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provement), optimal setting (hierarchic approach to operative location, enhanced PPE), optimal procedure and management after tracheostomy (McGrath 2020).

Lung Transplantation

As in other terminal lung diseases, lung transplantation (LTX) can be a potential therapeutic option. Of course, the indication needs to be considered especially careful. In an editorial published in August 2020, the authors list ten considerations that they believe should be carefully weighed when assessing a patient with COVID-19-associated ARDS regarding potential candidacy for lung transplantation (< 65 years, only single-organ dysfunction, sufficient time for lung recovery, radiological evidence of irreversible lung disease, such as severe bullous destruction or established fibrosis, etc) (Cypel 2020). Up to now, only case reports have been published. After 52 days of critical COVID-19, ECMO and several complications, a comprehensive interdisciplinary discussion on the direction of treatment resulted in a consensus that the lungs of the otherwise healthy 44-year-old woman from Klagenfurt, Austria had no potential for recovery. On day 58, a suitable donor organ became available, and a sequential bilateral lung transplant was performed. At day 144, the patient remained well. Despite the success of this case, the authors emphasize that lung transplantation is an option for only a small proportion of patients (Lang 2020).

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Christian Hoffmann Published 20 January 2021

Hundreds of articles have been published over the last twelve months, making well-meaning attempts to determine whether patients with different comorbidities are more susceptible for SARS-CoV-2 infection or at higher risk for severe disease. This deluge of scientific publications has resulted in worldwide uncertainty. For a number of reasons, many studies must be interpreted with extreme caution. First, in many articles, the number of patients with specific co-morbidities is low. Small sample sizes preclude accurate comparison of COVID-19 risk between these patients and the general population. They may also overestimate mortality, especially if the observations were made in-hospital (reporting bias). Moreover, the clinical manifestation and the relevance of a condition may be heterogeneous. Is the hypertension treated or untreated? What is the stage of the COPD, only mild or very severe with low blood oxygen levels? Is the “cancer” cured, untreated or actively being treated? Are we talking about a seminoma cured by surgical orchiectomy years ago or about palliative care for pancreatic cancer? What is a “former” smoker: someone who decided to quit 20 years ago after a few months puffing during adolescence or someone with 40 package-years who stopped the day before his lung transplantation? Does “HIV” mean a well controlled infection while on long-lasting, successful antiretroviral therapy or an untreated case of AIDS? Unfortunately, many researchers tend to combine these cases, in order to get larger numbers and to get their paper published. Second, there are numerous confounding factors to consider. In some case series, only symptomatic patients are described, in others only those who were hospitalized (and who have per se a higher risk for severe disease). In some countries, every patient with SARS-CoV-2 infection will be hospitalized, in others only those with risk factors or with severe COVID-19. Testing policies vary widely between countries. The control group (with or without comorbidities) is not always well-defined. Samples may not be representative, risk factors not correctly taken into account. Sometimes, there is incomplete information about age distribution, ethnicity, co-morbidities, smoking, drug use and gender (there is some evidence that, in female patients, comorbidities have no or less impact on the course of the disease, compared to

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