million cases (as of May 18) of infection in nearly 200 countries worldwide. 1 The route of transmission is not yet exactly understood; it is thought to be mainly transmitted through respiratory droplets or by direct contact. However, COVID-19 has also been detected in nonrespiratory specimens, such as stool, blood, ocular secretions, and semen, but the role of these sites in the transmission is uncertain. [4] [5] [6] As of 18 May, as in many countries, the number of daily new diagnosed cases in Turkey is still over 1000. 1 This is due to the ability of the COVID-19 virus to spread rapidly from human to human through direct contact or respiratory droplets. Especially within 2 m of an infected person, the transmission risk is even higher. 7 Although bronchoscopy is a procedure used for the diagnosis and treatment of various conditions, it is also known as an aerosolgenerating procedure, so it results in a high risk of infection for health care workers during the COVID-19 pandemic. 8 On the other hand, throughout the pandemic, patients continued to be admitted with symptoms not related to COVID-19 infection, but as a result of suspected lung cancer instead. In these patients, bronchoscopy or endobronchial ultrasonography (EBUS) played an important role in both diagnosis and treatment. In this study, we reviewed the bronchoscopic procedures performed during the pandemic in an interventional pulmonology unit in Turkey and stated how we proceeded with these bronchoscopic procedures and precautions without any published guidelines on this subject. Olympus, Tokyo, Japan) with a dedicated scanner (EU-ME1; Olympus, Tokyo, Japan) was used to examine the lymph nodes of patients. All procedures were done by a minimum possible number of health care workers, such as one or two bronchoscopists, one member of the medical staff, an anesthesiologist, and a technician. All physicians and ancillary staff were tested for COVID-19 during hospital health screening and no positivity was detected. Only one ancillary staff was tested again after traveled to another city and resulted as negative but he was also isolated for 14 days then continued to work again together with us.
performed are shown in Figure 1 . Accordingly, 66.7% (n = 24) of patients that underwent interventional procedures had a malignant central airway obstruction and, of these patients, 50% (n = 12) had no diagnosis (Figure 2A -F). While APC-assisted MTR was the most frequently used technique (n = 12), CR in addition to APC-assisted MTR was also used (n = 7). Dilatation with CR (n = 2) and MTR only (n = 2) were the other techniques used. All patients were presented with a diagnosis (Table 1 ) and treatments were started as soon as possible.
A silicone Y-stent was removed in one patient due to mucostasis, which caused severe dyspnea. Nine patients with postintubation tracheal stenosis presented with severe stridor. All patients were treated by tracheal dilatation and cryotherapy to the stenosis line.
Two patients underwent rigid bronchoscopy three times due to Table 1 . EBUS-TBNA was mostly performed to diagnose suspected malignancy (n = 36; 49%); however, it was also used for simultaneous diagnosis and staging in 20 patients (27%) and staging in a further 16 patients (22%; Figure 1 ). In 61% (34/56) of patients who received EBUS-TBNA, the result was a diagnosis of lung cancer.
As a result, of the patients who underwent EBUS, 59 (79.7%) were diagnosed with malignancy and quickly began treatment (Table 1) .
Before the procedures, 11 patients (15%) were tested for COVID-19, and all results were negative. another patient with COVID-19. 9 About 2 weeks following the first identified COVID-19 case, the possible case definition was changed, and all those with a cough or shortness of breath and a fever were tested for COVID-19. 10 Second, an announcement that no patients with COVID-19 should be directed to appointed nonpandemic hospitals was declared. Thus, the minimization of transmission from patients with COVID-19 to other patients or health care workers was ensured. Third, health care workers were allowed to rest by applying for rotation. Lastly, guidelines were constantly updated by a scientific committee by closely following the global developments of the pandemic.
COVID-19 is known to be transmitted through respiratory droplets and direct contact; the risk of transmission is higher within ∼2 m from an infected person; however, the maximum distance is still undetermined. 11 Bronchoscopy is an aerosol-generating procedure that leads to the pronounced formation of aerosols and thus poses a high risk of infection to proximate health care staff. 8 In addition, nosocomial outbreaks and pseudo-outbreaks caused by various bacteria or viruses linked to inadequately processed bronchoscopes have been reported in several studies. 7, 12 The present study site is a training and research hospital for respiratory diseases and thoracic surgery specifically in Ankara, Turkey, and was, therefore, classified as a nonpandemic hospital. Therefore, during the pandemic, patients with symptoms and signs of suspected lung cancer were referred from all over the country and admitted to our clinic for further examination and treatment. At the onset of the pandemic, there were no national or international guidelines determined for bronchoscopic procedures, which presented a significant problem. Although the COVID-19 Science Committee Guideline was updated on 14 April, there was still no clear recommendation regarding bronchoscopic procedures, 13 so the precautions applied before, during, and after this point in relation to bronchoscopic procedures were determined together with hospital administration and an infection committee.
We assigned the precise bronchoscopy indications for both outpatients and the intensive care unit patients and implemented the applications outlined below within the framework of protection measures determined by the Centers for Disease Control and Prevention in the United States. 14 
All procedures were performed in an independent bronchoscopy unit with separate ventilation and high-efficiency particulate air filters, close to intensive care; we did not have a negative pressure room.
Staff were reduced to a minimum throughout the day by creating a core team including a bronchoscopist, bronchoscopy assistants, nurses, and an anesthetist who carried out all the daily interventions.
Preprocedure, in the bronchoscopy unit and resting area, a surgical mask was worn by all patients. All personnel in the operating room were dressed in personal protective equipment (PPE), including an N95 mask, eye protection (reusable safety glasses), disposable gloves, an impervious gown, a face shield, and a cap. All procedures were implemented under deep sedation or general anesthesia. For flexible bronchoscopy, a transnasal approach was preferred. For rigid bronchoscopy, conventional closed-circuit ventilation, and reduction of the aerosol leakage were preferred; jet ventilation was avoided.
Patients who underwent EBUS-TBNA and FOB were discharged on the same day and were suggested to follow-up if they experienced symptoms such as fever, dyspnea, and cough for 14 days postprocedure. When the patients returned to the clinic after 10 days to receive their results, they were asked to disclose any of the aforementioned symptoms. Standard disinfection protocols were followed for the cleaning of bronchoscopes and video monitors, and at least 30 minutes were given for disinfection and ventilation between procedures.
In line with these precautions taken during the first 2 months of the pandemic period, a total of 36 interventional procedures, 74 EBUS-TBNA, and 16 FOB were performed. Even though Ost DE recommends testing all patients before the procedure, we only tested 31 of 126 (24.6%) patients. 15 Although this was due to the difficulty of accessing tests during the initial pandemic, we decided it was more appropriate to test patients with a higher likelihood of infection based on symptoms, since the false negativity of the test was about 67% in the following days. 16 The first American Association for Bronchology and Interventional Pulmonology statement was published in late March; in the following days, expert opinions on the use of bronchoscopy during the COVID-19 pandemic were published one after another. [17] [18] [19] [20] [21] While the use of PPE and bronchoscopy indications were similar between the published reports and our practice, not using negative pressure rooms, not testing all patients, using a reusable bronchoscope and only giving a 30-minute interval between the procedures are the notable differences between the reports and our practice. We proved that these differences did not cause any problems in the detection of COVID-19 in either patients and health care workers after the procedure.
Although it has been reported that a brief delay (2-3 weeks) will not harm cancer diagnosis and staging, 22 how long the COVID-19 pandemic will continue is still unknown. Bronchoscopy is often required both for diagnosis and staging, and timeliness of bronchoscopic diagnosis impacts every stage of lung cancer care. Also, EBUS for staging and diagnosis as the first test in patients with T1-3, N1-3, and M0 disease has been shown to decreases complications, the number of tests required and time to treatment. 23 Moreover, delays in care may lead to missed opportunities in terms of cure or palliation for lung cancer. So, whether it is judicious to delay bronchoscopy or EBUS of patients with known or suspected lung cancer in this unknown process is the question at hand. Based on our experience, the answer to this question is no, EBUS and/or bronchoscopy should not be postponed in patients with known or suspected lung cancer; we determined that COVID-19 transmission can be prevented by taken sufficient and necessary precautions.