Development a Method to Extract Antibiotic Concentration From Interstitial Lung and Epithelial Lining Fluid.

Development of a Method to Extract Interstitial Lung Fluid and Epithelial Lining Fluid for Antibiotic Concentration Measurement in Explanted Lung Tissue (Feasibility Study)

Infections are critical factors for the survival of critically ill patients. A serious problem is the high variability of antibiotic concentrations in critically ill patients. This may result in the risk of underdosage with possible ineffective therapeutic levels as well as in the risk of overdosage with possible adverse and toxic effects. Essential for the effectiveness of antibiotic therapy is the antibiotic concentration at target site. The goal of this study is to establish a method to extract Interstitial Lung Fluid (ILF) and Epithelial Lining Fluid (ELF) for antibiotic concentration measurements in patients following lung Transplantation and to calculate a tissue/serum concentration ratio. Improved knowledge regarding tissue penetration of Antibiotics may help to optimize drug dosing and management.

Informed consent will be obtained prior to inclusion. 30 patients following lung Transplantation at the University Hospital of Munich will be included in this study. Intravenous Meropenem will be administered as perioperative antibiotic prophylaxis for lung transplantation. Interstitial Lung Fluid and Epithelial Lining Fluid will be extracted immediately after explantation of the lung from explanted lung tissue. Concentrations of antibiotics will be determined by liquid chromatography-mass spectrometry (LC-MS/MS) in ILF and ELF. Serum samples will be collected according to our in clinical routine established therapeutic drug monitoring. Tissue/Serum concentration ratio will be calculated. ELF will be collected on postoperative day 1-5 when bronchoscopy is performed during clinical routine. Numerous clinical and laboratory parameters will be determined. The investigators expect that correlations between antibiotic target site and blood concentrations and clinical and laboratory parameters will be found.

Inclusion Criteria:

1. Lung Transplantation at University Hospital of Munich
2. Administration of Meropenem as perioperative antibiotic prophylaxis
3. Valid informed consent subscribed by the patient prior to inclusion

Exclusion Criteria:

1. missing informed consent
2. subsequent withdrawal of the participation in the study by the patient or the guardian