline characteristics
| Study no | Author/year | Design | Location | Subjects | Sample size | Age (years; mean or median) | PaO2/FiO2 ratio at baseline (mmHg; mean or median) | The ROX index at baseline (mean or median) | Duration of HFNC | Mortality (death/total) | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| HFNC success | HFNC failure | HFNC success | HFNC failure | |||||||||
| 1 | Blez/2020 | Prospective, single-centre | France | COVID-19 pneumonia patients treated with HFNC | 30 | 64 | NR | NR | 5 (4–7) days | 1 (0.9–2.5) day | NR | NR |
| 2 | Calligaro/2020 | Prospective, multi-centre | South Africa | COVID-19 pneumonia patients with AHRF | 293 | 52 | 68 | NR | 6 (3–9) days | 2 (1–5) days | 1/137 | 129/156 |
| 3 | Chandel/2021 | Retrospective, multi-centered | USA | COVID-19 pneumonia patients with AHRF | 272 | 57 | NR | NR | 4 (2–7) days | 2 (1–4) days | NR | 49/108 |
| 4 | Duan/2021 | Retrospective, multi-centered | China | COVID-19 pneumonia patients with AHRF | 66 | 67 | 194 | 9.0 | 242 (144–295) hours | 39 (15–117) hours | 0/37 | 14/29 |
| 5 | Daniel/2021 | Prospective, multi-centre | Colombia and Bolivia | Pneumonia patients with AHRF | 106 | 59 | NR | NR | NR | NR | 7/27 | 8/79 |
| 6 | Ferrer/2021 | Prospective, single-centre | Spain | COVID-19 pneumonia patients with AHRF | 85 | 65 | NR | NR | 3.29 ± 0.53 | 1.47 ± 0.21 | 2/38 | 17/47 |
| 7 | Goh/2020 | Prospective, single-centre | Singapore | Patients with AHRF (88% due to pneumonia) | 99 | 64 | 93 | 4.0 | 41.5 (22.1–70.1) hours | 16.2 (7.4–35.5) hours | 11/54 | 27/45 |
| 8 | Hu/2020 | Retrospective, multi-centered | China | COVID-19 pneumonia patients with AHRF | 105 | 64 | 116 | NR | 6.0 (3.5–8.5) days | 3.0 (2.0–11.0) days | 0/65 | 16/40 |
| 9 | Panadero/2020 | Retrospective, single-centre | Spain | COVID-19 pneumonia patients with AHRF | 40 | 59 | NR | 3.8 | 6 (5–8) days | 2 (1–4) days | 0/19 | 9/21 |
| 10 | Roca/2016 | Prospective, multi-centre | Spain and France | Pneumonia patients with AHRF | 157 | 52 | NR | 6.9 | 3 (2–6) days | 1 (1–4) days | NR | NR |
| 11 | Vega/2022 | Retrospective, multi-centered | Argentina and Italy | COVID-19 pneumonia patients with AHRF | 120 | NR | NR | NR | NR | NR | 0/85 | 9/35 |
| 12 | Xu/2020 | Retrospective, multi-centered | China | COVID-19 pneumonia patients with AHRF | 324 | 63 | 141 | 4.3 | 10 (7–15) days | 3 (1–4) days | NR | NR |
| 13 | Zucman/2020 | Retrospective, single-centre | France | COVID-19 pneumonia patients with AHRF | 62 | 55 | NR | NR | NR | NR | 0/21 | 2/41 |
COVID-19 coronavirus disease 2019, AHRF acute hypoxemic respiratory failure, MV mechanical ventilation, HFNC high-flow nasal cannula, ROX respiratory rate-oxygenation, PaO2 arterial oxygen partial pressure, FiO2 fraction of inspired oxygen, NR no record