ABSTRACT
Pressurized metered-dose inhalers attached to spacers are now the most common form of delivery of anti-asthma medication in children. However, no reliable data are available of how much drug reaches the lungs in children of different ages. This information is crucial, as it determines the efficacy of therapy. In this study, we present information on the amount of drug reaching the lungs in children from a pressurized metered-dose inhaler attached to a detergent-coated spacer. We studied 18 asthmatic children inhaling radiolabeled salbutamol through detergent treated spacers to minimize electrostatic charge on the spacer wall. Lung deposition was much higher than expected when using detergent-coated spacers. Mean (SD) lung deposition, expressed as a percentage of the total actuated dose (five actuations), was 16.4% (5.5) in younger children inhaling through a small volume spacer, and 28.2% (6.7) and 41.8% (3. 8) in older children inhaling with different breathing patterns through a large volume spacer. These findings have major implications for dosage regimens for inhaled anti-asthma medication in children. Lower doses may be sufficient for adequate drugs delivered through spacers treated for static to achieve a desired clinical response.
Subject(s)
Asthma/drug therapy , Bronchodilator Agents/administration & dosage , Nebulizers and Vaporizers , Administration, Inhalation , Bronchodilator Agents/pharmacokinetics , Child , Child, Preschool , Detergents , Drug Delivery Systems , Female , Humans , Infant , Lung/drug effects , Male , Reference ValuesABSTRACT
OBJECTIVE: To compare lung deposition from a nebulizer and a pressurized metered-dose inhaler (pMDI)/holding chamber to determine their efficiency in aerosol delivery to children. STUDY DESIGN: Children with stable asthma (n = 17) aged 2 to 9 years inhaled in random order radiolabeled salbutamol from a nebulizer and a pMDI through a nonstatic holding chamber. Body and lung deposition of radiolabeled salbutamol was assessed with a gamma camera. RESULTS: Mean (absolute dose) total lung deposition expressed as a percentage of the nebulized dose was 5.4% (108 microg) in younger children (<4 years) and 11.1% (222 microg) in older children (>4 years). Mean (absolute dose) total lung deposition expressed as a percentage of the metered dose was 5.4% (21.6 microg) in younger and 9.6% (38.4 microg) in older children. CONCLUSIONS: For the same age groups we have shown equivalent percentages of total lung deposition of radiolabeled salbutamol aerosolized by either a nebulizer or a pMDI/holding chamber. However, the delivery rate per minute and the total dose of salbutamol deposited were significantly higher for the nebulizer.
Subject(s)
Albuterol/administration & dosage , Asthma/drug therapy , Bronchodilator Agents/administration & dosage , Lung/chemistry , Nebulizers and Vaporizers , Analysis of Variance , Child , Child, Preschool , Humans , Infant , Radionuclide ImagingABSTRACT
STUDY OBJECTIVES: The aim of our study was to determine the in vitro delivery of salbutamol from a pressurized metered-dose inhaler (pMDI) containing hydrofluoroalkane (HFA) propellant through various delivery devices to four models of a pediatric lung. DESIGN: To determine the effect of electrostatic charge, delivery of salbutamol was initially assessed with a multistage liquid impinger (MSLI) through an inline nonchamber device (Baxter MDI Adapter) and a small (Aerochamber MV) and a large (Nebuhaler) inline chamber device. Following this, the delivery was assessed to four lung models appropriate for a child of 70 kg, 50 kg, 15 kg, and 4 kg, with the same three reduced static devices inserted directly into a pediatric ventilator circuit. MEASUREMENTS AND RESULTS: Reduction of electrostatic charge improved small particle delivery through holding chambers to the MSLI by 12 to 14%. In the ventilator model, the mean delivery was between 1.9% and 5.4% for the nonchamber device, between 14.3% and 27.2% for the small holding chamber, and between 7.2% and 25.7% for the large holding chamber. Delivery was the least efficient in the 4-kg model compared to the 70-kg, 50-kg, and 15-kg models. CONCLUSIONS: Salbutamol from an HFA pMDI is delivered efficiently through inline holding chambers with reduced static in pediatric ventilator settings. A large holding chamber has no advantage over a small holding chamber. In addition, salbutamol delivery is more efficient through a holding chamber than through a nonchamber device.
Subject(s)
Aerosol Propellants/administration & dosage , Albuterol/administration & dosage , Bronchodilator Agents/administration & dosage , Hydrocarbons, Fluorinated , Nebulizers and Vaporizers , Administration, Inhalation , Child , Drug Delivery Systems , Humans , Lung/drug effects , Models, Anatomic , Respiration, Artificial/methods , Static ElectricityABSTRACT
Atypical mycobacterial infection in HIV-negative children usually presents with cervical lymphadenopathy. We report on 10 children who are HIV-negative and who presented with pulmonary disease, in whom either culture-proven atypical mycobacterium infection (four), positive avian Mantoux test (five), or lack of response to human tuberculosis treatment (one) had been observed. One case was subsequently diagnosed as chronic granulomatous disease and illustrates that children with atypical mycobacterial pulmonary infection should have their immune status fully investigated. Bronchial obstruction was observed in eight cases, and of these, endobronchial disease was found in six children. The diagnosis of atypical mycobacterial disease is difficult, and a negative avian Mantoux test does not exclude the diagnosis. The availability of clarithromycin and rifabutin has offered new therapeutic options in treating atypical mycobacterial pulmonary infection, but management of these cases can be prolonged and difficult.
Subject(s)
Bronchial Diseases/complications , HIV Seronegativity , Lung Diseases/microbiology , Mycobacterium Infections, Nontuberculous/diagnosis , Child, Preschool , Female , Humans , Infant , Infant, Newborn , MaleABSTRACT
Exposure to environmental tobacco smoke (ETS) is strongly associated with childhood morbidity. Cotinine, the major metabolite of nicotine, is a useful marker of tobacco smoke exposure. Cotinine levels in infants are higher than in older children or adults exposed to the same reported quantity of ETS. One hypothesis to explain this difference is that the urinary elimination half-life of cotinine is different between infants and older children. Urine was collected at admission, 12, 24 and 48 h, cotinine levels were subsequently measured and then standardized by correcting for creatinine excretion. Urinary elimination half-life of cotinine was calculated in 31 infants and 23 older children. The median half-life was 28.3 h (range 6.3-258.5 h) in infants, and 27.14 h (range 9.7-99.42 h) in older children. A Mann-Whitney U test showed no significant difference in the median half-life of cotinine between the two age groups (P = 0.18). Multivariate linear regression analysis demonstrated no significant relationship between half-life of cotinine and corrected cotinine level (P = 0.24). Our results support the hypothesis that higher cotinine levels in infants is due to greater exposure, rather than slower metabolism of cotinine.
Subject(s)
Aging/metabolism , Cotinine/urine , Mothers , Smoking , Tobacco Smoke Pollution , Adolescent , Adult , Biomarkers/urine , Child , Child, Preschool , Cotinine/pharmacokinetics , Female , Half-Life , Humans , Infant , Infant, Newborn , Linear Models , Male , Tobacco Smoke Pollution/adverse effectsABSTRACT
Haemoptysis in otherwise healthy children is an uncommon event. Two cases of massive haemoptysis, subsequently requiring lobectomy, are discussed. In each case, foreign vegetable matter was identified despite previously normal bronchoscopy and minimal changes on chest radiograph.
