variable intrathoracic stenosis, the angle of the P–P curve during expiration is smaller than during inspiration.

Conclusions

Placement of the stent at the ow-limiting segment (FLS) provided the greatest functional beneft to patients with central airway stenosis [4, 5]. Although bronchoscopic imaging showed that tracheal patency was restored after procedures, the angle of P–P curve did not always improve. It is diffcult to estimate the outcome of interventional procedures by bronchoscopy alone. When the location of the FLS is assessed using ow– volume curves, the pressure difference and the angle of pressure–pressure curve are able to immediately estimate the outcomes of interventional bronchoscopy in real time.

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Introduction

Coronavirus disease (COVID) emerged in December 2019 as an important and worldwide infectious disease caused by a previous unknown pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The ability for human-to-human transmission, mainly through respiratory droplets or aerosols, facilitated its rapid dissemination [1].

According to the World Health Organization, as of December 2021, nearly 269 million people have been infected and more than 5 million people have died of this disease worldwide.

All airway and aerosol-generating procedures were immediately recognized as a major risk of spreading contaminated droplets, and health care facilities had to quickly adapt to this reality. Pulmonology departments and interventional pulmonology (IP) units were in the battle front of

F. Guedes (*)

Pulmonology Department, Centre Hospitalier du Nord, Ettelbruck, Luxembourg

ICBAS, Instituto de Ciências Biomédicas Abel Salazar, Porto, Portugal

A. Bugalho

Pulmonology Department, CUF Tejo Hospital and CUF Descobertas Hospital, Lisbon, Portugal

Comprehensive Health Research Centre, Chronic Diseases Research Center (CEDOC), NOVA Medical School, Lisbon, Portugal

this war since these are preferential locations to diagnose and treat respiratory and thoracic disorders.

The role of bronchoscopy in COVID-19 patients was rapidly evaluated after the beginning of the outbreak but is still a matter of debate. In patients with clinical and radiological suspicion of COVID-19 with negative nasopharyngeal swab specimen by real-time polymerase chain reaction with reverse transcription (RT-PCR), bronchoscopy can be useful, increasing sensitivity by obtaining samples from the lower respiratory tract [2]. On the other side, in patients with con rmed severe COVID-19, bronchoscopy can be required to manage complications such as atelectasis, hemoptysis, or to rule out superinfection [3].

Although many societies have drafted guidelines regarding this issue, none of the recommendations have a high level of evidence and some topics are quite incomplete and need further scienti c data and evaluation [4–9].

The IP department is a particularly high-risk area, given the procedures performed with airway manipulation, mainly in patients with respiratory diseases and with multiple staff involved. Although dedicated and new settings were designed to deal with airborne infectious diseases, they were not prepared to systematically execute high-risk cases/procedures, which causes an increased strain to health care systems, with diminished productivity, higher workload, and need for additional resources.