Modified HFNC Therapy for ARF Patients Undergoing Flexible Bronchoscopy

In the modified HFNC group, high-flow devices (AIRVOTM 2; Fisher \& Paykel Healthcare, Auckland, New Zealand) were utilized for respiratory support. The nasal cannula used was a modified single nasal cannula.

In the non-rebreathing reservoir mask group, oxygen was delivered via a non-rebreathing reservoir mask during bronchoscopy. The oxygen flow was set to achieve a saturation of pulse oxygen \> 90%.