Lower Airway Obstruction (lower + airway_obstruction)

Distribution by Scientific Domains


Selected Abstracts


Lower airway obstruction is associated with increased morbidity in children with sickle cell disease,

PEDIATRIC PULMONOLOGY, Issue 3 2009
Jessica H. Boyd MD
Abstract Rationale The association between pulmonary function and morbidity in children with sickle cell disease (SCD) has not been previously evaluated. Our objective was to study the relationship between abnormalities in pulmonary function and morbidity as represented by the rate of hospitalizations for pain or acute chest syndrome (ACS) in children with SCD. Methods Results of pulmonary function tests obtained for clinical indications in children ages 6,18 years were classified as lower airway obstruction (forced expiratory volume in 1 sec/forced volume capacity <95% confidence interval adjusted for age, gender, race, and height), restriction (total lung capacity <80% predicted adjusted for gender, age, race, and height), and normal lung function. Incidence rates of pain or ACS were compared between children with lower airway obstruction or restriction and children with normal lung function. Results A total of 102 children, mean age at evaluation 12.0 years with follow-up of 3.8 years, were included. Children with lower airway obstruction had twice the rate of morbidity compared to children with normal lung function (2.5 vs. 1.2 hospitalizations for pain or ACS per patient-year, P,=,0.003) (Risk ratio: 2.0; 95% CI: 1.3,3.3). Children with restriction did not have different rates of future morbidity compared to children with normal lung function (1.4 vs. 1.2 hospitalizations for pain or ACS per patient-year, P,=,0.68) (Rate ratio: 1.1; 95% CI: 0.6,2.1). Conclusions We conclude that children with SCD who have lower airway obstruction should have increased surveillance for future morbidity. Pediatr Pulmonol. 2009; 44:290,296. © 2009 Wiley-Liss, Inc. [source]


Longitudinal changes in lung function and somatic growth in children with sickle cell disease,

PEDIATRIC PULMONOLOGY, Issue 6 2007
Anastassios C. Koumbourlis MD
Abstract Background We studied the changes in the patterns of lung function and somatic growth over time in children and adolescents (10.6,±,3.5 years at first test) with hemoglobin SS (Hb-SS) sickle cell disease (SCD). Methods Lung function and somatic growth were measured twice with an interval of 42.3,±,23.3 months in 45 children (25 females and 20 males) with Hb-SS SCD. Results The lung volumes slightly decreased but remained borderline normal in both tests. All spirometric indices were within the normal range but significantly decreased (P,<,0.001) at the time of the second test indicating development of lower airway obstruction (forced expiratory volume in the first second (FEV1): 87,±,21 vs. 80,±,15; FEV1/forced vital capacity (FVC): 89,±,7 vs. 85,±,6; FEF25,75: 89,±,32 vs. 76,±,24). "Normal" pattern of lung function was initially found in 56% of the patients, but in only 29% in the second test. In contrast, those with "obstructive" pattern increased from 22 to 44%, and those with "restrictive" pattern from 22 to 27%. There was no association between history of asthma and pattern of lung function. "Normal" Body Mass Index (BMI) was found in 64% of the patients, whereas 13% had "High" BMI and 22% "Low" BMI. The two latter patterns were associated with abnormal lung function but only patients with normal BMI showed actual decline overtime. Conclusion SCD is characterized by a predominantly obstructive pattern of lung function that increases in prevalence over time. There was no apparent causal relationship between the pattern of somatic growth and the pattern of lung function. Pediatr Pulmonol. 2007; 42:483,488. © 2007 Wiley-Liss, Inc. [source]


Qualitative and quantitative evaluation of equine respiratory mechanics by impulse oscillometry

EQUINE VETERINARY JOURNAL, Issue 1 2006
E. VAN ERCK
Summary Reasons for performing study: The long- established conventional reference technique (CRT) for measuring respiratory mechanics in horses lacks sensitivity and there is a need for further refinement in new technology, such as the impulse oscillometry system (IOS). Objectives: To evaluate the potential use of the IOS as a clinical respiratory function test and compare it to the current CRT in horses suffering from common upper and lower airway dysfunctions. Methods: Six healthy horses were tested before and after induction of a unilateral nasal obstruction (UNO) or transient left laryngeal hemiplegia (LLH). Six heaves-affected horses were tested in clinical remission and during a heaves crisis, before and after nebulisation of cumulative doses of a bronchodilator therapy (ipratropium bromide; IPB). Results: As opposed to the CRT, the IOS was able to detect partial upper airway obstruction (UAO) caused by UNO or LLH in resting horses, without differentiating both conditions. Upper airway obstruction caused an upward shift of resistance (Rrs) from 5 to 35 Hz without altering reactance (Xrs). As for the CRT, IOS respiratory parameters measured in heaves-affected horses in crisis differed significantly from values measured during remission. The difference in frequency-dependent behaviour of Rrs and Xrs allowed discrimination between upper and lower airway obstructions. Bronchodilator treatment induced significant dose-dependent changes in Xrs at 5 and 10 Hz, from the first dose. Total pulmonary resistance (RL) and Rrs at 5 Hz were affected from the second dose and displayed similar sensitivity. Although post treatment RL values were comparable to remission, Rrs and Xrs remained significantly different, characterising persistent peripheral obstruction. Conclusions: The IOS was more sensitive than the CRT in detecting partial UAO in resting horses and persistent post treatment peripheral dysfunction in heaves-affected horses. The IOS is a sensitive test that provides graded quantitative and qualitative information on disease-induced respiratory dysfunctions as well as on treatment efficiency in horses. Potential relevance: The IOS could represent a practical and sensitive alternative respiratory function test for routine clinical investigations of common airway obstructive diseases and therapy in horses. [source]


The science of aerosol delivery in cystic fibrosis

PEDIATRIC PULMONOLOGY, Issue S9 2008
David E. Geller MD
Abstract Aerosolized drugs are universally used for treatment of cystic fibrosis airway disease. Inhalation can increase topical efficacy and reduce systemic exposure and toxicity of many drugs. A wide variety of inhaled drugs already exist with many more in the therapeutic pipeline. Understanding the principles of aerosol delivery and how aerosol devices function is important in designing the best therapeutic regimens for CF patients. The variables that determine where an aerosol deposits are numerous and complex. Important aerosol-related variables include particle-size distribution, hygroscopic properties, viscosity and surface tension of the drug. Patient-related variables include inspired flow rate, tidal volume, respiratory rate, breath-holding, upper airway anatomy, lower airways obstruction, and the cognitive and physical ability to use the device. These factors vary widely between patients of different age groups and disease severities, and cause the high variability in drug delivery seen with aerosol drugs. Classic aerosol delivery devices like metered dose inhalers and dry-powder inhalers are small, portable, and have short treatment times. However, they are limited by small drug payloads and user technique problems. Jet nebulizers are commonly used for CF drugs, are easy to operate, require no special breathing pattern, and can deliver very large quantities of drug. However, they require a power or air source, cleaning and sanitizing, and are relatively time consuming. Recently, novel aerosol delivery systems and formulations have been developed to improve delivery efficiency and reduce variability and delivery time. These new systems can ease the treatment burden and improve adherence and outcomes in cystic fibrosis. Pediatr Pulmonol. 2008; 43:S5,S17. © 2008 Wiley-Liss, Inc. [source]