Objective To investigate the death-related influencing factors and pathogenic distribution characteristics of type 2 diabetes mellitus (T2DM) patients complicated with severe community-acquired pneumonia (SCAP).

Methods The clinical materials of 202 T2DM patients complicated with SCAP in Zhengzhou Central Hospital Affiliated to Zhengzhou University from January 2020 to December 2021 were retrospectively analyzed, and they were divided into survival group with 147 cases and death group with 55 cases according to clinical outcomes. The clinical materials of patients in both groups were compared; the univariate and multivariate Logistic regression models were used to analyze prognostic risk factors for T2DM complicated with SCAP.

Results Age, ratios of complicating heart failure and chronic kidney disease, ratio of invasive ventilation, ratio of bloodstream infection, risks of septic shock and multiple organ failure and ratio of high-risk Pneumonia Severity Index (PSI) score in the death group were significantly higher than those in the survival group (P < 0.05). Multivariate Logistic regression analysis showed that age, glycosylated hemoglobin (HbA1c)>8.0%, high-risk PSI score, complicating heart failure and chronic kidney disease, invasive ventilation, bloodstream infection and septic shock were the independent risk factors for death of T2DM patients complicating with SCAP (P < 0.05). The results of pathogen detection in 202 patients showed that the top three pathogens were Acinetobacter baumannii, Klebsiella pneumoniae and Candida; the top three responsible pathogens were Klebsiella pneumoniae, Streptococcus pneumoniae and Escherichia coli; the risk of death in hospital in patients with Klebsiella pneumoniae pneumonia was correlated with bloodstream infection, lobulated lesions complicating with cavity and septic shock (P < 0.05); death in hospital was correled with complicating mixed infection (P < 0.05).

Conclusion Clinicians should pay attention to the factors such as advanced age, complicated multiple underlying diseases and HbA1c>8.0% in T2DM patients complicating with SCAP. Once there are bloodstream infection, septic shock and invasive ventilation for multiloba pneumonia, it indicates that the condition of disease is critical and fatality rate is relatively high, which requires early identification and intervention.