The Penetration Of Levofloxacin In Lung And The Role Of Its Prophylaxis In Lung Surgery

Background:Antibiotic prophylaxis has already proved effective in general thoracic surgery。It reduces the infective rate after operation.The routine use of Cefazolin intravenously 30 minutes before operation is recommended.Oral dosage of Levofloxacin(LVX) for prophylaxis in general thoracic surgery has not yet been evaluated.Objective:In this research,Levofloxacin concentration in lung tissue and bronchi mucosa was to be determined and its prophylactic role in lung surgery was to be evaluated.Methods:Thirty-two patients with no clinical evidence of pre-operational infection undergoing lobectomy were selected and randomized into 4 treatment groups.Informed consent had been obtained before drug administration in each patient.Five-hundred milligram levofloxacin tablet was administered orally 4 hours,8 hours,12 hours and 24 hours before the removal of the bronchi.Blood sample,lung tissue and bronchi mucosa were collected before and after operation,and pre-operative blood sample was also collected.The LVX concentration in blood serum,lung tissue and bronchi mucosa was determined by high performance liquid chromatogram(HPLC).The control group included 22 patients who had no pre-operational infection and had not received any antibiotic treatment were selected as the control group.Pearson x²,oneway anova and Kruskal Wallis ranksum test were used for the statistical analysis of infection rate, post-operation temperature and WBC count. Results:The average LVX concentration in serum,lung tissue,bronchi mucosa are 3.621±1.141μg/mL,6.413±4.652μg/g,8.742±7.574μg/g for the 4-hour-group;3.400±1.288μg/mL,6.080±3.678μg/g,6.706±3.461μg/g for the 8-hour-group;1.809±0.761μg/mL,3.723±1.929μg/g, 7.073±4.887μg/g for the 12-hour-group;0.469±0.164μg/mL, 1.591±0.545μg/g,4.067±3.334μg/g for 24-hour-group.The LVX concentrations in serum,lung tissue and bronchi mucosa are equal to or exceed the MIC90 of common bacteria in respiratory tract reported by other authors.Cmax of LVX in lung and bronchi mucosa are 6.413μg/g 8.742μg/g,AUC_0-24h of LVX in lung and bronchi mucosa are 89.3μg·h/gå’Œ143.1μg·h/g.Penetration rates in lung and bronchi mucosa are 170.9%,216.1%for 4 hours;179.7%,209.3%for 8 hours;227.9%,416.8%for 12hours and 375.3%,901.8%for 24 hours.There were no significant difference of the post-operation infection rate,WBC counts between the treatment groups and the control group. However,the post-operative temperature of the treatment group was lower than that of the control group.The Bonffernoli analysis showed statistical significance between the 12-hour-group and the control group.Conclusion:Levofloxacin has a tendency to accumulate in lung tissue and bronchi mucosa.Its clearance time in lung tissue and bronchi mucosa is longer than that in blood serum.A 500mg oral dosage of levofloxacin within 12 hours before operation can reach the effective bactericidal level in serum, lung tissue and brochi mucosa.Oral dosage of 500mg levofloxacin theoretically could be a method to prevent infection for lung surgery.