A randomised controlled trial comparing high‐flow nasal oxygen with standard management for conscious sedation during bronchoscopy

Abstract

Traditional conscious sedation for endobronchial ultrasound procedures places patients at risk of desaturation, and high-flow nasal oxygen may reduce the risk. We designed a parallel-group randomised controlled trial of high-flow nasal oxygen at a flow rate of 30-70 l.min via nasal cannulae, compared with standard oxygen therapy at 10 l.min via a bite block in adults planned for conscious sedation for endobronchial ultrasound. The primary outcome was the proportion of patients experiencing desaturation (defined as SpO < 90%). Secondary outcomes included oxygen saturation after pre-oxygenation, lowest oxygen saturation during procedure, number of hypoxic episodes, duration of hypoxia, end-procedure end-tidal CO , satisfaction scores and complications. Thirty participants were allocated to each group. Baseline patient characteristics, procedure time and anaesthetic agents used were similar between the groups. Desaturation occurred in 4 out of 30 patients allocated to the high-flow nasal oxygen group, compared with 10 out of 30 allocated to the standard oxygenation group, a non-significant difference (p = 0.07) with intention to treat analysis. The difference was significant (p = 0.047) when using a per-protocol analysis. Oxygen saturation after pre-oxygenation and the lowest oxygen saturation during procedure were significantly higher in the high-flow nasal oxygen group compared with the standard oxygenation group; median (IQR [range] 100 (99-100 [93-100]) vs. 98 (97-99 [94-100]), p = 0.0001 and 97.5 (94-99 [77-100]) vs. 92 (88-95 [79-98]), p < 0.001, respectively. There were no differences in other secondary outcomes. Although high-flow nasal oxygen may prevent desaturation due to some causes, it does not protect against hypoxaemia in all circumstances.

High‐flow nasal cannula vs standard respiratory care in pediatric procedural sedation: A randomized controlled pilot trial

“…Successful oxygenation using HFNC during procedural sedation was reported before in adults undergoing bronchoscopy. [10][11][12][13] In their randomized clinical trial Deitch et al 6 demonstrated that adult patients undergoing procedural sedation experienced less hypoxemic episodes if oxygen was applied at 15 L/min compared to room air at the same flowrate.…”

High‐flow nasal therapy – modelling the mechanism

“…High‐flow nasal therapy can be delivered to patients who are either breathing or apnoeic. The former group includes patients in acute respiratory failure , during elective and emergency awake airway management and during bronchoscopy under sedation . There is also interest in the use of HFNT in the postoperative setting, for example, following abdominal and cardiac surgery, to reduce the incidence of postoperative pulmonary complications, with mixed results so far .…”

A potential method for obtaining wave-form capnography during high flow nasal oxygen

“…Its use in anaesthesia is rapidly increasing, providing an alternative to low flow oxygen devices during sedation for procedures such as bronchoscopy and gastroenterology as well as a potential role in non-invasive cardiological, radiological, emergency medicine and persistent pain procedures. [1][2][3] The main advantages of heated and humidified HFNO are improved maintenance of adequate oxygenation with less drying of the upper airway mucosa, thereby improving patient comfort. However, one outstanding question is the role of wave-form capnography during patient sedation when HFNO is administered.…”