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Updated: Nov 29, 2025
The Bovine Lung in Biomedical Research: Visually Guided Bronchoscopy, Intrabronchial Inoculation and In Vivo Sampling Techniques
Published on: July 3, 2014
Comparative lung distribution of radiolabeled tobramycin between nebulized and intravenous administration in a
Jayesh A Dhanani1, Steven Goodman2, Benjamin Ahern3
1UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, Australia; Department of Intensive Care Medicine, Royal Brisbane & Women's Hospital, Brisbane, Australia; Critical Care Research Group, The University of Queensland, Brisbane, Australia.
Background:
Ventilator-associated pneumonia is common and is treated using nebulized antibiotics. Although adequate pulmonary biodistribution is important for antibiotic effect, there is a lack of data for both intravenous (IV) and nebulized antibiotic administration during mechanical ventilation.
Objective:
To describe the comparative pulmonary regional distribution of IV and nebulized technetium-99m-labeled tobramycin (99mTc-tobramycin) 400 mg in a mechanically-ventilated ovine model.
Methods:
The study was performed in a mechanically-ventilated ovine model. 99mTc-tobramycin 400 mg was obtained using a radiolabeling process. Computed tomography (CT) was performed. Ten sheep were given 99mTc-tobramycin 400 mg via either an IV (five sheep) or nebulized (five sheep) route. Planar images (dorsal, ventral, left lateral and right lateral) were obtained using a gamma camera. Blood samples were obtained every 15 min for 1 h (4 time points) and lung, liver, both kidney, and urine samples were obtained post-mortem.
Results:
Ten sheep were anesthetized and mechanically ventilated. Whole-lung deposition of nebulized 99mTc-tobramycin 400 mg was significantly lower than with IV (8.8% vs. 57.1%, P<0.001). For both administration routes, there was significantly lower deposition in upper lung zones compared with the rest of the lungs. Dorsal deposition was significantly higher with nebulized 99mTc-tobramycin 400 mg compared with IV (68.9% vs. 58.9%, P=0.003). Lung concentrations of 99mTc-tobramycin were higher with IV compared with nebulized administration. There were significantly higher concentrations of 99mTc-tobramycin in blood, liver and urine with IV administration compared with nebulized.
Conclusions:
Nebulization resulted in lower whole and regional lung deposition of 99mTc-tobramycin compared with IV administration and appeared to be associated with low blood and extra-pulmonary organ concentrations.
