OBJECTIVE To explore the changes of serum Toll-like receptor (TLR) 2, TLR4 and 25 hydroxyvitamin D 25(OH)D in the general anesthesia orthopedic surgery patients with postoperative pulmonary infections and analyze the distribution and drug resistance of pathogens.

METHODS A total of 59 general anesthesia orthopedic surgery patients with postoperative pulmonary infections who were treated in Tianjin Fifth Central Hospital from Jul. 2019 to Jul. 2024 were chosen as the infection group, meanwhile, 65 patients who underwent the same surgery but did not have postoperative pulmonary infection or other acute and chronic infections were chosen as the non-infection group. The etiological characteristics of the postoperative pulmonary infections and the drug resistance rates were analyzed. The clinical data and the levels of serum TLR2, TLR4 and 25(OH)D were observed and compared between the two groups of patients. The values of the above indicators in diagnosis of the postoperative pulmonary infections in the general anesthesia orthopedic surgery were analyzed.

RESULTS Totally 63 strains of pathogens were isolated from the 59 general anesthesia orthopedic surgery patients with postoperative pulmonary infections, 36 (57.14%) of which were gram-negative bacteria. 3 of 15 Pseudomonas aeruginosa strains were resistant to meropenem; 4 of 12 Klebsiella pneumoniae strians were resistant to meropenem; all of the 11 Staphylococcus aureus strains were methicilin-resistant S. aureus. The proportions of patients with age, hypoproteinemia and diabetes mellitus, the serum TLR2 and TLR4 levels were higher in the infection group than in the non- infection group (P < 0.05), while the 25(OH)D level of the infection group was lower than that of the no infection group (P < 0.05). The area under the curves (AUCs) of serum TLR2, TLR4, 25(OH)D and the joint detection of the above indicators were respectively 0.817, 0.801, 0.787 and 0.917 in diagnosis of postoperative pulmonary infections in the general anesthesia orthopedic surgery patients, and the AUC of the joint detection of the indicators was greater than that of the single detection (P < 0.05).

CONCLUSIONS The general anesthesia orthopedic surgery patients with postoperative pulmonary infections show high expressions of serum TLR2 and TLR4 and the low expression of 25(OH)D. The joint detection of the above indexes has higher diagnostic value. The gram-negative bacteria are dominant among the pathogens causing the infections. The pathogens vary in the drug resistance.