Clinical Features for Severely and Critically Ill Patients with COVID-19 in Shandong: A Retrospective Cohort Study

Abstract

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel pathogen, has caused an outbreak of coronavirus disease 2019 (COVID-19) that has spread rapidly around the world. Determining the risk factors for death and the differences in clinical features between severely ill and critically ill patients with SARS-CoV-2 pneumonia has become increasingly important.

Aim: This study was intended to provide insight into the difference between severely ill and critically ill patients with SARS-CoV-2 pneumonia.

Methods: In this retrospective, multicenter cohort study, we enrolled 62 seriously ill patients with SARS-CoV-2 pneumonia who had been diagnosed by March 12, 2020. Clinical data, laboratory indexes, chest images, and treatment strategies collected from routine medical records were compared between severely ill and critically ill patients. Univariate and multivariate logistic regression analyses were also conducted to identify the risk factors associated with the progression of patients with severe COVID-19.

Results: Of the 62 patients with severe or critical illness, including 7 who died, 30 (48%) patients had underlying diseases, of which the most common was cardiovascular disease (hypertension, 34%, and coronary heart disease, 5%). Compared to patients with severe disease, those with critical disease had distinctly higher white blood cell counts, procalcitonin levels, and D-dimer levels, and lower hemoglobin levels and lymphocyte counts. Multivariate regression showed that a lymphocyte count less than 10⁹/L (odds ratio 20.92, 95% CI 1.76-248.18; p=0.02) at admission increased the risk of developing a critical illness.

Conclusion: Based on multivariate regression analysis, a lower lymphocyte count (<10⁹/L) on admission is the most critical independent factor that is closely associated with an increased risk of progression to critical illness. Age, underlying diseases, especially hypertension and coronary heart disease, elevated D-dimer, decreased hemoglobin, and SOFA score, and APACH score also need to be taken into account for predicting disease progression. Blood cell counts and procalcitonin levels for the later secondary bacterial infection have a certain reference values.

Keywords: COVID-19; SARS-CoV-2; clinical features; critically ill patients; severely ill patients.

Figure 1

Characteristics of patients whose initial symptom was not fever. (A) Duration (days) from illness onset to fever for these patients; the median duration was 3 days. (B) Major initial symptoms other than fever.

Figure 2

Evolution of chest computed tomographic image findings of a patient with critical COVID-19 during hospitalization. (A) CT image on admission (day 3 after illness onset) showing diffuse bilateral ground glass opacities (GGOs), which were mostly concentrated in the right lung. High-density shadows were distributed in the right inferior lobar bronchus close to the pleura. (B) CT image on the day 9 after illness onset when the patient became severely ill. Large areas of subpleural GGOs and consolidation with air bronchogram signs were observed. (C and D) show the lesions being gradually absorbed on day 19 and 26 after symptom onset.

Figure 3

Treatment strategies for patients with severe COVID-19. (A) Recovery time (from severe to moderate disease) between the gamma globulin/thymosin-treated group and the control group. (B–D) Chi-square test comparing control patients and patients treated with thymosin (p=0.15)/globulin (p=1)/glucocorticoid (p=0.16) during the severe illness phase (14 patients were excluded because of their short severe stage (less than 2 days)). (E) Dosage of glucocorticoids within 3 days after the diagnosis of severe for the severe and critical groups. (F) Types and frequency of glucocorticoids for treating patients with severe COVID-19. (G) Types and frequency of antibiotics for treating patients with severe COVID-19.