Background: Patients on prolonged invasive ventilation following early intubation and the associated mortality rate during the COVID-19 pandemic have triggered the utility of noninvasive respiratory supports such as high-flow nasal cannula and noninvasive ventilation as an initial approach. Nevertheless, the patient's self-inflicted lung injury with worsened lung mechanics remains a serious concern, while delaying intubation with noninvasive respiratory support. Early reports during the pandemic also stressed viral aerosolization with noninvasive support, thereby creating debates among healthcare professionals to justify their actions. It eventually proved that the utility of the right noninvasive respiratory support for the right patients with the right protective techniques for the healthcare professionals warrants beneficial outcomes. This systematic review and meta-analysis aimed to compare the utility of high-flow nasal cannula and noninvasive ventilation, in terms of clinical outcome. Methods: A sequential systematic review via PubMed and Scopus was conducted and then was followed by a meta-analysis. The results and the risk of bias were assessed using RevMan 5.4. The primary aim was to measure and assess SpO2 and PaO2 of patients under noninvasive respiratory support. The secondary outcome was to compare the length of hospitalization of patients and the mortality rate between high-flow nasal cannula and noninvasive ventilation. Results: In total, 7 studies from 3,010 studies were included for meta-analysis. The mean difference (MD) pooled was -4.38 -18.40, 8.74 units and I2 = 79% was observed for the oxygenation index in the 4 studies. Three studies were used to evaluate the length of hospitalization and the pooled MD was -0.07 -0.78, 0.63 units, and I2 = 9% was noted. Assessment of mortality rate was done in 3 studies in the noninvasive ventilation group and high-flow nasal cannula group. The pooled MD was 32.32 -31.95, 96.43 units and I2 = 100% was noted. Conclusions: The use of noninvasive ventilation and high-flow nasal cannula in acute hypoxemic respiratory failure were compared in terms of oxygenation index, mortality, and length of hospitalization. High-flow nasal cannula was better in terms of improvement of oxygenation index, but noninvasive ventilation fared better in terms of lesser mortality. There was no significant difference in terms of length of hospitalization.Demographic characteristicsSOURCETYPE OF HOSPITALGROUP:nAGE (Mean/SD)FEMALE/MALEBMI(kg/m2)(mean/SD)Duan et alMulticentreNIV:1350/141/12NRHFNC:2365/1411/12NRDomenico et alMulticentreNIV:5465/NR12/4227HFNC:5563/NR9/4628Claudia crime et alMulticentreNIV:18158.92/14.7769/11227.99/4.45HFNO:18159.01/14.8862/11928.55/4.33Riccardo et alCovid Centres (Multicentric)NIV:1286647/81NRNANANANAMichael et alNANIV:87863513/35929.5HFNC:2859641159/168328.9Julia et alMulticentreNIV:81165346/46532.37HFNC:27070111/15930.29Gioacchino schifino et alPublic HospitalNIV:2163/9.00NA27/4.05NANANANANA- Not available, NR-Not ReportedRisk of Bias traffic light plot
Sreedharan et al. (Sun,) studied this question.