Effect Of CO2 On Nebulized Tobramycin.

Pseudomonas aeruginosa colonization is an independent predictor of mortality in bronchiectasis patients. Non-CF bronchiectasis patients often experience symptom relief and improvement in lung function, however studies have failed to show significant improvement. Enhancing deposition of inhaled antibiotics and lung recruitment may improve the response to inhaled antibiotic treatment. Inhaling a low concentration of carbon dioxide (CO2) during antibiotic nebulization alters respiratory parameters. By changing these parameters one can try to alter the peripheral deposition of inhaled medication, which may improve treatment. SPECT/CT is the preferred technique to obtain information on deposition of inhaled drugs. However it is unknown if these measurements are feasible with inhalation of technetium DTPA (99mTc-DTPA) and tobramycin, due to the requirement of a relatively steady state uptake. This randomised cross-over proof of principle study investigates the feasibility of SPECT-CT scans in the evaluation of pulmonary deposition of Tobramycin. In addition, concomitant inhalation of CO2 enriched ambient air and the use of the breath-actuated mode of the AeroEclipse II nebulizer with adjusted Tobramycin dose are evaluated.

1. Evaluation of pulmonary deposition of inhaled Tobramycin with 99mTc-DTPA tracer is feasible using SPECT-CT scans;

2a. Pulmonary deposition of Tobramycin improves with concomitant inhalation of carbon dioxide enriched ambient air;

2b. Pulmonary deposition of Tobramycin with the breath-actuated mode of the AeroEclipse II nebulizer and adjusted dose is equal to deposition with the Pari LC plus nebulizer.

Analysis at end of study.

1. Nebulization of 99mTc-DTPA and tobramycin 125 mg without carbon dioxide enriched air with an Aero Eclipse II ® nebulizer;

2. Nebulization of 99mTc-DTPA and tobramycin 125 mg with carbon dioxide enriched ambient air with an Aero Eclipse II ® nebulizer;

3. Nebulization of 99mTc-DTPA and tobramycin 300 mg without carbon dioxide enriched air with a Pari LC Plus ® nebulizer.



The interventions have a duration of 3 days with at least 72 hours in between and a maximum pause of 1 week.