Down syndrome (DS) is the most common chromosomal anomaly in humans. Numerous congenital malformations associated with DS have been described. However, there are insufficient data available about airway anomalies. Our objective was to characterize the clinical presentation, frequency, and type of airway anomalies in a population of patients with DS. A retrospective evaluation of flexible bronchoscopies performed in 24 DS patients due to significant respiratory morbidity was compared to the findings in 324 non-DS patients during the same time period. The procedure was carried out under sedation, using an Olympus BF3C20 bronchoscope. The main indications for the procedure were atelectasis of the right upper lobe (12/24) and stridor (7/24). The most common associated conditions were congenital heart disease (12/24) and reactive airways disease (12/24). The most important endoscopic findings were: laryngomalacia (12/24), tracheomalacia (8/24), tracheal bronchus (5/24), and bronchomalacia (5/24). Only six patients had a normal examination. Multiple airway anomalies (>/=2) were a common finding in this series. We conclude that patients with DS and respiratory symptoms have a high incidence of airway anomalies compared to non-DS patients. The clinician should have a high index of suspicion for airway anomalies in DS patients with respiratory symptoms.

Tracheobronchial anomalies (TBA) originate between the third and sixteenth week of gestation, and they primarily affect the main bronchi. The reported incidence varies between 1-3% of pediatric endoscopic studies. The objective of our review was to describe the clinical characteristics of patients with TBA diagnosed by flexible bronchoscopy (FB). During the period from March 1993-May 2001, we performed 580 FB at the Pediatric Services of the Catholic University Hospital. During this study period, 52 patients (9.65%) had a TBA (32 males, or 61.5%), with a mean age of 21.2 months (range, 7 days to 6 years). In 39 cases (75%), the diagnosis was made under age 2 years. Thirty-six patients with symptoms related to TBA were symptomatic (70%), and in 16 cases (30%) the TBA was an accidental finding during FB. The main clinical manifestations were recurrent atelectasis of the right upper lobe (RUL), recurrent pneumonia, or congenital stridor. Most of the TBA were localized at the RUL bronchus (47%) and were characterized by an anomaly at its origin, either agenesis or a supernumerary bronchus. Also, we found patients with tracheal bronchus and congenital tracheal stenosis. In 6 patients (12%), we had more than one TBA, the most frequent being the association between RUL and RML anomalies. In 12 cases we found another congenital airway anomaly, mainly laryngomalacia. Patients had associated diseases, such as genetic disorders in 16 cases (particularly Down syndrome), and congenital cardiopathies. In summary, in our clinical experience, TBA are more frequent than previously reported. The majority of young patients have symptoms or signs, and most are localized to the RUL. We found patients with more than one TBA, laryngomalacia associated with TBA, and at a high frequency related to Down syndrome.

The objective of this study was to identify wheezing recurrences and related risk factors in two groups of infants with bronchiolitis: respiratory syncytial virus (RSV)+ and RSV- as determined by RSV enzyme immunoassay. A 1-year prospective cohort study was conducted with infants younger than 2 years old. Follow-up was made monthly, by a clinical visit and/or by telephone, checking the number of wheezing episodes per month and possible related risk factors. There were 96 subjects enrolled, of whom 77 reached complete follow-up: 36 were RSV+ (46.8%), and 41 were RSV- (53.2%). In the RSV+ group, there were 17 males (47%), vs. RSV- with 30 males (73%) (P < 0.05); 22 RSV+ (61%) were admitted to hospital, vs.14 RSV- (34%) (P < 0.05). Mean age was not significantly different in both groups. The mean number of recurrences was 3.36 episodes/infant/year in the RSV+ and 2.34 in the RSV- group (P = 0.06). Crude relative risk (RR) for a new recurrence of an obstructive episode was 1.33 (95% CI, 0.99-1.79). After adjustment for several potential confounders, the RR was 1.41 (95% CI, 1.03-1.93). Hospitalization stay was longer in the RSV+ than the RSV- group (P < 0.05). In the RSV+ group, patients who had been hospitalized showed more recurrences (4.18) than those with outpatient treatment (2.07) (P < 0.05); this difference did not exist in the RSV- group. The related risk factors for recurrent wheeze in the RSV- group were male gender, number of siblings, and daycare attendance (P < 0.05). In the RSV+ group, the risk of recurrent wheeze was only increased by admission to hospital during the acute bronchiolitis episode (P < 0.05). We speculate that there may be a higher rate of increased airway reactivity and/or preexisting diminished lung function in RSV+ infants requiring hospitalization for their initial illness. In conclusion, RSV-proven bronchiolitis, particularly in those infants who are hospitalized, is associated with a higher recurrence of wheezing episodes in the subsequent 12 months. Other factors appear to account for recurrent wheeze in the RSV- group.

Atopic asthmatic schoolchildren have greater hyperresponsiveness to methacholine than nonatopics (only among those with normal nutritional status). However, atopic and nonatopic asthmatic preschoolers have similar hyperresponsiveness to methacholine. Therefore, factors different from atopy may be responsible for wheeze in younger children.

Normal values of lung volumes of Chilean school children and adolescents are significantly higher than the current predictive values. These differences may be related to differences in anthropometric characteristics. We recommend using these data in our population and postulate that Latin-American populations like ours may have similar lung volumes.