Efficacy of different respiratory supports to prevent hypoxia during flexible bronchoscopy in patients of COPD: a triple-arm, randomised controlled trial

Abstract

BackgroundPatients with chronic-obstructive-pulmonary-disease (COPD) undergo bronchoscopy for various reasons, and are at relatively higher risk of complications. This study evaluated the efficacy of non-invasive ventilation (NIV) and high-flow-oxygen-therapy (HFOT) compared with conventional-oxygen-therapy (COT) in patients with COPD undergoing bronchoscopy, to prevent hypoxia.MethodsIt was a triple-arm, open-label, randomised controlled trial. Ninety patients with COPD were randomly assigned into three intervention arms in 1:1:1 ratio. The incidence of hypoxia, lowest recorded oxygen saturation measured by plethysmography (SpO2), ECG, patient vitals and comfort levels were assessed.ResultsMean age of the study population was 61.71±7.5 years. Out of 90 cases enrolled, 51, 34 and 5 were moderate, severe and very-severe COPD, respectively, as per GOLD (Global Initiative for Chronic Obstructive Lung Disease) classification. Rest of the baseline characteristics were similar. SpO2during flexible bronchoscopy (FB) was lowest in COT group (COT: 87.03±5.7% vs HFOT: 95.57±5.0% vs NIV: 97.40±1.6%, p<0.001). Secondary objectives were similar except respiratory-rate (breaths-per-minute) which was highest in COT group (COT: 20.23±3.1 vs HFOT: 18.57±4.1 vs NIV: 16.80±1.9, p<0.001). Whereas post FB partial of oxygen in arterial blood was highest in NIV group (NIV: 84.27±21.6 mm Hg vs HFOT: 69.03±13.6 mm Hg vs COT: 69.30±11.9 mm Hg, p<0.001). Post FB partial pressure of carbon dioxide in arterial blood was similar in the three arms. Operator’s ease-of-performing-procedure was least in the NIV group as assessed with Visual Analogue Scale (p<0.01). A higher number of NIV group participants reported nasal pain as compared with the other two arms (p<0.01).ConclusionNIV and HFOT are superior to COT in preventing hypoxia during bronchoscopy, but NIV is associated with poor patient-tolerance and inferior operator’s ease of doing procedure.Trial registration numberCTRI/2021/03/032190.

The effectiveness of transnasal high flow nasal cannula in bronchoscopy under sedation: a systematic review and meta-analysis

“…The selected studies mainly focused on bronchoscopy, flexible bronchoscopy, bronchial ultrasonography, and fiberoptic bronchoscopy. In all studies, bronchoscopy was performed by using a local anesthetic (lidocaine) sprayed over the entire scopal passage (e.g., oropharynx, airway), together with different combinations of the following sedation: short-acting opioids (fentanyl/alfentanyl/remifentanil) ( 4 , 6 , 10 , 12 , 15 , 20 ), intravenous propofol ( 4 , 10 , 12 , 18 ) and midazolam ( 5 , 6 , 10 , 12 , 15 , 17 ). The depth of sedation was titrated to pre-defined clinical endpoints (Ramsay sedation scale, modified observer’s alertness/sedation scale, sedation state scale, Richmond Agitation Score); EEG monitoring (bispectral index); or society-based recommendations (e.g., ASA guidelines) in all the included trials.…”

“…This finding can be attributed to the fact that NIV enhances pulmonary ventilation function and alleviates dyspnea symptoms, thereby effectively addressing hypoxia and hypoxemia. Sharma et al ( 17 ) conducted a study in which the NIV group employed a fraction of inspired oxygen (FiO 2 ) level of 30%. Furthermore, the ventilation parameters were set to a positive end-expiratory airway pressure of 4 cm H 2 O and a pressure support of 8 cm H 2 O.…”