Lung deposition after inhalation with various nebulisers in preterm infants

Abstract

Aim: This study was conducted to compare pulmonary deposition following inhalation with three different nebulisers in preterm infants under conditions relevant to practice.

Methods: The relative lung deposition (bioavailability) was estimated by inhalation of the marker substance, sodium cromoglycate (SCG) and measurement of urinary excretion of SCG. Seventeen spontaneously breathing preterm infants received 20 mg of SCG as nebuliser solution by means of (a) LC Star® jet nebuliser, (b) LS 290® ultrasonic nebuliser, and (c) Projet® ultrasonic nebuliser in a randomised three-period crossover design. Serial urine samples were collected until about 12 hours after inhalations, and the excreted SCG was determined by means of high-performance liquid chromatography.

Results: The total amounts of SCG excreted in urine measured after inhalation with the LC Star nebuliser (0.089±0.036 mg) were significantly higher compared with those obtained when the LS 290 (0.055±0.019 mg) or the Projet nebuliser (0.046±0.025 mg) was used. The average pulmonary deposition after inhalation via the LC Star, LS 290, and Projet devices was estimated as, respectively, 0.89%, 0.55%, and 0.46% of the nominal dose. Conclusion: Inhalation with the LC Star jet nebuliser producing the greatest proportion of droplets < 2 μm yielded a higher lung deposition in preterm infants compared with LS 290 and Projet ultrasonic nebulisers.