Abstract: Objective To study the pharmacokinetics of different doses of linezolid in the treatment of postoperative pulmonary infection in patients undergoing neurosurgery. Methods From January 2020 to August 2022, a total of 80 patients with pulmonary infection after brain surgery admitted were divided into 600 mg/d group （n=40） and 1 200 mg/d group （n=40） according to initial linezolid dose. After 4 days of treatment, venous blood samples of the two groups of patients were collected, and the plasma concentrations of linezolid at 40% time interval （C_40%T） and 100% time interval （C_100%T） were detected by high performance liquid chromatography. After one week of treatment, the treatment effectiveness of both groups of patients were evaluated. Pearson correlation analysis was conducted on the correlation between blood concentration and clinical efficacy of linezolid. Results The C_40%T concentration in the 600 mg/d group was significantly higher than that in the 1200 mg/d group, while the C_100%T concentration was significantly lower （P<0.05）. The two groups of patients showed no differences in PD target attainment rate of 40%T>4×MIC and 100%T>MIC （P>0.05）. The total effective rate of the 600 mg/d group was 67.50%, while that of the 1200 mg/d group was 72.50%, and there was no significant difference between the two groups （P>0.05）. The C_40%T and C_100%T of linezolid in both groups of patients showed a positive correlation with clinical efficacy （both P<0.05）. Conclusion There is no significant difference in the PD target attainment rate between 600 mg/d and 1200 mg/d linezolid in the treatment of postoperative pulmonary infection patients in neurosurgery. There is a positive correlation between blood drug concentration and clinical treatment efficacy.

Key words: Post neurosurgery, Pulmonary infection, Linezolid, Blood concentration, Pharmacokinetics