Fig. 3.

Schematic diagram demonstrating the principle of lung microdialysis. The unidirectional perfusate flow provides a concentration gradient for diffusion of analytes across a semi-permeable membrane placed in the lung interstitium. The dialysate is then collected in microvials for analysis. a Principles of lung microdialysis with nebulised antibiotics—showing higher antibiotic concentration in the alveoli. b Principles of lung microdialysis with intravenous antibiotics—showing higher antibiotic concentration in the pulmonary arteriole