Definitions and Diagnosis
Axillary temperature over 37.3°C was regarded as fever. Presence of signs and symptoms of bacteremia or pneumonia together with an endotracheal aspirate or lower respiratory tract sputum culture positive for a new pathogen was evaluated as secondary bacterial infection. Patients diagnosed as having ventilator-associated or hospital-acquired pneumonia were treated according to the available guidelines. ARDS was diagnosed and classified using the 2015 Berlin diagnostic criteria. If the daily cardiac-specific troponin-I level of the patients was above normal, the patient was evaluated by echocardiography for newly developed cardiac pathologies. Coagulopathy was defined as prothrombin and partial thromboplastin times prolonged by 3 s and 5 s, respectively. Based on disease severity, treatment was planned according to the COVID-19 adult diagnosis and treatment guidelines published by the Turkish Ministry of Health. Patients exhibiting findings such as persistent fever, C-reactive protein (CRP), and ferritin levels that remain high or continue to increase, D-dimer elevation, thrombocytopenia or lymphopenia, abnormal liver function tests, hypofibrinogenemia, or elevated triglyceride levels despite treatment were followed up for MAS. If repeated measures of these parameters showed continued deterioration that could not be explained by secondary bacterial infection, the patients were given 400 mg tocilizumab for MAS if not contraindicated. Clinical and laboratory response was evaluated after 24 hours. Only patients who did not respond were given another 400 mg of tocilizumab.