Abstract:

Objective

To analyze the changes in pathogen resistance and inflammatory factors in secondary lung infections in lung cancer patients after chemotherapy.

Methods

A total of 157 lung cancer patients admitted to the respiratory department from February 2019 to February 2023 were hospitalized due to chemotherapy were selected as the study subjects. There were a total of 69 patients in the observation group who developed secondary pulmonary infections， and 88 patients in the control group who did not develop secondary pulmonary infections. Respiratory samples from infected patients were sent to be tested for pathogen types.Levels of C-reactive protein（CRP）， procalcitonin（PCT）， tumor necrosis factor-α（TNF-α）and interleukin-6（IL-6） in two groups of patients were compared.

Results

A total of 84 strains of pathogenic bacteria were detected in respiratory samples. Gram-negative bacteria accounted for 61.91%（n=52）， while gram-positive bacteria accounted for 30.95% （n=26）， and fungi accounted for 7.14% （n=6）. There were differences in the resistance of different pathogens to common antibiotics. The 52 strains contained Gram-negative bacteria， 26 Pseudomonas aeruginosa， 15 Klebsiella pneumoniae， 10 Acinetobacter baumannii， and 1 other strain. Gramnegative bacteria showed high resistance to ceftriaxone， cefepime， and ampicillin， certain resistance to gentamicin， levofloxacin， and co-trimoxazole， and low resistance to imipenem.The 26 gram-positive strains，included S. aureus 15 strains ， Streptococcus pneumoniae 7 strains， S. haemolytica 4 strains. Gram-positive strains showed high resistance to penicillin， erythromycin， clindamycin， some resistance to linezolid and gentamicin， and low resistance to vancomycin and levofloxacin. Fungal 6 strains included， C. albicans 5 strains and C. glabrata 1 strain. Fungal strains showed high resistance to fluorouracil and low resistance to fluconazole，ketoconazole， and amphotericin B.In observation group CRP（24.16±5.88）mg/L， PCT（4.21±1.96）ng/ml，TNF-α（25.76±5.34）ng/L， IL-6（36.34±2.24）ng/L higher than control group（11.97±3.55）mg/L， （1.02±0.98）ng/ml， （18.55±4.21）ng/L， （22.68±1.08）ng/L（P＜0.05）. The imaging examination of secondary lung infection in lung cancer chemotherapy patients mostly showed scattered distribution sheet infiltrative changes，which could involve both lung fields， and the imaging absorption was slower.

Conclusions

Pathogens in the body of lung cancer patients with secondary lung infections after chemotherapy are various， with Gram negative bacteria having the highest infection rate. There are differences in resistance to common antibiotics and strong inflammatory reactions. Clinical selection of antibiotics should be based on drug sensitivity results and the actual situation of patients.

Key words: Bronchiogenic carcinoma, Secondary pulmonary infection, Drug resistance, Pathogenic bacteria, Inflammatory factors