We read with interest the article "Home high-flow nasal cannula as a treatment for severe tracheomalacia: A pediatric case report" by Vézina et al 1 The authors have successfully implemented high-flow nasal cannula (HFNC) oxygen therapy in children with tracheomalacia. However, we want to draw attention to some points about HFNC during clinical practice.Firstly HFNC in children is considered to be a generally safe choice among respiratory support modalities. However, the optimal gas flow during HFNC is unclear in children. The flow rate is generally used at 2-8 L/min. 2 Chang et al reported that there is a linear relationship between pressure and flow, and the HFNC pressures are higher compared to continuous positive airway pressure (CPAP). 3 As a result of increased pressure with the airway, the risk of serious adverse effect including pneumothorax and pneumomediastinum is likely increased during HFNC. 4 Vézina et al stated that HFNC at a flow of 10 L/min was successfully used on a child with severe tracheomalacia. 1 In this context, we would like to underline that patients must be closely monitored while on HFNC treatment at high flow rates to avoid complications.Secondly the authors said that the child used a nasojejunal pathway because of severe gastroesophageal reflux. 1 In an in vitro study it was reported that for safe and effective use of HFNC, an appropriate nasal prong to nares ratio is required. 5 In our opinion, the use of nasojejunal pathway for nutrition may impair suitable nasal prong to nares ratio, and consequently, the effectiveness of HFNC may decrease during treatment.Lastly the diagnosis of the child was tracheomalacia plus bronchomalacia. Thus, respiratory impairment likely results from a combination of the dynamic properties of the extrathoracic and the intrathoracic airway. 6 Hypoxemia as well as hypercapnia may be seen in these patients. In a recently published study by Testa et al, HFNC did not effectively reduce increased carbon dioxide levels. 7 Therefore, patients with tracheomalacia should be assessed both for hypoxemia and hypercapnia during HFNC treatment.
CONFLICT OF INTERESTThe authors declare no conflict of interest.
ORCIDZ. Hatipoğlu