Xingang Hu

Background Aspiration pneumonia (AP) is a common complication in the intensive care unit (ICU), which is associated with significantly increased morbidity and mortality and has a significant impact on patient prognosis. Antibiotics are commonly used in the clinical treatment of AP. However, the prognostic impact of antibiotics on patients with AP has not been adequately characterized. The purpose of this study is to illustrate the relationship between the use of antibiotics and in-hospital mortality of AP patients, as well as to analyze the effects of different antibiotic treatment regimens on the prognosis of the patients, and to further understand the distribution of pathogens and drug resistance in AP patients, so as to provide guidance information for the rational use of medication for patients in the clinic. Methods Clinical data of AP patients were extracted from the MIMIC-IV database. Statistical methods included multivariate logistic regression, propensity score matching (PSM), and inverse probability weighting (IPW) based on propensity scores to ensure the robustness of the findings. In addition, the characteristics of the medications used by patients with AP were described using statistical graphs and tables. Results A total of 4132 patients with AP were included. In-hospital mortality was significantly lower in the group using antibiotics compared to the group not using antibiotics (odds ratio [OR] = 0.44, 95% confidence interval [CI] 0.27- 0.71, P = 0.001). Furthermore, in the group using mechanical ventilation (MV), antibiotics use significantly reduced in-hospital mortality (OR = 0.30, 95% CI 0.15-0.57, P < 0.001). Vancomycin and cephalosporins are the most commonly used antibiotics to treat AP. Specifically, vancomycin in combination with piperacillin-tazobactam was used most frequently with 396 cases. The highest survival rate (97.6\%) was observed in patients treated with levofloxacin combined with metronidazole. Additionally, vancomycin combined with piperacillin-tazobactam had many inflammation related features that differed significantly from those in patients who did not receive medication. Conclusions Antibiotics use is closely associated with lower in-hospital mortality in ICU patients with AP. Moreover, understanding antibiotics use, the composition of pathogenic bacteria, and the rates of drug resistance in patients with AP can aid in disease prevention and prompt infection control.