Epidemiological characteristics, baseline clinical features, and outcomes of critically ill patients treated in a coronavirus disease 2019 tertiary center in continental Croatia

Aim To describe epidemiological characteristics and base - line clinical features, laboratory findings at intensive care unit (ICU) admission, and survival rates of critically ill coro - navirus disease 2019 (COVID-19) patients treated at a ter - tiary institution specialized for COVID-19 patients. Methods This retrospective study recruited 692 patients (67.1% men). Baseline demographic data, major comorbid - ities, anthropometric measurements, clinical features, and laboratory findings at admission were compared between survivors and non-survivors. Results The median age was 72 (64-78) years. The median body mass index was 29.1 kg/m 2 . The most relevant comor - bidities were diabetes mellitus (32.6%), arterial hyperten - sion (71.2%), congestive heart failure (19.1%), chronic kid - ney disease (12.6%), and hematological disorders (10.3%). The median number of comorbidities was 3 and median Charlson Comorbidity Index (CCI) was 5. A total of 61.8% patients received high-flow nasal oxygen therapy (HFNO) and 80.5% received mechanical ventilation (MV). Median duration of HFNO was 3, and that of MV was 7 days. ICU mortality rate was 72.7%. Survivors had significantly lower age, number of comorbidities, CCI, sequential organ failure assessment score, serum ferritin, C-reactive protein, D-dim - er, and procalcitonin, interleukin-6, lactate, white blood cell, and neutrophil counts. They also had higher lymphocyte counts, Pa O 2 /FiO 2 ratio, and glomerular filtration rate at ad - mission. Length of ICU stay was 9 days. The median surviv - al was 11 days for mechanically ventilated patients, and 24 days for patients who were not mechanically ventilated. Conclusion The parameters that differentiate survivors from non-survivors are in agreement with published data. Further multivariate analyses are warranted to identify in - dividual mortality risk factors