Results: Warm season, a history of chronic obstructive pulmonary disease, longer time from onset to admission (TO-A), higher percentages of CD4+ T, CD8+ T, and double-negative T (DNT) lymphocytes, as well as higher levels of C-reactive protein (CRP), low-density lipoprotein cholesterin (LDL-C), serum sodium ion (Na+), and free-calcium ion (FCa2+) were regarded as independent risk factors, while T lymphocyte percentage (T%) and total cholesterol (TC) were identified as protective factors. Here, CRP is linked to chronic obstructive pulmonary disease.