Improvement of nebulised antibiotic delivery in cystic fibrosis

AIM—To investigatedeposition patterns and to assess the delivery rate of two nebulisersystems in children with cystic fibrosis (CF).
METHODS—Thirty threechildren with CF on regular treatment with nebulised antibiotics hadradioisotope scans performed using technetium-99m labelled aerosolantibiotic generated by a Ventstream nebuliser (median mass diameter(MMD), 3.3 µm; delivery rate, 0.075 ml/min) under conditionssimilar to their routine home practice. The inhomogeneity of the imageswas scored on a 1-10 rating scale (a low score indicating evendistribution of the antibiotic), and stomach deposition was measured asa percentage of overall deposition. Twenty patients had a repeat scanusing an Optimist nebuliser (MMD, 1.8 µm; delivery rate,0.02 ml/min).
RESULTS—The meaninhomogeneity scores were 5.4 in the Ventstream group and 3.5 in theOptimist group. Mean stomach deposition was 17.3% in the 33 patientsusing the Ventstream nebuliser. There was an inverse relation betweenheight and stomach deposition (r = 0.69).In the 20 patients who had both nebulisers, the mean percentages ofstomach deposition for the Ventstream and Optimist nebulisers were11.8% and 1.6%, respectively. The Ventstream nebuliser deliveredantibiotic at an average 2.8 times faster rate than the Optimist nebuliser.
IMPLICATIONS—A smallerparticle size results in a more homogenous distribution of theantibiotic in the lungs with decreased stomach deposition. This shouldnot be seen as a recommendation to use the Optimist nebuliser becausemore antibiotic was delivered to most parts of the lung with theVentstream because of its increased delivery rate.