bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variability of pulmonary function tests in cystic fibrosis
Authors: Cooper Peter J. , Robertson Colin F. , Hudson Irene L. , Phelan Peter D. 
Published: March 2007

AbstractThe aim of this study was to define the within‐subject variability for tests of respiratory function in patients with cystic fibrosis (CF) within the day, from day to day and from week to week. Twenty‐eight patients with CF (aged 9–19 years) and 23 healthy height matched controls (aged 9–18 years) had measurements made of spirometry, lung volumes, maximal flows at three lung volumes and maximal inspiratory and expiratory pressures at the mouth. Testings were done on nine occasions, three times within a day, on consecutive days at one week intervals. Each individual's variability was summarized both as the within‐subject coefficient of variation (WCV) and within‐subject standard deviation (WSD). Means of WSD and median WCV are reported for both the patients with CF and normal subjects.The within‐subject variability of VC, FEV1, TLC, RV, and RV/TLC was more appropriately assessed by the use of WSD rather than WCV. The WSDs in the CF group were significantly more variable (P <0.005) than in the normals for VC and FEV1. WCV best summarized within‐subject variation for FEF25–75, FRC, V̇25, V̇50max and V̇75max for which the CF subjects were significantly more variable (P <0.005). Individuals' variability was very consistent, therefore assessment of significant change could be made more accurately by predetermining the variability of that individual, rather than using group data.We stress the importance to consider increased variability from day to day and week to week in the interpretation of change in lung function in patients with CF, and provide reference values for accurate interpretation of serial pulmonary function test results. Pediatr Pulmonol 1990; 8:16‐22.
Effects of dexamethasone on macrophages in fetal and neonatal rat lung
Authors: Lortie C. , King G. M. , Adamson I. Y. R. 
Published: March 2007

AbstractThe effects of injecting dexamethasone to pregnant and newborn rats on the subsequent production of macrophages in the lung and on their phagocytic activity and lysosomal enzyme content were evaluated from late gestation to postnatal day 10 using an organ culture system to collect macrophages. Pieces of lung tissue cultured 6 days on cover glasses produced a halo of macrophages adherent to the glass around the explants. Thymidine labeling showed that the macrophages were derived from dividing precursors in the pulmonary interstitium. DNA synthesis was reduced after steroid treatment, and fewer cells were obtained on cover glasses, particularly just after birth when the macrophage number usually increases. Phagocytic function was also diminished in cells collected after dexamethasone injection, particularly when derived from neonatal animals. In contrast, intracellular levels of non‐specific esterase and glucosaminidase were increased, probably indicative of lower phagolysosome formation and lower enzyme secretion. These results demonstrate that steroid administration to fetal or newborn animals subsequently reduces the number and phagocytic activity of macrophages in the lungs. This could reduce the defense mechanisms of the neonate and increase susceptibility to infection. Pediatr pulmonol 1990; 8:138‐144.
Total respiratory compliance in infants and young children with congenital heart disease
Authors: Davies C. J. , Cooper S. G. , Fletcher M. E. , Hatch D. J. , Helms P. J. , Gordon I. , Stocks J. 
Published: March 2007

AbstractThe multiple occlusion technique was used to measure total respiratory system compliance (Crs) in 62 infants and young children with congential heart disease (age range, 2 days to 2 years). Measurements were found to be reproducible in nine infants in whom repeat measurements were possible (maximum deviation between measurements < 10%). The incidence of failure to obtain accurate results was no greater than when studying infants without cardiopulmonary disease. However, in the presence of severe growth retardation or alinearity of volume‐pressure data, results may be difficult to interpret in individuals.Results of Crs were related to non‐invasive assessments of cardiac disease severity using chest radiography and echocardiography. After the effects of growth had been taken into account, a significant negative relationship was found between Crs and the right pulmonary artery to aortic ratio, which reflects pulmonary vascular engorgement (P = 0.003, R2 = −0.40). However, no significant relationship was found between Crs and chest X‐ray score (P = 0.27). Pediatr Pulmonol 1990; 8:155‐161.
Pulmonary function and respiratory morbidity in school‐age children born prematurely and ventilated for neonatal respiratory insufficiency
Authors: Hakulinen A. L. , Heinonen K. , Länsimies E. , Kiekara O. 
Published: March 2007

AbstractWe examined 72 children aged 6–9 years to assess the effects of prematurity and ventilator treatment on subsequent lung function and respiratory morbidity. The preterm study group (n = 42) was divided into children with a history of bronchopulmonary dysplasia (BPD) (n = 10), children who had had neonatal respirator treatment but no BPD (n = 19), and children without severe neonatal respiratory problems (n = 13). The BPD children as a group had markedly lower specific airway conductance and larger residual volume than did the full‐term control group, but there were no significant differences in spirometric measurements. The BPD group also had higher respiratory morbidity requiring hospitalizations, particularly during the first 2 years of life, than did the children in the other study groups. Therefore, BPD may improve but does not disappear as age increases. Non‐BPD children who had had ventilator treatment as neonates recovered well and suffered no severe respiratory problems after infancy. Pulmonary function parameters in prematurely born children without neonatal ventilator treatment did not differ from those in the full‐term control group. Thus, neonatal lung disease seems to be a more important determinant of abnormal pulmonary function at a later age than is prematurity alone. Pediatr Pulmonol 1990; 8:226‐232.
Differential effects of pancuronium bromide on cardiopulmonary function in the neonatal lamb
Authors: Wolfson Marla R. , Shaffer Thomas H. 
Published: March 2007

AbstractThe effect of pancuronium bromide (Panc Br) on resting cardiopulmonary function and cardiopulmonary responses to intravenous injection of acetylcholine (Ach) and histamine (H) was evaluated in neonatal lambs. The animals were mechanically ventilated and managed to maintain physiologic gas exchange and acid‐base conditions. A proximal segment of the cervical trachea was bypassed; the developed pressure response of this segment (Pcervical trach) was used as a direct indication of airway smooth muscle contraction and bronchoconstriction. Pulmonary resistance (RP) and functional residual capacity were determined. The change in RP from resting values was used as a functional indicator of central and peripheral airway bronchoconstriction. Cardiovascular function and responses were evaluated from changes in mean arterial pressure and heart rate. Following Panc Br, there was a significant reduction in Ach‐induced Pcertical trach (−50 ± 9.2% SE) and RP (−46 ± 2.4% SE). In contrast, Panc Br did not significantly change Ach‐induced bradycardia and hypotension, cardiopulmonary responses to H, and resting cardiopulmonary function. The differential effects of Panc Br on cardiopulmonary function appear to be related to regional differences between cardiovascular and airway smooth muscle muscarinic receptors in the neonate. The results of this study elucidate a mechanism which may explain previously reported variability in the effect of Panc Br on neonatal cardiopulmonary function. Furthermore, the Panc Br‐related attenuation of airway smooth muscle responses suggests that this form of neuromuscular blockade affects the regulation of airway tone and may influence the susceptibility of the neonate to airway deformation consequent to mechanical ventilation. Pediatr Pulmonol 1990; 8:233‐239.
Investigation of cyanotic/apneic episodes and sleep‐related upper airway obstruction by long‐term non‐invasive bedside recordings
Authors: Abraham N. G. , Stebbens V. A. , Samuels M. P. , Southall D. P. 
Published: March 2007

AbstractOver a 4 year period, investigations were performed on 226 infants and children suffering cyanotic episodes and 160 suspected to be the victims of sleep‐related upper airway obstruction. These investigations have been considerably aided by long‐term tape recordings of multiple cardiorespiratory and neurophysiological variables from non‐invasive sensors. In addition to identifying the underlying mechanisms responsible for cyanotic episodes, recordings have identified the presence or absence of airway obstruction, documented its severity by its effects on oxygenation and on sleep‐state organization, and evaluated objectively the effects of treatment. The recording system, which is transportable, has been especially developed for use outside of the specialized sleep laboratory and was used on patients in hospital wards and at home. Pediatr Pulmonol 1990; 8:259‐262.
Respiratory complications in children with spondyloepiphyseal dysplasia congenita
Authors: Harding Cary O. , Green Christopher G. , Perloff William H. , Pauli Richard M. 
Published: March 2007

AbstractMild respiratory distress at birth is a common occurrence in infants with spondyloepiphyseal dysplasia congenita (SEDC) while severe repiratory insufficency and death have been reported only rarely. We describe three infants with SEDC who experienced severe respiratory complications and required tracheostomies. Two of these infants have also needed long‐term continuous positive airway pressure to maintain adequate ventilation. The features and clinical course of these children are described, previous reports of respiratory complications in SEDC are summarized, mechanisms resulting in respiratory problems in SEDC are postulated, and comparison is made with mechanisms giving rise to respiratory risks in other skeletal dysplasias. Pediatr Pulmonol 1990; 9:49–54.
Accurate, noninvasive quantitation of expiratory gas leak from uncuffed infant endotracheal tubes
Authors: Knauth Alison , Baumgart Stephen 
Published: March 2007

AbstractAccurate measurement of expiratory gas leak from uncuffed infant endotracheal tubes is an important requirement for evaluating the rates of metabolic gas exchange by indirect calorimetry in neonates receiving mechanical ventilation. The present study reports a new, noninvasive technique for the efficient collection and analysis of expiratory gases leaked from a closed‐circuit metabolic monitoring system recently described. A loose‐fitting face mask is placed over the infant's endotracheal appliance and air is entrained from the mask cavity at 100 mL/min for CO2 analysis by infrared capnometry. In vitro calibration of this apparatus demonstrates a relative error of less than 5% of simulated endotracheal tube leak. In vivo application to metabolic rate assessment (using the MGM Jr. metabolic cart) in 12 intubated, ventilated infants ranging from 1.56 to 4.07 kg study weight demonstrated endotracheal tube leaks from 0.49 to 7.40% of net CO2 production, which ranged 10.67 to 70.91 mL/min (or mean 8.22 ± 0.93 SEM mL/kg/min). The magnitude of tube leakage of mixed expiratory gases could not be predicted from endotracheal tube diameter, ventilator settings, or infant activity or posture. As new instrumentation becomes available to measure the rates of metabolic gas exchange in intubated infants, systematic evaluation of uncuffed endotracheal tube gas leaks becomes critical. Pediatr Pulmonol. 1990; 9:55–60.
Respiratory papillomas: Presentation before six months
Authors: Chipps Bradley E. , McClurg F. L. Don , Freidman Ellen M. , Adams George L. 
Published: March 2007

AbstractThe prognosis of respiratory papillomatosis (RP) in newborns appears to be less favorable than in infants and older children. In this series of four patients who developed symptoms of the disease within the first 6 months of life, the mortality was 100%. In these premature and term newborn infants, endoscopic laser surgery and medical and immunologic therapy were unable to control the growth of RP. Meticulous local removal of the airway lesions is the most reliable form of management. Pediatr Pulmonal 1990; 9:125–130.
A comparison of lung lamellar body phospholipids from premature and term infants: Is sphingomyelin a contaminant of surfactant?
Authors: Neumann M. A. , McMurchie E. J. , Gibson R. A. 
Published: March 2007

AbstractLamellar bodies were isolated from homogenates of lungs obtained at autopsy from premature infants (n = 9), and compared to lamellar bodies from three full term reference groups including 55 infants with sudden infant death syndrome (SIDS), 14 control infants, and 3 who succumbed to intra‐uterine death (IUD) at term. Analysis of the phospholipids was expected to reveal a high proportion of sphingomyelin (Spm) in the lamellar bodies isolated from the lungs of premature infants (24 to 33 weeks gestational age) since at this stage of their development the percentage of Spm in the amniotic fluid is high. However, Spm was either absent or a small proportion of the total phospholipid in lamellar body surfactant from these premature infants. Spm was also a small percentage of phospholipid in the lamellar body surfactant of infants with SIDS and from control and IUD specimens. It is suggested that Spm may not be a normal constituent of lamellar body surfactant but rather a contaminant from membranes. Pediatr Pulmonal 1990; 9:162–165.
Surfactant protein‐A in bronchoalveolar lavage fluid from neonates with RDS on conventional and high‐frequency oscillatory ventilation
Authors: Gerdes Jeffrey S. , Abbasi Soraya , Karp Karen , Hull William , Whitsett Jeffrey A. 
Published: March 2007

AbstractSurfactant protein‐A (SP‐A) was measured in bronchoalveolar lavage (BAL) samples from ventilated neonates in order to study the concentration of SP‐A with regard to: 1) high‐frequency oscillatory ventilation (HFOV) vs. conventional mechanical ventilation (CMV); 2) the postnatal course and ontogeny of SP‐A; and 3) the correlation with measurements of pulmonary function. Patients on HFOV had markedly lower BAL SP‐A concentrations on days 1 and 2 compared to those on CMV, which may indicate influence of mode of ventilation on surfactant metabolism. The SP‐A concentrations increased postnatally concurrent with resolution of acute respiratory distress syndrome. Finally, there were only weak correlations between BAL SP‐A concentration and dynamic lung compliance and oxygen requirement. Pediatr Pulmonal 1990; 9:166–169.
Ventilation‐perfusion abnormalities in the preterm infant with hyaline membrane disease: A two‐compartment model of the neonatal lung
Authors: Hand Ivan L. , Shepard Eric K. , Krauss Alfred N. , Auld Peter A. M. 
Published: March 2007

AbstractArterial‐alveolar differences for oxygen, carbon dioxide, and nitrogen were measured in 7 non‐distressed preterm infants and 21 ventilator‐dependent preterm infants with hyaline membrane disease. The preterm infants with hyaline membrane disease had a significantly lower average arterial pH (7.34 vs. 7.44; P < 0.001), and significantly higher arterial‐alveolar differences for oxygen (286 mm Hg vs. 34 mm Hg; P < 0.005) and nitrogen (118 mm Hg vs. 7 mm Hg; P < 0.005). Both groups had elevated arterial‐alveolar differences for P (9 mm Hg in infants with hyaline membrane disease, 5 mm Hg in nondistressed infants; P < 0.2). When acute changes in mean airway pressure were produced in 14 distressed infants, arterial‐alveolar CO2 and N2 differences moved in opposite directions in 11 infants. This observation suggests that changes in mean airway pressure do not acutely recruit atelectatic alveoli, but cause redistribution of ventilation within alveoli already ventilated. Pediatr Pulmonal 1990; 9:206–213.
Effect of forced expiration on thoracic gas volume in wheezy infants
Authors: Lanteri Celia J. , Raven Joan M. , Sly Peter D. 
Published: March 2007

AbstractPartial expiratory flow‐volume curves are commonly used in infant pulmonary function testing. The flow measurements are volume dependent and thoracic gas volume (TGV) is often measured in conjunction with forced expiratory maneuvers. Since it is not possible to make continuous, simultaneous measurements of TGV during forced expiration, it is assumed that lung volume returns to its original value after forced expiration. To test this assumption we measured TGV using a whole body plethysmograph in 14 wheezy infants before and after a series of forced expirations produced with an inflatable jacket. Forced expiration did not cause a significant change in group mean TGV measurements. Examination of individual data did not show any systematic difference between TGV measured before and after forced expiration. These results suggest that repeated forced expirations do not alter TGV within the time scale of usual pulmonary function testing protocols. Pediatr Pulmonal 1990; 9:220–223.
External intercostal muscle activity during acute hypoxia in the kitten
Authors: Guthrie Robert D. , Klesh Kenneth W. , O'Day Terrence L. , Watchko Jon F. 
Published: March 2007

AbstractThe effects of acute hypoxia on the recruitment of external intercostal muscle activity were determined in 12 kittens, aged 14 to 36 days. The animals were anesthetized with 1.23 ± 0.23% halothane and bipolar electrodes were placed in the costal and crural diaphragm and in dorsal external intercostal muscles. Acute hypoxia was induced by the animals breathing 13% oxygen; arterial gases were sampled during baseline conditions and at 1 and 5 min after induction of hypoxia. Peak‐moving average (PA) and minute electromyogram (EMG) activity (PA × f) were recorded during baseline conditions and at 1 and 5 min after onset of acute hypoxia. At 1 min of acute hypoxia, PA and PA × f of the costal diaphragm, crural diaphragm, and external intercostal muscles were significantly increased above baseline values (P < 0.01). After 5 min of acute hypoxia, PA of all three muscles remained elevated above baseline values (P < 0.05) but PA × f returned toward baseline levels. Respiratory frequency remained unchanged during the hypoxic stimulus. These data document that the newborn is capable of increasing inspiratory external intercostal muscle EMG activity during acute hypoxia. We speculate that this phasic recruitment could be of physiologic benefit to the newborn by stabilizing the compliant chest wall and by increasing the contribution of rib cage expansion to tidal breathing. Pediatr Pulmonal 1990; 9:233–237.
Digital clubbing and pulmonary function abnormalities in children with lung disease
Authors: Paton James Y. , Bautista Daisy B. , Stabile Michael W. , Waldman Amy E. , Nassar Annette G. , Platzker Arnold C. G. , Keens Thomas G. 
Published: March 2007

AbstractDigital clubbing and pulmonary function tests were measured in children, adolescents, and adults with chronic lung diseases to determine pulmonary function correlates with a quantitative measure of clubbing. The group had a mean age of 13.8 ± 6.0 (SD) years, mean Pa of 81 ± 21 mm Hg, and mean FEV1 of 60% ± 26% predicted. Digital clubbing was diagnosed in 43 cases when the distal phalangeal depth to interphalangeal depth (DPD/IPD) ratio, measured on a finger cast, was ⩾1 (>3 SD above mean from 85 controls; no history of pulmonary disease; mean age, 14.8 ± 7.6). The Pa of patients with digital clubbing was 69.4 ± 2.1 (SEM) mm Hg compared with 88.3 ± 1.3 mm Hg in those without digital clubbing (P < 0.0001). Digital clubbing was present in 39 of the 84 (46%) hypoxic patients (Pa ⩽ 88) but only four of the 78 (5%) normoxic patients (P < 0.0001). The DPD/IPD ratio was negatively correlated with Pa in subjects with cystic fibrosis and interstitial fibrosis. Weak negative correlations were seen for all other subjects except asthmatics. Overall, the DPD/IPD ratio was significantly correlated with Pa (r = −0.53; P < 0.0001). The DPD/IPD ratio was correlated with other lung function abnormalities (increased RV, decreased FEV1, and FEF25%–75%) only for the subjects with cystic fibrosis. We conclude that digital clubbing is associated with hypoxemia and airway obstruction. The relation is seen most clearly in subjects with cystic fibrosis, possibly reflecting the prolonged duration of hypoxemia. Digital clubbing is rarely seen in normoxic subjects. Pediatr Pulmonol 1991; 10:25–29.
Circulating levels of tumor necrosis factor and interleukin‐1 in cystic fibrosis
Authors: Brown Mark A. , Morgan Wayne J. , Finley Paul R. , Scuderi Philip 
Published: March 2007

AbstractTo assess the role of tumor necrosis factor (TNF) and interleukin‐1 (IL‐1) in the pathophysiology of cystic fibrosis (CF)‐associated growth failure/cachexia and lung disease we measured height, weight, triceps skin fold, forced vital capacity, forced expiratory volume in 1 second, and plasma levels of TNF, interleukin‐1‐alpha (IL‐1α), interleukin‐1‐beta (IL‐1β), and alpha‐1‐antitrypsin (A1AT) in 12 patients with CF, and in 12 age‐ and gender‐matched healthy controls. The patients as a group had significantly lower values for the anthropomorphic measurements and lung function parameters as compared to controls. They also had higher circulating levels of A1AT than controls. TNF, however, was detected less frequently in patients than in controls. Neither group had detectable levels of circulating IL‐1α or IL‐1β, which is consistent with the observation that CF patients infrequently present with fever. Potential explanations for these findings include compartmentalization of secreted TNF/IL‐1, altered regulation of TNF/IL‐1 secretion as a result of the chronic inflammatory state seen in CF, or increased degradation of TNF/IL‐1, also a result of chronic inflammation. The role of these cytokines in the pathophysiology of CF remains unclear, but should be explored further; however it seems unlikely that circulating TNF plays a role in the growth failure/cachexia associated with CF. Pediatr Pulmonol 1991; 10:86–91.
Pulse oximetry versus measured arterial oxygen saturation: A comparison of the Nellcor N100 and the Biox III
Authors: Lebecque Patrick , Shango Polycarpe , Stijns Maddy , Vliers André , Coates Allan L. 
Published: March 2007

AbstractPulse oximetry is noninvasive, fast, and simple, making it a very popular way of assessing oxygenation in pediatric patients. However, there are few studies that establish the accuracy of this technology over a wide range of oxygen saturations in children. This study, done in 47 children aged from 1 day to 16 years with congenital heart disease and undergoing cardiac catheterization, compared the direct measurement of arterial oxygen saturation to values from pulse oximetry. Oxygen saturation was measured by an IL‐282 Co‐oximeter, which also measured carboxyhemoglobin and methemoglobin, and was compared to values obtained from both a Biox III and Nellcor N100. Both pulse oximeters gave values that closely correlated with the actual saturation (r = 0.91 and 0.93, respectively) with standard errors of the estimate of 4.1 and 3.2%, respectively. For both devices, the error increased with decreasing saturations, being progressively larger below a saturation of 80%. The difference between the actual saturation and that measured by pulse oximetry bore no relationship to the presence of carboxyhemoglobin, methemoglobin, fetal hemoglobin, bilirubin, cardiac index, or age of the patient. In conclusion, pulse oximetry, while a very useful technology in pediatrics, must be interpreted with some caution in children with severe cyanosis. Pediatr Pulmonol 1991; 10:132–135.