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

AimTo describe epidemiological characteristics and baseline clinical features, laboratory findings at intensive care unit (ICU) admission, and survival rates of critically ill coronavirus disease 2019 (COVID-19) patients treated at a tertiary institution specialized for COVID-19 patients.MethodsThis retrospective study recruited 692 patients (67.1% men). Baseline demographic data, major comorbidities, anthropometric measurements, clinical features, and laboratory findings at admission were compared between survivors and non-survivors.ResultsThe median age was 72 (64-78) years. The median body mass index was 29.1 kg/m². The most relevant comorbidities were diabetes mellitus (32.6%), arterial hypertension (71.2%), congestive heart failure (19.1%), chronic kidney 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-dimer, and procalcitonin, interleukin-6, lactate, white blood cell, and neutrophil counts. They also had higher lymphocyte counts, PaO₂/FiO₂ ratio, and glomerular filtration rate at admission. Length of ICU stay was 9 days. The median survival was 11 days for mechanically ventilated patients, and 24 days for patients who were not mechanically ventilated.ConclusionThe parameters that differentiate survivors from non-survivors are in agreement with published data. Further multivariate analyses are warranted to identify individual mortality risk factors.

The first case of coronavirus disease 2019 (COVID-19) in Croatia was confirmed on February 25, 2020 (1). Very soon, on March 11, the World Health Organization (WHO) declared a COVID-19 pandemic (2). As of February 25, 2021, there were more than 240 000 confirmed cases and 5489 deaths in Croatia.As a part of the national strategy against COVID-19 pandemic, the Ministry of Health and Civil Protection Headquarters decided that University Hospital Dubrava (UH) is to be repurposed into a Primary Respiratory Center for patients with confirmed COVID-19 infection. The intensive center of primary respiratory intensive center (PRIC-IC) is a subunit of UH Dubrava reserved for the treatment of patients with severe symptoms of COVID-19 who require mechanical ventilation, vasoactive hemodynamic support, continuous renal replacement therapy, and other aspects of intensive care (3). UH Dubrava became a COVID-19 tertiary center treating a third of all COVID-19 positive ICU patients in the country.As the pandemic was surging through Europe, the number of critically ill COVID-19 patients in UH Dubrava continued to grow, and ICU capacities needed expansion. During winter months, six intensive care units in PRIC were operating at the same time: Three were run by intensivists from UH Dubrava and three by intensivists from other hospitals in Zagreb, including University Hospital Center Zagreb, University Hospital Center Sestre Milosrdnice, University Hospital Sveti Duh, University Hospital Merkur, and Children''s Hospital Zagreb. The outcomes of critically ill patients treated in PRIC-IC therefore represent the work of intensivists from all hospitals in Zagreb.Although scientific knowledge of COVID-19 increases daily, limited information is available regarding early identification of individuals who are at risk of developing severe symptoms. Previous studies reported certain demographic features and clinical characteristics of patients who were likely to develop severe symptoms of COVID-19 and thus require mechanical ventilation (4-7). Studies worldwide reported high mortality rates for patients requiring mechanical ventilation, ranging from 40% to 97% (4,8-10). Unfortunately, some of these reports were preliminary and included patients without a completed ICU stay. The aim of our cohort retrospective study is to describe the demographic characteristic, clinical features, laboratory values, and outcomes among critically ill COVID-19 patients treated in PRIC-IC, UH Dubrava.