Efficacy of different respiratory supports to prevent hypoxia during flexible bronchoscopy in patients of COPD: a triple-arm, randomised controlled trial
Vinod Sharma, Pawan Singh, Manjunath B Govindagoudar, Athul Thulasi, Dhruva Chaudhry, Chaudhari Pramod Shriram, Lokesh Kumar Lalwani, Aman Ahuja
Abstract
Background Patients 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. Methods It 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 (SpO 2 ), ECG, patient vitals and comfort levels were assessed. Results Mean 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. SpO 2 during 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). Conclusion NIV 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 number CTRI/2021/03/032190.