Convalescent Plasma Infusion in Italian Hospitalized Patients with Severe COVID 19 Pneumonia: Evaluation of Late Mortality Associated Factors

Background: This was a single center prospective study about factors related with mortality in hospitalized patients with severe COVID-19 pneumonia treated with convalescent plasma (CCP) infusion in Venice Prefecture.

Methods: In this study were enrolled all the (376) consecutive hospitalized patients with severe COVID-19 pneumonia treated with CCP observed from 30/04/2020 to 31/10/2021. At hospital admission, in order to evaluate correlation with prognosis, study recorded demographic data, clinical data, presence of co morbidities, Rx findings, laboratory results. The endpoint was mortality at 30 days.

Results: Using multivariate analysis, considering demographic data and co morbidities four variables emerged as significant independent predictors of 30-day mortality: age>70 years, tobacco smoke, obesity (BMI>30), Diabetes. Considering Patients’ clinical characteristics at hospital admission two variables emerged as significant independent predictors of 30-day mortality in this cohort of hospitalized patients with severe COVID-19 Pneumonia: PaO2/FiO2 ratio under 200 and lungs imaging with a score >3.

Discussion: Late mortality was investigated in a series of consecutive, hospitalized, patients with severe COVID-19. We therefore believe that any influence linked to the level of expertise of the clinical staff and available technology was minimal. Furthermore, we also tried to reduce, as much as possible, the variables related CCP infusion using plasma with a neutralizing antibody titer> 80 and a standardized dose: a 200 mL unit per day for three consecutive days. Moreover, using both a univariate and multivariate analytical approach, numerous demographic variables were considered, relating to comorbidities, all clinical characteristics, to laboratory data; correlating them with mortality at 30 days.