bluuebunny/crossref_metadata_2025_split huggingface dataset:
Total respiratory impedance in healthy children
Authors: Hantos Z. , Daróczy B. , Gyurkovits K. 
Published: March 2007

AbstractImpedance of the total respiratory system was measured in 121 healthy children aged 4–16 years during spontaneous breathing by pseudo‐random forced oscillations between 3 and 10 Hz. Total respiratory resistance (Rrs), inertance (Irs) and compliance (Crs) were determined by least‐mean‐squares fitting. Estimates for inertance were reliable only for the larger children, where the values of Irs (0.0127 ± 0.0034 SD) were similar to those reported for normal adults. Rrs correlated significantly (P < 0.001) with height (r = −0.868), age (r= −0.865), and, in a subpopulation of the 6‐ to 16‐year‐old children, with forced vital capacity (r = −0.803), The corresponding correlation coefficients for Crs were 0.873, 0.844, and 0.853, respectively. Crs amounted to about a third of the static total compliance values of Sharp et al. (J Appl Physiol 1970; 29: 775–779) over the same interval of heights. In these relationships no significant difference was found between boys and girls.
Normal values for forced oscillatory respiratory resistance in children
Authors: Hordvik Nancy L. , König Peter , Morris Debra A. , Kreutz Cynthia , Pimmel Russell L. 
Published: March 2007

AbstractForced oscillatory respiratory resistance was measured in 138 healthy children aged 2‐ to 16‐years‐old using a commercial unit. Regression analysis was performed using the resistance measurements obtained at frequencies of 6 Hz and 26 Hz and averages of measurements obtained at frequencies of from 6–26 Hz, 6–10 Hz, and 22–26 Hz. The analysis suggested that regression curves and 95% confidence intervals obtained using a quadratic model with height as the independent variable provided the best prediction of normal values and their ranges. Three independent sets of resistance measurements, which were obtained for all 138 subjects, were used to calculate the average individual coefficients of variation (CV) for the five resistance parameters noted above; these ranged from 9 to 13%. This analysis suggested that the expected CV of repeated measurements would be about 10%. Finally, values from 13 children who had asthma with mild bronchial obstruction (FEV1 less than 80% of predicted) were compared with the normal values derived from the regression curves. Values from all but two of the children fell within the reference intervals, suggesting that FEV1 may be a more sensitive measure of obstruction than forced oscillatory resistance. The main applications of this new approach may be in the evaluation of young children, in following individual patients, and in bronchodilation and bronchial challenge tests.
Chronic bronchopulmonary disease and gastroesophageal reflux in children
Authors: Hoyoux CI. , Forget P. , Lambrechts L. , Geubelle F. 
Published: March 2007

AbstractFifty‐four children who had chronic bronchopulmonary disease (CBPD) were investigated for the incidence of gastroesophageal reflux (GER). An activity score for CBPD and a numerical reflux score using criteria from a pH probe study were established. Results of barium esophagography, endoscopy, and prolonged esophageal pH probe monitoring were abnormal in 67, 78, and 53% of the patients, respectively. A significant relationship was found between the CBPD activity score and the reflux score; this strongly suggests that, in the patients studied, GER was responsible for the bronchopulmonary symptoms. Antireflux therapy resulted in an improvement of the CBPD activity score in all patients who had abnormal reflux scores. The mean CBPD activity score was 4.4 and 1.3 before and after antireflux therapy, respectively (P < 0.01). Most patients who had normal reflux scores did not improve on antireflux therapy.
Lung function in children and adolescents with idiopathic interstitial pulmonary fibrosis
Authors: Zapletal A. , Houštěk J. , Šamánek M. , Čopová M. , Paul T. 
Published: March 2007

AbstractLung function of 65 patients who had idiopathic interstitial pulmonary fibrosis (IIPF) that had been treated with prednisone was evaluated by tests of ventilatory function, lung mechanics, and gas exchange at rest and during exercise. Ages on initial investigation ranged from 5 to 20 years. In 35 of 65 patients the studies were repeated an average of four times over a period of 1 to 9 years. Results of the first testing were as follows: 1) vital capacity (VC)—significantly reduced in all patients; 2) inspiratory capacity (IC)—significantly reduced in all patients; 3) total lung capacity (TLC)—reduced in 91%; 4) functional residual capacity (FRC)—reduced in 31%; 5) residual volume (RV)—reduced in 6%; 6) elastic recoil of the lungs (Pst/)—significantly increased in 97% at 100% TLC, significantly increased in 52% at 90% TLC, reduced in 68% at 60% TLC; 7) static compliance (Cst)—reduced in 83%; 8) dynamic compliance (Cdyn)—reduced in 88%; 9) specific airway conductance at FRC level (Gaw/TGVex)—significantly increased in 50%; 10) maximum expiratory flow rates at 60% TLC (Vmax 60% TLC, in TLC/s)—significantly reduced in 33%; 11) upstream airway conductance (Gus 60% TLC, in TLC/s/cm H2O)—reduced in 32%; 12) diffusing capacity of the lungs for carbon monoxide (DLCO) related to body‐surface area—abnormal in 58% (when corrected for lung size, i.e., DLCO/TLC, abnormal in only 8%); 13) PaO2 at rest and after 6 minutes submaximal exercise—reduced in 25% and 63%, respectively. Changes in lung function that occurred with growth were assessed in terms of percentages of predicted values. Results showed that the VC and IC remained significantly reduced. An actual reduction of TLC, FRC, RV, breathing frequency, DLCO, and Pst/ at 100% and 90% TLC was observed. Increases were seen in Pst/ at 60% TLC, Gaw/TGVex, V̇max, and Cst/. Indices of lung elasticity suggested that regions of fibrosis and emphysema had become present. Smaller patients were also noted to have stiffer lungs.
Bronchodilators and diuretics in children with bronchopulmonary dysplasia
Authors: Logvinoff M. M. , Lemen R. J. , Taussig L. M. , Lamont B. A. 
Published: March 2007

AbstractPulmonary function tests (PFT) were obtained during the course of a selfcontrolled study of six children aged 5 to 43 months who had moderate to severe bronchopulmonary dysplasia (BPD). Changes after the administration of intravenous (IV) furosemide (2 mg/kg), inhaled isoproterenol (0.2 cc, 1:200), inhaled atropine sulfate (0.05 mg/kg), and a placebo were assessed. The study indicated the furosemide and atropine significantly (P < 0.05) increased dynamic compliance (CL) for the group. A decrease in total pulmonary resistance (RL) and work of breathing (W) was observed after isoproterenol, although the responses were not significant (P = 0.08 and P = 0.09, respectively). It was speculated that pulmonary edema and increased vagal tone may contribute to small airway dysfunction in children who have BPD.
Increased dosage requirements of tobramycin and gentamicin for treating Pseudomonas pneumonia in patients with cystic fibrosis
Authors: Mann Henry J. , Canafax Daniel M. , Cipolle Robert J. , Daniels Charles E. , Zaske Darwin E. , Warwick Warren J. 
Published: March 2007

AbstractThe pharmacokinetic behavior of tobramycin and gentamicin was evaluated in 27 patients who had cystic fibrosis (CF). A previously studied, age‐matched group of 334 patients who had been treated with gentamicin and who did not have CF served as controls. The CF patients, who ranged in age from 2 to 32 years and who had normal renal function, received 36 treatment courses with either tobramycin (19) or gentamicin (17) to treat Pseudomonas pneumonia. Serum concentrations were determined after a 1.5‐mg/kg dose to compute half‐life (t1/2), elimination rate constant (k), and apparent volume of distribution (V). From these values, doses were calculated to produce steady‐state peak concentrations of 8.0 μg/ml with a dosing interval of every six hours. For tobramycin the mean (± SD) t1/2 was 1.0 (0.4) hours, V was 0.18 (0.06) I/kg, total body clearance (TBC) was 2.19 (0.71) ml/min/kg, and the calculated dose was 8.2 (2.1) mg/kg/day. For gentamicin t1/2 was 1.1 (0.5) hours, V was 0.20 (0.06) I/kg, TBC was 2.28 (0.89) ml/min/kg, and the calculated dose was 8.8 (2.4) mg/kg/day. The pharmacokinetic parameters were not statistically different between the two drugs, but the mean values of t1/2 and TBC of CF patients differed significantly from those of the control group. The calculated doses were larger than the manufacturer's maximum recommended dose of 7.5 mg/kg/day for 63% of tobramycin and 71% of gentamicin treatment courses. A dosing interval change to every four hours would have been appropriate in 28 of the 36 treatment courses (78%). There was wide interpatient and intrapatient variation in pharmacokinetic parameters, and TBC did not correlate with creatinine clearance (CLcr). CF patients require larger doses of aminoglycosides than non‐CF patients, and they must have individualized doses and dosing intervals to obtain desired drug concentrations.
The forced oscillation technique in children with respiratory disease
Authors: Solymar L. , Aronsson P‐H. , Sixt R. 
Published: March 2007

AbstractThe single‐frequency forced oscillation technique was used to estimate the total respiratory impedance, resistance, and reactance at 2, 4, and 12 Hz of children who had cricoid stenosis (CS; n = 11), provoked bronchoconstriction (PB; n = 6), or cystic fibrosis (CF; n = 13). The selection criteria for patients who had CS and CF were abnormal forced expiratory volume in 1 sec (FEV!) and/or maximal expiratory flow at 50% vital capacity (Vmax 50%). Sixteen of the 17 patients who had CS or PB were found to have resistance (Rrs) values outside the normal range at 4 Hz; at 2 Hz, 14 were found to have abnormal values and, at 12 Hz, only 9. The reactance in the CS and PB groups was somewhat less discriminative than Rrs at all frequencies. Of the 13 patients who had CF, only 4 had abnormal Rrs values; in this clinical condition, the reactance at 2 Hz was the most discriminative variable, being abnormal in 6 of the 13 patients. Irrespective of the clinical group, the Rrs was, in absolute terms, highest at 2 Hz, and it decreased with increasing frequency. This pattern of negative frequency dependence was, however, not obviously specific for any of the tested clinical conditions and offered no information in addition to a single low‐frequency determination.
Proximal high‐frequency jet ventilation of the newborn
Authors: Donn Steven M. , Nicks Joanne J. , Bandy Kenneth P. , Naglie Ronald A. 
Published: March 2007

AbstractDuring a 14‐month period 11 preterm infants were treated with high‐frequency jet ventilation for severe respiratory failure that had been unresponsive to conventional mechanical ventilation. Primary indications included intractable air leaks (pulmonary interstitial emphysema, pneumothorax, or both), congenital diaphragmatic hernia, and progressive pneumonia. The Sechrist 990 HFV respirator, a solenoid‐driven, pulse‐generated high frequency jet ventilator, was used. This device delivers a volume of gas at a controlled pressure to a jet located in the patient connector proximal to a standard single lumen endotracheal tube. The ventilator was operated in tandem with a Sechrist IV‐100B ventilator to provide a sigh effect and to improve humidification. Although only 3 of 11 patients survived, 9 displayed short‐term benefits from HFJV with significant reduction in mean airway pressure and improvement in mean arterial blood pressure, and no concomitant adverse effects on oxygenation or ventilation. Preliminary results suggest shortterm benefits of HFJV in infants who have severe respiratory failure that is unresponsive to conventional mechanical ventilation.
Nicotine‐induced neuroepithelial cell changes in young rabbits: A preliminary communication
Authors: Chen M. F. , Diotallevi M. J. , Kimizuka G. , King M. , Wang N. S. 
Published: March 2007

AbstractNicotine 1 mg/kg body weight/day, was injected subcutaneously in 3 female rabbits during gestational and lactating periods, and the lungs of the offspring were studied by scanning and transmission electron microscopy (SEM and TEM) on days 5, 10, and 25 postpartum. Three other female rabbits served as controls. The size and number of neuroepithelial bodies (NEB) as estimated by SEM were larger in the experimental group than in the control group, especially on days 5 and 25. Moreover, the NEB in the nicotineexposed groups showed loss of normal boundaries and derangement of cells and granules by TEM. Neural components also became prominent. These findings suggest that chronic maternal exposure to nicotine may directly, or, through the neural route, indirectly induce hyperplasia and dysplasia of the NEB in the offspring of rabbits. Because NEB are suspected to regulate regional bronchial and vascular smooth muscle cells, such alterations may be similar to respiratory functional impairments found in infants of mothers who smoke.
Cold air provocation of airway hyperreactivity in patients with cystic fibrosis
Authors: Darga Linda L. , Eason Lawrence A. , Polgar George , Zach Dozent Maximilian S. 
Published: March 2007

AbstractThirty‐four patients with cystic fibrosis (CF) were assessed for baseline pulmonary functions before, and 5 and 15 minutes after cold air challenge (CACh). Most of the patients had no change in forced expiratory volume in 1 second (FEV1) and maximum expiratory flow at 25% vital capacity (Vmax25%VC) post‐CACh. Five patients responded with reduced FEV1 and 13 with reduced Vmax25%VC. However, paradoxical increases were noted in 10 patients for FEV1 and in 5 for Vmax25%VC. Paradoxical responses were most frequent in patients with severe lung disease. The explanation for this variability may lie in the varying degrees of airway instability and volume of airway contribution (VAC) to early flows, resulting from the damage caused by chronic infection. Conventional challenges may be useless in determining the true incidence of bronchial hyperreactivity in patients with CF.
Bronchial carcinoid tumor in a 12‐year‐old child
Authors: van Steensel‐Moll H. A. , de Groot R. , Neijens H. J. , den Hollander J. C. , Meradji M. 
Published: March 2007

AbstractSymptoms (hemoptysis, recurrent pulmonary infections), diasnostic work‐up (roentgenology, bronchoscopy with biopsy), and treatment (surgical resection of a bronchial carcinoid tumor in a 12 year old girl) are discussed. Special attention was paid to the tumor histochemistry, showing serotonin containing granules. Levels of circulating hormones and vasoactive agents, including serotonin, were within normal limits.
The potential value of a 750‐ml spacer for the administration of inhaled corticosteroids to children
Authors: Reiser J. , Frame M. H. , Warner J. O. 
Published: March 2007

AbstractAn open, cross‐over trial was conducted on 25 asthmatic children, aged 6–13 years, who required inhaled steroids. They inhaled Budesonide 200 μg twice daily, either directly from the metered dose inhaler or via the pear spacer (PS), for 2 months on each, in randomized order. The effects of the treatment were monitored with diary cards recording peak expiratory flow rates twice daily, symptoms and treatment taken, and with monthly clinical assessments including more sensitive lung function studies (flow‐volume loops and single breath nitrogen wash‐out tests). There was no specifically PS‐related improvement in symptoms or in the majority of tests, but the results showed improvement with time when using either method. The improvement was more distinct in some tests reflecting proximal airway calibre (i.e., PEFR) than in tests thought to reflect predominantly peripheral airway calibre (i.e., F50, RV). The bronchodilator responsiveness, as shown by the increase in lung function tests after a β‐agonist was given, was significantly greater for FVC during the periods when the PS was used, although there was no significant improvement in FEV2 or PEFR. The improvement in tests reflecting proximal airways may have been due to optimization of the inhalation technique, greater understanding of asthma, or better compliance with medication associated with regular attendance for the study. The greater bronchodilator response whilst children were inhaling budesonide by the PS may have been due to increased deposition or better distribution of the steroid but was probably related to a difference between the two groups in initial baseline function tests.
Clinical observations on mechanical ventilation for respiratory failure in bronchiolitis
Authors: Frankel Lorry R. , Lewiston Norman J. , Smith David W. , Stevenson David K. 
Published: March 2007

AbstractAn unusually large number of infants (82) were admitted to Stanford University Hospital from November 1,1983, through May 31,1985, with a diagnosis of bronchiolitis requiring oxygen therapy. A larger percentage of these infants (17/82 = 21%) than generally expected required mechanical ventilation for respiratory failure. Fourteen infants had respiratory syncytial virus (RSV) infections, and three had parainfluenza virus infections. Ten patients had respiratory difficulties as neonates. The mechanical ventilation of the children requiring respiratory assistance was characterized by high minute ventilation with high tidal volumes (15 to 20 ml/kg) and slow respiratory rates (16 to 22 breaths/min). Peak inspiratory pressure averaged (mean ± SD) 35 ± 6 cm H2O in the RSV group and 34 ± 6 cm H2O in the parainfluenza group. The mean number of days on the ventilator was 9.7 ± 3.1 for the RSV group and 8.3 ± 2.9 for the parainfluenza group. All were extubated within 17 days of presentation and discharged within 28 days. The complications encountered included pneumothorax and acute pulmonary hypertension.
Total respiratory compliance and functional residual capacity in young children
Authors: Greenough A. , Stocks J. , Nothen U. , Helms R 
Published: March 2007

AbstractMeasurements of total compliance of the respiratory system (CRS) by the weishted spirometer technique and functional residual capacity (FRC) by helium gas dilution were attempted in 63 healthy children (aged 2 to 7 years). Weighted spirometry was well tolerated in all but six children, and FRC measurements were successful in 42. Both measurements were reproducible and not affected by posture. Good correlations were found between CRS and height (r = 0.73) and age (r = 0.83) as well as between FRC and height (r = 0.83) and age (r = 0.74). No differences were found between boys and girls. CRS also correlated significantly with FRC (r = 0.67). In five children with cystic fibrosis, measurements of CRS, FRC and specific compliance correlated with disease severity. Our data suggest these well‐tolerated techniques may provide a useful means to distinguish the effects of disease from those of growth.
Effect of high‐frequency jet ventilation on preterm and rabbit tracheal mechanics
Authors: Bhutani Vinod K. , Abbasi Soraya , Spitzer A. R. , Fox W. W. , Shaffer Thomas H. 
Published: March 2007

AbstractThe effect of high‐frequency jet ventilation (HFJV) on both tracheal dimensions and mechanics was evaluated in preterm and term rabbit airways. Seven tracheal segments were studied at 27 days (group I) and 31 days (group II) of gestation, respectively. Tracheal dimensions and segmental pressure‐volume relationships were determined before and after 60 minutes of HFJV (peak pressure 20 cm H2O; mean airway pressure 6.7 to 6.8 cm H2O at 10 Hz). Both tracheal lengths and diameters increased significantly (p < 0.01) in each group and resulted in increased tracheal volumes: 109% in group I (p< 0.01) and 60% in group II (p < 0.01). The mean specific tracheal compliance decreased in group I, from 0.036 cm H2O−1 to 0.015 cm H2O−1 (p < 0.01), and in group II from 0.029 cm H2O−1 to 0.021 cm H2O−1 (p < 0.01). Furthermore, the collapsing transmural pressure (the pressure required for total collapse of tracheal segments) decreased significantly (p< 0.01) in both groups. These data demonstrate significant dimensional and mechanical deformation of tracheal segments after HFJV. An increased propensity toward collapsibility is also observed following HFJV. These changes are similar to those with tracheomala‐cia. The influence of such deformation on tracheal gas flow during HFJV needs to be further investigated.
Compliance measurement in respiratory distress syndrome: The prediction of outcome
Authors: Graff Michael A. , Novo Robert P. , Diaz Masaly , Smith Cathy , Hiatt I. Mark , Hegyi Thomas 
Published: March 2007

AbstractDynamic compliance (Cdyn) measurements within the first three days of life predicted survival in 60 preterm infants suffering from respiratory distress syndrome. Cdyn was measured in 47 survivors at 2.3 ± 1.4 days of life and in 13 nonsurvivors on 2.7 ± 1.7 days. All nonsurvivors died from respiratory failure within the first two weeks of life. Mean Cdyn of the survivors was 0.83 ± 0.33 ml/cm H2O and of the nonsurvivors 0.35 ± 0.19 ml/cm H2O (p < 0.001). Cdyn values below 0.45 ml/cm H2O predicted 11 of 13 deaths in infants, and Cdyn measurements above this value predicted 45 of 47 survivals, with a specificity of 81% and a sensitivity of 89%. Eleven of the survivors, who subsequently developed bronchopulmonary dysplasia (BPD), had a mean Cdyn of 0.56 ± 0.23 ml/cm H2O. When these infants were matched with infants of comparable weight without evidence of BPD, the BPD group had a significantly lower Cdyn (p < 0.05). Cdyn measurements during the first three days of life are useful in predicting outcome of respiratory failure secondary to respiratory distress syndrome.
Diurnal variation in bronchial responsiveness in asthmatic children
Authors: Sly Peter D. , Landau Louis I. 
Published: March 2007

AbstractTo establish the presence of a diurnal variation in bronchial responsiveness in asthmatic children, the increase of peak expiratory flow rate (PEFR) followins sympathomimetic inhalation and the response to bronchial provocation with histamine and hyperventilation of cold dry air (HVCDA) were studied. Twenty‐nine patients (20 boys, nine girls, aged 9.3 to 17.8 years) measured PEFR before and after sympathomimetic inhalation three times a day for four weeks. A further 15 patients (eight boys, seven girls, aged 6.9 to 18.0 years) underwent bronchial provocation testing every six hours for 24 hours. A diurnal variation in bronchodilator responsiveness was demonstrated in 55% of the first group. Mean amplitude was 60.8% of patients' mean increase in PEFR following bronchodilators. On grouped data, bronchodilation was greater in the morning than in the afternoon (p < 0.0005) or in the evening (p < 0.0005). A diurnal variation in the response to bronchial provocation was also found in the second group, but the timing of the rhythm depended on the stimulus used. On grouped data, airways were most sensitive to histamine at 0400 hours and most sensitive to HVCDA at 1600 hours. The diurnal variation demonstrated in bronchial responsiveness could not be attributed to changes in baseline airway caliber and was present despite the patients' taking sufficient medication to control their asthmatic symptoms.
Effect of cisapride on gastroesophageal reflux in children with chronic bronchopulmonary disease: A double‐blind cross‐over pH‐monitoring study
Authors: Saye Zimbu N. , Forget Pierre Ph. , Geubelle Fernand 
Published: March 2007

AbstractFourteen patients with chronic bronchopulmonary disease and suspected of having gastroesophageal reflux were studied for 16 hr by intraesophageal pH monitoring to investigate the effect of the prokinetic drug cisapride. Cisapride was administered orally in a double‐blind cross‐over study. The initial dose was 0.3 mg/kg, followed by 0.15 mg/kg every 4 hr for 12 hr. Cisapride was shown to be superior to placebo in reducing gastroesophageal reflux. Both during the total recording period and during the sleep period, cisapride significantly decreased the percentage of time during which the pH was 4 or less (vs placebo; total period, −60%; sleep, −80%) and reduced the number of reflux spells of at least 5 min (−64%; −92%). No adverse effects of cisapride were observed. Pediatr Pulmonol 1987; 3:8–12.