ABSTRACT
The present work aimed to investigate whether lung deposition can be improved by using a device that optimizes the breathing pattern through electronic control. The relative lung deposition was estimated by inhalation of the marker substance, sodium cromoglycate (SCG), and measurement of urinary excretion of SCG. Thirteen cystic fibrosis (CF) patients (aged 8-20 years) received 20 mg of SCG as nebulizer solution by means of (a) conventional inhalation (Parimaster + Pari LC Star nebulizer, manual interrupter) and (b) electronically breath-controlled inhalation (AKITA + Pari LC Star nebulizer). Inhalations were trained and supervised by a physiotherapist. Patients were asked to provide answers to a questionnaire about the convenience of electronically breath-controlled inhalation. Urine was collected in five fractions until 12 h p.a., and the excreted SCG was determined by means of high-performance liquid chromatography (HPLC). Following breath-controlled inhalation, the amount of SCG excreted in urine was significantly greater than after conventional inhalation (2.22 +/- 0.61 mg vs. 1.63 +/- 0.59 mg, p < 0.001). The absorption half-life for SCG following breath-controlled inhalation was significantly shorter when compared with conventional inhalation (78 +/- 23 min vs. 107 +/- 29 min; p < 0.01), suggestive of a more peripheral deposition for the former. Ninety-two percent of the patients judged that the electronically breath-controlled inhalation was good or very good. In conclusion, inhalation with an electronically optimized breathing pattern yields a greater and more peripheral lung deposition of SCG compared with the manually triggered conventional nebulizer technique in CF patients with several years of aerosol inhalation experience.
Subject(s)
Cromolyn Sodium/administration & dosage , Cromolyn Sodium/pharmacokinetics , Cystic Fibrosis/drug therapy , Drug Delivery Systems/instrumentation , Electronics , Lung/metabolism , Nebulizers and Vaporizers , Administration, Inhalation , Adolescent , Adult , Aerosols , Child , Cystic Fibrosis/metabolism , Female , Humans , Inhalation/physiology , Male , Surveys and QuestionnairesABSTRACT
Using nebulization, only a small proportion of the dose reaches the lungs, while the remainder is swallowed, exhaled into the atmosphere, or remains in the nebulizer. It was the purpose of this study to investigate whether wearing a noseclip during inhalation can improve lung deposition. Relative lung deposition was compared by inhalation of the marker substance, sodium cromoglycate (SCG), and measurement of urinary excretion of SCG. The SCG absorption half-life allows one to differentiate indirectly between a more or less peripheral deposition. Ten CF patients (9-18 years old) inhaled, under routine conditions, a solution containing 20 mg of SCG in a randomized crossover design through a mouthpiece, without and with a noseclip being worn. Following inhalation without and with a noseclip, no statistically significant difference was seen in the amount of SCG excreted in urine (0.9 +/- 0.4 mg vs. 1.0 +/- 0.5 mg; p = 0.402) and absorption half-life (93 +/- 25 min vs. 113 +/- 36 min; p = 0.083). In conclusion, wearing a noseclip during inhalation under conditions relevant to practice does not increase the amount deposited into the lungs of CF patients and, also, there has been no indication of a more peripheral lung deposition.
Subject(s)
Cromolyn Sodium/administration & dosage , Cromolyn Sodium/pharmacokinetics , Cystic Fibrosis/drug therapy , Lung/drug effects , Surgical Instruments , Administration, Inhalation , Adolescent , Biological Availability , Child , Cross-Over Studies , Cystic Fibrosis/diagnosis , Female , Humans , Male , Nebulizers and Vaporizers , Nose , Respiratory Function Tests , Sensitivity and Specificity , Treatment OutcomeABSTRACT
This study was conducted to compare pulmonary deposition following inhalation with an ultrasonic and a jet nebulizer in CF patients under conditions relevant to practice. The marker substance used to estimate the relative lung bioavailability was sodium cromoglycate (SCG), which is poorly absorbed from the gastrointestinal tract, but is completely absorbed from the lungs. Ten CF patients (aged 9-21 years) used an ultrasonic nebulizer (Multisonic compact 2.4 MHz) and a jet nebulizer (Parimaster, LC Plus Turbo) in a crossover design to inhale a solution containing 20 mg of SCG and a beta(2)-agonist. Urine was collected in five fractions until 12 h p. a., and the excreted SCG was determined by means of HPLC. Prior to each inhalation, the patients' pulmonary function was measured employing a Pneumoscope. Using the ultrasonic nebulizer, the amount of SCG excreted in urine was significantly greater than that after inhalation with the jet nebulizer (1.43 +/- 0.47 mg vs. 1.04 +/- 0.47 mg; p = 0.002), despite the larger residual volume in the ultrasonic nebulizer. The absorption half-life for SCG following ultrasonic nebulization was significantly shorter when compared with jet nebulization (84 +/- 14 min vs. 101 +/- 19 min; p = 0.005), being suggestive of a more peripheral deposition. Furthermore, an inverse relationship was found between absorption half-life and FEV(1) (% pred.) (r = -0.655, p = 0.04) or MMEF(75/25) (% pred.) (r = -0.844, p = 0.031), but only with the ultrasonic nebulizer. In conclusion, the ultrasonic nebulizer tested when used for inhalation in CF patients was found to be at least equivalent to the jet nebulizer.
