Risk factors for COVID-19 incidence and mortality in patients on maintenance hemodialysis

ABSTRACT

Patients on maintenance hemodialysis (MHD) are highly susceptible to SARS-CoV-2 and with high mortality rates due to Coronavirus disease 2019, mainly because of the older age in this group of patients, comorbidities, compromised immune status due to uremia, as well as inability to keep social isolation because of the necessity for regular physical presence in dialysis facility. Several retrospective studies of patients on MHD in Europe, America and Asia, show high susceptibility to SARS-CoV-2 in this group of patients with very high rates of critical course of the disease and high mortality rates, reaching more than 40% The aim of this retrospective observational study was to identify risk factors among patients on intermittent hemodialysis for infection with SARS-CoV-2 as well as predictors of severe COVID-19 and fatal outcome. Materials and methods. We analyzed 69 patients receiving intermittent dialysis in Aleksandrovska University Hospital - Hemodialysis Unit. 34 of them have been tested positive for SARS-CoV-2 in the period from September 2020 (when the first case of the disease was registered for our dialysis center) up to March 2022, and are compared with a control group of 35 dialysis-dependent patients without COVID-19. Data about comorbidities, main laboratory and radiologic findings, need of hospitalization and treatment in ICU, as well as data for conducted treatment, are collected from electronic medical records. To identify predictors of severe COVID and poor outcome we compared the group of survivors with the one of non-survivors. Results. There are no significant differences between patients on MHD with and without COVID-19 except higher frequency of COPD and hypoproteinemia in the positive group. Older age, female gender, history of smoking, lymphopenia with neutrophilia, treatment in ICU and need of mechanical ventilation, signs of malnutrition - hypoproteinemia and lower levels of serum creatinine, are risk factors for severe disease and fatal outcomes. Conclusions. The course of COVID infection in dialysis-dependent patients is severe and with high mortality rate, in line with other studies worldwide. Malnutrition is the main risk factor for COVID and also main predictor for poor outcomes.