Search

Background The mechanical in-exsufflator (MIE) is commonly used to augment cough in patients with neuromuscular disease from infancy to adulthood. Little is known about the alveolar pressures, lung volumes, and expiratory flow rates generated by the MIE when used via tracheostomy tube in infants and children. Methods A high-fidelity mechanical lung model was programmed to simulate infants with tracheostomy tubes. Generated pressures, volumes, and expiratory flows using the MIE device at variable insufflation/exsufflation pressures and times were recorded. The primary measure of interest was maximal expiratory flow (MEF). Results Pressure equilibration across the tracheostomy tube did not occur with insufflation time 70% vital capacity attained at insufflation pressures as low as 20 cmH2O. Though higher insufflation pressures resulted in increased expiratory flow rates, more negative exsufflation pressure had a greater absolute impact on MEF. Conclusions Using the MIE via tracheostomy tube in an infant lung model, we found that an insufflation time of >1 sec is required for equilibration of insufflation pressure and alveolar pressure. Longer exsufflation time does not significantly alter MEF. Higher insufflation and exsufflation pressures both increased MEF, but greater exsufflation pressure had more substantial impact. Pediatr Pulmonol. 2011; 46:211–217. © 2011 Wiley-Liss, Inc.

Mycobacterium abscessus complex and other non-tuberculous mycobacteria are infrequently encountered respiratory pathogens in patients with tracheostomies. We report a 4-year-old girl with a tracheostomy, placed during infancy for management of severe bronchopulmonary dysplasia and laryngeal stenosis, who developed a M. abscessus complex lung infection. There was clear evidence of parenchymal involvement and true infection beyond colonization. She demonstrated dramatic clinical, laboratory, and radiographic improvement after prolonged anti-mycobacterial therapy.

Our objective was to compare adherence to montelukast with adherence to inhaled corticosteroids (ICS) in children with persistent asthma. In this retrospective study, we obtained data from a computerized hospital pharmacy database and medical records on 14l patients, 3-18 years of age, who received care for asthma at a military medical center. For each patient, we collected fill/refill data from a consecutive 6-month period and calculated an adherence rate, i.e., (# doses filled/# doses prescribed) x 100. We then determined whether the patient had "good adherence" (adherence rate, > or =70%) or "very poor adherence" (adherence rate

Mycobacterium abscessus complex and other non-tuberculous mycobacteria are infrequently encountered respiratory pathogens in patients with tracheostomies. We report a 4-year-old girl with a tracheostomy, placed during infancy for management of severe bronchopulmonary dysplasia and laryngeal stenosis, who developed a M. abscessus complex lung infection. There was clear evidence of parenchymal involvement and true infection beyond colonization. She demonstrated dramatic clinical, laboratory, and radiographic improvement after prolonged anti-mycobacterial therapy.

Breathing helium-oxygen (HeO2,) mixtures of 20.9% O2/79.1% He has been shown to increase exercise ventilation and peak oxygen uptake in healthy subjects. The improved exercise performance is thought to be due to the reduced density of HeO2 compared to air and the resulting increases in ventilation. Patients with cystic fibrosis (CF) frequently have abnormal pulmonary function test results, low exercise ventilations and diminished exercise tolerance. This led to the hypothesis that in CF the exercise tolerance of patients might improve when breathing HeO2. To test this hypothesis, 11 patients with CF or mild to severe airway obstruction performed spirometry and progressive maximal exercise tests while breathing air or HeO22. The HeO2 mixture significantly increased (P

The purpose of this study was to determine if the interrupter technique, a noninvasive method for measuring airflow resistance, could be used to assess airway obstruction in children. In 107 children (74 with asthma, 12 with cystic fibrosis, and 21 without lung disease) conductance (mostly of airways) measured with the interrupter technique (Gint) was correlated with both forced expiratory volume in 1 second (FEV1) and the forced expired flow rate between 25% and 75% of vital capacity (FEF25–75. In addition, 17 children with significant airway obstruction due to asthma also had airway resistance measured by body plethysmography (Raw) before and after treatment. Resistance and conductance measurements made with the interrupter technique were subdivided into inspiratory (Rint-insp, Gint-insp) and expiratory (Rint-exp Gint-exp) values. In the 107 children, a high degree of linear correlation was found between Gint-exsp and FEV1 for Gint-insp, r = 0.77 (P < 0.001), and for r = 0.76 (P < 0.001). There was also good linear correlation between Gin, and FEF25–75 for r = 0.70 (P < 0.001), and for Gint-insp, r = 0.67 (P < 0.001). In the 17 asthmatic children who were tested before and after treatment of their airway obstruction, Rint correlated highly with Raw; for Rint-exp, r = 0.91 (P < 0.001), and for Rint-insp, r = 0.83 (P < 0.001). The pre- to posttreatment changes in R, and Raw were similar. We conclude that the interrupter technique can be used to assess changes in airway obstruction, but normal values must be established and further investigation is required before the complete extent of its clinical utility will be known. Pediatr Pulmonol. 1994; 17:211–217. © 1994 Wiley-Liss, Inc.

Background There is considerable variation in the management of pediatric empyema, and there are no clear criteria for when to perform pleural drainage. Our study aims were: (1) to retrospectively review our experience with an empyema treatment strategy that started with intravenously administered (IV) antibiotics alone in medically stable patients with procession to pleural drainage only if there was no clinical improvement after 48 hr, and (2) to identify predictors for undergoing pleural drainage. Methods We performed a retrospective review of 182 previously healthy children, 1–18 years old, hospitalized with empyema from December 1996 through December 2008. The primary outcome measures were the proportion of patients requiring pleural drainage procedures and hospital length of stay (LOS). Results Ninety-five children (52%) received antibiotics alone, and 87 (45%) underwent drainage procedures (21 chest tube alone, 57 VATS/thoracotomy, and 8 chest tube followed by VATS/thoracotomy); only 4 received fibrinolytics. Mean (standard deviation) LOS was significantly shorter in the antibiotics alone group, 7.0 (3.5) versus 11 (4.0) days. The strongest predictors of undergoing pleural drainage were admission to the intensive care unit and large effusion size (>½ thorax filled). Conclusions Some children with empyema can be treated with IV antibiotics alone and have reasonably short LOS. At our institution, those that required intensive care or had large effusions with mediastinal shift were more likely to require pleural drainage. Pediatr Pulmonol. 2010; 45:475–480. © 2010 Wiley-Liss, Inc.

The mechanical in-exsufflator (MIE) is commonly used to augment cough in patients with neuromuscular disease from infancy to adulthood. Little is known about the alveolar pressures, lung volumes, and expiratory flow rates generated by the MIE when used via tracheostomy tube in infants and children.A high-fidelity mechanical lung model was programmed to simulate infants with tracheostomy tubes. Generated pressures, volumes, and expiratory flows using the MIE device at variable insufflation/exsufflation pressures and times were recorded. The primary measure of interest was maximal expiratory flow (MEF).Pressure equilibration across the tracheostomy tube did not occur with insufflation time1 sec. Longer insufflation time significantly increased measured alveolar pressures, lung volume, and MEF until TLC was reached. Longer exsufflation time did not significantly increase MEF. Higher insufflation pressures resulted in greater lung volumes, with70% vital capacity attained at insufflation pressures as low as 20 cmH2 O. Though higher insufflation pressures resulted in increased expiratory flow rates, more negative exsufflation pressure had a greater absolute impact on MEF.Using the MIE via tracheostomy tube in an infant lung model, we found that an insufflation time of1 sec is required for equilibration of insufflation pressure and alveolar pressure. Longer exsufflation time does not significantly alter MEF. Higher insufflation and exsufflation pressures both increased MEF, but greater exsufflation pressure had more substantial impact.

We determined the prevalence of gastroesophageal reflux disease (GERD) symptoms and the associations between GERD symptoms and asthma morbidity in a population of adolescents with asthma. Two thousand, three hundred and ninety-seven students attending six middle schools in Seattle completed the International Study of Asthma and Allergy in Children (ISAAC) written and video survey that included additional questions pertaining to GERD symptoms and asthma morbidity. Based on their responses, children were categorized as having undiagnosed current asthma, physician-diagnosed current asthma, or no asthma symptoms. The prevalence of GERD symptoms occurring at least weekly or daily was determined for each group. The asthma morbidity outcomes were emergency department visits, physician visits, missed school days, and use of inhaled medications for respiratory symptoms within the past year. Associations between GERD symptoms and asthma morbidity outcomes were determined using logistic regression. The prevalence of GERD symptoms was significantly higher among students with current asthma (19.3%; 95% confidence interval (CI), 14.9–24.2) than students with no asthma symptoms (2.5%; 95% CI, 1.8–3.4). In children with current asthma (n = 296), symptoms of GERD that occurred at least weekly were strongly associated with emergency department visits (odds ratio (OR), 5.0; 95% CI, 2.6–9.6), physician visits (OR, 2.5; 95% CI, 1.3–4.6), missed school (OR, 2.0; 95% CI, 1.1–3.7), and inhaled medication use (OR, 2.5; 95% CI, 1.3–4.7). The associations between GERD symptoms and emergency department visits, physician visits, and inhaled medication use were stronger among children with asthma who reported daily GERD symptoms (n = 14) than among children reporting weekly GERD symptoms (n = 57). The prevalence of GERD symptoms was greater in adolescents with current asthma than in those without asthma. In addition, the presence of at least weekly GERD symptoms was strongly associated with greater asthma morbidity and the use of asthma medications. Pediatr Pulmonol. 2006; 41:475–481. © 2006 Wiley-Liss, Inc.