Factors associated with the effectiveness of high-flow therapy in patients with acute hypoxemic respiratory failure: An observational study

Backward

The COVID-19 pandemic has severely tested global health systems. Non-invasive respiratory support, especially combining high-flow nasal cannula (HFNC) and continuous positive airway pressure, has effectively treated COVID-19 induced Acute Hypoxemic Respiratory Failure and reduced mortality. However, HFNC alone is more comfortable, better tolerated, and less costly than non-invasive ventilation. Understanding which patients benefit from HFNC monotherapy versus combined therapies is essential.

Methods

This observational study included patients admitted to the intermediate respiratory care unit of a COVID-19 hospital between December 2020 and September 2021. All patients treated with HFNC were included (n = 1301). HFNC failure was defined as the need for escalated therapy (non-invasive ventilation, intubation) or death. Epidemiological, clinical, non-invasive respiratory support parameters, and laboratory data were collected, and a multivariable analysis identified key determinants.

Results

HFNC was successful in 39.9 % of patients. (n = 511) Risk factors for HFNC failure included increased age, male gender, obesity, obstructive sleep apnea, higher respiratory rate, initial SpO2/FiO2 ≤ 148, and initial PaO2/FiO2 ≤ 100. An increase in the ROX Index at 24 h and slower disease progression were associated with successful treatment. These findings led to the developmet of an index to identify patients who benefit most from HFNC monotherapy.

Conclusions

HFNC monotherapy can be effective for a specific profile of patients with Acute Hypoxemic Respiratory Failure due to COVID-19. This tool may help manage these patients more appropriately. Further studies are needed to determine if these findings can be applied to Acute Hypoxemic Respiratory Failure caused by other pathologies.

Implications for Clinical Practice

This study underscores the importance of early identification and management of patients at risk of HFNC failure in intermediate respiratory care units. By recognizing factors such as age, comorbidities, and respiratory indices, healthcare providers can implement targeted strategies to enhance HFNC success. These strategies may include more stringent monitoring, tailored respiratory support, and timely escalation to more intensive therapies if needed. Our findings highlight the need for a comprehensive approach to managing severe respiratory failure in critical care settings, ultimately improving patient outcomes and reducing the burden on healthcare systems.