When to Apply to Which Patient in MSC?

The study was conducted retrospectively in patients diagnosis of COVID-19 in the intensive care units. Patients with severe ARDS \[partial pressure of arterial blood oxygen and inhaled oxygen fraction (PaO2: FiO2) ratio of 100 or less\] were included in the study. Demographic data of the patients (gender, age), comorbidities (hypertension, coronary heart disease, diabetes, cerebrovascular diseases, hepatitis B infection, cancer, chronic kidney disease, and immunodeficiency), Charlson comorbidity index (CMI), date of diagnosis, date of admission to the hospital, date of admission to the ICU, Acute Physiology And Chronic Health Evaluation (APACHE) II score, presence of high flow nasal oxygen (HFNO) or mechanical ventilator (MV) support, laboratory findings (blood cell count, blood biochemistry, hepatorenal function, coagulation function, D-dimer, C-reactive protein (CRP), procalcitonin, ferritin, arterial blood gas analysis) before (day 0) and after MSC application, on 3rd and 7th days, partial oxygen/fractionated oxygen (Pa/Fi) ratio, discharge or death information, and attributed causes of death were recorded on the study form. Pa/Fi ratio was calculated with the formula (oxygen dissolved in arterial blood gas / oxygen liter given to the patient).