HRCT has the potential to be a useful outcome surrogate in CF. A necessary attribute of an outcome surrogate is that it improves rapidly with effective therapy. Despite widespread belief among radiologists and pulmonologists that HRCT meets this criterion, no previous report has demonstrated this ability in children. These findings support further development of HRCT as an outcome surrogate in children with CF.

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Asthma has been identified as a possible risk factor for Obstructive Sleep Apnea (OSA) in children. It is not known whether parent-reported asthma increases the likelihood of the diagnosis of OSA in snoring children. We hypothesized that snoring children with asthma are more likely to have OSA than snoring children without asthma. This study is a 1-year retrospective review of polysomnogram and questionnaire data collected on 236 patients referred to the University of Maryland Pediatric Sleep laboratory for evaluation of snoring. Of the 236 patients, 58% (137/236) were boys, and 79% (173/219 reporting race) were African-American (AA). The age at referral was 7.2±3.7 years (mean±S.D.). Mean body mass index (BMI) percentile was 73.4±32.3%, with 43.2% (54/125) >95th percentile. A history of asthma was reported by 31.4% (74/ 236); no subject was symptomatic on the night of the study. We found no increased risk for polysomnographically diagnosed OSA for asthmatics. To the contrary, by logistic regression analysis, a parent/guardian report of asthma decreased the odds of having OSA by 34% (p=0.027), controlling for individual and socioeconomic factors and assessment results. Polysomnographic (PSG) differences between asthmatic and non-asthmatic children were found in only the arousal index (11.0 vs.9.3±6.5/h, p=0.099) and total sleep time (337.1± 64.3 vs. 347±65.2 min, p=0.1) In a referral-based group of predominantly AA inner-city snoring children, asymptomatic asthma decreased the likelihood of OSA.

The use of inhaled tobramycin for prophylaxis and treatment of respiratory symptoms in cystic fibrosis (CF) is now widespread. There have been concerns that inhaling the intravenous (I.V.) formulation of tobramycin causes bronchoconstriction. Previous studies using this formulation have either not specified the nebulizing equipment, or studied older, more severely affected patients. This study investigated the incidence of bronchoconstriction with tobramycin inhalation in children with mild to moderate CF. We studied 26 patients between the ages of 7 and 17 years, with mild to moderate CF (20 female). Prior to being placed on prolonged inhaled tobramycin therapy, they underwent a “tobramycin challenge.” FEV1 was measured pre and post challenge. For the test, standard I.V. solution (80 mg/2 mL) diluted with 2 mL of normal saline was nebulized, using the Hudson (Temecula, CA) RCI Updraft II nebulizer. The nebulization lasted 2 min. There was a 3‐min “quiet period,” following which FEV1 was measured. A decrease in FEV1 by at least 10% post‐tobramycin inhalation was considered to be a positive test. Results were analyzed using the Pearson Chi‐square test. Five of 26 (19%) had a positive reaction to tobramycin. Sixteen of 26 (61.5%) were using salbutamol on a daily basis at the time of testing but not for 48 hr before the challenge, and 16 of 26 (61.5%) had a pre‐tobramycin FEV1 of ≤80%. Neither an FEV1 of <80% (P = 0.93) nor regular use of salbutamol (P = 0.34) were associated with a positive tobramycin challenge. This study suggests that, while bronchoconstriction does occur, many patients do not exhibit bronchoconstriction in response to the standard I.V. preparation and, as prior work suggests, this may be reduced further by pretreatment with salbutamol. Pediatr Pulmonol. 2000; 29:366–370. © 2000 Wiley‐Liss, Inc.

Background/objectives Particulate matter (PM) and its constituents are recognized risk factors for the development of respiratory symptoms and illness in children. Most measurements of exposure have relied upon stationary indoor monitors (SIMs), overlooking the role of resuspended PM. To improve exposure characterization to resuspended aerosol particulate matter a recently developed methodology has been employed. The goal of this study is to characterize the resuspendable fraction of house dust and early childhood exposures to PM and its constituents in the child's home and compare conventional SIM and the Pre-toddler Inhalable Particulate Environmental Robotic (PIPER), an innovative mobile sampler. The study seeks to demonstrate that PIPER provides a more relevant estimate of exposure from inhalable particulate through improved correlation with respiratory symptoms in young children. Methods Seventy-five households with children between 3-59 months of age were recruited from clinics in central New Jersey. Demographic information and a health questionnaire based upon that used by the International Study of Allergies and Asthma in Childhood (ISAAC) and household data were collected. Household exposures to inhalable PM (PM100) and endotoxin were determined with simultaneous SIM and mobile (PIPER) sampling. Results Univariate and multivariate analyses were carried out. History of wheeze [’recent’ (<1 year) and ’ever’], cough, asthma, and eczema were evaluated. Multivariate analysis models included PM100 and endotoxin levels by tertiles of exposure. Risk of asthma for the highest tertile of PM100, as measured by PIPER (Odds Ratio = 4.2; 95% Confidence Interval 0.7 – 24.0) was compared to measurements by SIM (Odds Ratio = 0.7; 95% Confidence Interval 0.2 – 2.6). Conclusions Measurement of PM and its constituents with PIPER are more strongly associated with asthma, eczema and wheeze than measurements using SIMs. Application of this methodology may provide useful insights into early childhood exposures related to the etiology of childhood illnesses associated with inhalation exposures.