[Comparative analysis of clinical features between severe coronavirus disease 2019 and severe community acquired...

To compare and analyze the clinical features of patients with severe coronavirus disease 2019 (sCOVID-19) and severe community acquired pneumonia (sCAP) who meet the diagnostic criteria for severe pneumonia of the Infectious Diseases Society of America/American Thoracic Society (IDSA/ATS).

A retrospective comparative analysis of the clinical records of 116 patients with sCOVID-19 admitted to the department of critical care medicine of Wuhan Third Hospital from January 1, 2020 to March 31, 2020 and 135 patients with sCAP admitted to the department of critical care medicine of Shanghai First People's Hospital from January 1, 2010 to December 31, 2017 was conducted. The basic information, diagnosis and comorbidities, laboratory data, etiology and imaging results, treatment, prognosis and outcome of the patients were collected. The differences in clinical data between sCOVID-19 and sCAP patients were compared, and the risk factors of death were analyzed.

The 28-day mortality of sCOVID-19 and sCAP patients were 50.9% (59/116) and 37.0% (50/135), respectively. The proportion of arterial partial pressure of oxygen/fraction of inspired oxygen (PaO₂/FiO₂) ≤ 250 mmHg (1 mmHg ≈ 0.133 kPa) in sCOVID-19 patients was significantly higher than that of sCAP [62.1% (72/116) vs. 34.8% (47/135), P < 0.01]. The possible reason was that the proportion of multiple lung lobe infiltration in sCOVID-19 was significantly higher than that caused by sCAP [94.0% (109/116) vs. 40.0% (54/135), P < 0.01], but the proportion of sCOVID-19 patients requiring mechanical ventilation was significantly lower than that of sCAP [45.7% (53/116) vs. 60.0% (81/135), P < 0.05]. Further analysis of clinical indicators related to patient death found that for sCOVID-19 patients PaO₂/FiO₂, white blood cell count (WBC), neutrophils (NEU), neutrophil percentage (NEU%), neutrophil/lymphocyte ratio (NLR), total bilirubin (TBil), blood urea nitrogen (BUN), albumin (ALB), Ca²⁺, prothrombin time (PT), D-dimer, C-reactive protein (CRP) and other indicators were significantly different between the death group and the survival group, in addition, the proportion of receiving mechanical ventilation, gamma globulin, steroid hormones and fluid resuscitation in death group were higher than survival group. Logistic regression analysis showed that the need for mechanical ventilation, NLR > 10, TBil > 10 μmol/L, lactate dehydrogenase (LDH) > 250 U/L were risk factors for death at 28 days. For sCAP patients, there were significant differences in age, BUN, ALB, blood glucose (GLU), Ca²⁺ and D-dimer between the death group and the survival group, but there was no significant difference in treatment. Logistic regression analysis showed that BUN > 7.14 mmol/L and ALB < 30 g/L were risk factors for 28-day death of sCAP patients.

The sCOVID-19 patients in this cohort have worse oxygen condition and symptoms than sCAP patients, which may be due to the high proportion of lesions involving the lungs. The indicators of the difference between the death group and the survival group were similar in sCOVID-19 and sCAP patients. It is suggested that the two diseases have similar effects on renal function, nutritional status and coagulation function. But there were still differences in risk factors affecting survival. It may be that sCOVID-19 has a greater impact on lung oxygenation function, inflammatory cascade response, and liver function, while sCAP has a greater impact on renal function and nutritional status.