bluuebunny/crossref_metadata_2025 huggingface dataset:
Radiographic evidence of bronchopulmonary dysplasia in high‐risk congenital diaphragmatic hernia survivors
Authors: Bos Albert P. , Hussain Shahid M. , Hazebroek Frans W. J. , Tibboel Dick , Meradji Morteza , Molenaar Jan C.
Published: March 2007

Congenital diaphragmatic hernia is a congenital malformation associated with pulmonary hypoplasia. It often leads to respiratory failure, requiring artificial ventilation with high inflation pressures and high percentages of oxygen. We evaluated radiographic evidence of bronchopulmonary dysplasia (BPD) in survivors, who presented with respiratory distress within 6 hours after birth, by a radiographic scoring system measuring the severity of BPD by the Toce score and the degree of pulmonary hypoplasia by the Touloukian score. Fifteen of 45 survivors (33 percent) had clinical and radiological lung disease resembling BPD. As a group they had significantly higher Touloukian and Toce scores than survivors without BPD. Morbidity expressed as the duration of artificial ventilation, supplemental oxygen, and hospital stay was much higher in the BPD group. The hypoplastic lung in infants with congenital diaphragmatic hernia appears to be as susceptible to barotrauma and pulmonary oxygen toxicity as the lungs of prematurely born infants. To what extent BPD occurring in congenital diaphragmatic hernia survivors might influence the future development of lung function is not yet known. © 1993 Wiley‐Liss, Inc.
Effects of anti‐mouse EGF antiserum on prenatal lung development in fetal mice
Authors: Yasui S. , Nagai A. , Oohira A. , Iwashita M. , Konno K.
Published: March 2007

To clarify the precise role of epidermal growth factor (EGF) on fetal lung development, rabbit anti‐mouse EGF (anti‐mEGF) antiserum was administered to pregnant mice from days 10 to 17 during late gestation. Control mice were administered either normal rabbit serum (NRS) or physiological saline (PS). Serum EGF was not detected in fetuses from anti‐mEGF antiserum treated mothers, but the level in NRS treated control animals was 4.73 ± 0.66 ng/mL. One day prior to birth, the fetuses were removed and their body and lung weights were measured. There was no difference between body weights and lung weights of anti‐mEGF antiserum treated animals and NRS‐treated control animals. On light microscopic morphometry, there was no obvious difference between pulmonary architecture of anti‐mEGF antiserum treated animals and NRS treated control animals. On transmission electron microscopy, osmiophillic lamellar inclusion bodies were less prominent in the type II epithelial cells in anti‐mEGF antiserum treated animals. Electron microscopic morphometric study revealed that the osmiophillic lamellar inclusion bodies in type II epithelial cells of anti‐mEGF antiserum treated animals were fewer in number and had decreased area fraction. These findings support the previous finding that EGF promotes epithelial cell differentiation of the fetal lung without affecting body weight and lung weight. © 1993 Wiley‐Liss, Inc.
Host inflammatory responses to first isolation of Pseudomonas aeruginosa from sputum in cystic fibrosis
Authors: Elborn J. S. , Cordon S. M. , Shale J. D.
Published: March 2007

Pseudomonas aeruginosa infection of the respiratory tract in patients with cystic fibrosis is a major determinant of morbidity and mortality. However, it has been postulated that the earliest phase of colonization is not associated with injury. To test this hypothesis we determined the association of the first recorded isolation of P. aeruginosa from the sputum on circulating markers of the inflammatory response in 6 patients with cystic fibrosis. At this time circulating C‐reactive protein was increased in all 6 and neutrophil elastase α1‐antitrypsin complex (elastasecomplex) was increased in 5 patients compared with healthy controls. This inflammatory response was associated with a reduction in the FEV, and FVC of all patients [FEV, 1.42 ± 0.87 L (mean ± SD) at first isolation vs. 2.08 ± 0.74 L before isolation; P < 0.05; FVC, 1.94 ± 0.93 L vs. 2.87 ±1.01 L, P < 0,05]. At a median interval of 10 months, 5 patients had raised titres of positive IgG antibody to P. aeruginosa, indicating significant exposure to this organism. At this time, lung function had returned to preinfection levels, whilst 3 patients showed continuing features of an inflammatory response, and the group mean value for elastase‐complex was raised. Our findings demonstrate that at the time of first isolation of P. aeruginosa from the sputum of patients with cystic fibrosis, there is a concomitant systemic host response and an acute deterioration of pulmonary function. © 1993 Wiley‐Liss, Inc.
Response to added dead space in ventilated preterm neonates and outcome of trial of extubation
Authors: Fox Grenville F. , Alexander John , Marsh Michael J. , Milner Anthony D.
Published: March 2007

The ventilatory response to an added external dead space was assessed in preterm babies, recovering from respiratory distress syndrome, immediately prior to extubation. All babies were ready for extubation as defined by routine clinical criteria. Baseline measurements of respiratory rate, tidal volume, and minute ventilation were made over a 2 min period using a computerized system consisting of a pneumotachometer connected directly to the proximal end of the endotracheal tube. The measurements were repeated after addition of an external dead space equivalent to 2 anatomical dead spaces (4.4 mL/kg body weight). Thirty‐four babies were studied on 40 occasions. Twenty‐four infants (60%) were successfully extubated and 16 (40%) required reintubation. Infants in the success and failure groups were matched for gestation at birth, postconceptional age and weight at the time of study, maximum ventilatory requirements, and treatment with methylxanthines. The added external dead space resulted in an increase in minute ventilation in 38 out of the 40 studies. Extubation success and failure groups were compared by expressing the minute ventilation after addition of the external dead space as a percentage of the baseline minute ventilation (OhMVl). Successful extubation was associated with a higher median %MV1 compared with babies who failed extubation (156; range, 89.3 to 230; compared to 131; range, 75.2 to 165; P = 0.006). This test may be useful in deciding which babies could be successfully extubated. © 1993 Wiley‐Liss, Inc.
Atrial natriuretic factor and pulmonary status in premature infants with respiratory distress syndrome: Preliminary investigation
Authors: Pesonen Erkki , Heldt Gregory P. , Allen Merritt T. , Sahn David J. , Elias William , Tikkanen Ilkka , Fyhrquist Frej , Andersson Sture
Published: March 2007

We studied the correlation of atrial natriuretic factor (ANF) with lung compliance in a series of 16 premature infants with respiratory distress syndrome (RDS). The infants were followed during the first week of life by sequential Doppler echocardiography, lung compliance, and ANF measurements. Plasma ANF concentration varied between 38 and 2220 pg/mL; mean concentrations of 393 and 123 pg/mL with the ductus open and with it closed, respectively (P < 0.01). The arteriolar/alveolar oxygen‐tension ratio showed an inverse correlation with the logarithm (In) of the ANF concentration (r = −0.55, P = 0.0002). Both mean airway pressure and In ANF showed an inverse correlation with the arteriolar/alveolar oxygen tension ratio (R = −0.77, F = 20.5 and 13.8, respectively). Plasma ANF was inversely correlated to lung compliance (r = −0.64, P < 0.0001). In infants with RDS, plasma ANF concentrations increase with the severity of respiratory distress. Because ANF increases endothelial permeability, in this preliminary investigation lead to the hypothesis that it may contribute to respiratory distress by causing extravasation of fluid from the pulmonary circulation in these patients. © 1993 Wiley‐Liss, Inc.
Pulmonary sarcoidosis in children: Serial evaluation of bronchoalveolar lavage cells during corticosteroid treatment
Authors: Chadelat Katarina , Baculard Armelle , Grimfeld Alain , Tournier Guy , Boule Michelle , Boccon‐Gibod Liliane , Clement Annick
Published: March 2007

The clinical course of sarcoidosis in children has not been well defined. Eight children with symptomatic sarcoidosis included in this study underwent pulmonary function tests and bronchoscopy with bronchoalveolar lavage (BAL) before treatment and during steroid therapy. At the start of therapy, functional parameters, mostly dynamic lung compliance and lung transfer factor for CO, were impaired. This was associated with abnormalities of BAL cell populations: increased total cell number with a high proportion of lymphocytes, modifications of lymphocyte subpopulation with an elevated CD4+/CD8+ ratio, and enhanced ability of alveolar macrophages to release hydrogen peroxide. Although respiratory abnormalities seemed to be similar at the initial stage of sarcoidosis in children and adults, the course of the disease appeared to be different. Despite the absence of respiratory symptoms and disappearance of chest radiographic abnormalities on prolonged steroid treatment, we found slow improvement of pulmonary functions associated with persistence of BAL lymphocytosis and elevated CD4+/CD8+ ratios. However, the ability of alveolar macrophages to release hydrogen peroxide was significantly reduced after 6 months of steroid treatment, and it remained identical to the control group. Therefore, the evaluation of disease activity appears to be critical for therapy in pediatrics, and for this purpose studies of alveolar macrophage activation may be of particular interest. Pediatr Pulmonol. 1993; 16:41–47. © 1993 Wiley‐Liss, Inc.
Fractal and morphometric analysis of lung structures after canine adenovirus‐induced bronchiolitis in beagle puppies
Authors: Witten Mark L. , McKee Joseph L. , Lank R. Clark , Hays Allison M. , Quan Stuart F. , Sobonya Richard E. , Lemen Richard J.
Published: March 2007

Acute viral respiratory infections are commonly associated with alteration in lung growth and with chronic obstructive disease. However, it is difficult to quantify these changes in lung function. We determined that the recently described techniques of fractal analysis gave additional information about the changes in lung function after viral illness compared to standard morphometric techniques. Fractal and morphometric parameters change with lung growth after acute infection with canine adenovirus type 2 (CAV2, n = 5) or no infection (controls, n = 6) in beagle puppies. Lung pathological studies showed areas of obliterative bronchiolitis and chronic small airways inflammation but no emphysema in the CAV2‐infected puppies. Morphometric studies at −236 days of age demonstrated accelerated lung growth in the CAV2‐infected dogs as evidenced by significant increases in lung volume (VL ) and internal surface area (ISA). Fractal analysis showed an increased fractal dimension (Df) of the alveolar perimeter length in the CAV2 group associated with increased growth that was similar to the percentage change in VL and ISA. These data suggest that a single infection with CAV2 in beagle puppies accelerates lung growth and increases the complexity (Df) of the alveolar structure. Pediatr Pulmonol. 1993; 16:62–68. © 1993 Wiley‐Liss, Inc.
A simplified method for determining the frequency response of pneumotachographs used in infants
Authors: Vallinis P. , Retfalvi S. , Davis G. M. , Coates A. L.
Published: March 2007

In all rapidly changing systems, an appropriate response time of all sensing devices is essential for the accurate conversion of a physiological parameters to a proportional electrical signal. The frequency response of equipment is the ability to accurately reflect both the magnitude and temporal relationship of dynamic events over a defined frequency range. The phase lag expresses the temporal delay between the physical event being measured and the output signal. The attenuation expresses diminution of the amplitude ratio of the output signal in relation to the input signal over a range of frequencies. We have developed a method that specifically addresses the measurement of frequency response and attenuation of pneumotachographs and low pressure transducers. The system consists of a 81 liter rectangular box separated in the middle by a 30.5 cm acoustic loudspeaker, the cone sealed by latex, and driven by a signal generator coupled to a low frequency amplifier. This system can produce an undistorted sinu‐soidal signal between 0 and 20 Hz, and the peak flow through the pneumotachograph is only minimally affected by changes in frequency. Rapid analysis is possible using an oscilloscope to produce Lissajou loops. There is no measurable attenuation between the electrical signal and the pressure generated over frequencies from 1 to 20 Hz. The system is accurate at low frequencies and can generate appropriate signals over the frequency range of interest for respiratory applications, and it can be inexpensively constructed. Pediatr Pulmonol. 1993; 16:109–115. © 1993 Wiley‐Liss, Inc.
Predictive value of measurements of respiratory mechanics in preterm infants with HMD
Authors: Freezer Nicholas J. , Sly Peter D.
Published: March 2007

Conventional methods for measuring respiratory mechanics model the respiratory system as a single compartment. The interrupter technique allows the respiratory system to be considered as a two compartment model with “flow resistance” of the conducting airways (Pinit), calculated from the initial pressure drop (Pinit), considered separately from Pdiff, as a measure of the viscoelastic properties of the lung and chest wall and any pendelluft present. The pulmonary mechanics of 50 intubated and mechanically ventilated preterm infants (≤1500 g) were studied during the first week of life using conventional methods and the interrupter technique to determine whether it was possible to predict which infants would develop bronchopulmonary dysplasia (BPD). Pulmonary mechanics of preterm infants intubated and ventilated for apnea of prematurity were also studied. The dynamic compliance of the respiratory system (Crsdyn) was significantly lower on day 1 (P<0.001) and during the first week of life in the infants with HMD who developed BPD (ANOVA, P<0.0001). There was no significant difference in the respiratory system resistance (Rrs), Rinit, or Pdiff between BPD and no‐BPD groups. However, Pdiff was significantly higher in infants with HMD, regardless of the outcome, when compared to the infants ventilated for apnea of prematurity. This suggests that the pathology of HMD is distal to the conducting airways and significantly alters the viscoelastic properties of the lung on day 1. Using stepwise logistic regression, Crsdum on day 1 and birth weight or gestational age were significant independent predictors of the development of BPD, correctly classifying 92% of infants. Due to the correlation between birth weight and gestational age (r = 0.72, P<0.0001). only one of these variables was necessary in the prediction model. In conclusion, Crsdyn is a better independent predictor of the development of BPD in preterm infants with HMD than gestational age or birth weight. Pediatr Pulmonol. 1993; 16:116–123. © 1993 Wiley‐Liss, Inc.
An isotopic study of nasal mucociliary transport in newborns: Preliminary investigation
Authors: Escribano A. , Armengot M. , Marco V. , Basterra J. , Brines J.
Published: March 2007

The diagnosis of primary ciliary dyskinesia (PCD) depends on electron microscopic examination of cilia obtained from mucosal biopsies of the nasal turbinates or the trachea. This is an invasive, time‐consuming, and expensive technique. The low incidence of this abnormality, the large number of infants and children with suggestive symptoms, and the lack of a reliable screening test make the decision to proceed with diagnostic biopsy a common problem in recurrent or chronic respiratory pediatric conditions. To improve this situation early in infancy, nasal mucociliary transport was evaluated in 10 normal newborns using the Tc‐99m‐labeled seroalbumin technique, and the results obtained were compared with those corresponding to a newborn with Kartagener's syndrome. Transport velocity in normal newborns was similar to that observed in older children and in adults, in contrast to the tracer immobility seen in the affected newborn. This technique is simple, safe, objective, and well tolerated in this age group and might be used as an early screening test to ruling out PCD. Pediatr Pulmonol. 1993; 16:167–169. © 1993 Wiley‐Liss, Inc.
Flexible fiberoptic bronchoscopy in children on extracorporeal membrane oxygenation
Authors: Karlson Karl H. , Pickert Curtis B. , Schexnayder Stephen M. , Heulitt Mark J.
Published: March 2007

Bleeding is one of the most feared complications of veno‐arterial (V‐A) extracorporeal membrane oxygenation (ECMO), and is also a potential complication of flexible fiberoptic bronchoscopy (FFB). We retrospectively reviewed 14 patients who underwent FFB procedures with bronchial washings (BW) and bronchoalveolar lavage (BAL) to evaluate the safety of this procedure in children on ECMO. Standard FFB with BAUBW technique was used after stabilization on ECMO. Three patients underwent two procedures each, and one patient underwent three, for a total of 19 procedures. No significant complications, such as bleeding have occurred. Three patients required additional ECMO support shortly after FFB. After the 16 procedures done for atelectasis, seven patients improved radiographically, three had increased opacifications, and six were unchanged. The remaining three patients had suspected pulmonary infections, and in each, therapeutic decisions were guided by the BAL results. Lung compliance was unchanged or improved after 11 of 13 procedures. We conclude that FFB with BAUBW in children on ECMO is safe and may benefit certain patients. Pediatr Pulmonol. 1993; 16:215–218. © 1993 Wiley‐Liss, Inc.
Nedocromil sodium vs. Sodium cromoglycate pressurized aerosol in the prevention of bronchoconstriction induced by ultrasonic nebulized distilled water in asthmatic children
Authors: Spezia E. , Del Col G. , Richelli C. , Sette L. , Boner A. L.
Published: March 2007

To compare the effectiveness of nedocromil sodium (NS) and sodium cromoglycate (SCG), administered by metered dose inhaler (MDI) with a 700 mL holding chamber (Fisonair Fisons UK) in preventing bronchoconstriction induced by inhalation of ultrasonically nebulized distilled water (UNDW), 12 asthmatic children were studied in a randomized, double‐blind, placebo‐controlled, intrapatient study. Following a baseline challenge with UNDW, the protective effect of NS, SCG, or placebo was evaluated in each subject. Cumulative doses of delivered nebulized water producing a 20% fall in forced expiratory volume in 1 sec (PD20 UNDW) was measured. Mean (± SD) PD20, UNDW was 4.83 (± 4.84), 10.16 (± 7.05), 15.8 (± 0.5), and 15.93 (± 0.23) respectively, for baseline, and placebo, SCG, and NS‐treated groups. A significant (P < 0.05) protection from UNDW induced bronchoconstriction by NS was observed in comparison with placebo, while no such effect was evident when the children were treated with SCG. Pediatr Pulmonol. 1993; 16:243–247. © 1993 Wiley‐Liss, Inc.
Chronic respiratory failure of infancy and childhood: Clinical outcomes based on underlying etiology
Authors: Wheeler William B. , Maguire Eleanor L. , Kurachek Stephen C. , Lobas Jeffrey G. , Fugate John H. , McNamara John J.
Published: March 2007

To assess whether underlying diagnosis affects morbidity and mortality outcomes in patients with chronic respiratory failure, we studied 55 patients with chronic respiratory failure of infancy and childhood (CRFIC). Entry criteria included patients with chronic respiratory failure due to static neurologic or neuromuscular conditions or secondary to other disease processes considered likely to improve or resolve over time. Subjects were grouped into those having chronic lung disease (CLD, n = 22), neurologic or neuromuscular diseases (NM, n = 21), or congenital abnormalities affecting the respiratory system (CA, n = 12). The average duration of follow‐up was 21.3 months. There were no differences between groups in mortality with only four deaths (7%). Patients with CLD fared better than those with NM or CA in duration of ventilatory support, duration of tracheostomy, percentage of successful weaning from mechanical ventilation, and neurodevelopmental outcomes. Subjects with CLD had a significantly greater frequency of tracheomalacia (86%), feeding disorders (86%), and hypogammaglobulinemia G (77%). There were no differences between groups for respiratory readmissions or family dysfunction.

We conclude that almost all patients with CRFIC will survive, but morbidity outcomes will vary based on the underlying diagnosis. Pediatr Pulmonol. 1994; 17:l–5. © 1994 Wiley‐Liss, Inc.
Changes in lung mechanics following sighs in premature newborns without lung disease
Authors: Davis G. M. , Moscato J.
Published: March 2007

Sighs, the interspersed breaths of larger tidal volume (VT) than those preceding or following them, occur more frequently in the newborn than in adults. It has been postulated that the sigh augments functional residual volume (FRC), increases lung compliance (CJ, and recruits atelectatic alveoli. Since the premature infant has relatively low FRC, we hypothesized that sighs might be more frequent in these babies and that CL could be shown to change before and/or after a sigh. We studied 14 premature infants (gestational age, 30 ± 2.2 weeks; mean ± SD) without lung disease during quiet sleep. Minute ventilation (VE) was measured by pneumotachography and pleural pressure changes via a water‐filled catheter in the esophagus. In the 78 sighs examined, the incidence was 0.71 sighs/min, similar, to previous reports for full‐term newborns. There was no change in respiratory frequency, VT/VE, nor mean inspiratory flow (VT/Tt, where Tt is the inspiratory time) before or after the event. The volume of the sigh increased from 7.8 ± 0.2 mL/kg to 21.5 ± 0.5 mL/kg, in concert with an increase in breath duration (TTOT) from 0.98 ± 0.02 ± to 2.56 ± 0.12 s, resulting in an unchanged VE, VT/TI). and respiratory duty cycle (TI/TTOT/). This suggests that the increased VT was matched by a prolongation in both TI and TTOT. Following the sigh, CL increased from 1.43 ± 0.13 cmH2O/kg to 1.66 ± 0.27 cmH2O/L/s/kg (paired t‐test, P < 0.001) whilst the lung resistance RL, fell from 62 ± 8 cmH2O/L/s/kg to 55 ± 3.8 cmH2O/L/s/kg (P < 0.05). As reflected by the end—expiratory volume (EEV), FRC did not change. This stability of FRC, coupled with the increase in CL and fall in RL, suggests a recruitment of atelectatic acini with a redistribution of lung volume, such that the previously atelectatic and overdistended acini achieve a more optimal pressureivolume relationship following a sigh. Pediatr Pulmonol. 1994; 17:22–25. © 1994 Wiley‐Liss, Inc.
Role of adenosine in the hypoxic ventilatory response of the newborn piglet
Authors: Lopes Jose‐Maria , Davis G. Michael , Mullahoo Krishna , Aranda Jacob V.
Published: March 2007

The role of intracerebral adenosine levels in the control of ventilatory response to hypoxia was explored in 15 spontaneously breathing intubated piglets, 1–5 days old, sedated with chloral hydrate. Respiration was recorded via by a pneumotachograph. In all animals exposed to hypoxia (12% 02) for 10 minutes. There was an initial increase in ventilation followed by a late decrease (the biphasic ventilatory response). Both intravenous caffeine citrate (20 mg/kg) and an Fiico of 0.05 separately abolished or attenuated the late ventilatory depression associated with hypoxia. In the same piglets, the administration of 10 pg dipyridamole, a competitive inhibitor of adenosine receptors, directly into the cerebral ventricles abolished the hyperventilatory response to hypoxia. Conversely, the use of 20 μg intraventricular 8‐phenyltheophylline abolished the late ventilatory depression associated with hypoxia. Neither drug had a direct effect on ventilation at the time of injection. These results suggest that adenosine is a part of the diphasic ventilatory response to hypoxia. Pediatr Pulmonol. 1994; 17:50–55. © 1994 Wiley‐Liss, Inc.
Validation of esophageal pressure occlusion test after paralysis
Authors: Lanteri Celia J. , Kano Sohei , Sly Peter D.
Published: March 2007

Measurements of respiratory mechanics are frequently made in ventilated infants and children. Esophageal pressure measurements (Pes using a balloon on a catheter have been used to partition the respiratory mechanics into lung and chest wall components. Appropriate positioning of this balloon is crucial to obtain accurate estimates of pleural pressure. Traditionally, in spontaneously breathing subjects the balloon position is assessed with an occlusion test. In ventilated subjects, it is not always possible to perform an occlusion test prior to paralysis, and even if such a test is performed it may not be relevant under conditions of positive pressure ventilation. We have assessed a positive pressure occlusion test that is suitable for paralyzed subjects. By occluding the airway opening and applying gentle pressure to the abdomen or rib cage, positive swings in pressure can be measured by both Pes and airway opening pressure (Pao). We compared traditional occlusion tests measured in 16 spontaneously breathing puppies to the positive pressure occlusion test performed after paralysis. In 2 pups we were unable to obtain a reasonable traditional occlusion test (>15% difference between Pes and Pao) but we obtained 10 traditional occlusion tests in each of the remaining 14 pups (2.1–14 kg). In 11 of these animals Ape, was within 10% of Pao. This compared well to positive pressure occlusion test using abdominal pressure performed after paralysis, where Apes was within 10% of ΔPao in 10 animals. In 9 of these pups occlusion tests were also performed by applying pressure on the rib cage, where ΔPes was within 10% of ΔPao in 6 animals. These results suggest that it is possible to perform accurate occlusion tests in paralyzed subjects by abdominal or rib cage compression with the airway occluded. Pediatr Pulmonol. 1994; 17:56–62. © 1994 Wiley‐Liss, Inc.
Improved oxygenation with exogenous surfactant administration in experimental meconium aspiration syndrome
Authors: Al‐Mateen K. Bakeer , Dailey Kimberly , Grimes Margaret M. , Gutcher Gary R.
Published: March 2007

Fifteen adult New Zealand white rabbits were used to determine if exogenous surfactant immediately improves oxygenation in experimental meconium aspiration syndrome (MAS). They were ventilated with 100% 02 before insufflating 3 mL/kg of 40% filtered meconium. Arterial blood gases, dynamic lung compliance (CLdyn) and resistance (RL) were monitored for 2 hours before and 1 hour after the intratracheal administration of calf lung surfactant extract or air placebo. The arteriallalveolar O2 tension ratio [P] increased 133% within 1 hour of surfactant therapy but CLdyn did not change. The increase of RL, was comparable in the surfactant and control groups after meconium instillation. A further increase of 44% in RL occurred after surfactant administration with no change in the controls. Qualitative histologic analysis confirmed the presence of alveolar meconium as well as inflammation and atelectasis. Persistently elevated RL suggested airway obstruction in both groups throughout the study. Most likely no increase in CLdyn occurred with surfactant administration or it could not be detected because it was measured only with ventilator‐induced breaths and ventilator settings were held constant. In the face of airway obstruction CLdyn is an inadequate reflection of pulmonary elasticity. We conclude that exogenous surfactant therapy improves oxygenation in this model of MAS. Further studies are needed to understand the mechanism of this improvement. Pediatr Pulmonol. 1994; 17:75–80. © 1994 Wiley‐Liss, Inc.
Bronchodilator responsiveness in infants with bronchiolitis
Authors: Tepper Robert S. , Rosenberg David , Eigen Howard , Reister Teresa
Published: March 2007

We evaluated 34 infants with bronchiolitis, (17 of both genders; mean age, 4.6 mos; ranges, 0.7–14.5 mos). The 20 inpatients were significantly younger than the 14 outpatients (2.6 vs. 8.2 months, P < 0.05), and more females were inpatients. Forced expiratory flows at functional residual capacity (VmaxFRC) were obtained at baseline, after aerosolized normal saline (NS), and metaproterenol (0.025 mL/kg in 2 mL NS). Flows were expressed as 2‐scores, the difference between the measured and predicted flows, divided by the standard deviation for the predicted value. At baseline, outpatients were more obstructed than inpatients (−1.64 vs. −0.95, P < 0.05), infants >2 months old were more obstructed than infants s2 months old (−1.54 vs. −0.80, P < 0.05), and males more than females (− 1.45 vs. −1.02, P < 0.05). Following NS the whole group had a small but significant decrease in 2‐scores (−1.23 to −1.31, P <: 0.05). Following metaproferenol, the younger infants had significantly (P < 0.05) higher Z‐scores compared to baseline and NS (−0.80 vs. −0.86 vs. −0.59). However, no significant changes occurred in older infants. Females also had an increased flow after metaproterenol and were less obstructed than after NS (−1.11 vs. −0.86, P < 0.015). In males no increased flows occurred after metaproterenol (− 1.45 vs. − 1.48). Bronchodilator responsiveness did not relate to severity of airway obstruction, history of family asthma, allergy, or passive smoke exposure. We conclude that inhaled metaproterenol improves airway function in a subgroup of infants with bronchiolitis, but the subgroup could not clearly be identified because age and gender were confounding factors. Pediatr Pulmonol. 1994; 17:81–85. © 1994 Wiley‐Liss, Inc.
Measuring clinical status in cystic fibrosis: Internal validity and reliability of a modified NIH score
Authors: Sockrider Marianna M. , Swank Paul R. , Seilheimer Dan K. , Schidlow Daniel V.
Published: March 2007

We examined measurement properties of the NIH Clinical Score for Cystic Fibrosis (CF) as an index of disease status. This score is being employed as a research tool for defining study populations and as an outcome measure, yet there are no published data on its reliability or how its items contribute to the overall measure of disease status. Criteria for scoring some items in the original index lack specificity. In this study, we used a modified score to have more clearly specified criteria, while retaining the original weightings and structure. For 200 patients with CF in two centers, we analyzed the total NIH Score and its subscores for internal consistency, interrater reliability, and factor analysis. Internal consistency indicates how inter‐related the items are. The pulmonary subscore and overall score had fairly high internal consistency. However, the general subscore had low internal consistency, suggesting that the items are not measuring a single element of disease status and should not be added. Factor analysis provides additional information on the underlying structure and relationships among items. Five factors (groups of items) were identified accounting for 85% of the consistent variance of 14 items. These factors were designated by items accounting for most of their variance: general pulmonary, weight, disability, psychosocial, and acute infiltrate. While inter‐rater reliability for the overall index was high, individual items showed less agreement. The results indicate that most of the variability in the NIH Score is attributable to pulmonary items in the first factor. The analyses suggest a new scoring structure for the NIH Score; the general subscore items do not contribute to the reliability or account for significant variance. Therefore, they will likely require further refinement or be eliminated. Pediatr Pulmonol. 1994; 17:86–96. © 1994 Wiley‐Liss, Inc.
High frequency jet ventilation: Intraoperative application in infants
Authors: Greenspan Jay S. , Davis Deborah A. , Russo Pierantonio , Antunes Michael J. , Spitzer Alan R. , Wolfson Marla R.
Published: March 2007

The potential advantages of the intraoperative use of high frequency jet ventilation (HFJV) when compared with conventional ventilation (CV) include the maintenance of adequate gas exchange and lung function with a relatively motionless surgical field. To determine the pulmonary response to HFJV ventilation in infants during cardiac surgery, we evaluated lung function in nine infants supported with CV and HFJV during a Blalock‐Taussig shunt procedure. Infants were randomized to each mode of ventilation with inspiratory and expiratory pressures and FiO2, held constant. Heart rate, blood pressure, arterial blood gases, pulmonary mechanics (lung compliance and resistance), and functional residual capacity (FRC) were compared after 10 minutes of stabilization of each ventilation mode, with the infants in the thoracotomy position and the surgical field adequately exposed. Pulmonary mechanics were measured using esophageal manometry and pneumotachography, and FRC by helium dilution. There was no difference in vital signs, pulmonary mechanics, FRC, or PaO2 on HFJV ventilation when compared with CV. Arterial P was lower with a lower mean airway pressure on HFJV when compared with CV. The surgical team subjectively observed a diminished need for lung manipulation and improved ease of access to the surgical field with HFJV. These results indicate that the use of HFJV during closed‐heart cardiac surgical procedures in infants provides similar cardiopulmonary stability and some potentially important clinical benefits when compared with CV. Pediatr Pulmonol. 1994; 17:155–160. © 1994 Wiley‐Liss, Inc.
Acute effects of ambient ozone on respiratory function of swiss schoolchildren after a 10–minute heavy exercise
Authors: Braun‐Fahrländer Ch. , Künzli N. , Domenighetti G. , Carell C. F. , Ackermann‐Liebrich U.
Published: March 2007

This study was conducted in Switzerland between May and October 1989 to assess possible decrements in lung function occurring as a result of 10 minute exposure to ambient air containing different ozone concentrations. Once a month, 128 children in two different areas of Southern Switzerland (Chiasso and Aurigeno) had a pulmonary function test before and after a standardized 10 minute exercise (pulse rate, 170imin) on a cycle ergometer, outdoors. Ozone concentrations were similar in both areas, ranging from 40 to 157 μg/m3 (112h means) during the exercise tests. The two communities differed with respect to long‐term average pollution levels. The mean NO2 concentration over the six months study period was 70 μg/m3 in Chiasso and 18 μg/m3 in rural Aurigeno.

Of the eligible children 85% participated and attended 4–6 tests. Parents completed a standardized questionnaire on family background, home characteristics and the child's early and present illness history.

A total of 500 acceptable pairs of spirograms and corresponding ozone concentrations (average 3.8 per child) were available for analysis. Regressions of each individual's pre‐post differences of FVC, FEV, and peak flow on ozone concentrations measured during the outdoor exercise indicated that elevated ozone levels significantly reduced peak flow values. Adjustments for temperature and relative humidity increased the magnitude of the peak flow slopes. The average adjusted regression coefficient for A‐peak flow on ozone was −2.28 mL/s/μg/m3 (95% Cl, −0.57 −3.99). It is noteworthy that the observed relationships occurred at ozone concentrations below 160 μg/m3 and after an exercise duration of only 10 minutes. Pediatr Pulmonol. 1994; 17:169–177. © 1994 Wiley‐Liss, Inc.
Disease severity and optimum mean airway pressure level on transfer to high frequency oscillation
Authors: Chan V. , Greenough A. , Giffin F.
Published: March 2007

The aim of this study was to assess whether the severity of the infant's lung disease determined the most appropriate change in mean airway pressure (MAP) level to use on transfer from conventional ventilation to high frequency oscillation (HFO). In addition, we wished to assess whether the oscillatory frequency employed affected gas exchange. Ten premature infants with respiratory distress syndrome (RDS) were studied at a mean postnatal age of 1.5 days. During HFO, the infants were studied at a MAP equivalent of that used during conventional ventilation (baseline MAP), then at 2 and 5 cmH2O above baseline at 10 Hz. At the MAP identified as optimum, that is, the one associated with the best oxygenation, the infants were then studied at 10, 15 and 20 Hz. Each oscillatory setting was maintained for 20 minutes after which time arterial blood gases were measured. Prior to transfer to the oscillator, the peak inspiratory pressure was recorded, the P calculated and compliance of the respiratory system Crs) measured. In nine infants, the optimum baseline MAP was +5 cmH2O. Oxygenation at that level was better than on conventional ventilation (P < 0.05), but there was no significant change in CO2 elimination. The optimum MAP was related to the peak pressure during conventional ventilation (P < 0.01) and inversely related to Crs (P < 0.01). There was no significant relationship with the P. At the optimum MAP, the only significant effect of frequency was an impairment of oxygenation at 20 Hz. We conclude that if a volume optimization strategy is pursued among infants with stiff lungs due to RDS, the appropriate starting level of MAP can be identified by stepwise changes in MAP. Impairment of oscillator performance at high frequencies can affect gas exchange. Pediatr Pulmonol. 1994; 17:178–182. © 1994 Wiley‐Liss, Inc.
Influence of duration mechanics measured of occlusion time on respiratory with the single‐breath technique in infants
Authors: Mallol Javier , Willet Karen , Burton Paul , Sly Peter D.
Published: March 2007

To determine the effect of the length of end‐inspiratory occlusion on the values of respiratory system compliance (Crs and resistance (Rrs) calculated from the single‐breath technique, 6 infants with cystic fibrosis were studied. End‐inspiratory occlusions lasted between 0.3 and 1.2 seconds, and between 8 and 32 separate occlusions were made in each infant. Examination of the individual data showed a systematic tendency for C, to decrease as the length of the airway occlusion increased, with statistical significance reached in two subjects. Using a random effects model, it was demonstrated that there was a decrease of 0.1 5 Ml/cmH2O in Crs for each 0.1 s increase in occlusion time. The influence of length of plateau time for C, was similar to that of total occlusion time. No such tendency was seen for Rrs. These data reinforce the current emphasis on greater standardization in the methodologies used for infant lung function testing and for more fully reporting methodological details. Pediatr Pulmonol. 1994; 17:250–257. © 1994 Wiley‐Liss, Inc.
Effective pulmonary blood flow in children with acute asthma attack requiring hospitalization
Authors: Yiallouros Panayiotis K. , Milner Anthony D.
Published: March 2007

In children with acute obstructive lung disease gas exchange is affected by ventilation‐perfusion mismatch and the degree of bronchoconstriction. Standard lung function measurements do not reflect the impairment in gas exchange. Alternatively, the effective pulmonary blood flow (EPBF), that is, the proportion of the cardiac output that is supplying well‐ventilated lung units, can give accurate and noninvasive estimates of ventilation‐perfusion mismatch. We measured EPBF with the argon freon −22 rebreathing technique in children with acute severe asthma to assess their response to nebulized salbutamol and to determine whether induced changes in the EPBF could be predicted from baseline measurements. Twenty‐four children admitted with an acute asthma attack had spirometry and triplicate EPBF measurements before and after nebulized salbutamol. Eighteen patients had repeated tests 50 days later when fully recovered; 4 patients were taking methylxanthines on at least one occasion. The mean forced expiratory volume in 1 sec (FEV1) rose from 55% of predicted to 66% after salbutamol and to 83% with recovery. The mean coefficients of variation for EPBF measurements on the three test occasions were 11.3%, 8.2%, and 9%. Except in children on methylxanthines, the EPBF values were reduced during the acute asthma attack (median, 2.53 L/min/m2; range, 1.99–3.60 L/min/m2) compared with paired values obtained after recovery (median, 2.89 L/min/m2; range, 2.2Eb4.04 L/min/m2) (P = 0.009). Salbutamol caused a highly significant increase in EPBF from 2.88 L/min/m2 (range, 1.86–3.80) before treatment to 3.34 L/min/m2 (range, 2.264.65) immediately afterwards (P = 0.0003). The spirometric indices did not relate to the changes in the EPBF values. However, when the effective stroke volume index was calculated in 11 patients, the changes induced by nebulized salbutamol had a significant inverse relation with the pretreatment FEV, (P = 0.61; P = 0.02). In conclusion, the argon freon‐22 rebreathing technique can be used successfully and reproducibly to measure EPBF in children with an acute asthma attack. Except in children taking methylxanthines, EPBF during the acute attack is reduced and rises significantly after salbutamol. EPBF values after recovery were significantly higher than the presalbutamol values during the attack. Spirometric indices do not relate to the EPBF changes but are inversely related to the effective stroke volume changes. Pediatr Pulmonol. 1994; 17:370–377. © 1994 Wiley‐Liss, Inc.
β2‐Agonists and running economy in prepubertal boys
Authors: Unnithan Viswanath B. , Thomson Kevin J. , Aitchison Thomas C. , Paton James Y.
Published: March 2007

Asthmatic athletes (adults and junior) have competed successfully at the highest level for many years assisted by pre‐event medication with β2‐agonists. To examine the impact of (β2–agonists upon submaximal running economy (oxygen consumption at a given submaximal work load), we studied 10 nonasthmatic boys (age, 10.4 ± 0.48 years, mean ± SD). They each completed submaximal (speeds, 7.2, 8.0, and 8.8 km/hr) and peak treadmill running protocols preceded by treatment with β2‐agonist (terbutaline, 500 (μg via nebuhaler) or placebo in a randomized, crossover single‐blind study. No significant differences were found between running economy and heart rate during the submaximal exercise tests or between peak oxygen consumption (V02), peak respiratory exchange ratio, peak heart rate (HR), or total running time during the peak V02 test. Pretreatment with terbutaline did produce small but nonsignificant increases in aerobic fractional utilization (percent peak V02 on drug: 65.9%, 72.6%, and 76.7% vs. placebo: 65.1%, 70%, and 75.5%), at the three submaximal work loads. Respiratory exchange ratio (RER) values were elevated throughout the submaximal tests (on drug: 0.94, 0.93, and 0.94 vs. placebo: 0.91, 0.92, and 0.91, P < 0.05). No significant differences were found between drug and placebo for minute ventilation (VE) and ventilatory equivalent for oxygen (VE/V02), at both submaximal and peak exercise intensities. The significant increase in forced expiratory volume in 1 second (FEV1) (% predicted) found following submaximal (pre: 107 ± 13 vs. post: 111 ± 17, P < 0.001) and peak exercise (pre: 103 ± 10 vs. post: 106 ± 14, P < 0.001), both with drug and placebo, suggests an effect of exercise rather than of drug. These results indicate that therapeutic doses of an inhaled β2–agonist administered immediately pre‐exercise do not enhance the submaximal running economy or peak V02 of nonasthmatic children.
Bronchopulmonary infection with Moraxella catarrhalis in infants requiring extracorporeal membrane oxygenation
Authors: Fenton Alan C. , Foweraker Juliet E. , Pearson Gale A. , Firmin Richard K.
Published: March 2007

Moraxella (formerly Branhamella) catarrhalis is now a well‐recognized pathogen of the upper and lower respiratory tract. Four pediatric cases of life‐threatening pneumonia requiring extracorporeal membrane oxygenation are presented. M. catarrhalis was isolated within 48 hours of admission in three of the cases and within 24 hours of an acute deterioration in the fourth. We conclude that M. catarrhalis is either a significant pathogen in its own right, a marker of severe disease, or a secondary invader. Pediatr Pulmonol. 1994; 17:393–395. © 1994 Wiley‐Liss, Inc.
Prenatal cocaine exposure alters postnatal hypoxic arousal responses and hypercarbic ventilatory responses but not pneumocardiograms in prenatally cocaine‐exposed term infants
Authors: Gingras Jeannine L. , Muelenaer Andre , Dalley Linda B. , O'Donnell Karen J.
Published: March 2007

To test the hypothesis that respiratory control is altered in cocaine‐exposed infants, we evaluated the hypoxic arousal response and the ventilatory response to carbon dioxide (CO2) in 18 term newborn infants prenatally exposed to cocaine and in 10 healthy, term newborn infants within the first week of life. Three infants could not be tested for the hypoxic arousal response because of low baseline oxygen saturation, and data from these infants were excluded from analysis. Twelve hour overnight pneumocardiograms were performed on all infants. Results show that 60% (9/5) of the prenatally cocaine‐exposed infants had an abnormal hypoxic arousal response and 87% (13/15) had abnormal hypercarbic ventilatory response. Only 6% (1/15) of the prenatally cocaine‐exposed infants demonstrated any abnormality on pneumocardiogram. In contrast, all control infants (10/10) were aroused by the hypoxic challenge and 80% (8/10) had normal ventilatory response to CO2. No abnormalities were found in the assessment of the overnight pneumocardiogram in the control infants. For the cocaine‐exposed infants, test abnormalities were not correlated with a concurrent positive urine toxicology for cocaine, suggesting that the injury occurs early in development. These findings support the hypothesis that infants prenatally exposed to cocaine demonstrate abnormalities of respiratory control.Pediatr Pulmonol. 1994; 18:13–20 © 1994 Wiley‐Liss. Inc.
Maturation of the cholinergic response of tracheal smooth muscle in the piglet
Authors: Rodriguez Ricardo J. , Dreshaj Ismail A. , Kumar Ganesh , Miller Martha J. , Martin Richard J.
Published: March 2007

Maturational changes of the contractile properties of airway smooth muscle have been suggested to occur during the late prenatal and early postnatal period in the piglet. However, the timing and mechanisms involved remain elusive. Therefore, we studied isometric contraction of tracheal smooth muscle (TSM) to evaluate the effects of maturation on (1) the response of TSM to the muscarinic agonist acetylcholine (Ach); and (2) the regulatory activity of acetylcholinesterase (AChE) during the early postnatal period in the piglet. Studies were per‐ formed in 1–5‐day‐old (n = 6) and 14–22‐day‐old (n = 8) anesthetized, mechanically ventilated piglets. Changes in tracheal tension were measured in vivo from an open tracheal segment and normalized for both longitudinal length of the tracheal segment and cross‐sectional area. Dose‐ response curves to locally applied Ach were obtained before and after the intravenous administration of the AChE inhibitor physostigmine (Phys). Ach‐induced changes in tracheal tension significantly increased with maturation during the first 3 weeks of life (P < 0.01), regardless of normalization method. The addition of Phys significantly increased the cholinergic responses of TSM in both age groups (P < 0.02). However, this increase was comparable between age groups. There was also no difference in AChE activity measured in tracheal smooth muscle homogenates between the 1–5 and 14–22‐day‐old animals. These data indicate that maturation significantly enhances the cholinergic responses of tracheal smooth muscle in the early postnatal period in the piglet. As the regulatory activity of AChE is equally developed in the first and third postnatal weeks, this does not account for the observed differences in force generation at these ages. Pediatr Pulmonol. 1994; 18: 28–33. © 1994 Wiley‐Liss. Inc.