Preterm birth intrinsically changes the normal development of lung function, according to Swedish researchers. By studying 32 healthy preterm infants whose gestational age ranged from 25 to 33 weeks at birth and comparing them with 53 healthy full-term infants, they note that premature birth per se has evident implications for lung volume, the mechanics of breathing, gas mixing efficiency, and ventilation. They point out that, in preterm infants, lung development normally taking place gestationally instead occurs after birth and under very different conditions. Those conditions include active breathing with strain and relaxation of immature lung tissue, as well as lung perfusion with full cardiac output and with exposure to considerably higher oxygen tension than during fetal life. The authors said that the lung function abnormalities in healthy preterm infants shown in the study reflect disturbances in lung development that may have started either before or after birth. The research appears in the first of two January issues of the American Thoracic Society peer-reviewed American Journal of Respiratory and Critical Care Medicine.
LEUKOTRIENE ANTAGONISTS IMPROVE TREATMENT OF ASTHMA
In a study involving 80 aspirin-intolerant patients with moderate to severe asthma, researchers reported that treatment with leukotriene antagonists, which block the proinflammatory actions of leukotrienes, improved pulmonary function and provided better control of the illness than did conventional therapy. (Approximately 90 percent of the study patients were currently being treated with moderate to high doses of glucocorticosteroid, a drug that did not interfere with the antileukotriene medication.) Among the 40 patients who received the 4-week oral trial of 10 mg of leukotriene antagonists at bedtime, researchers found that the pulmonary function of the patients increased by almost 10 percent, along with improvement in daily peak expiratory flow rates, while these same patients used 27 percent less rescue medication. Among the treated group, there was also a 54 percent decrease in asthma exacerbations, fewer asthma symptoms reported, and increased asthma-specific quality of life scores. In addition, the patients with nocturnal asthma who received treatment slept more than one night extra per week as compared with the placebo group. Finally, more than 50 percent of the treated patients improved their lung function test scores by more than 5 percent, with over 22 percent improving by more than 15 percent. In the 40-person placebo group, one-third showed deterioration of lung function test results, one-third had no change, and one-third improved (more than 5 percent increase). The research appears in the first issue for January of the American Thoracic Society peer-reviewed American Journal of Respiratory and Critical Care Medicine.
PERSONALIZED ORAL, JAW-POSITIONING APPLIANCE IMPROVES CHILDHOOD SLEEP APNEA
The respiratory symptoms of a group of children with obstructive sleep apnea (OSA) either completely regressed or improved considerably following their use for 6 months of a personalized oral, jaw-positioning appliance, Italian researchers reported. After a 6-month trial, the respiratory symptoms of all 14 treated patients improved considerably, with half undergoing complete regression of their symptoms. The results of the sleep study test after the 6-month trial showed that apnea-hypopnea index scores were significantly lower for the treated children but unchanged for the control group of 9 children. (All appliances of the type studied work their therapeutic action by enlarging the upper airway.) All young people in the treated group were fitted with an acrylic resin oral bite plate for lower jaw (mandible) positioning. All appliances were designed by an orthodontist to correct each patient’s mandibular malpositioning in three spatial planes. They were checked monthly by the orthodontist to monitor functioning of the oral appliances. The research appears in the first issue for January of the American Thoracic Society peer-reviewed American Journal of Respiratory and Critical Care Medicine.
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Journal
American Journal of Respiratory and Critical Care Medicine