Coronavirus disease 2019 (COVID-19) can cause severe respiratory failure requiring mechanical ventilation. The abnormalities observed on chest computed tomography (CT) and the clinical presentation of COVID-19 patients are not always like those of typical acute respiratory distress syndrome (ARDS) and can change over time. This manuscript aimed to provide brief guidance for respiratory management of COVID-19 patients before, during, and after mechanical ventilation, based on the recent literature and on our direct experience with this population. We identify that chest CT patterns in COVID-19 may be divided into three main phenotypes: 1) multiple, focal, possibly overperfused ground-glass opacities; 2) inhomogeneously distributed atelectasis; and 3) a patchy, ARDS-like pattern. Each phenotype can benefit from different treatments and ventilator settings. Also, peripheral macro-and microemboli are common, and attention should be paid to the risk of pulmonary embolism. We suggest use of personalized mechanical ventilation strategies based on respiratory mechanics and chest CT patterns. Further research is warranted to confirm our hypothesis.

Objectives To describe clinical characteristics, management and outcome of individuals with coronavirus disease 2019 (COVID-19); and to evaluate risk factors for all-cause in-hospital mortality. Methods This retrospective study from a University tertiary care hospital in northern Italy, included hospitalized adult patients with a diagnosis of COVID-19 between 25 February 2020 and 25 March 2020. Results Overall, 317 individuals were enrolled. Their median age was 71 years and 67.2% were male (213/317). The most common underlying diseases were hypertension (149/317; 47.0%), cardiovascular disease (63/317; 19.9%) and diabetes (49/317; 15.5%). Common symptoms at the time of COVID-19 diagnosis included fever (285/317; 89.9%), shortness of breath (167/317; 52.7%) and dry cough (156/317; 49.2%). An ‘atypical’ presentation including at least one among mental confusion, diarrhoea or nausea and vomiting was observed in 53/317 patients (16.7%). Hypokalaemia occurred in 25.8% (78/302) and 18.5% (56/303) had acute kidney injury. During hospitalization, 111/317 patients (35.0%) received non-invasive respiratory support, 65/317 (20.5%) were admitted to the intensive care unit (ICU) and 60/317 (18.5%) required invasive mechanical ventilation. All-cause in-hospital mortality, assessed in 275 patients, was 43.6% (120/275). On multivariable analysis, age (per-year increase OR 1.07; 95% CI 1.04–1.10; p < 0.001), cardiovascular disease (OR 2.58; 95% CI 1.07–6.25; p 0.03), and C-reactive protein levels (per-point increase OR 1.009; 95% CI 1.004–1.014; p 0.001) were independent risk factors for all-cause in-hospital mortality. Conclusions COVID-19 mainly affected elderly patients with predisposing conditions and caused severe illness, frequently requiring non-invasive respiratory support or ICU admission. Despite supportive care, COVID-19 remains associated with a substantial risk of all-cause in-hospital mortality.

Highlights Physiotherapy may help prevent or mitigate sequelae related to bed rest, thus improving physical function and outcomes and reducing length of stay by increasing ventilator free-days. Before starting chest physiotherapy, we recommend the use of adequate personal protective equipment, limiting healthcare workers in the room to one physician and one physiotherapist, as well as choosing a negative-pressure chamber if available. Chest physiotherapy should be tailored to the specific phenotype of COVID-19 patients. Patients who might be eligible for a spontaneous breathing trial should receive chest physiotehrapy before and after extubation. NIV, CPAP, and HFNO should also be considered for short periods after extubation, until complete respiratory autonomy is reached.

Background Critically ill COVID-19 patients have pathophysiological lung features characterized by perfusion abnormalities. However, to date no study has evaluated whether the changes in the distribution of pulmonary gas and blood volume are associated with the severity of gas-exchange impairment and the type of respiratory support (non-invasive versus invasive) in patients with severe COVID-19 pneumonia. Methods This was a single-center, retrospective cohort study conducted in a tertiary care hospital in Northern Italy during the first pandemic wave. Pulmonary gas and blood distribution was assessed using a technique for quantitative analysis of dual-energy computed tomography. Lung aeration loss (reflected by percentage of normally aerated lung tissue) and the extent of gas:blood volume mismatch (percentage of non-aerated, perfused lung tissue—shunt; aerated, non-perfused dead space; and non-aerated/non-perfused regions) were evaluated in critically ill COVID-19 patients with different clinical severity as reflected by the need for non-invasive or invasive respiratory support. Results Thirty-five patients admitted to the intensive care unit between February 29th and May 30th, 2020 were included. Patients requiring invasive versus non-invasive mechanical ventilation had both a lower percentage of normally aerated lung tissue (median [interquartile range] 33% [24–49%] vs. 63% [44–68%], p < 0.001); and a larger extent of gas:blood volume mismatch (43% [30–49%] vs. 25% [14–28%], p = 0.001), due to higher shunt (23% [15–32%] vs. 5% [2–16%], p = 0.001) and non-aerated/non perfused regions (5% [3–10%] vs. 1% [0–2%], p = 0.001). The PaO2/FiO2 ratio correlated positively with normally aerated tissue (ρ = 0.730, p < 0.001) and negatively with the extent of gas-blood volume mismatch (ρ = − 0.633, p < 0.001). Conclusions In critically ill patients with severe COVID-19 pneumonia, the need for invasive mechanical ventilation and oxygenation impairment were associated with loss of aeration and the extent of gas:blood volume mismatch. Graphic abstract

In critically ill patients with acute respiratory distress syndrome (ARDS) coronavirus disease 2019 (COVID-19), a high incidence of thromboembolic and hemorrhagic events is reported. COVID-19 may lead to impairment of the coagulation cascade, with an imbalance in platelet function and the regulatory mechanisms of coagulation and fibrinolysis. Clinical manifestations vary from a rise in laboratory markers and subclinical microthrombi to thromboembolic events, bleeding, and disseminated intravascular coagulation. After an inflammatory trigger, the mechanism for activation of the coagulation cascade in COVID-19 is the tissue factor pathway, which causes endotoxin and tumor necrosis factor-mediated production of interleukins and platelet activation. The consequent massive infiltration of activated platelets may be responsible for inflammatory infiltrates in the endothelial space, as well as thrombocytopenia. The variety of clinical presentations of the coagulopathy confronts the clinician with the difficult questions of whether and how to provide optimal supportive care. In addition to coagulation tests, advanced laboratory tests such as protein C, protein S, antithrombin, tissue factor pathway inhibitors, D-dimers, activated factor Xa, and quantification of specific coagulation factors can be useful, as can thromboelastography or thromboelastometry. Treatment should be tailored, focusing on the estimated risk of bleeding and thrombosis. The aim of this review is to explore the pathophysiology and clinical evidence of coagulation disorders in severe ARDS-related COVID-19 patients.