Abstract
The objective was to study the clinical characteristics and prognostic factors of patients with severe pneumonia combined with COVID-19 and influenza A (IFV-A). We retrospectively collected the diagnostic and treatment data of 170 patients with severe pneumonia, 90 of whom were infected with IFV-A and 80 with COVID-19. We then performed statistical analysis of continuous variables based on the clinical characteristics and influencing factors of the 2 groups. Compared with the group without poor prognosis (n = 129), the group with poor prognosis (n = 41) was older (79 [70-85] vs 73 [65-79] years old, P = .005); the inflammatory level was higher (hsCRP 84.90 vs 47.67 mg/L, P = .044; PCT 1.89 vs 0.59 ng/mL, P = .005), worse oxygenation (PaO2/FiO2 179.20 vs 219.70 mm Hg, P = .011), accompanied by more obvious myocardial injury and impaired renal function (cTnI 0.060 vs 0.020 µg/L, P = .001; urea 10.60 vs 7.30 mmol/L, P = .006) and coagulation/fibrinolytic activation (D-dimer 3.42 vs 1.41 µg/mL, P = .001); pathogen subgroup analysis showed: Among IFV-A patients, PCT (OR = 1.02, P = .04) and urea (OR = 1.10, 95% CI = 1.03-1.18, P = .01) were the main risk factors, and longer hospital stay was associated with lower risk (OR = 0.85, 95% CI = 0.76-0.96, P = .01). Among COVID-19 patients, age (OR = 1.05, 95% CI = 1.00-1.11, P = .04), lower PaO2/FiO2 (OR = 0.99, 95% CI = 0.99-1.00, P = .04), and longer duration of mechanical ventilation (OR = 1.01, 95% CI = 1.00-1.01, P = .01) was significantly associated with adverse outcomes. This study indicates that patients with severe pneumonia who have higher levels of inflammation, lower oxygenation, more obvious myocardial injury and renal function impairment, as well as significantly longer duration of coagulation/fibrinolysis activation and mechanical ventilation have a poor prognosis. In severe pneumonia caused by IFV-A, PCT and urea nitrogen are the main risk factors. In severe pneumonia caused by COVID-19, age, lower oxygenation index and prolonged mechanical ventilation were significantly associated with adverse outcomes.