Key words:
coronavirus disease 2019; severity; clinical characteristics; risk factors; mortality
Introduction
The emerging pandemic of coronavirus disease 2019 (COVID-19), an infectious disease caused by a novel strain of human coronaviruses, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2),1 has become worldwide the focus of attention. Since its first report in late December 2019 in Wuhan, China,2 COVID-19 has aggressively spread across the world and dramatically impacted people’s health and daily life. As of June 7, 2020, according to the Situation Report issued by the World Health Organization (WHO), the number of confirmed COVID-19 cases were reported in over two hundred countries/areas and exceeded 6.9 million, with about 397,000 reported deaths.3 The clinical patterns of COVID-19 ranged from asymptomatic cases to critically ill patients.4 Fever, dry cough, and radiological changes in lungs tend to be the common clinical manifestations in COVID-19 patients. Severe viral pneumonia with respiratory failure and the deterioration of underlying diseases are the main cause of death of severe patients. According to the data provided by the China National Health Commission, the mortality rate of COVID-19 patients was 7.7% in Wuhan,5 which was higher to that in the world at present (5.8%).3
As the number of infected and fatal cases are dramatically increasing throughout the world, it is vital to reveal the clinical, radiological and laboratory characteristics, and more importantly, the risk factors of mortality in severe COVID-19 patients. Our previous study found that higher levels of C-reactive proteins (CRP), D-dimer and procalcitonin (PCT) were associated with severe patients when compared to non-severe patients.6 However, the risk factors for mortality of the COVID-19 patients have not yet been well described. Elder age, the presence of comorbidities , leukocytosis, high level of D-dimer, lactate dehydratase (LDH) and low platelet counts were reported to be the risk factors associated with in-hospital death of severe patients.7-11 Due to the distinct criteria used for severe and/or critically ill patients, the prediction value of these risk factors for death in severe patients may be diverse.
The purpose of this study is to compare the clinical, radiological and laboratory characteristics and longitudinal variations in laboratory parameters of the 289 hospitalized patients with COVID-19 with different severity and clinical outcomes. Potential risk factors and clinical findings associated with death in severe COVID-19 patients were analyzed.
Methods2.1 Study design and patients’ enrollment
Hospitalized patients admitted to Zhongnan hospital of Wuhan University (n=178) and No.7 hospital of Wuhan (n=241) (admission date between Dec 29th, 2019 and Feb 16th, 2020), who were diagnosed as ‘viral pneumonia’ according to the clinical symptoms and chest CT images were primarily enrolled in this study. 289 patients with positive real-time reverse transcription–polymerase chain reaction (rRT-PCR) results of SARS-CoV-2 nucleic acid test were diagnosed as COVID-19 and included in the analysis set. According to the disease severity and clinical outcome, these patients were divided into three groups: 1) non-survived cases; 2) survived severe cases; 3) non-severe cases. All the patients were treated following the guidance issued by China National Health Commission (trial version 3-5).12 In accordance with the criteria stated in the guidance13 for hospital discharge of a COVID-19 patient, all the following four conditions should be met: 1) normal temperature lasting longer than 3 days; 2) significantly improved respiratory symptoms; 3) substantially improved acute exudative lesions on chest CT images; 4) two consecutive negative nucleic acid test results of respiratory tract samples (at least 24 hours apart). To be noticed, part of the result of these patients had been reported as letter to editor in Allergy which only demonstrated the difference of clinical characteristics between patients with initial negative and positive nucleic acid results of SARS-CoV-2.6 This study was approved by the Zhongnan Hospital of Wuhan University institutional ethics board (No.2020015 and No. 2020028).