High-Flow Nasal Interface Improves Oxygenation in Patients Undergoing Bronchoscopy

Abstract

During bronchoscopy hypoxemia is commonly found and oxygen supply can be delivered by interfaces fed with high gas flows. Recently, the high-flow nasal cannula (HFNC) has been introduced for oxygen therapy in adults, but they have not been used so far during bronchoscopy in adults. Forty-five patients were randomly assigned to 3 groups receiving oxygen: 40 L/min through a Venturi mask (V40,N=15), nasal cannula (N40,N=15), and 60 L/min through a nasal cannula (N60,N=15) during bronchoscopy. Gas exchange and circulatory variables were sampled before (FiO₂= 0.21), at the end of bronchoscopy (FiO₂= 0.5), and thereafter (V40, FiO₂= 0.35). In 8 healthy volunteers oxygen was randomly delivered according to V40, N40, and N60 settings, and airway pressure was measured. At the end of bronchoscopy, N60 presented higher PaO₂, PaO₂/FiO₂, and SpO₂than V40 and N40 that did not differ between them. In the volunteers (N60) median airway pressure amounted to 3.6 cmH₂O. Under a flow rate of 40 L/min both the Venturi mask and HFNC behaved similarly, but nasal cannula associated with a 60 L/min flow produced the better results, thus indicating its use in mild respiratory dysfunctions.