Treatment of Acute Respiratory Failure in the Course of COVID-19. Practical Hints from the Expert Panel of the Assembly of Intensive Care and Rehabilitation of the Polish Respiratory Society

Abstract

In 2019, a pandemic began due to infection with a novel coronavirus, SARS-CoV-2. In many cases, this coronavirus leads to the development of the COVID-19 disease. Lung damage in the course of this disease often leads to acute hypoxic respiratory failure and may eventually lead to acute respiratory distress syndrome (ARDS). Respiratory failure as a result of COVID-19 can develop very quickly and a small percent of those infected will die because of it. There is currently no treatment for COVID-19, therefore the key therapeutic intervention centers around the symptomatic treatment of respiratory failure. The main therapeutic goal is to maintain gas exchange, mainly oxygenation, at an appropriate level and prevent the intensification of changes in the lung parenchyma. Depending on the severity of hypoxemia different techniques can be used to improve oxygenation. Medical staff dealing with COVID-19 patients should be familiar with both, methods used to treat respiratory failure and the epidemiological risks arising from their use. In some patients, conventional (passive) oxygen therapy alone is sufficient. In patients with worsening respiratory failure high flow nasal oxygen therapy (HFNOT) may be effective. The continuous positive airway pressure (CPAP) and non-invasive ventilation (NIV) methods can be used to a limited extent. With further disease progression, invasive ventilation must be used and in special situations, extracorporeal membrane oxygenation (ECMO) can also be administered. The authors of this article set themselves the goal of presenting the most current knowledge about the epidemiology and pathophysiology of respiratory failure in COVID-19, as well as the methods of its treatment. Given the dynamics of the developing pandemic, this is not an easy task as new scientific data is presented almost every day. However, we believe the knowledge contained in this study will help doctors care for patients with COVID-19. The main target audience of this study is not so much pneumonologists or intensivists who have extensive experience in the application of the techniques discussed here, but rather doctors of other specializations who must master new skills in order to help patients during the time of a pandemic.

Continuous positive air pressure (CPAP) should be used in all COVID-19 patients when the first and mild respiratory symptoms commence

“…in regular wards or at patient's homes. This method would prevent periods of hypopnea and hypoxia which can stimulate the synthesis of ACE in lung endothelial cells, finally leading to cytokine storm, which can cause ARDS and multi-organ failure [9,14,110,112,116,118].…”

“…Nonetheless, the use of HFVO remains controversial in suspected and confirmed severe cases of COVID-19 disease. As a result, currently in the UK, the national guidance does not recommend HFNO in COVID-19 because for the lack of evidence of efficacy, the high oxygen usage, and risk of infection spread [8,14,35,110].…”

“…The application of Positive End Expiratory Pressure (PEEP) assists in maintaining the patient's airway pressure prevents alveolar collapse, in turn increasing lung volumes and distends them to reduce the distance between the alveolar and the blood vessels to improve gaseous exchange. In severe COVID-19, initial CPAP setting have been suggested 10 cm H2O and 60% oxygen [14,110,112,[116][117][118][119][120][121][122].…”

“…The mechanisms of lung damage and hypoxemia in COVID 19 include ventilation/perfusion mismatch, loss of hypoxic vasoconstriction and increased coagulopathy. Hence, it is of particular attention that acute lung injury, hypoxemia, systemic inflammatory response syndrome (SIRS), and ARDS occur after SARS-CoV-2 infection [9,10,[11][12][13][14].…”

SARS-CoV-2 and lung transplantation. What do we know?

“…Advanced age and comorbidities are considered as risk factors for severe disease. In 97% of the patients undergoing acute Covid-19 infection pathological changes in the chest are seen on CT images [1]. In case of irreversible and serious lung parenchyma damage, lung transplantation (LuTx) might be necessary to restore respiratory efficiency.…”