bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predicting survival in infants with persistent pulmonary hypertension of the newborn
Authors: Davis Jonathan M. , Spitzer Alan R. , Cox Christopher , Fox William W. 
Published: March 2007

AbstractSince persistent pulmonary hypertension of the newborn (PPHN) often occurs as a life‐threatening illness, it would be advantageous to identify the highest‐risk infants within the first 24 hours of life so that transfer to centers with extracorporeal membrane oxygenation (ECMO) or high‐frequency ventilation can be facilitated. Fifty‐three infants with PPHN were evaluated retrospectively. A multivariate discriminant analysis of risk factors determined that lowest pH, critical PaCO2, highest inspiratory pressure (PI), maximum ventilator rate, and 5‐minute Apgar score were significantly different between the 35 survivors (66%) and the 18 infants (34%) who had died when examined with in the first 24 hours of life. A clinical scoring system was designed based on these five criteria, which predicted outcome accurately in 93% of infants. A logistic regression analysis was performed as a check on these results and found that lowest pH, critical PaCO2, and PI predicted outcome with great accuracy. These results suggest that the use of these scoring systems within the first 24 hours of age may help predict outcome in infants with PPHN.
Unusual ventilation‐perfusion patterns in primary lung tuberculosis
Authors: Chanoine J.‐P. , Toppet M. , Dab I , Toppet V. , Tondeur M. , Ham H. , Piepsz A. 
Published: March 2007

AbstractWe report two cases of primary lung tuberculosis in children with unusual perfusion ventilation scintigraphic patterns. In the first case, a mismatch in the right upper lobe suggests an elective compression of the bronchi by the mediastinal lymph nodes; in the second case, the total absence of ventilation and perfusion of the left lobe at scintigraphy illustrates the discrepancy sometimes encountered between chest x‐ray and lung scintigraphy.
Influence of ventilatory technique on pulmonary baroinjury in baboons with hyaline membrane disease
Authors: Gerstmann D. R. , Delemos R. A. , Coalson J. J. , Clark R. H. , Wiswell T. E. , Winter D. C. , Kuehl T. J. , Meredith K. S. , Null D. M. 
Published: March 2007

AbstractTo assess the influence of ventilatory technique on pulmonary baroinjury in experimental hyaline membrane disease, we randomized 24 premature baboons to six treatment groups according to ventilator (PPV, positive pressure ventilator; HFO, high frequency oscillator; HFI, high frequency flow interrupter) and O2therapy Flo2as clinically indicated, or Flo21.0). PaCO2was adjusted by varying pressure amplitude, and for PPV, also by rate (< 60/min). HFO and HFI were set at a frequency of 10 Hz. Animals were cared for with standard NICU techniques until death or sacrifice at 11 days. One animal died at delivery and was excluded from data analysis. There were no intergroup differences in Paw, Pa/Ao2, PaCO2or oxygenation index (IO2= [Pa/AO2]/Paw) prior to death of the first study animal at 13 h. Animals who subsequently developed airleak had higher Paw, lower Pa/AO2, and lower IO2during this period. The degree of airleak was significantly less with HFO compared to PPV or HFI. The effect of O2exposure did not appear different with respect to the degree of airleak or the frequency of severe tracheal injury, although survival was shortened. Severe tracheal injury was more frequent with HFI compared to PPV or HFO. BPD was found only in 100% O2exposed animals surviving > 1 wk. Management of premature baboons with HFO and appropriate O2resulted in less severe airleak, 100% survival, and no evidence of severe tracheal injury or BPD. These outcomes were not achieved with clinically similar strategies using PPV or HFI.
Effect of chloral hydrate on arterial oxygen saturation in wheezy infants
Authors: Mallol Javier , Sly Peter D. 
Published: March 2007

AbstractChloral hydrate is commonly used to sedate infants for pulmonary function tests and other investigations. However, sedation is generally not recommended for infants with acute wheezing illnesses. The commonly used dose range exceeds the maximum recommended dose; however, the effects of this dosage regimen during pulmonary function testing have not been studied. The present study shows that 70–100 mg/kg of chloral hydrate, a dose commonly used to sedate infants for pulmonary function testing, causes a fall in arterial oxygen saturation and a decrease in clinical score of infants recovering from acute viral bronchiolitis, but not in infants with clinically stable cystic fibrosis. These findings suggest that wheezy infants with baseline SaO2 ≤94% are more susceptible to central respiratory depression following sedation with chloral hydrate. The results of the present study raise serious doubts about the advisability of sedation with chloral hydrate, in the currently used doses, in wheezy infants.
The saccharin method for testing mucociliary function in patients suspected of having primary ciliary dyskinesia
Authors: Canciani M. , Barlocco E. G. , Mastella G. , De Santi M. M. , Gardi C. , Lungarella G. 
Published: March 2007

AbstractIn order to evaluate the clinical value of the saccharin test as a practical and simple measure of mucociliary clearance, nasal mucociliary clearance (NMCC) and ciliary ultrastructure were studied in 22 patients suspected of having primary ciliary dyskinesia (PCD) based on the saccharin test. Ten patients fulfilling the diagnostic criteria of PCD had a pathological response to the saccharin test (transport time greater than 60 minutes), and this was consistently associated with ultrastructural defects, specific for PCD. These results validate the suitability of the clinical use of the saccharin test as a screening procedure for NMCC. The false‐negative results obtained in three cases of PCD, all with borderline values, cannot be ascribed to ineffectiveness of the test, but rather to the persistence of some motility by certain defective cilia, detectable by microphoto‐oscillographic investigation of specimens obtained by nasal biopsy or brushing.
An inexpensive spacer for use with metered‐dose bronchodilators in young asthmatic children
Authors: Teo Joseph , Kwang Lee Woon , Yip William C. L. 
Published: March 2007

AbstractA 1‐liter soft drink plastic bottle was modified as a spacer for use with a metereddose bronchodilator. Its efficacy was tested on 22 children aged 3.9–7.5 years who had acute asthma. They were randomly selected to receive aerosolized salbutamol or placebo via the plastic bottle. Children who received the salbutamol showed significantly greater degree of bronchodilation than those who received the placebo. No significant adverse effects were observed. Cylindrical plastic bottles of 1‐liter capacity may thus be used as a convenient and cheap spacer to effectively deliver metered‐dose bronchodilators to children during acute asthma.
A trial of metaproterenol by metered‐dose inhaler and two spacers in preschool asthmatics
Authors: König Peter , Gayer Debra , Kantak Anand , Kreutz Cynthia , Douglass Barbara , Hordvik Nancy Louise 
Published: March 2007

AbstractBecause most young children have difficulty in coordination for correct use of metered‐dose inhalers (MDI), a trial of two spacer devices attached to MDls was performed. In 13 children with asthma, aged 2–5 years old, a collapsible bag (Inspir‐Ease) and a tube spacer (Aerochamber) were tested in a double‐blind crossover trial with metaproterenol (1,300 μg). Respiratory resistance was measured by the forced oscillation method. Thirty minutes after metaproterenol administration there was a significant decrease in resistance with both spacers, while no significant change occurred after placebo administration. There was no difference in degree of bronchodilation between the two spacers. It is concluded that metaproterenol can be safely and effectively administered to preschool asthmatics by an MDI with spacer devices.
Evaluation of the flow‐volume loop as an intra‐operative monitor of respiratory mechanics in infants
Authors: Brown K. , Sly P.D. , Milic‐Emili J. , Bates J.H.T. 
Published: March 2007

AbstractAirway pressure is currently the primary indicator of respiratory mechanics used by the anesthetist in the operating room. This quantity can signal that the mechanical properties of the respiratory system have changed. However, there is a need for more sophisticated monitors of mechanics, capable of indicating the nature of the change. We have investigated the use of the tidal flow‐volume loop in differentiating between an obstruction of the endotracheal tube and changes in the distribution of regional ventilation, using a computer model. Endotracheal obstruction caused the descending limb of flow‐volume loop to become convex to the volume axis, whereas ventilation inhomogeneity caused the curve to become concave to the volume axis. In contrast, examination of peak airway pressure did not allow differentiation between the two conditions. We conclude that, while the peak airway pressure is useful in signaling a change in a patient's condition, the combination of airway pressure and the flow‐volume loop serves as a more comprehensive monitor of respiratory mechanics.
Resting oxygen consumption and ventilation in cystic fibrosis
Authors: Hirsch Judith Ann , Zhang Shao‐Ping , Rudnick Michael P. , Cerny Frank J. , Cropp Gerd J. 
Published: March 2007

AbstractResting oxygen consumption (Vo2) and minute ventilation (VE) were measured on nine control subjects and 13 patients with cystic fibrosis (CF). In patients with CF, O2 was 20% higher (P < 0.01) when expressed per m2 and 47% higher (P < 0.001) when expressed per kg body weight, and E was 58% higher when expressed per m2 and 94% higher when expressed per kg body weight (P < 0.001) than in control subjects. Repeated measures of O2 and E were highly reproducible over 2 hours (within‐subject coefficients of variation: in controls, O2 = 5.5%, E = 7.4%; in CF, O2 = 3.1%, E = 5.1%). Since the increases in E were greater than those in O2, the ventilatory equivalent (E/O2) was 32% higher in CF than in controls. We conclude that size‐corrected total energy expenditures and E at rest are higher in patients with CF than in control subjects. Ventilation appears mechanically inefficient but necessary to keep arterial PCO2 from rising and oxygen saturation from falling at rest. Our results are consistent with observations that these patients have an abnormally large physiological dead space (Featherby et al.: Ann Rev Respir Dis 1969; 102:737).
Immunoreactive trypsinogen screening for cystic fibrosis: Characterization of infants with a false‐positive screening test
Authors: Rock Michael J. , Mischler Elaine H. , Farrell Philip M. , Bruns W. Theodore , Hassemer David J. , Laessig Ronald H. 
Published: March 2007

AbstractBlood immunoreactive trypsinogen (IRT) is elevated in newborns with cystic fibrosis (CF) and has been used as a neonatal screening test. However, not only is the benefit of early diagnosis unknown, but also the sensitivity, specificity, and time related decline of IRT values have yet to be comprehensively evaluated. This report describes the characteristics of infants with a false‐positive IRT in our experience with CF screening of 87,000 infants. The IRT value was elevated in 92 newborns; 13 had a confirmed diagnosis of CF by quantitative pilocarpine iontophoresis sweat testing, and 79 infants did not have CF and were therefore classified as false positives by IRT screening. In order to test the hypothesis that perinatal stress factors are associated with high neonatal IRT values, we evaluated Apgar scores at 1 and 5 minutes. We found that the scores of false‐positive infants were significantly lower (P = 0.0004 and P = 0.0102 at 1 and 5 minutes, respectively), compared with infants in the general population. While perinatal asphyxia as reflected by low Apgar scores is an associated factor accounting for an elevated IRT value, the majority of non‐CF newborns with an elevated IRT have normal Apgar scores.
Effect of inhaled ipratropium bromide on methacholine and exercise provocation in asthmatic children
Authors: Boner A. L. , De Stefano G. , Vallone G. 
Published: March 2007

AbstractTo determine whether doses of ipratropium bromide (IB) greater than those usually administered by aerosol (75–250 μg) give a greater degree of protection from exercise‐induced asthma (EIA) in children, 12 patients with chronic asthma, ages 7–13 yr, were challenged with methacholine and exercise after inhalation of saline or 125, 250, 500, and 750 μg of IB on different days. A small and similar bronchodilation (mean increase over baseline: 5.26%) was observed 60 min after the administration of each dose of IB. IB prevented the bronchoconstriction caused by methacholine in all doses we used without statistically significant differences between them. All doses gave an all‐or‐none protection from EIA. Mean percent fall in FEV, after exercise was 36.8, 18.3, 23.7, 27.1, and 23.2 following inhalation of saline or 125, 250, 500, or 750 μg of IB, respectively. The degree of protection from EIA was not correlated with the bronchodilation caused by IB. We suggest that muscarinic mechanisms are only partly responsible for the pathogenesis of EIA in children. Their importance varies among subjects and also may be variable in the same subject. Alternative mechanisms may be responsible for bronchoconstriction.
A computer‐model analysis of the influence of the upper airway on passive flow‐volume loops in infants
Authors: Sly Peter D. 
Published: March 2007

AbstractThe present study was undertaken to determine the effects of upper airway resistance (Rua) and elastance (Eua) on the mechanical parameters calculated from the expiratory limb of the passive flow‐volume curve in normal infants, using a computer model. The model included separate compartments for the respiratory system, upper airway, and measurement equipment. Inclusion of Rua in the model decreased the slope of the expiratory limb of the flow‐volume loop, and the resistance calculated from the flow‐volume loop accurately reflected the total resistance of the model. Inclusion of Eua in the model caused a decrease in the end‐inspiratory (driving) pressure and a corresponding decrease in the peak expiratory flow but did not alter the slope of the linear portion of the expiratory limb of the flow‐volume loop. Resistance calculated from the loop underestimated true model resistance by 14.5%. However, further small fluctuations in Eua did not cause significant variability in the value of resistance calculated. Total elastance was accurately calculated whether or not Rua and Eua were included in the model. The results of this analysis demonstrate that, while Eua causes the true resistance to be underestimated, fluctuations in Eua are not likely to be an important source of variability in the mechanical parameters calculated from the passive flow‐volume loop; however, any changes in Rua will be reflected in the value of resistance calculated and therefore are likely to cause substantial variability in the calculated resistance.
Increased bronchial responsiveness to histamine associated with shortened inhalation time
Authors: Vázquez C. , Rodrĺguez‐Soriano J. 
Published: March 2007

AbstractA study was undertaken to assess the variability of results of histamine inhalation tests with the tidal breathing method, keeping the total dose of histamine delivered to the mouth constant but using either different nebulizers or the same Wright nebulizer operated under changing conditions. Seventeen asthmatic children had double histamine bronchial provocation tests with a Bennett‐Twin nebulizer (output 0.31 ml/min, nebulization time 1 min) and a Wright nebulizer (output 0.15 ml/min, nebulization time 2 min), with a driving flow rate, in both instances, of 7 L/min. Another group of 15 asthmatic children had double provocation tests with a Wright nebulizer driven by a flow rate of either 7 L/min (output 0.15 ml/min, nebulization time 2 min) or 12 L/min (output 0.30 ml/min, nebulization time 1 min). In each experiment the volume of histamine solution delivered was about 0.30 ml. PC20‐FEV1 was significantly lower, indicating an increased bronchial response, when both methods using “faster” delivery of histamine were used. We conclude that comparison of results obtained with histamine inhalation tests by the tidal breathing method cannot be made unless the nebulizer and operating criteria are the same.
Respiratory syncytial virus alters electrophysiologic properties in cotton rat airway epithelium
Authors: Cloutier Michelle M. , Wong David , Ogra Pearay L. 
Published: March 2007

AbstractThe effect of respiratory syncytial virus (RSV) infection on the electrophysiologic properties of the airway epithelium was studied in tracheas obtained from cotton rats, after in vivo exposure to the virus. RSV infection was documented by tissue culture infectivity and immunofluorescent antibody techniques. Light microscopic studies of the tracheas 72 hours after exposure to RSV revealed normal epithelial morphology. RSV infection produced a 28% decrease in short‐circuit current (Isc) and an almost 100% increase in tissue resistance. The decrease in Isc was partially attributed to a decrease in CI secretion, while the increase in tissue resistance was associated with significant restriction to sodium and chloride movement through the paracellular pathway in RSV‐infected tracheas. We conclude from these studies that RSV infection in the cotton rat trachea produces significant changes in active and passive ion flows. Alterations in ion transport across the airway epithelium may result in changes in secondary water transport across the airways and may contribute to the pathophysiology of RSV bronchiolitis and other locally invasive mucosal viral infections in children.
Dimensions of the trachea to age 6 years related to height
Authors: Thorne Griscom N. , Wohl Mary Ellen B. , Fenton Terence 
Published: March 2007

AbstractIn an effort to establish normal values for both investigational and patient care purposes, computed tomography was used to determine the length, diameters, cross‐sectional area, and volume of the tracheas of 34 children up to the age of 6 years. The measurements were taken when patients were asleep or resting quietly during tidal breathing, at perhaps 30–60% of total lung capacity. The results were related to body height (in infancy, to body length). There was virtually no difference between boys and girls. Each mean diameter correlated well with mean cross‐sectional area. Tracheal diameters and area were reasonably constant over the length of individual tracheas. The slopes of the functions relating height to tracheal dimensions in these 34 infants and young children were slightly less steep than those previously measured near total lung capacity in 90 older children and adolescents.
Noncomparability of cross‐sectional and longitudinal estimates of lung growth in children
Authors: Pattishall Edward N. , Helms Ronald W. , Strope Gerald L. 
Published: March 2007

AbstractResults from longitudinal and cross‐sectional studies of pulmonary function are often compared. However, previous studies in adults suggest that results from longitudinal and cross‐sectional studies are different and may not be comparable. In order to evaluate these differences further, prospectively collected data in a group of children were analyzed by both longitudinal and cross‐sectional methods. Spirometry was performed longitudinally over a period of 8 years on 58 healthy children. Straight‐line regressions of expiratory flow‐volume parameters on height were computed by averaging the individual regression lines for each child. A cross‐sectional sample from these same children was analyzed and compared to the longitudinal analysis. For all expiratory flow‐volume parameters, the cross‐sectional analysis resulted in a significantly greater increase in growth with increasing height than the longitudinal analysis (P < 0.005 for slope for all parameters except PEFR, P < 0.05 and V̇max75, P < 0.01). These differences cannot be explained by learning or horse‐racing effects, loss to follow‐up, or regression to the mean; however, they could be explained by cohort changes, time trends of pulmonary function, differences in the weighted averages used in the two analyses, or incorrect modeling. These observations indicate that comparisons between cross‐sectional and longitudinal investigations must be made cautiously. These data do not support many of the reasons suggested for the differences in previous reports. It is recommended that studies of pulmonary function use a control group and investigate the groups at the same time and in the same manner. Pediatr Pilmonol. 1989; 7:22–28.
Home measurement of oxygen saturation during sleep in patients with cystic fibrosis
Authors: Montgomery Mark , Wiebicke Wolfram , Bibi Haim , Pagtakhan Reynaldo D. , Pasterkamp Hans 
Published: March 2007

AbstractFeasibility and reproducibility of home measurement of arterial oxygen saturation (Sa) were evaluated in 14 clinically stable patients with cystic fibrosis (CF). Changes in Sa Sa during sleep were compared to the clinical status and pulmonary function while awake to identify predictors of nocturnal oxyhemoglobin desaturation. Each patient was assessed by clinical score, spirometry, and arterial blood gas analysis within 72 hours of the overnight study. Eight patients were studied on more than one occasion to assess dependence of Sa, on position and reproducibility of overnight studies. A pulse oximeter stored up to 8 hours of nocturnal Sa measurements in its memory. Off‐line analysis of trend data provided the proportion of sleep with Sa <90% and <85%. We found that patients with daytime Pa <60 mm Hg spent >80% of their sleep with Sa <90%, while those with Pa >70 mm Hg spent <20% of the night with Sa <90%. Patients with daytime Pa of 67–70 mm Hg were desaturated to less than 90%, from 0 to 98% of the night. No consistent body position dependence of daytime Sa was found. Home measurement of Sa during sleep was reproducible, with a difference on two repeat occasions of 4% ± 2 (mean ± SEM) for %time with Sa <90% and 3% ± 2 for %time with Sa <85%. The severity of hemoglobin desaturation during sleep could not be reliably predicted from clinical scores or awake pulmonary function. Thus, monitoring of nocturnal Sa is needed to evaluate the extent of desaturation in these patients. Pediatr Pilmonol. 1989; 7:29–34.
Lung function values from a longitudinal study of healthy children and adolescents
Authors: Hibbert Marienne E. , Lannigan Anna , Landau Louis I. , Phelan Peter D. 
Published: March 2007

AbstractFrom a cohort of 543 healthy children and adolescents, subjects were studied annually to obtain longitudinal data so that precise predictive values for lung volumes and flows from ages 8 to 19 years could be obtained. Strict guidelines for subject selection and pulmonary function testing were used. These data are presented in a readily usable form as equations, graphs, and tables. Pediatr Pilmonol. 1989; 7:101–109.