Safety and efficacy of high-flow nasal cannula therapy in acute hypercapnic respiratory failure: a retrospective audit.

BACKGROUND

While the role of high-flow nasal cannulae (HFNC) in the management of respiratory failure continues to expand, few studies describe its use in acute hypercapnic respiratory failure.

AIMS: In this retrospective study, we assessed the safety and efficacy of HFNC for the treatment of acute hypercapnic respiratory failure.

METHODS

Admissions with acute hypercapnic respiratory failure to a thoracic medicine unit at a tertiary centre between January and August 2018 were included if treated with either HFNC or non-invasive ventilation (NIV). The primary outcome was post-treatment change in arterial pCO2 . Demographics, comorbidities, length of stay, readmission rate and mortality were also collected.

RESULTS

Sixty-four patients were identified, comprising 69 presentations grouped according to initial treatment: HFNC (n = 24) or NIV (n = 45). Patients in the NIV group had more severe blood gas derangement. In both groups, mean arterial pCO2 improved significantly (-10 (95% confidence interval: -14 to -6) mmHg) from baseline with no evidence of a differential effect between groups. Six (25%) patients, of whom three had comorbid obesity and two had sleep-disordered breathing, were transitioned from HFNC to NIV. No significant differences in hospital length of stay, 30-day readmission rate or 90-day mortality were observed.

CONCLUSIONS

HFNC might be a reasonable initial treatment for patients with mild acute hypercapnic respiratory failure who do not have comorbid obesity or sleep-disordered breathing. A prospective study might help identify clinical factors or phenotypes predictive of success with this treatment modality.