High-flow nasal cannula oxygen therapy versus conventional oxygen therapy in patients undergoing bronchoscopy: a retrospective study

Patients undergoing bronchoscopy, particularly those with pre-existing hypoxemia, face a significant risk of further deterioration in their oxygen saturation levels. This heightened risk necessitates the provision of supplemental oxygen therapy throughout the procedure, rendering it mandatory. High-flow nasal cannula (HFNC) has been widely employed in the management of hypoxemic acute respiratory failure (ARF) in adults. Based on this, HFNC has been used in endoscopic procedures, but there are still few studies on HFNC in fiberoptic bronchoscopy (FOB) patients. The purpose of this study was to evaluate the comparative efficacy of HFNC with nasal cannula oxygen in maintaining adequate oxygen saturation during fiberoptic bronchoscopy in patients with pre-existing hypoxemia.

We retrospectively investigated 232 patients with hypoxemia who underwent bronchoscopy between January 2018 to August 2023 who received either HFNC or nasal cannula oxygen supplementation. The control group received nasal cannula oxygen, and the observation group received HFNC. The changes of oxygen saturation, heart rate, blood pressure and adverse events during the operation were compared between the two groups.

The patients were divided into the HFNC (n = 78) and nasal cannula oxygen (n = 154) groups. During FOB, although the lowest oxygen saturation (SpO₂) was similar in both groups (intraoperative minimum SpO₂ was defined as the lowest value of SpO₂ occurring between the start of anesthesia and the end of the operation), the occurrence of the lowest SpO₂ < 90% was significantly lower in the HFNC group (3.8% vs. 17.5%, p = 0.003). No serious complications were reported in either group, however, the overall incidence of general adverse events was 7.7% and 20.1% in the HFNC and conventional oxygen therapy (COT) groups, respectively (p = 0.015). Multifactorial analysis showed that higher arterial partial pressure of oxygen versus the fraction of inspired oxygen (PaO₂/FiO₂; P/F) was a protective factor against desaturation events (p = 0.032, OR = 0.990, 95% CI: 0.982–0.999). In patients with baseline PaO₂/FiO₂ ≥ 200 mmHg, the HFNC group exhibited smoother vital sign changes from pre-procedure to the end of bronchoscopy, although there were no significant differences between the two groups regarding the rates of deoxygenation events as well as adverse events.

The use of HFNC therapy can effectively reduce the incidence of SpO₂ < 90% during bronchoscopy in patients with hypoxemia. Additionally, HFNC significantly reduces the overall incidence of adverse events compared to COT. In patients with milder hypoxemia, its advantages in maintaining operational stability during bronchoscopy should not be overlooked.