Effect of high flow nasal cannula <i>versus</i> conventional nasal cannula oxygen therapy in patients undergoing endobronchial ultrasound-guided transbronchial needle aspiration

Patients undergoing endobronchial ultrasound-guided fine needle aspiration may have multiple comorbidities, contributing to higher risks of hypoxia and adverse events, such as arrhythmias. The current study compared the efficacy of two oxygenation modalities: the high-flow nasal cannula (HFNC) vs. conventional oxygen therapy (CNC). Patients were randomized to either the HFNC or the CNC arm. HFNC and CNC were initiated and escalated as per predefined protocols. The number of desaturation events [fall in saturation of peripheral oxygen (SpO2) by 3% from the baseline] and change in levels of transcutaneous CO2 (tcCO2) from baseline were noted. Subgroup analysis was done in patients with cardiopulmonary comorbidities and in patients with SpO2<97%. A total of 122 patients were randomized. Overall, there was no significant difference in the number of desaturation events and change in tcCO2 levels; however, in patients with cardiopulmonary comorbidities (obstructive sleep apnea, heart diseases, and stable chronic obstructive airway disease), 50% in the HFNC arm had no desaturation compared to 11.7% in the CNC arm (p=0.007). 41.17% of patients in the HFNC arm had a rise in tcCO2 levels, compared to 36.11% of patients in the CNC arm (p>0.5). In patients with SpO2<97%, 48.88% in the HFNC arm had no desaturations compared to 14.70% in the CNC arm (p=0.001); there was no statistical difference in rise in tcCO2. Hence, HFNC would be a better modality for oxygenation in patients with a high risk of hypoxia without increasing the risk of hypercapnia.