Pulmonary & Respiratory Medicine

Evaluation of Patient Outcomes of High Flow vs. Low Flow Nasal Oxygen during Outpatient Bronchoscopy under Conscious Sedation at Thoracic Procedure Suite in Lyell McEwin Hospital

Abstract

Singankutti Mudalige Thanuja Nilushi Priyangika*, Moayed Alawami and Shanka Karunarathne

Background and objective: High flow nasal oxygen (HFNO) has been shown to reduce desaturations during flexible bronchoscopy. We evaluated outcomes of HFNO vs. low flow nasal oxygen (LFNO) on intraprocedural hypoxemia, the demand of sedative and reversal medications, postprocedure complications, procedure conversion to general anaesthesia and patient comfort during outpatient standard and EBUS (Endo Bronchial Ultrasound) guided bronchoscopy under conscious sedation.

Methods: A Prospective open-label study where the first 42 patients were allocated to LFNO and subsequent 42 patients were allocated to HFNO. Baseline and lowest oxygen saturation, duration of hypoxemia, procedure type, amount of sedative and reversal medications and patient comfort were assessed.

Results: Both HFNO and LFNO had similar characteristics at baseline. The odds ratio of being hypoxic (<90%) was 13.8 times more in the LFNO group (CI 3.55-70.7, p < 0.001) after adjustment for confounders. In addition, the LFNO group had a longer period of desaturation (OR 11.24, CI 3.18-49.78, p < 0.001). There was no statistically significant difference in median lowest peripheral oxygen saturation, the amount of sedative and reversal medications, patient comfort, procedure conversion to general anaesthesia, and post-procedure complications between the two groups.

Conclusion: During outpatient standard and EBUS guided bronchoscopy, HFNO is associated with a statistically significant reduction in oxygen desaturation and duration of hypoxemia. However, there was no clinically significant difference in adverse outcomes, or patient comfort between the two groups. We would like to highlight that LFNO can be considered safe to be used during outpatient bronchoscopy under conscious sedation which is cost effective. However, further multicentre studies are needed to identify high risk patients who will benefit most from HFNO.