Background: Hypoxemia is a frequent adverse event occurring during flexible bronchoscopy and is usually prevented by close monitoring and, if needed, oxygen supplementation by nasal cannula. Objective: We aim to demonstrate that tracheal oxygen supplementation during flexible bronchoscopy is a feasible, safe and effective method to restore oxygen saturation levels after oxygen desaturation. Methods: In a first phase, we compare oxygen supplementation by the tracheal or nasal route in a single blinded cross-over design in healthy volunteers. In a second phase, we study patients referred for diagnostic flexible bronchoscopy, who desaturate despite oxygen supplementation by nasal cannula, in order to assess the ability to correct hypoxemia through tracheal oxygen supplementation. Results: In the first phase, the mean capillary partial pressure of oxygen was 181 mm Hg when oxygen at a flow rate of 4 liters/min was administered by the tracheal route, compared to 125 mm Hg by the nasal route (p < 0.001). The capillary partial pressure of carbon dioxide was not significantly different. During 950 bronchoscopic procedures in the second phase of the trial, 30 patients desaturated below 90% despite oxygen supplementation by nasal cannula. In 22 out of these 30 patients, switching to the tracheal route resulted in a correction of the saturation within 120 s. In the remaining 8 patients, saturation levels were corrected after increasing the oxygen flow rate to 4 liters/min. After restoring saturation levels, the bronchoscopy could be completed in 25 of 30 patients. Conclusions: Tracheal oxygen supplementation is safe, feasible and an effective way to restore oxygen saturation levels during flexible bronchoscopy.

Background and objectivesAzithromycin was rapidly adopted as a repurposed drug to treat COVID-19 early in the pandemic. We aimed to evaluate its efficacy in patients hospitalised for COVID-19.MethodsIn a series of randomised, open-label, phase 2 proof-of-concept, multicenter clinical trials (Direct Antivirals Working against the novel Coronavirus [DAWn]), several treatments were compared with standard of care. In 15 Belgian hospitals, patients hospitalised with moderate to severe COVID-19 patients were allocated 2:1 to receive standard of care plus azithromycin or standard of care alone. The primary outcome was time to live discharge or sustained clinical improvement, defined as a two-point improvement on the WHO ordinal scale sustained for at least 3 days.ResultsPatients were included between April 22 and December 17, 2020. When 15-day follow-up data were available for 160 patients (56% of preset cohort), an interim analysis was performed at request of the independent Data Safety and Monitoring Board. Subsequently, DAWn-AZITHRO was stopped for futility. In total, 121 patients were allocated to the treatment arm and 64 patients to the standard of care arm. We found no effect of azithromycin on the primary outcome with Hazard ratio of 1.044 (95% confidence interval, 0.772–1.413; p=0.7798). None of the predefined subgroups showed significant interaction as covariates in the Fine-Gray regression analysis. No benefit of azithromycin was found on any of the short- and longer-term secondary outcomes.ConclusionTime to clinical improvement is not influenced by azithromycin in patients hospitalised with moderate to severe COVID-19.

BackgroundExacerbations affect the disease trajectory of patients with COPD and result in an acute drop of functional status and physical activity. Timely detection of exacerbations by non-medical healthcare professionals is needed to counteract this decline. The use of digital health applications in patient interaction allows embedded detection of exacerbations. However, it is unknown if this is an effective way to pick up exacerbations.MethodWe investigated the detection of exacerbations in patients with COPD enrolled in a physical activity coaching program, by prompting a weekly question on changes in medication via the smartphone application. Data on response rate and occurrence of exacerbations were collected.ResultsResponse rate to the medication question, evaluated in 42 patients, was 72% (n = 497). A change in medication was reported through the smartphone application in 38 (7.6%) of the answered questions. The response rate was significantly lower at 6 months follow-up compared to the first month (p =0.03). When evaluating the occurrence of adverse events in a subset of patients who completed 6 months of follow-up (n = 27), 18 exacerbations were registered in eight patients, of which 10 of these exacerbations (56%) were picked up by the medication question in the coaching application.ConclusionElectronic interaction through a weekly medication question, embedded in a smartphone application, is feasible to support the detection of the occurrence of COPD exacerbations and can be used complementary to regular forms of detecting exacerbations. Compliance and smartphone literacy should be optimized when further using this method to report on COPD exacerbations.

A 65-year-old man was referred to the emergency department because of hoarseness and progressive swelling of the neck and face. The clinical examination revealed visible collateral veins on the upper thoracic cage wall. A computed tomography (CT) scan of the chest and upper abdomen showed a bilobar mass in the right upper lobe of the lung that was suspicious for malignancy ( Fig. 1). In addition, there were multiple enlarged mediastinal lymph nodes, poorly defined vertebral body densities in vertebrae T2 and T3 that were suspicious for bone metastasis (Fig. 2), and a small right-sided pleural effusion. The examination of bronchoscopic biopsy specimens revealed squamous cell lung cancer, and the clinical stage was cT2aN2M1b according to the TNM 7 classification.Dilatation and stent placement in the superior vena cava (SVC) was performed first because of the symptomatic SVC syndrome. Over a few days, this resulted in rapid symptomatic improvement.There were no other metastases on conventional imaging, and therefore an 18 F-fluorodeoxyglucose positron emission tomography CT ( 18 F-FDG PET-CT) scan was performed to discuss a potential oligometastatic approach at our multidisciplinary tumor board. It revealed the highly hypermetabolic rightsided lung tumor, the mediastinal lymph node metastases, but surprisingly no sign at all of vertebral body metabolic activity. Moreover, the CT scan no longer showed any vertebral body abnormality (Fig. 3). The patient subsequently started concurrent chemoradiation therapy for a tumor with final clinical staging cT2aN2M0. DiscussionThe SVC-initially nearly completely obstructed by the mediastinal lymph nodes-resumed a normal flow pattern after the successful stent placement. The initial CT scan suggested that the sclerotic vertebral body metastases were most likely caused by increased density of the contrast-filled vertebral venous plexus in response to the obstructed SVC. This image returned to normal after the SVC obstruction was treated, with regression of the collateral venous flow in the (hemi-) azygos vein system. There was also no increased 18 F-FDG uptake on the PET-CT scan.SVC syndrome is a frequent complication of primary lung cancer, as are osseous lesions detected on a staging CT scan. When SVC syndrome develops, multiple venous collateral pathways also develop, including uncommon ones, such as breast, brain, and liver venous networks. 1 Paravertebral collateral flow is a more common finding, but until now only a few case reports have described contrast-enhanced lesions inside the vertebrae. [2][3][4] In one retrospective study, Kim et al. 5 reviewed CT scans of patients with patients with SVC syndrome and unusual vertebral body enhancement. In these 13

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