A Retrospective Cohort Study of High-Flow Nasal Cannula Oxygen and Swallowing

Background: High-flow nasal cannula (HFNC) is an oxygen therapy delivery method used with severely ill patients. The literature regarding the effects of HFNC on overall swallowing function and aspiration risk is limited, and results from current studies are mixed. This study aimed to investigate the possible association between HFNC and swallowing impairment. Methods: This was a single-center, within-subjects, repeated-measures retrospective study of 21 hospitalized subjects. Participants underwent flexible endoscopic evaluation of swallowing (FEES) while receiving oxygen therapy via HFNC and had another instrumented swallow assessment, a FEES or a modified barium swallow study, when they no longer required HFNC oxygen. Three markers of swallowing function were extracted from reports-aspiration, silent aspiration, and overall swallowing function, and statistical analyses were conducted to assess their relationship to HFNC status. Results: There was a statistically significant difference in the proportion of subjects who aspirated while they were receiving oxygen via HFNC as compared to when they were not on HFNC (P = .033). When on HFNC, 61.9% (13/21) of subjects had an aspiration event during instrumented swallow evaluation; and when off HFNC, 23.8% (5/21) of subjects aspirated. Findings related to silent aspiration during instrumented swallowing evaluation were not significant (P = .32). When subjects were on HFNC, their overall swallowing function was significantly more impaired than when they were off HFNC (P < .001). Conclusions: The results of this study indicate that HFNC is a factor to consider when determining if a patient is appropriate for oral alimentation. Given the limited data on HFNC and swallowing function and the fragility of this population, instrumented examination of swallowing prior to initiation of oral intake may be beneficial. Future prospective studies with larger populations that stratify subjects into risk categories based on subject characteristics and pathophysiology are needed.