bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cough flow‐volume relationships in normal and asthmatic children
Authors: Beardsmore Caroline S. , Park Alan , Wimpress Stephen P. , Thomson Anne H. , Simpson Hamish 
Published: March 2007

AbstractThe flow‐volume profile of a maximum voluntary cough resembles that of a maximum expiratory flow‐volume (MEFV) curve with superimposed transient peak flows at the onset of each cough effort and portions of zero flow corresponding to periods of glottis closure. A straight line (the cough slope) can be drawn through the transient peak flows, and the ratio of MEFV‐equivalent flow to the cough peak flow can be calculated. This cough ratio has been shown to fall during adult life and may be related to changes in airway compliance and crosssectional area with age. The present study investigated the cough ratio, cough slope, and maximum flows measured from the cough flow‐volume curve in a group of normal children aged 7 to 16 years. Maximum flows and the cough slope increased with height, but the cough ratio did not change with growth or age. In a similar group of asthmatic children, baseline measurements of cough showed a reduction in cough peak flow rates, MEFV‐equivalent flow, and the cough ratio. These changes are related to alterations in airway compliance and cross‐sectional area and are partly reversed following inhalation of a bronchodilator.
Expression of results of histamine challenge
Authors: Reiser J. , Wadsworth J. , Nunn A. , Warner J. O. 
Published: March 2007

AbstractDifferent aspects of standardization of histamine challenges have been extensively investigated. However, several methods have been used for the actual derivation of the provocation concentration causing a 20% fall in lung function (PC20) from the results of the serial lung function tests (e.g. forced expiratory volume in 1 second [FEV1]). We have compared these methods on a series of 21 histamine challenges to see if any were systematically inconsistent with the others. The simplest method, with least potential for further error, is interpolation of two points, on either side of the line for 20% fall in lung function, calculated by computer. We conclude that, as this method was consistent with the majority of others, it is the method of choice for deriving the PC20.
Subglottic inflammatory pseudotumor in a 6‐year‐old child
Authors: Zapatero J. , Lago J. , Madrigal L. , Baschwitz B. , Rodriguez E. Perez , Penalver R. , Candelas J. 
Published: March 2007

AbstractInflammatory pseudotumors have been given diverse—no fewer than 19—names in the literature. The most frequent localization is in the lung, the gastrointestinal tract, and salivary glands. The case presented here at the subglottic level is exceptional. Although the intraoperative diagnosis is not easy, the prognosis is usually good. Malignant degenerations have not been described. In those cases that cannot be operated on or that extend into the mediastinum, radiotherapy is indicated.
Changes in functional residual capacity in response to bronchodilator therapy among young asthmatic children
Authors: Greenough Anne , Pool Jeni , Price J. F. 
Published: March 2007

AbstractMeasurements of functional residual capacity (FRC) by helium gas dilution and peak expiration flow rate (PEFR) were made in 63 young asthmatic children aged 2 and 7 years before and after bronchodilator therapy. All 63 children tolerated two measurements of FRC, but only 33 children were able to perform the peak flow maneuver. Bronchodilator therapy was associated with significant change in FRC in the majority (80%) of children; in some, however, this change was an increase rather than a decrease. The change in FRC was significantly correlated with both prebronchodilator FRC and the change in PEFR. An increase in FRC following bronchodilator therapy was more common in children with severe and symptomatic asthma. We suggest that changes in FRC may be used in asthmatic children to demonstrate bronchodilator responsiveness, particularly in those too young to perform other respiratory function tests. Pediatr Pulmonol. 1989; 7:8–11.
Costal and crural diaphragm, and intercostal and genioglossal electromyogram activities during spontaneous augmented breaths (sighs) in kittens
Authors: Watchko Jon F. , Brozanski Beverly S. , O'Day Terrence L. , Klesh Kenneth W. , Guthrie Robert D. 
Published: March 2007

AbstractSpontaneously occurring augmented breaths (sighs) are common in infants. The pattern of electrical activity of the inspiratory muscles of the thorax and upper airway during augmented breaths, however, has not been fully characterized in this less than fully mature age group. We therefore examined costal and crural diaphragm and external intercostal and genioglossal EMG activities during spontaneous augmented breaths (n = 46) in 10 anesthetized (1.35% halothane) 1‐month‐old kittens breathing room air. EMG responses were assessed by comparing the spontaneous augmented breaths (AB) to the five immediately preceding breaths (control). The peak moving time average EMG activity observed during the AB was 240 ± 32% (mean ± SD) of control for the costal diaphragm, 279 ± 66% of control for the crural diaphragm, and 274 ± 68% of control for the external intercostal muscle. The mean increase in EMG activity during the AB was not significantly different among these three muscle groups (P > 0.25). Genioglossal EMG activity during AB was observed in only 1 of 10 study animals. These results document that during AB in anesthetized kittens, activity of the thoracic inspiratory muscles (costal/crural diaphragm and external intercostal muscles) increase in parallel, suggesting that they are modulated in a uniform manner. The infrequent observance of genioglossal activity during AB suggests that either (1) halothane anesthesia depresses genioglossal activity more than diaphragmatic and intercostal activity during AB or (2) that genioglossal recruitment is not necessary to maintain upper airway patency during this period of heightened respiratory drive. Pediatr Pilmonol. 1989; 7:94–100.
Exercise tolerance and effects of training in young patients with cystic fibrosis and mild airway obstruction
Authors: Braggion C. , Cornacchia M. , Miano A. , Schena F. , Verlato G. , Mastellay G. 
Published: March 2007

AbstractWe evaluated the effects of an 8‐week aerobic training (1 hr, three times a week) on physical performance of ten patients with cystic fibrosis (CF) (median age, 12.5 yr; range 11.1–15.3 yr), with mild airway obstruction (FEV1 = 77 ± 22% pred.), and ten healthy age‐matched children (CONTR) (median age, 12.7 yr; range 12.2–15.2 yr). Physical performance was tested with maximal incremental (MAX) and submaximal (SMAX) (fixed workload of 1.7 W/kg during 6 min) exercise tests on a cycle ergometer. These and standard spirometric and anthropometric measurements were performed at the beginning and end of a period with usual daily activity and one with the training program. The kinetics of ventilatory parameters at the onset and end of SMAX were displayed by fitting data on oxygen uptake and minute ventilation by monoexponential curves (least‐squares method). At the start and the end of the training period, all children were timed for endurance run to voluntary exhaustion and for sprinting through an obstacle course. A pattern of relative hyperventilation during SMAX and of poor performance in endurance and obstacle runs were evident at the start of the training period in patients with CF. The effects of training on MAX and SMAX were small and partial; the improvement in field test performances was significant only for CF and could be attributed to improvement of skill and motivation. Pediatr Pilmonol. 1989; 7:145–152.
Measurement of ventilatory mechanical impedance in infants using a head pressure generator
Authors: Marchal F. , Peslin R. , Duvivier C. , Gallina C. , Crance J. P. 
Published: March 2007

AbstractTwo methods of measuring ventilatory mechanical impedance (Z) by forced oscillations between 6 and 20 Hz were compared in 24 infants aged 2 to 49 months: (1) the application of pressure oscillations at the airway opening (Z1); and (2) the application of pressure oscillations around the head (Z2). The latter has been recently proposed to minimize the influence of compliant upper airway walls (Peslin et al., J Appl Physiol. 1985, 59:1790–1795). Ventilatory resistance and compliance (Rsb, Csb) were also obtained with the single breath method. The real part of Z1 (R1) was markedly lower than that of the corresponding Z2 (R2), at any frequency. R1 exhibited a systematic negative frequency dependence, in contrast with R2. At any frequency, the slope of the regression equation on Rsb was closer to unity for R2 than for R1. The imaginary part of Z1 (X1) was negative over the whole frequency interval, and negative values of inertance were derived from X1. X2 was negative at low and positive at high frequencies. Resonant frequency (mean ± SD = 10.5 ± 3.5 Hz) was always reached with Z2 and correlated negatively with body weight (r = −0.61). Inertance estimated from X2 was positive and correlated negatively with body height (r = −0.66). The compliance derived from Z1 (C1 = 3.35 ± 2.32 103 L·cm H2O−1) was not significantly different from that derived from Z2 (C2 = 2.99 ± 2.02 10−3 L·cm H2O−1). The marked difference observed between Z1 and Z2 is related to the importance of the upper airway shunt and may be explained by inaccuracies of both methods. The ventilatory system impedance (Zrs) is underestimated by Z1 because some of the flow through the flowmeter does not reach the airway, and is overestimated by Z2 because some of the flow from the subject does not reach the flowmeter. The latter effect is negligible in mouth breathers, but becomes quite substantial in nose breathers. Although computer simulations suggest that the error in estimating Zrs from Z2 appears to be lower than that resulting from Z1, the potential benefit offered by the routine use of a head generator in infants remains to be established. Pediatr Pulmonol 1989; 7:209–216.
Outcome of mechanical ventilation in children with acquired immunodeficiency syndrome
Authors: Marolda Joanne , Pace Bella , Bonforte Richard J. , Kotin Neal , Kattan Meyer 
Published: March 2007

AbstractWe retrospectively reviewed the records of 18 children with acquired immunodeficiency syndrome (AIDS) who required mechanical ventilation for respiratory failure. These patients represented 35% of the patients seen with pulmonary disease and AIDS. The most common causes of respiratory failure were Pnuemocystis carinii pneumonia (77%) and bacterial pneumonia (33%). Bronchial lavage by fiberoptic bronchoscopy or endotracheal tube suctioning in mechanically ventilated children with AIDS had a high yield for P. carinii. Eight of 18 (44%) children survived the episode of respiratory failure and were weaned from the ventilator. However, four of eight survivors died within 6 months. Arterial oxygen tension on admission and maximum peak inspiratory pressure on the ventilator did not differ between survivors and non‐survivors. We conclude that children with AIDS who are mechanically ventilated can be weaned from the respirator but that the subsequent course remains poor. Pediatr Pulmonol 1989; 7:230–234.
Clinical significance of airway responsiveness in children of low birthweight
Authors: Chan K. N. , Elliman A. , Bryan E. , Silverman M. 
Published: March 2007

AbstractWe report a prospective study of airway responsiveness in a cohort of 121 children of low birthweight (under 2,000 g) at 7 years and a random sample of 100 local schoolchildren of the same age. A positive airway response was defined as a 20% fall in peak expiratory flow rate in response to a cumulative histamine dose of 3 μmol or less. We found a moderate increase in airway responsiveness to inhaled histamine in the cohort (44%) compared with the reference group (22%). There was no significant association between airway responsiveness and any perinatal variables including the level of respiratory support. The findings suggested that neonatal respiratory illness or its treatment did not play a major role in determining the long‐term airway responsiveness in these children. Amongst all factors examined, reduced airway function at the age of 7 was most strongly associated with airway responsiveness, independent of perinatal and familial factors. Airway responsiveness was associated with significantly more chest symptoms. We suggest that increased airway responsiveness to inhaled histamine in low birthweight children is a consequence rather than the cause of reduced airway function and argue against the presence of any other form of airway dysfunction as a cause of airway responsiveness. Pediatr Pulmonol 1989; 7:251–258.
Prematurity is associated with abnormal airway function in childhood
Authors: Galdès‐Sebaldt Michèle , Sheller J. R. , Grogaard Jens , Stahlman Mildred 
Published: March 2007

AbstractTo evaluate the long‐term effect of prematurity and/or hyaline membrane disease (HMD) on pulmonary function and airway reactivity, we studied 49 prematurely born children aged 10 to 13 years. They were divided into three groups according to birth weight and HMD status: Groups I and II comprised the children weighing less than 1,500 g at birth, and Group III those whose birth weight exceeded 1,500 g. Children without HMD at birth were classified as Group I and those with HMD as Group II or III. We performed both pulmonary function tests and methacholine (MCh) challenges and compared the results with those of 27 age‐matched controls born at term. We found that FEV1 and RV/TLC ratios were significantly different from control values in the groups with birth weights less than 1,500 g, regardless of their HMD status (Groups I and II). In Group I, results for FEF25–75%, V̇max50%, and DLCO were lower than those of controls. Airway reactivity was significantly increased in Groups I and II. A 20% drop in FEV1 after MCh challenge was found in 88%, 62%, 53%, and 36% of children in Groups I, II, and III and controls, respectively, and a 35% drop in SGaw occurred in 87%, 88%, 53%, and 59%. We conclude that prematurity and not HMD per se leads to long‐term pulmonary abnormalities and to an increase in nonspecific airway reactivity. Pediatr Pulmonol 1989; 7:259–264.
Prospective pneumogram recordings in preterm infants with and without clinical apnea and bradycardia
Authors: McCulloch Kristine M. , Kelly Dorothy H. 
Published: March 2007

AbstractRecordings of breathing movements and heart rate (pneumograms) were obtained prospectively in 89 preterm infants at 0–28 days of age to determine if those who develop apnea and/or bradycardia with cyanosis (Group 1) differ from those who do not (Group 2). The 148 pneumograms were blindly analyzed for periodic breathing, bradycardia, longest apnea, and quiet time. Pneumograms were compared between groups at weekly intervals during the first 4 weeks. Significant differences were found among infants who had pneumograms recorded during the 1st week of life. Although mean gestational age and mean postconceptional age at recording were similar, birthweight and weight at recording were significantly lower in Group 1 infants. Total time spent in periodic breathing and the longest episode of periodic breathing were significantly greater in Group 1 infants. Logistic regression analysis revealed significant independent relationships between birthweight and periodic breathing at ≤7 days of age and the occurrence of symptomatic apnea and/or bradycardia. It is concluded that preterm infants who develop apnea and/or bradycardia with cyanosis have a lower mean birthweight and mean weight at recording at ≤7 days of age than similar asymptomatic preterm infants. Periodic breathing at ≤7 days of age is associated with the occurrence of clinical symptoms of apnea and/or bradycardia. Normal pneumogram values for groups of 6–21 asymptomatic preterm infants are provided for the first 4 weeks of life. Pediatr Pulmonol 1990; 8:33‐39.
Titration of continuous positive airway pressure by the pattern of breathing: Analysis of flow‐volume‐time relationships by a noninvasive computerized system
Authors: Schulze Andreas , Mädler Hans‐Jürgen , Gehrhardt Bernd , Schaller Peter , Gmyrek Dieter 
Published: March 2007

AbstractInfants can defend or even dynamically elevate their functional residual capacity with additional respiratory muscle work by retarding early expiratory airflow (V̇) with postinspiration inspiratory muscle activity and/or laryngeal narrowing, or by starting inspiration before expiration to the relaxation volume has been completed.In order to study the effect of continuous positive airway pressure (CPAP) on both phenomena in 23 infants (birthweight 1,746 ± 417 g), we elevated the airway pressure stepwise in 0.2 kPa increments. A computerized bedside flow‐volume (V̇/V) analysis was used for evaluation. In 16 “responders” early expiration braking decreased and “premature inspiratory interruption” was postponed at an “appropriate CPAP level.” The linear segment (relaxation line) of the V̇/V‐loop was lengthened until expiratory time reached a maximum. Elevation of CPAP beyond this level again produced a rapid, shallow pattern, often combined with flow acceleration late in expiration (recruitment of expiratory muscles). In the remaining seven infants (non‐responders) these latter signs of excessive airway pressure already occurred at the lowest CPAP levels applied during the “titration trials.” Respiratory rate without CPAP was different between responders (84 ± 17/min) and non‐responders (46 ± 17/min). This approach for determining the appropriate CPAP level might reduce the risk of respiratory muscle fatigue. Pediatr Pulmonol 1990; 8:96‐103.
Adult respiratory distress syndrome in severely neutropenic children
Authors: Sivan Yakov , Mor Celia , Al‐Jundi Sana , Newth Christopher J. L. 
Published: March 2007

AbstractIt has been suggested that polymorphonuclear cells (PMNs) are required for the development of the adult respiratory distress syndrome (ARDS). We investigated the occurrence of ARDS with acute respiratory failure in 30 children with severe neutropenia (<500 PMNs/mm3) who met the clinical diagnostic criteria for ARDS and in whom postmortem histopathology findings were available within 7 days of the onset of ARDS. In 26 patients the histopathology was consistent with ARDS. In 12/26 children no white blood cells (WBC) were found in the lung tissue, 10/26 had moderate infiltration of mononuclear cells, 2/26 had massive tumor cell infiltration, and in 2/26 PMNs were found. Thus, in at least 22/26 patients ARDS developed without neutrophilic infiltration of the lungs. The maximum active lung infection rate was found to be 69% (18/26) by endotracheal and post mortem lung cultures and histology. Thus 5/26 children had ARDS without any WBC in the lung tissue. We conclude, as have other studies in adults that the absence of PMNs does not protect children from the development of ARDS and that the mechanism which involves PMNs is probably only one of several pathways for diffuse alveolar damage, some of which is neutrophil‐independent. Pediatr Pulmonol 1990; 8:104‐108.
Effects of indoor air pollution on lung function of primary school children in Kuala Lumpur
Authors: Azizi B. H. O. , Henry R. L. 
Published: March 2007

AbstractIn a cross‐sectional study of 7–12 year‐old primary school children in Kuala Lumpur city, lung function was assessed by spirometric and peak expiratory flow measurements. Spirometric and peak expiratory flow measurements were successfully performed in 1,214 and 1,414 children, respectively. As expected, the main predictors of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory flow between 25% and 75% of vital capacity (FEF25–75), and peak expiratory flow rate (PEFR) were standing height, weight, age, and sex. In addition, lung function values of Chinese and Malays were generally higher than those of Indians. In multiple regression models which included host and environmental factors, asthma was associated with significant decreases in FEV1, FEF25–75, and PEFR. However, family history of chest illness, history of allergies, low paternal education, and hospitalization during the neonatal period were not independent predictors of lung function.Children sharing rooms with adult smokers had significantly lower levels of FEF25–75. Exposures to wood or kerosene stoves were, but to mosquito repellents were not, associated with decreased lung function. Pediatr Pulmonol 1990; 9:24–29.
Estimation of intrapleural pressure in the newborn
Authors: Mayock Dennis E. , Watchko Jon F. , Standaert Thomas A. , Woodrum David E. 
Published: March 2007

AbstractWe examined the changes in esophageal (Pes), proximal airway (Paw), and direct intrapleural (Ppl) pressure measurements following end‐expiratory airway occlusion in anesthetized spontaneously breathing newborn piglets. Simultaneous occluded pressure measurements were obtained during resting ventilation, inspiratory resistive loaded (IRL) breathing, and bilateral transvenous phrenic nerve stimulation. During spontaneous resting ventilation, occluded Paw/Ppl averaged 104 ± 4% and occluded Pes/Ppl averaged 89 ± 3%. Similar values were found for occluded spontaneous breaths with IRL. During phrenic nerve stimulation at end‐expiratory lung volume, occluded Paw/Ppl averaged 104 ± 6% while occluded Pes/Ppl decreased to 70 ± 22%. We conclude that proximal airway pressure more accurately reflects intrapleural pressure than esophageal pressure with occlusion in newborn swine. During phrenic nerve stimulation, esophageal pressure measures are grossly inaccurate estimates of intrapleural pressure with occlusion. Pediatr Pulmonol 1990; 9:30–33.
Pulmonary function in infancy and in childhood following mechanical ventilation in the neonatal period
Authors: Lebourges F. , Moriette G. , Boulé M. , Delaperche M. F. , Relier J. P. , Gaultier C. 
Published: March 2007

AbstractPulmonary function was evaluated in both infancy and childhood in the same 19 prematurely born infants, who required mechanical ventilation (MV) during the neonatal period. Results of our patients were compared with those of control subjects. Upon first evaluation, we found that lung resistance (RL) was significantly elevated (24.85 ± 6.06 vs. 17.77 ± 2.39 cmH2O/L/s; P < 0.01). The mean value of dynamic lung compliance (CLdyn) was low, but the difference compared to controls did not reach significance. From infancy to childhood, elevated RL persisted (9.33 ± 2.51 vs. 6.52 ± 1.52 cm H2O/L/s; P < 0.01), and the decrease of CLdyn became significant (46.86 ± 12.84 vs. 59.34 ± 15.68 mL/cmH2O; P < 0.05). In addition, maximum flow at functional residual capacity was significantly decreased (0.824 ± 0.284 vs. 1.215 ± 0.358 L/s; P < 0.01); whereas pulmonary diffusing capacity for carbon monoxide was similar in the patients (7.62 ± 2.16 mL/min/mm Hg) and in the controls (8.38 ± 1.6). Pulmonary dysfunction following premature birth, respiratory distress, and prolonged MV may not resolve from infancy to childhood. Pediatr Pulmonol 1990; 9:34–40.
Peak expiratory flow measured with the mini wright peak flow meter in children
Authors: Sanz José , Martorell Antonio , Saiz Rosa , Alvarez Vicente , Carrasco José I. 
Published: March 2007

AbstractWe established pediatric reference values for peak expiratory flow rate (PEFR), using the Mini Wright Peak Flow Meter. The study was based on 1,566 Mediterranean white children, aged 7 to 14 years from Valencia (Spain) schools. Height was the biometric variable with the greatest correlation to PEFR in both sexes; significant differences were noted between males and females. Prediction equations and percentile tables are presented for each sex. The performance of the Mini Wright Peak Flow Meter was compared with that of a spirometer. Pediatr Pulmonal 1990; 9:86–90.