Thank you for your interest in our case series, where we found that high-flow oxygen therapy via tracheostomy (HFT) did not lead to improvements in inspiratory effort, as measured by diaphragmatic ultrasound, in patients weaning from mechanical ventilation.1

Your insights regarding the potential influence of peripheral muscle weakness and the duration of mechanical ventilation on our results are highly pertinent. In our study, among patients with muscle weakness (MRC < 48), HFT increased diaphragmatic excursion by 0.45 mm (IQR −7.5, 2.8), while standard oxygen therapy (SOT) led to a slight decrease of 0.15 mm (IQR −2.7, 1.9). In patients with an MRC score > 48, HFT increased excursion by 2.1 mm (IQR −12, 12.7), compared to a 1 mm decrease (IQR −3.6, 8.1) with SOT. However, these differences were not statistically significant.

For changes in diaphragmatic thickening fraction (Tfdi), in patients with an MRC score < 48, HFT led to a slight decrease of 0.1% (IQR −0.49, 0.095), whereas SOT resulted in a small increase of 0.11% (IQR 0.04, 0.145). In patients with MRC > 48, HFT increased Tfdi by 0.21% (IQR −0.16, 0.36) compared to a 0.02% increase with SOT (IQR −0.21, 0.12). Once again, no statistical significance was observed. These findings suggest that peripheral muscle weakness did not affect the results of our study.

We also examined the potential impact of mechanical ventilation duration, using 17 days (the median in our study) as a cutoff. Among patients ventilated for less than 17 days, HFT led to an increase in diaphragmatic excursion of 2.8 mm (IQR 1, 3.1) and a small decrease in Tfdi of 0.03% (IQR −0.09, 0.06). In the SOT group, diaphragmatic excursion increased by 2 mm (IQR −1.3, 3) and Tfdi by 0.02% (IQR 0, 0.13). These findings were not statistically significant, suggesting that ventilation duration did not influence the outcomes.

Regarding the inspiratory flow rate used, your observation about its relationship with peak inspiratory tidal flow during pressure support ventilation before disconnection is very insightful.2 Our study focused on inspiratory effort measured by diaphragmatic ultrasound, so we did not assess airway pressure or peak inspiratory flow. However, based on previous research, we used flow rates of 60 L/min, which we believe are sufficient to obtain the physiological benefits of HFT.3–5

Lastly, the changes we observed in respiratory rate during HFT were minimal: 0 rpm (IQR −1, 2) compared to 0 rpm (IQR 0, 2) with SOT. Given the lack of significant changes, we conclude that HFT does not improve inspiratory effort in tracheostomized patients weaning from mechanical ventilation.

Thank you for your detailed observations. Addressing these clarifications is essential for accurately interpreting our findings and guiding further investigations in this specific area.

During the preparation of this work, the authors used ChatGPT to enhance the writing and understanding of the text. After utilizing this tool/service, the authors reviewed and edited the content as needed and take full responsibility for the final version of the publication.