bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of nasal impedance using the forced oscillation technique in infants
Authors: Desager K. N. , Willemen M. , van Bever H. P. , de Backer W. , Vermeire P. A.
Published: March 2007

By applying oscillations to the respiratory system through a rigid face mask, the infant‐adapted Lándsér forced oscillation technique measures impedance of the total respiratory system including the nose, at frequencies from 4 to 52 Hz. The present study was aimed at evaluating nasal impedance in infants from consecutive forced oscillation measurements through both nostrils and each nostril separately, using a simple electrical model. In 30 asthmatic infants with varying degrees of nasal obstruction, aged 1–16 months, calculated nasal resistance (Rn) at 24 Hz ranged from 1 to 16 cm H2O · L−1 · s. The ratio of Rn to total respiratory system resistance varied between 1 and 48% (mean: 16%). In seven non‐asthmatic infants, aged 0‐12 months, Rn was between 1 and 11 cm H2O · L−1 · s. Nasal patency (evaluated clinically) was correlated with the calculated Rn (P < 0.05). Rn showed almost no frequency dependence between 24 and 48 Hz as demonstrated by a mean slope of −0.09 ± 0.08 cm H2O · s2/L for the asthmatic and of −0.08 ± 0.07 for the non‐asthmatic infants. In seven of the asthmatic infants the differences between two Rn determinations at a 45 min interval ranged from −1.7 to 3.8 cm H2O · L−1 · s−1 at 24 Hz and from −3.6 to 1.0 at 48 Hz. Changes in Rn did not correlate with changes in total respiratory system resistance (P > 0.05). In conclusion, nasal impedance can be approximated from three consecutive measurements through both nostrils and through each nostril separately.Pediatr Pulmonol. 1991 ; 11 :1‐7.
Pulmonary function in newborns after repair of congenital diaphragmatic hernia
Authors: Nakayama Don K. , Motoyama Etsuro K. , Mutich Rebecca L. , Koumbourlis Anastassios C.
Published: March 2007

Congenital diaphragmatic hernia (CDH) is associated with pulmonary hypoplasia that limits survival, but the nature and extent of pulmonary dysfunction in neonates with CDH have not been studied. We performed pulmonary function tests (PFTs) in eight intubated infants who survived neonatal repair of CDH (wt, 3.33 ± 0.15 kg; age, 20.1 ± 2.7 d; mean ± S.E.M.). PFTs obtained from six full‐term infants (wt, 3.56 ± 0.10 kg; age, 25.0 ± 3.3 d) with no respiratory illness served as controls. The deflation flow‐volume curve technique produced maximum expiratory flow‐volume (MEFV) curves, giving reproducible measurements of forced vital capacity (FVC) and maximal expiratory flow at 25% of FVC (MEF25). Respiratory system compliance (Crs) and resistance (Rrs) were obtained with a modified passive mechanics technique. In seven of eight infants PFTs were repeated after nebulized bronchodilator (0.1% isoetharine). In neonates surviving CDH repair, as compared to those with normal lung function, FVC was significantly reduced (20.78 ± 3.32 vs. 39.83 ± 3.30 mL · kg−1, P < 0.05). MEF25 was also markedly reduced (8.41 ± 1.46 vs. 32.32 ± 4.35 mL · kg−1 · s−1, P < 0.05), indicating lower airway obstruction. After administration of nebulized bronchodilator, PFTs showed significant increases from control values in both FVC (15.9%) and MEF25 (200%) without changes in Crs and Rrs. These findings indicate that neonates with CDH have restrictive lung defects, reflecting hypoplasia. After surgical repair and mechanical ventilation airway reactivity develops, primarily in smaller airways, and this may complicate the postoperative course. Pediatr Pulmonol. 1991 ; 11 :49‐55.
Respiratory responses of piglets to hypercapnia during postnatal development: Effects of opioids
Authors: Segal B. Scott , Inman Jamie D. G. , Moss Immanuela R.
Published: March 2007

Resting respiratory and cardiovascular functions and the response to CO2 rebreathing were compared between 2.5 ± 0.7 (mean ± SE) and 34.1 ± 1.9 day old piglets, before and after the opioid antagonist naltrexone (1 mg/kg IV). At rest, tidal volume, both absolute and per m2, inspiratory and expiratory time, absolute minute ventilation, and mean arterial pressure increased with age, and breathing frequency, minute ventilation per m2, and heart rate decreased, all of these with as well as without naltrexone. During hypercapnia, the pattern, but not the quantitative aspects of breathing changed with age.

At rest, naltrexone produced hyperventilation in the young, but not in the older group. During hypercapnia, naltrexone had a sparse effect in both ages.

We conclude that, in the anesthetized piglet, ventilatory functions at rest undergo change with postnatal age, but breathing responses to hypercapnia exhibit maturation in pattern only and not in magnitude. Whereas resting ventilation of young piglets is modulated by endogenous opioids, hypercapnia may activate opioids to a limited extent and in a manner unrelated to age.
Regional cycles of perfusion and non‐perfusion in the lung of the term fetal rabbit
Authors: Lipsett Jill , Gannon Bren
Published: March 2007

The spatial distribution of pulmonary blood flow and its change over time was investigated in term fetal rabbits, using the plasma tracer fluorescein‐isothiocyanate‐labeled bovine serum albumin (FITC‐BSA). A tracer bolus was injected intravenously and allowed to circulate in vivo for increasing periods of time (2–30 minutes) prior to arrest of the circulation and tissue preparation.

Initially, fluorescence was present in the vasculature of 43% of lung parenchymal tissue, disposed as discrete regions or “lobules.” Interspersed regions of lung tissue received no tracer inflow. With increasing tracer circulation times (10, 20, and 30 minutes), a greater percentage of lung cross‐sectional area contained vessels exhibiting tracer fluorescence (64, 96, and 100%, respectively).

In the fetal lung, a high pulmonary vascular resistance (PVR) is maintained. Our studies indicate that, at any given moment, fetal pulmonary blood flow is distributed only to a proportion of discrete lung “lobules,” while interspersed “lobules” receive no flow at all. The “lobules” alternate between these “high” and “low” vascular resistance states with a periodicity of approximately 35 minutes, comprising 22 minutes of non‐perfusion followed by 13 minutes of perfusion.

This circulatory pattern permits both the maintenance of high PVR and uniform lung development. Further, by directing flow to only a portion of the vasculature, greater microvascular flow rates are achieved and hence the risk of blood sludging and stasis is reduced. Recruitment of these “non‐perfused” regions at birth could thus produce a significant reduction in PVR.
Effects of a clinically detectable PDA on pulmonary mechanics measures in VLBW infants with RDS
Authors: Balsan Michael J. , Jones Judith G. , Guthrie Robert D.
Published: March 2007

We examined the effect of a clinically detectable patent ductus arteriosus (PDA) and its successful treatment with indomethacin on serial measures of pulmonary mechanics in 10 very‐low‐birthweight (VLBW) intubated infants with respiratory distress syndrome (RDS). Pulmonary mechanics were measured by the passive expiratory flow technique. Total respiratory system compliance (Crs) gradually improved as RDS resolved. However, a significant decrease in mean Crs was associated with the development of a clinically detectable PDA, ranging from 1.51 ± 0.21 to 0.90 ± 0.08 mL/cmH2O/m (P < 0.05). We also noted an increase in mean Crs, from 0.90 ± 0.08 to 1.49 ± 0.21 mL/cmH2O/m (P < 0.05), after successful treatment of a PDA with indomethacin. Total respiratory system resistance (Rrs) did not change. We conclude that a clinically significant PDA is associated with a decreased Crs and that successful treatment of a PDA with indomethacin is associated with an improvement in lung compliance. These findings imply that the development of a clinically detectable PDA and its subsequent treatment complicates the interpretation of pulmonary mechanics data in VLBW infants with RDS.
Hyperinflation in children with liver disease due to alpha‐1‐antitrypsin deficiency
Authors: Hird M. F. , Greenough A. , Mieli‐Vergani G. , Mowat A. P.
Published: March 2007

Fifty‐nine patients (median age 6.0 years) with liver disease and ten healthy children without liver disease (median age 7.5 years) had serial measurements of functional residual capacity (FRC) over a period of at least 6 months. Twenty‐eight children with alpha‐1‐antitrypsin deficiency (A1ATD) tended to have higher lung volumes than 26 with extrahepatic biliary atresia (EHBA). Fifteen children had persistent hyperinflation (FRC > 120% predicted for height; 2 SD above the mean of controls); in five children (four with A1ATD) this was unresponsive to bronchodilator therapy. Two of the children with A1ATD who had persistent unresponsive hyperinflation on three serial measurements were only 3 and 4 years of age. No healthy child without liver disease was hyperinflated. These results suggest that A1ATD may be associated with lung function abnormalities even in very young children.
Psychological change associated with theophylline treatment of asthmatic children: A 6‐month study
Authors: Bender Bruce G. , Lerner Joey A. , Ikle David , Comer Carolyn , Szefler Stanley
Published: March 2007

Theophylline has been associated with a variety of behavioral side effects in asthmatic children. This study was a 6‐month investigation of the relationship between theophylline treatment and psychological changes in 8 to 16 year old asthmatic children. Included were a group receiving theophylline (n = 19), a control group not receiving theophylline (n = 44), and a nonasthmatic control group (n = 24). The three groups had similar age, socioeconomic status, and IQ. The two groups of children with asthma demonstrated greater emotional dysfunction, characterized by tendency toward withdrawal and depression, than the nonasthmatic control group. Each of five assessment appointments (baseline and 1 week, 1 month, 3 months, and 6 months after beginning theophylline treatment) included measures of pulmonary function, attention, impulsivity, memory, fine motor control, activity level, self‐reported mood, and parental observation of difficult behavior. Pulmonary functions were lower in the theophylline group at baseline but improved significantly after commencement of theophylline therapy. Over the 6‐month interval, children in the theophylline group demonstrated improved scores on a laboratory measure of attention, while their parents reported increased conduct problems and hyperactivity. On the whole, psychological score changes were subtle, and no other betweengroup differences emerged in the remaining laboratory measures.
Respiratory mechanics of the piglet during the first month of life
Authors: Standaert Thomas A. , Wilham Bruce E. , Mayock Dennis E. , Watchko Jon F. , Gibson Ronald L. , Woodrum David E.
Published: March 2007

Piglets at 3, 14, and 30 days of age were studied to assess the postnatal changes in lung, chestwall, and total respiratory system compliance associated with normal growth. Static deflation compliance of the lung and total respiratory system increased significantly with age; there was no change in chestwall compliance. When normalized for body weight or lung volume, all measures of compliance tended to decrease with postnatal age. Measures of lung and chestwall compliance obtained with an end‐inspiratory occlusion technique were less than the static compliance measures, but demonstrated the same relative changes with postnatal maturation. Chestwall compliance at 3 days of age was only 1.3 times greater than lung compliance and there was no significant change in this ratio with postnatal age. In contrast to the trend for the human infant,1 the piglet's chestwall at 3 days of age is stiff relative to the lung and does not become stiffer with age over the first 4 weeks of life.
The effect of intravascular complement activation and brief episodes of hypoxia on protein in bronchoalveolar lavage fluid in C5 sufficient and deficient mice
Authors: Larsen Gary L. , Presley Debra M. , Graves Juanita P. , Giclas Patricia C.
Published: March 2007

Our earlier investigations indicated that systemic complement activation with iv cobra venom factor (CVF) or infused zymosan‐activated rabbit plasma or rabbit C5a does not significantly increase bronchoalveolar lavage albumin in rabbits (Am Rev Respir Dis 1982; 125:335–340); but that complement activation due to CVF combined with a brief episode of hypoxia increases lavage albumin and is associated with the presence of neutrophils for its expression (J Clin Invest 1985; 75:902–910). In order to determine if intravenous CVF and hypoxia cause similar alterations in mice, and to investigate the time course of the response as well as the importance of C5 fragments to the process, we challenged the B10.D2/oSn strain of C5 sufficient mice (C5+) and the congenic B10.D2/oSn strain of C5 deficient mice (C5−) with intravenous CVF, 15 min of 12% oxygen, or CVF followed by hypoxia. Neither C5+ nor C5− mice had significant increases in lavage protein after either CVF or hypoxia. However, the combined insults significantly increased lavage protein in C5+ but not C5− mice; polyacrylamide gel electrophoresis showed increased amounts of proteins of low and high molecular weights in lavage fluid from the C5+ strain. While the time course of abnormalities in mice was different from that in rabbits, both meclofenamate pretreatment and neutrophil depletion attenuated the increases in lavage protein after the combined insults in both animal species. Infusion of prostaglandin E2 (PGE2) with CVF in the C5+ mice also led to significant increases in lavage protein. We conclude that in mice, intravenous complement activation, as an isolated event, does not cause a significant increase in lavage protein. However, combining complement activation with another stimulus (hypoxia or intravenous PGE2) leads to significant increases in protein accumulation in the lung. With CVF and hypoxia in this system, the presence of neutrophils, the fifth component of complement, and an intact cyclooxygenase pathway of arachidonic acid metabolism may be necessary to produce an increase in lavage protein.
Hering‐breuer reflex in young asthmatic children
Authors: Greenough A. , Pool J.
Published: March 2007

The aim of this study was to assess if the Hering‐Breuer reflex could be provoked in young children. Thirty asthmatic children with a mean age of 5.3 years and 18 healthy children with a mean age of 7.0 years were studied. The presence of the reflex was indicated by prolongation of the spontaneous expiratory time following application of continuous positive airways pressure (CPAP). The occurrence of the reflex was then related to age, compliance of the respiratory system (Crs) measured by weighted spirometry, functional residual capacity (FRC) determined by helium gas dilution, and the change in lung volume resulting from the application of CPAP. The asthmatic children in whom the Hering‐Breuer reflex was observed tended to be younger (P < 0.01) and the reflex was present in those children of both groups who had more compliant lungs (P < 0.05). The FRC was not different in asthmatic children with and without the Hering‐Breuer reflex, but healthy children in whom the reflex was present tended to have smaller lung volumes. The change in lung volume resulting from application of CPAP was significantly greater in those children of both groups in whom the reflex was present (P < 0.01 asthmatics, P < 0.02 healthy children). We conclude that the Hering‐Breuer reflex may be provoked in young children.
Optimal electrode location for monitoring the ECG and breathing in neonates
Authors: Baird Terry M. , Goydos Janie M. , Neuman Michael R.
Published: March 2007

Continuous monitoring of breathing in infants is commonly performed using transthoracic impedance. This method employs skin surface electrodes measuring changes in electrical impedance and relates these changes to respiratory events. Typically, two electrodes on the infant's chest monitor both the ECG and breathing. We have attempted to identify separate electrode locations that give the best signal for breathing and ECG, and a single location that optimizes both of these signals. Thirty‐seven infants were studied by placing 12 electrodes on the infant's chest and abdomen, and serially sampling pairwise combinations of electrodes. The optimal signal for breathing was obtained when electrodes spanned the diaphragm. Optimal ECG signal was seen with one electrode at the right mid‐clavicle and one at the xyphoid. Clinicians should be aware of these locations in order to provide the best signal available.
Correcting for the Bernoulli effect in lateral pressure measurements
Authors: Bates J. H. T. , Sly P. D. , Sato J. , Davey B. L. K. , Suki B.
Published: March 2007

Measurement of airway pressure is essential in the study of respiratory mechanics, and is usually done via a lateral tap in the conduit (e.g., endotracheal tube, cannula, or mouth‐piece) leading into the subject's airway. Such pressure measurements, however, may be severely affected by the Bernoulli effect if the diameter of the conduit is small and the gas flow through it sufficiently high. We present in this note a simple method of assessing whether or not the Bernoulli effect is important in any particular situation. The technique involves comparing the pressure‐flow relationships of the conduit obtained both by blowing air through it from one end and sucking air in the reverse direction by applying negative pressure at the same end. If the resistance of the conduit is the same for gas flow in both directions, then half the magnitude of the difference between the two pressure‐flow relationships gives the magnitude of the Bernoulli effect pressure. We give results of an experimental situation in which this was the case. We also show that those conditions under which the Bernoulli effect is likely to be a problem are also those under which the velocity profile is likely to be approximately flat, thereby permitting the magnitude of the Bernoulli effect to be easily calculated.
A radiographic method for estimating lung volumes in sick infants
Authors: Fumey Marie‐Hélène , Nickerson Bruce G. , Birch Martha , McCrea Ray , Kao Lily C.
Published: March 2007

Estimation of lung volumes by conventional methods in sick infants is technically difficult and is the subject of controversy. In this study, we compared both thoracic gas volume (TGV), measured with an infant whole body plethysmograph, and functional residual capacity (FRC), determined by the nitrogen washout technique, to planimetric measurements of anteroposterior chest radiographs in 26 infants with bronchopulmonary dysplasia (BPD). © 1992 Wiley‐Liss, Inc.

The tidal volume (TV) of each patient was added to TGV and FRC because these were measured at the end of expiration whereas chest radiographs were taken at the end of spontaneous inspiration. The regression equations expressing the relationships between TGV and right + left lung field areas [A + B], and between FRC and lung areas are expressed as follows: [TGV + TV](mL) = 3.3 mL/cm2 × [A + B] cm2 + 24 mL and [FRC + TV](mL) = 3.5 mL/cm2 × [A + B] cm2 − 13.5 mL. Correlation coefficients of 0.9 and 0.7 for TGV and FRC, respectively, suggest a stronger correlation between TGV and lung areas than between FRC and lung areas.

Lung areas measured by planimetry correlate closely with physiological measurement of lung volumes. We conclude that the planimetric method is an inexpensive and reliable technique for estimating lung volumes in young infants with BPD when chest radiographs are available.
Partial and massive lung lavages in an infant with severe pulmonary alveolar proteinosis
Authors: Mahut B. , de Blic J. , le Bourgeois M. , Beringer A. , Chevalier J. Y. , Scheinmann P.
Published: March 2007

Pulmonary alveolar proteinosis is a rare disease of unknown etiology, characterized by progressive respiratory failure. Lung lavage has only been applied in a few children. A 6 month old boy suffering from severe pulmonary alveolar proteinosis was treated with three lung lavages. The first two were partial (or unilateral) lavages; a 3.5 mm flexible bronchoscope was introduced adjacent to a no. 3 cuffed endotracheal tube. This procedure allowed selective ventilation of one lung, and contralateral lung lavage. Respiratory improvement was observed during 1 week after the two procedures. At the third lavage we used partial veno‐venous extracorporeal circulation because of severe respiratory failure. A significant improvement during the 5 following months was achieved. These results suggest that both partial and total lung lavage can be performed even in young infants and they may control the declining respiratory status in severe pulmonary alveolar proteinosis. © 1992 Wiley‐Liss, Inc.
Dissociation of symptom scores and bronchial hyperreactivity: Study in asthmatic children on long‐term treatment with inhaled beclomethasone dipropionate
Authors: Benoist Marie R. , Brouard Jean J. , Rufin Patrick , Waernessyckle Serge , de Blic Jacques , Paupe Jean , Scheinmann Pierre
Published: March 2007

The aim of the study was to evaluate the effects of inhaled steroids (IS) on the improvement of clinical asthma symptoms and on the decrease in bronchial hyperreactivity (BHR). Twenty‐four children with severe asthma were given 1,000 μg beclomethasone dipropionate (BDP) daily and compared with ten asthmatic control children. The study included the evaluation of daily clinical score, of exercise induced asthma, of bronchial obstruction (forced expiratory volume in 1 sec, FEV1), and of BHR at months 0, 1, 2–3, and 4–5 (MO, M1, M2–3, and M4–5) BHR was assessed by standardized inhaled carbachol provocation measuring plethys‐mographic specific airway resistance (SRaw). The carbachol dose causing a 40% decrease in specific conductance (SGaw) was determined (PD40 SGaw). © 1992 Wiley‐Liss, Inc.

Clinical scores decreased at M1 (P < 0.01) and throughout the study. FEV1 increased at M1 (P < 0.05), M2‐3 (P < 0.01), and M4‐5 (P < 0.05) compared to MO. PD40 SGaw only increased significantly at M1 and M2‐3.

No individual correlation was found between clinical scores and PD40 SGaw at any testing, or between the decrease of clinical scores and the decrease of BHR.

We conclude that bronchoconstrictive challenge tests do not adequately assess the clinical efficacy of IS. In clinical practice non‐specific BHR should be preferentially measured for diagnosing atypical forms of asthma.
Clinical characteristics of parainfluenza virus infection in hospitalized children
Authors: Heidemann Sabrina M.
Published: March 2007

Severity of illness and clinical characteristics of parainfluenza virus (PIV) infection were evaluated in 81 hospitalized children over a 4 year period. Fifty three patients were previously healthy and 28 had preexisting pulmonary abnormalities associated with bronchopulmonary dysplasia (BPD), congenital heart disease (CHD), asthma, or prematurity. When compared with formerly healthy children, the patients with preexisting pulmonary abnormalities were more likely to develop lower than upper respiratory tract illness (P < 0.0001). In the lower respiratory tract infection group, patients with preexisting pulmonary abnormalities were sicker (P = 0.047), were hospitalized longer (P = 0.016), required more supplemental oxygen (P = 0.004), and were older (8.8 vs. 5.1 months) than previously healthy patients. Nosocomial infection occurred only in BPD patients. All these patients developed pneumonia. They were sicker (P = 0.0018), requiring more therapy (P 0.0038) than other patients with preexisting pulmonary abnormalities and lower respiratory tract disease. Patients with BPD should be placed in protective isolation during PIV epidemics. © 1992 Wiley‐Liss, Inc.
Cardiorespiratory effects of changing inspiratory to expiratory ratio during high‐frequency oscillation in an animal model of respiratory failure
Authors: Courtney Sherry E. , Weber Kaye R. , Spohn William A. , Bender Charles V. , Malin Seth W. , Gotshall Robert W.
Published: March 2007

To examine the effects of varying inspiratory/expiratory ratio (I/E) on cardiorespiratory function during high‐frequency oscillation (HFO), 11 saline‐lavaged rabbits were ventilated at I/E = 1:2, 1:1.5, 1.5:1, and 2:1 in a paired comparison to a baseline of I/E = 1:1. HFO was delivered by a SensorMedics model 3100 oscillator at a frequency of 10 Hz. Pressure amplitude and proximal mean airway pressure (PPaw) were held constant as I/E was varied from baseline to the experimental I/E. During each paired observation, Pa, Pa, cardiac output, blood pressure, and distal mean airway pressure (DPaw) were measured. © 1992 Wiley‐Liss, Inc.

We found that as I/E was increased or decreased from 1:1, no significant changes in Pa, Pa, blood pressure, or cardiac output occurred. We conclude that in this model, varying I/E has no significant effect on oxygenation, ventilation, or cardiovascular function.
Branhamella catarrhalis colonization in preschool asthmatics
Authors: Seddon Paul C. , Sunderland Deborah , O'Halloran Susan M. , Hart C. Anthony , Heaf David P.
Published: March 2007

Branhamella catarrhalis has been associated with exacerbations of chronic bronchitis and asthma in adults. To investigate the possible role of B. catarrhalis in asthma of early childhood, we took posterior pharyngeal swabs from 24 normal children, 20 well asthmatics, and 20 acutely wheezy asthmatics, all between 1 and 4 years of age. On culture, 33% of the normal children were colonized with B. catarrhalis; colonization rates in the well asthmatics (70%) and in the wheezy asthmatics (75%) were significantly higher than in normals. The nature of this association requires further study. © 1992 Wiley‐Liss, Inc.
Apnea and periodic breathing in healthy full‐term infants, 12–18 months of age
Authors: Kelly Dorothy H. , Riordan Linda , Smith Michael J.
Published: March 2007

Many children older than 12 months of age are now on home monitors. Home pneumograms performed on normal infants have established standards, and have been used to evaluate infants during their first year. However, no standards have been described for infants older than 12 months. We, therefore, recorded the standard pneumogram on 88 full‐term healthy infants who were 12–18 months of age. We analyzed the recordings for average respiratory and heart rates, apnea (≧6 seconds) density, longest apnea, periodic breathing, and bradycardia for 12 hours. We compared the values in males vs. females and in infants 12–14.9 months vs. 15.0–18.0 months of age. Since there was no difference in any parameter measured in any group, we combined the values to determine the normal values for this population. © 1992 Wiley‐Liss, Inc.
Temperature affects mechanics and stability during initial inflation–deflation of mature fetal lung
Authors: Mautone Alan J. , Antonio‐Santiago Maria T. , Clutario Bella C. , Scarpelli Emile M.
Published: March 2007

Volume‐pressure (VP) curves of initial aeration of mature (0.94–0.97 term) rabbit fetuses were compared in three groups, respectively, at 37°C, with maximal inflation pressure of 25 cm H2O (P25); 22°C, P25; and 22°C, P30. Anesthetized fetuses were delivered through uterotomy; chest was opened; trachea of fetal pulmonary liquid (FPL)‐filled lungs cannulated; and lungs inflated‐deflated in 5 cm H2O, 2 min steps under continuous microscopic observation. As distending pressure was increased, FPL moved peripherally with airways inflation by free gas and with saccular recruitment by free gas and bubbles. Saccular aeration continued during initial reduction of P from Pmax. At end‐deflation, air was retained in saccules virtually exclusively as bubbles. Airways inflation‐required less P at 37°C, though airways volume (V) was the same at both temperatures. Opening P was lower, and saccular aeration was larger and more rapid at 37°C. The apparently higher distensibility at 37°C was most likely due to temperature effects on fluid dynamics rather than on tissue elasticity. Maximal V attained during early P reduction in all groups, was total lung capacity (TLC) at 37°C and < TLC at 22°C. Air retention at end‐deflation, with films of near‐zero surface tension, was greatest at 37°C and least at 22°C, P25. Lung stability, greater at 37°C than at 22°C, was best discriminated when V at PO was taken into account. This study shows that all quasistatic parameters of lung function are enhanced at 37°C; it provides a new perspective on the relative ease with which the mature fetal lung effects initial aeration at 37°C; and it establishes the requirement that assessment of perinatal lung function should take temperature into account. © 1992 Wiley‐Liss, Inc.
Adenotonsillectomy for upper airway obstruction carries increased risk in children with a history of prematurity
Authors: McGowan Francis X. , Kenna Margaret A. , Fleming Julia A. , O'Connor Theresa
Published: March 2007

To define better the clinical presentation and perioperative outcome in children undergoing adenotonsillectomy (T&A) for relief of upper airway obstruction (UAO), we reviewed the hospital records of 60 consecutive, otherwise normal children aged 12 years or younger. Seven patients with trisomy 21, neurologic impairments, or preoperative corpulmonale were excluded. Intraoperative and postoperative complications were experienced by 15 (34%) and 13 (25%), respectively, of the 53 children with preoperative UAO. The most severe complications comprised pulmonary edema and prolonged postoperative oxyhemoglobin desaturation. Multivariate logistic regression analysis found a history of prematurity and/or low birth weight to be the most significant risk factors related to the occurrence of complications. Twenty‐eight % of the study population had a history of prematurity and they had approximately 85% of the perioperative complications seen in children with UAO undergoing T&A. Other significant risk factors included adenoidal facies and evidence of respiratory distress at the time of surgery. It appears that T&A poses significant risk for children with UAO who were born prematurely and have evidence of abnormal facial development or respiratory distress preoperatively. © 1992 Wiley‐Liss, Inc.
Noninvasive breathing analysis: Repetitive chloral hydrate in neonatal guinea pigs
Authors: Olsen George D. , Weil Jeffrey A.
Published: March 2007

A noninvasive method was used to record neonatal breathing, heart rate (HR), and the electroencephalogram (EEG) in guinea pig pups. Neonates were randomly assigned at birth to chloral hydrate (CH) or placebo (PLA) treatment. Treatments were administered 30 min before each study on days 1, 3, 5, 7, 14, and 21 after birth. Animals were studied while they breathed room air followed by air with 5% CO2 and 30% O2. CH decreased breathing frequency (f) and inspiratory minute volume (\documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm V}\limits^. $\end{document}I), but not tidal volume (VT) during the first week (P < 0.05), and reduced the rate of growth throughout the study (P < 0.01), whereas breathing of CO2 increased f, VT, \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm V}\limits^. $ \end{document}I, HR, and the relative power in the delta frequency band of the EEG. The percent change in VI induced by CO2, however, was not affected by drug treatment. There was a significant day of life effect on all breathing parameters and HR. CH has cumulative effects on breathing and growth that should be considered when it is used as a sedative for repeated neonatal studies in guinea pigs. © 1992 Wiley‐Liss, Inc.
Exosurf® treatment investigational new drug phase: Effect of an individualized third dose in infants with respiratory distress syndrome
Authors: Easa David , Pelke Susan , Nakamura Kenneth T. , Barrett Janet , Balaraman Venkataraman , Loo Sherry W. H. , Ibarra‐Pratt Elenita , Smith Martha B.
Published: March 2007

Of 95 infants treated with the synthetic surfactant, Exosurf®, under a Treatment Investigational New Drug protocol, 17 received one dose, 40 received two, and 38 received three doses. Seventy‐six (80%) of the infants were treated by rescue protocol. We retrospectively reviewed the clinical course of the 67 surviving rescue infants. We found that, compared to one‐and two‐dose infants, those treated with three doses of Exosurf® were more premature, smaller, required a longer ventilator course, and had more frequent complications, including patent ductus arteriosus (PDA), intraventricular hemorrhage, nosocomial pneumonia, and apnea. They required higher oxygen concentrations starting 8 hr after their first dose and higher mean airway pressure (MAP) from the time of their second dose. These trends continued during all subsequent time points, as compared to infants treated with two doses. The third dose was administered an average of 17 hr after the second, resulting in little change of MAP, but some reduction in oxygen requirements. By 24 hr after the last dose, only 4% of three‐dose infants were extubated compared with 30% of the two‐dose and 71% of one‐dose infants. In conclusion, repeated administration of Exosurf® is not equally effective in every treated infant with respiratory distress syndrome (RDS) and complications of prematurity may affect or accompany poor response. We speculate that (1) the group of infants treated with three doses of Exosurf® had a greater degree of surfactant deficiency than the other groups, (2) PDA may account for this refractory response to surfactant, and (3) the three‐dose group might have responded better to earlier treatment and/or more surfactant doses, or to earlier PDA closure. © 1992 Wiley‐Liss, Inc.
The in vitro effect of triamcinolone acetonide on branching morphogenesis in the fetal rat lung
Authors: Massoud Emad A. S. , Sekhon Harmanjatinder S. , Rotschild Avi , Thurlbeck William M.
Published: March 2007

We have studied the effect of triamcinolone acetonide (TAC) on airway morphogenesis of the Sprague‐Dawley fetal rat in whole organ lung cultures from day 15 to day 21 of equivalent gestational age (6 days in culture). TAC produced an increased number of peripheral buds from day 18 onward and the airway and airspaces had larger lumens. Airway branching was increased compared to controls, and there was a higher proportion of airway epithelium and a lower proportion of mesenchyme. Cell height was significantly lower in TAC treated lungs except on day 17. This was due to accumulation of glycogen prior to the increased branching activity. In both controls and TAC—treated lungs, peripheral bud number and volume proportion of epithelium increased with time in culture, whereas volume proportion of mesenchyme, mean chord length of airways and airspaces, and epithelial cell height decreased. These changes were more pronounced in the TAC—treated group and were significant. However, TAC—treated lungs were morphologically irregular. We conclude that TAC has a direct effect on airway morphogenesis and it promotes growth of morphologically abnormal lungs. TAC also appears to enhance airway branching and morphologic changes interpreted as increased epithelial maturation. © 1992 Wiley‐Liss, Inc.
IgG subclass antibody responses to alginate from Pseudomonas aeruginosa in patients with cystic fibrosis and chronic P. aeruginosa infection
Authors: Pressler Tacjana , Pedersen Svend S. , Espersen Frank , Høiby Niels , Koch Christian
Published: March 2007

Chronic bronchopulmonary infection with alginate‐producing, mucoid Pseudomonas aeruginosa is characteristically associated with cystic fibrosis (CF). A significant correlation between the antibody response to alginate and poor lung function has been reported. Enzyme‐linked immunosorbent assays were developed for the quantitation of human IgG1, IgG2, IgG3, and IgG4 antibodies to P. aeruginosa alginate. We investigated the pattern of IgG subclass antibodies against P. aeruginosa alginate in serum of patients with CF, others with chronic P. aeruginosa infection, and healthy controls. Healthy controls and patients with CF, before they acquired P. aeruginosa infection, had no or very low titers of antibodies against P. aeruginosa alginate. The latter with chronic infection had significantly higher antibody levels than all others groups, including patients with chronic P. aeruginosa infection but no CF. CF with chronic P. aeruginosa infection led to an inverse correlation between lung function parameters and levels of IgG3 and IgG4. Fifty‐seven patients with CF have been followed for an average of 12 years with multiple antibody assays covering the preinfection, early, and late stage of chronic infection. All of them developed IgG1 and IgG3 antibodies to alginate at the start of infection. IgG2 antibodies developed later and showed only a slow increase during the chronic infection. Patients who died had significantly higher IgG2 anti‐alginate antibody levels than other investigated groups. Elevated levels of IgG2 and IgG3 antibodies to P. aeruginosa alginate are a sign of poor prognosis in CF. © 1992 Wiley‐Liss, Inc.
Generalized lymphangiomatosis and chylothorax in the pediatric age group
Authors: Shah A. R. , Dinwiddie R. , Woolf D. , Ramani R. , Higgins J. N. P. , Matthew D. J.
Published: March 2007

Four patients with generalized lymphangiomatosis presenting with chylothoraces are described. All four had bone involvement, two had involvement of the spleen, and one of the pericardium. The diagnosis was confirmed by typical radiology, histology, and in three patients by immunohistochemistry. Treatment was mainly palliative. Three patients died within 1/2 to three years of presentation. © 1992 Wiley‐Liss, Inc.
The clinical and imaging spectrum of findings in patients with congenital lobar emphysema
Authors: Stigers Kimberly B. , Woodring John H. , Kanga Jamshed F.
Published: March 2007

Congenital lobar emphysema (CLE) is an important cause of infantile respiratory distress that may require surgical intervention. We retrospectively reviewed the clinical and imaging findings in eight infants with CLE. In our series, CLE was more common in females, predominantly involved the right lung, often presented with an opaque lobe from retained fetal lung fluid, and frequently involved the lower lobes, multiple segments or lobes, and both lungs. Most patients with CLE were diagnosed and managed on the basis of clinical and plain radio‐graphic findings alone. Computed tomography, and occasionally ventilation/perfusion scintigraphy, were helpful in confirming the diagnosis and in guiding management decisions in several cases; bronchoscopy showed that stenosis of the right mainstem bronchus was the cause of CLE in one case. Three patients experienced progressive worsening of respiratory distress and required surgical resection of the affected lobe for cure; the remaining five patients were managed medically with eventual remission of symptoms. © 1992 Wiley‐Liss, Inc.
Steroid resistance in asthma: Our current understanding
Authors: Kamada Alan K. , Leung Donald Y. M. , Szefler Stanley J.
Published: March 2007

While much information has recently been obtained regarding the features of steroid‐resistant asthma, it continues to be a dilemma for practitioners, and investigation into its mechanisms will remain an important part of asthma research. Until a clear marker defining steroid‐resistant asthmatics is found, the principle first put forth by Carmichael and colleagues6 should be adhered to: that is, asthmatics resistant to glucocorticoid therapy need to be identified at an early stage so that unnecessary and perhaps harmful therapy can be discontinued. A 10 day course of high‐dose (≥30 mg/day) systemic glucocorticoid therapy, as suggested by Kamada and colleagues,11 may constitute an adequate trial and may sufficiently identify asthmatics who may require alternative treatments. A more rational approach to the selection of alternative asthma treatments will be gained when the mechanisms of steroid resistance are identified. © 1992 Wiley‐Liss, Inc.
Lung function in 6–20 month old infants born very preterm but without respiratory troubles
Authors: Yuksel B. , Greenough A.
Published: March 2007

Lung function results of 21 healthy infants born very prematurely are reported. The median gestational age was 29 weeks, but none had developed respiratory distress or required any form of respiratory support in the neonatal period. Lung function was assessed by measurements of thoracic gas volume (TGV) and airway resistance (Raw) plethysmographically, and of functional residual capacity (FRC) using a helium gas dilution technique. Two separate measurements were made between 6 and 20 months of age; all infants were measured once in the first and once in the second year of life. Regression equations were calculated for TGV. Raw, and FRC related to weight, height, and postnatal age. These data provide a new set of values for very preterm infants, in part small for gestational age, without neonatal respiratory trouble. © 1992 Wiley‐Liss, Inc.
Atypical thrombotic and septic complications of totally implantable venous access devices in patients with cystic fibrosis
Authors: Sola Juan E. , Stone Marshall M. , Wise Barbara , Colombani Paul M.
Published: March 2007

The use of vascular access systems in patients with cystic fibrosis (CF) is well accepted, with lower overall complications and maintenance costs than percutaneous silastic catheters. We report our 6 year experience with 22 infusaports in 15 CF patients. Our patients had indwelling catheters for an average of 539 days per catheter (range, 142,224 days). These infusaports were used for home antibiotic therapy, blood sampling, and total parenteral nutrition. The overall complication rate was relatively low, 1 in every 1,483 catheter days. Infectious complications were extremely infrequent at a rate of 1 in 5,929 catheter days. The rate of mechanical complications was 1 in 1,976 catheter days. However, superior vena caval syndrome or deep venous thrombosis was associated with 3 of 22 catheters (13.6%). Due to this high incidence of major thrombotic events with the attendant risk of pulmonary embolism, all patients with CF using infusaports and without evidence of liver disease or bleeding problems receive aspirin prophylaxis. © 1992 Wiley‐Liss, Inc.
Obstructive apnea, associated patterns of movement, heart rate, and oxygenation in infants at low and increased risk for SIDS
Authors: Hoppenbrouwers Toke , Hodgman Joan E. , Cabal Luis
Published: March 2007

Repetitive polysomnograms were recorded between 40 weeks post‐conceptional age and 6 months in a total of 49 infants, 19 healthy preterm infants, 14 normal term infants, and 16 subsequent siblings of infants who died of sudden infant death syndrome (SIDS). These nighttime recordings lasted 2–4 hours, except at 3 months when an overnight 12–hour recording was perfomed. Obstructive apneas (OA) > 3 seconds were divided into 3 categories: 1) clear obstructive, 2) mixed and 3) unclear because of movement artifacts. More than half belonged in category 3 and were excluded from further analysis unless accompanied by a transient episode of bradycardia (TEB), defined as heart rate ≤100 beats per minute. Each OA with TEB was also examined for changes in transcutaneous oxygen tension (PtcO2). Most pauses were brief (median, 4 seconds), the longest (27 seconds) seen only once in the youngest premature infant. The majority of OA were accompanied by heart rate accelerations. The number of clear obstructive and mixed apneas was similar. The scores were combined to calculate a density (number per 100 minutes of recording). OA were not common: Their density decreased from 2 in 100 minutes at 40 weeks in the preterm to once every 300 minutes (5 hours) in the 6‐month‐old term infant. Ten percent of the OA were accompanied by TEB. Of these, 10% were accompanied by a Ptc02 decrease of >10 mm Hg. OA with TEB followed a nonmonotonic curve, the highest percentage of infants showing this pattern at the age of highest risk for SIDS. Minor differences among study groups were confined to less movements with OA in subsequent siblings and an earlier peak incidence of OA with TEB in prematures, compared to normal term infants. OA were seen in all study groups, were self‐limited, and apparently were devoid of pathological consequences. © 1993 Wiley‐Liss, Inc.
The effect of age on bronchodilator responsiveness
Authors: Turner D. J. , Landau L. I. , Lesouëf P. N.
Published: March 2007

The relationship between age and bronchodilator responsiveness (BDR) in children has not been studied using objective parameters. The aim of this study was to seek such a relationship in young asthmatic children using dose—response curves (DRC). Fourteen asthmatic subjects (age 3–9 years) with a forced expiratory volume in 1 sec (FEV1) less than 80% predicted were studied after being trained to use a spirometer reliably. Each subject completed a DRC by inhaling 5 doses of salbutamol (albuterol) at 15 min intervals until a cumulative total of 6.84 mg of salbutamol had been administered. FEV1, forced vital capacity (FVC), and forced expiratory flow at mid vital capacity (FEF25−75) were measured before and after each nebulization. In addition, arterial oxygen saturation (SaO2) and heart rate (HR) were measured in some of the subjects. All lung function parameters, SaO2 and HR increased significantly between baseline and completion of the DRC. A significant age effect on BDR was detected in FEV1 and FVC, with older children showing a greater response than young ones. The response had plateaued after the maximum dose in the younger but not in the older children. These findings suggest that the level of response to a bronchodilator increases significantly with increasing age in young asthmatics. © 1993 Wiley‐Liss, Inc.
Late‐onset miliary pneumonitis after near drowning
Authors: Mangge H. , Plecko B. , Grubbauer H. M. , Popper H. , Smolle‐Jüttner F. , Zach M.
Published: March 2007

We report a 7‐year‐old pediatric patient with an apparently self‐limiting, subacute miliary pneumonitis that occurred 6 weeks after a near‐drowning accident in shallow, muddy water. After biopsy, histological examination revealed aspirated foreign bodies (algae and pollen grains) in the affected lung areas and a foreign body reaction in the form of a granulomatous inflammation. The lack of any detectable infectious agents suggested a causative role of these aspirated algae and pollen grains in the development of lung disease. © 1993 Wiley‐Liss, Inc.
Compliance of the respiratory system in newborn infants pre‐ and postsurfactant replacement therapy
Authors: Kelly Edmond , Bryan Heather , Possmayer Fred , Frndova Helena , Bryan Charles
Published: March 2007

Surfactant administration causes a rapid and dramatic improvement in gas exchange, but paradoxically, studies have failed to show an improvement in the mechanical properties of the lung. We have measured dynamic and static (passive flow‐volume technique) compliance before and after a single dose of bovine lipid extract surfactant in 22 premature infants with RDS. This had no effect on the measured dynamic compliance. In contrast, surfactant significantly increased static compliance from 0.41 ± 0.02 to 0.55 ± 0.04 mL/cm H2,O/kg. This improvement was the result of a substantial recruitment of lung volume after surfactant administration. This led us to reduce ventilator pressures, which produced an increase in both dynamic and static compliance, but did not recruit additional volume. We conclude that surfactant causes a substantial increase in static compliance due to volume recruitment, which is consistent with reports of increase in the measured FRC. However, despite this improvement, the compliance is still below our normal range. © 1993 Wiley‐Liss, Inc.