Demographics and baseline characteristics in severe COVID-19 patients
Between January 5, 2020, to Feb 22, 2020, 101 patients (87 from Jin Yin-tan hospital, 14 from Wuhan Union hospital) with severe COVID-19 who underwent chest CT scans on admission were included in this study. According to hospital data, of 87 patients from Jin Yin-tan hospital, 16 have been described by Wu et al and Zhou et al.
Of all patients with severe COVID-19, 66 patients (65.3%) have recovered from severe pneumonia and were discharged from hospital, 35 cases (34.7%) died despite supportive treatment. As Table 1 showed, the mean age was 56.6±15.1 years (ranged from 23 to 82 years old). 67 (66.3%) were male, 15 (14.9%) had direct exposure to the Huanan seafood market, 8 cases (7.9%) were familial clusters. The most common symptom at onset were fever (96, 95.0%) and cough (79, 78.2%). Of the 101 patients, the most common coexisting conditions was hypertension (38, 37.6%), followed by cardiovascular disease, diabetes and chronic pulmonary disease. In addition, 14 (13.9%) patients were complicated with bacterial infection.
The mean duration from onset of symptoms to hospital admission, ARDS and ICU admission were 11.2±5.5 days, 15.0±6.6 days, and 15.4±5.4 days, respectively. The mean hospital day and duration of disease were 15.6±8.1 days and 26.6±8.5 days, respectively. The mean duration from onset of symptoms to ICU admission was significantly longer in deceased patients than discharged patients (p＜0.05). The hospital day and duration of disease were significantly longer in discharged patients than deceased groups (p＜0.05) (Table 1).
Compared with discharged patients, deceased patients were significantly older and were more likely to have ARDS and comorbidities, including cardiovascular disease , diabetes, hypertension, and chronic pulmonary disease (p＜0.05) (Table 1).
All patients were treated oxygen therapy (100%). 93 (92.1%) patients received antibacterial treatment, 88 (87.1%) patients received antiviral treatment, 49 (50%) received glucocorticosteroids, 45 (86.5%) received immunoglobulin, 22 (21.8%) received tracheal intubation, and 4 (4.1%) patients received extracorporeal membrane oxygenation (ECMO). Compared with discharged patients, deceased patients were more likely to receive glucocorticosteroids, immunoglobulin, tracheal intubation and ECMO (Table 1).
The mean survival time in the death group from disease onset to death were 22.6±7.2 days. Among the 35 severe deceased cases, 21 patients (60%) died of respiratory failure, 4 patients (11.4%) with myocardial damage died of circulatory failure, 8 patients (22.9%) died of respiratory and circulatory failure, and 2 (5.7%) with severe sepsis died of multiple organ failure (Figure 1).
Baseline laboratory findings in severe COVID-19 patients
The laboratory findings showed lymphocytopenia in 62 (82.7%) patients on admission. 54 (68.4%) patients were noted to have elevated alanine transaminase (ALT), 49 (64.5%) had elevated aspartate aminotransferase(AST), 77 (96.3%) had elevated lactate dehydrogenase (LDH), 56 (87.5%) patients had elevated D-dimer, 45 (84.9%) had elevated hypersensitive troponin I, and 31 (57.4%) had elevated myoglobin. The levels of hyper-sensitive C-reactive protein, Serum amyloid A protein, and erythrocyte sedimentation rate were markedly increased in almost all patients (Table 2).
The lymphocyte count, hemoglobin, albumin level on admission and oxygen saturation on room air were significantly lower in deceased patients than discharged patients (p＜0.05). Lactate dehydrogenase (LDH), creatinine, D-dimer and hypersensitive troponin I level on admission were higher in deceased patients than discharged patients (p＜0.05) (Table 2).
Baseline HRCT findings in severe COVID-19 patients
The median time interval from admission to baseline CT scan in all patients were 4 days (IQR 1,9), with no difference between discharged and deceased patients (Table 3). The typical chest CT findings of severe COVID-19 on admission were diffuse bilateral GGO and consolidation in peripheral areas (Figure 2-7). GGO (90, 89.1%) is main diffusion lesion characteristics in all patients, and consolidation proportion (8[22.9] vs 3[4.5], p＝0.005) was comparatively higher in deceased patients than discharged patients (Table 3). The mean total CT scores in all patients was 17.4±5.1. Deceased patients had higher CT scores than discharged patients (20.9±3.0 vs 15.6±5.0, p＜0.001) (Figure1).
The other common CT findings were interlobular septal thickening (72/101, 71.3%), crazy paving (48/101, 47.5%) and air bronchograms (75/101, 74.3%). The relatively less common CT findings were pleural effusion (28/101, 28%), emphysema (15/101, 14.9%), hydropericardium (10/101, 9.9%) and pneumomediastinum (3/101, 3.0%) (Table 3).
Interlobular septal thickening, crazy-paving, air bronchogram, and pleural were significantly more common in deceased patients than discharged patients (p＜0.05) (Table 3).
Univariate and multivariable analysis of predictors of mortality risk
By univariate regression analysis in severe COVID-19 patients, the following baseline characteristics were predictors of mortality risk: older age, faster respiratory rate, ARDS, history of diabetes, history of hypertension; the following laboratory findings were predictors of mortality risk: reduced lymphocyte count, reduced albumin, elevated lactate dehydrogenase, elevated D-dimer, reduced SpO2 at room air; the following baseline HRCT findings were predictors of mortality risk: elevated total HRCT score, higher consolidation proportion, pleural effusion (Table 4).
The multivariable regression analysis showed older age (OR:1.142, 95% CI:1.059-1.231, p＜0.001), ARDS (OR:10.142, 95% CI:1.611-63.853, p=0.014), reduced lymphocyte count (OR:0.004, 95% CI: 0.001-0.306, p=0.013), and elevated HRCT score (OR:1.276, 95% CI:1.002-1.625, p=0.049) independent predictors of mortality risk on admission in severe COVID-19 patients (Table 4).