ABSTRACT
Background and Aim of the study: Evidence suggests that most patients who recovered from COVID-19 carry residual respiratory symptoms. Aim of the study was to evaluate blood gas changes in post-COVID-19 patients. Materials and Methods: Hospitalized COVID-19 patients attending the outpatient clinic for post-COVID-19 patients in Magenta (Italy) were included in this retrospective study. They underwent blood draw (for inflammatory biomarkers and arterial blood gas analysis [ABG]) and chest high-resolution computed tomography (HRCT) scan. The primary endpoint was the assessment of blood gas exchanges after 3 months. Other endpoints included assessment of symptoms and chest HRCT scan abnormalities and changes in inflammatory biomarkers after 3 months from hospital discharge. Results: Eighty-eight patients (n=65 men) were included. Admission ABG showed hypoxia and hypocapnia and a PaO2/FiO2 of 271.4 (IQR 238-304.7) mmHg, that greatly improved after 3 months (426.19 [IQR 395.2-461.9] mmHg, p<0.001). Forty percent of patients were hypocapnic after 3 months, while inflammatory biomarkers improved. Fever, resting dyspnea, and cough were common at hospital admission and improved after 3 months, when dyspnea on exertion and arthralgias arose. On chest HRCT scan, more than half of individuals still presented interstitial involvement after 3 months. Conclusions: While inflammatory biomarkers normalized after 3 months, signs of lung damage persisted for a longer period, suggesting the need for an adequate follow-up of post-COVID- 19 patients.
ABSTRACT
Background: COVID-19, the disease caused by SARS-CoV-2, ischaracterized by multiple lung infiltrates and extensive venous andarterial thromboembolism. Little is known about the natural historyof the disease, so we plan an outpatient clinic to follow COVID-19patients.Materials and Methods: All patients discharged alive who hasdeveloped respiratory insufficiency (i.e., arterial pO2 less than 60mmHg), or have needed mechanical ventilation for at least 72hours, or had lung infiltrates >40% of pulmonary parenchyma waseligible for the study. All those patients were re-evaluated at 1 and3 months after discharge with high-resolution CT (HRCT) of thechest, blood gases, blood chemistry, and Doppler color flow of theinvolved vessels.Results: Between February and May 2020, seventy-one COVID-19 patients were re-evaluated. Of these, with HRCT study, 12(17.14%) had pulmonary fibrosis, 19 (27,14%) had ground-glassopacities and 25 (35%) had multiple lesions;15 (21,43%) wasnormal;52 (73%) had persistent hypocapnia (mean pCO2 35.9;SD 3.26);14 had to start steroid therapy again;all patients hadcomplete vein recanalization at CUS. Conclusions: Our preliminary report showed that an outpatientclinic for patients convalescent from COVID-19 is highly advisableand may result in better knowledge of the natural history of thedisease and may help to clarify which patients will need in prolonged treatment and interventions. Furthermore, we speculatedthat a high incidence of persistent hypocapnia may result frompulmonary venous vessel microthrombosis.