bluuebunny/crossref_metadata_2025 huggingface dataset:
Corticosteroid treatment for pulmonary lymphoid hyperplasia in children with the acquired immune deficiency syndrome
Authors: Rubinstein Arye , Bernstein Larry J. , Charytan Morris , Krieger Ben Zion , Ziprkowski Micha
Published: March 2007

Five children with positive serology for human immunodeficiency virus (HIV) infection by enzyme‐linked immunosorbent assay and Western blot were followed for chronic pulmonary disease. Lung biopsies were performed in all patients, and confirmed the diagnosis of pulmonary lymphoid hyperplasia. All children demonstrated progressive hypoxia and increasing alveolar capillary oxygen gradients over at least 1 year of follow‐up. All children were on periodic intravenous gamma globulin treatment for a B‐cell defect prior to the initiation of corticosteroid therapy. Prednisone was initially given at a dose of 2 mg/kg daily and was subsequently tapered to an alternate day regimen. All children showed improvement in oxygenation. No deterioration in immune function was noted, and there was no increase in bacterial infection. This study indicates that corticosteroids can successfully reverse the severe hypoxia that may result from pulmonary lymphoid hyperplasia in pediatric AIDS patients.
Respiratory pattern at hospital discharge in asymptomatic preterm infants
Authors: Hageman Joseph R. , Holmes Diane , Suchy Steven , Hunt Carl E.
Published: March 2007

Pneumogram (PG) recordings were performed in 87 very low birthweight (VLBW) asymptomatic infants just prior to hospital discharge to determine the relationships between: 1) a prior history of apnea of prematurity (AOP) and cardiorespiratory pattern; and 2) cardiorespiratory pattern at hospital discharge and postconceptional age. Apnea density (A6/D%) and longest apnea were significantly greater in those with (n = 66), versus without (n = 21) a prior history of AOP (P < 0.05 and P < 0.01, respectively). Although PG values for the 21 VLBW infants without a prior history of AOP did not differ significantly from those of full‐term infants, for the 66 VLBW infants with a prior AOP history A6/D% (P < 0.01), episodes of periodic breathing (P < 0.05) and longest apnea (P < 0.001) were significantly greater compared with full‐term infants. Postconceptional age was significantly less in the VLBW infants with A6/D% values above, compared with those within the 95th percentile for normal infants (median age, 36 and 37.5 weeks; P = 0.01). Therefore, respiratory pattern abnormalities in asymptomatic VLBW infants ready for hospital discharge are related to a prior history of AOP and may be significantly higher than in full‐term infants at the postconceptional ages at which hospital discharge now tends to occur.
Airway responsiveness to cold, dry air in normal infants
Authors: Geller David E. , Morgan Wayne J. , Cota Kathryn A. , Wright Anne L. , Taussig Lynn M.
Published: March 2007

Reactive airway disease may be related to genetic, infectious, and environmental factors. The latter two have been well documented, but there are no data on nonspecific airway responsiveness in normal infants prior to any insult to the respiratory tract. We measured forced expiratory flow by the thoracic compression technique and lung volume in 30 normal infants before and after challenge with cold, dry air (CDA) and compared the results with those in 12 infants who did not receive CDA challenge. As a group, infants challenged with CDA had a mean decrease in VmaxFRC of 17.9 ± 24.1% SD. This was significantly different (P < 0.01) from the lack of change (+ 1.3 ± 18.1% SD) seen in the control group. We conclude that nonspecific airway reactivity may exist from early infancy and may predate any known lung injury. The relationship of this airway responsiveness to subsequent reactive airway disease and other respiratory illnesses is unknown and requires longitudinal study.
Prevalence and significance of methicillin‐resistant stapHylococcus aureus in patients with cystic fibrosis
Authors: Boxerbaum Bernard , Jacobs Michael R. , Cechner Ronald L.
Published: March 2007

Recent reports indicate that methicillin‐resistant Staphylococcus aureus (MRSA) may be emerging as a significant pediatric nosocomial pathogen. Children with cystic fibrosis (CF) pulmonary disease are subject to many of the risk factors for MRSA colonization and/or infection. We retrospectively investigated the prevalence and significance of MRSA from sputum and throat cultures in 452 patients with CF followed during 1986. No MRSA had been isolated during 1984 or 1985. Although S. aureus was isolated from 212 patients (47%) in 1986, only 14 (3%) showed MRSA. The MRSA strains had 11 different antimicrobial susceptibility patterns. Neither age, clinical condition, nor recent prior hospitalization correlated with MRSA acquisition. Acquisition did not appear to directly affect the course of the pulmonary disease in these patients even though no patient received any treatment for their MRSA. The prevalence of MRSA is low, although patients with CF are subject to many risk factors. MRSA appears to be mainly community‐acquired and to represent colonization rather than infection. However, the potential for nosocomial MRSA infection is present, and vigilance is required in monitoring any changes in frequency of isolation or infection with these organisms.
Use of a single silastic IV catheter for cystic fibrosis pulmonary exacerbations
Authors: Dietrich Kenneth A. , Lobas Jeffrey G.
Published: March 2007

Use of a single percutaneous silastic IV catheter for cystic fibrosis hospitalizations was evaluated among 23 patients during 45 hospitalizations. Patient ages ranged from 4 to 20 years and weights from 18 to 60 kg. Percutaneous silastic catheters were used for infusion of all IV antibiotics and IV fluids. Catheters remained in place for a total of 549 patient days (mean 12.2, range 2–34). No patient demonstrated clinical signs of local infection or sepsis. Thirty six catheters served as the single IV access for a patient's entire hospitalization. Nine catheters were removed because of discomfort, obstruction, or mechanical dysfunction before the conclusion of the hospitalization. A single, percutaneously placed silastic catheter appears to be a safe and effective way of maintaining IV access throughout the duration of hospitalization for cystic fibrosis exacerbations.
Postnatal development of rat lung following retarded fetal lung growth
Authors: Adamson Ian Y. R. , King Gillian M.
Published: March 2007

Postnatal lung development was examined in rats born with smaller than normal lungs after either prenatal exposure to glucocorticoid or to an inhibitor of collagen synthesis. At birth, treated animals had lower than normal lung weights, lung to body weight ratios, hydroxyproline (HYP) levels, total DNA; and rates of DNA synthesis. Rats exposed to steroid showed a rapid recovery in growth during the normal postnatal cell proliferative phase from 4 to 11 days, though collagen levels did not return to normal until 3 weeks of age. Rats exposed to a prenatal proline analog showed a much slower rise in lung weight and total DNA, and these levels were still much below normal at 2–3 weeks when the cell proliferation phase was completed. Levels of disaturated phosphatidylcholine were significantly below normal up to 11 days, whereas total HYP was significantly reduced and less fibrillar collagen was seen in the lung throughout the study. The results indicate that the smaller but mature lungs at birth after antenatal steroid show a growth rebound and quickly become structurally normal. In contrast, inhibition of fibroblast growth and collagen deposition produces small lungs at birth, which continue to show inhibited growth and development at least up to 3 weeks of age, when the cell division phase is over.
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

Since 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

We 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

To 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

Chloral 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

In 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

A 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

Because 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

Airway 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

Resting 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

Blood 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

To 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

The 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

A 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

The 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

In 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

Results 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

Feasibility 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

From 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.
Postnatal growth of genioglossal motoneurons
Authors: Brozanski Beverly S. , Guthrie Robert D. , Volk Etta A. , Cameron William E.
Published: March 2007

The postnatal growth of kitten genioglossal motoneurons was examined in six different age groups (newborn, 2, 4, 8, and 12 weeks and adult) using the technique of retrograde transport of horseradish peroxidase (HRP). The cell bodies of 100–150 motoneurons in each age group were analyzed in a transverse plane of section using standard techniques.

Somatic genioglossal motoneuron growth occurred primarily along the major axis, which increased from 25.2 μm to 41.3 μm between birth and 8 weeks of postnatal age, after which time there was no further increase in either major or minor dimension of the cell body. The form factor decreased from 0.94 to 0.80 from birth to adulthood indicating an increased eccentricity of the cell body. The number of primary dendrites visible with this technique remained constant throughout the postnatal period.

Calculated somal surface area increased in a linear fashion from birth through 8 weeks of postnatal life. There was no further increase in surface area beyond this age. The rate of increase in somal surface area with age was significantly different from both the rate of increase of animal weight and animal surface area with age.

The correlations between the demonstrated immature genioglossal morphology and its cellular electrophysiology or integrated respiratory function remain unknown. The recent demonstration of decreased activation of the genioglossus muscle following airway occlusion in premature infants with apnea suggests that the relationships between developing genioglossal motoneuron structure and function warrant further investigation. Pediatr Pilmonol. 1989; 7:133‐139.
Childhood asthma following hospitalization with acute viral bronchiolitis in infancy
Authors: Sly Peter D. , Hibbert Marienne E.
Published: March 2007

A prospective follow‐up of 48 infants hospitalized with respiratory syncytial virus bronchiolitis in the first year of life revealed that 44 of these infants had symptoms suggestive of asthma in the 5 years following their initial illness (cumulative prevalence 92%). Symptoms became less frequent and less troublesome during the follow‐up period. Thirty‐five of these children visited the laboratory for clinical examination, pulmonary function testing, and histamine challenge. Twenty‐five children were believed to have clinical evidence of asthma at the time of the laboratory visit (point prevalence 71%). Five children were unable to perform pulmonary function tests; 25 of the remaining 30 (67%) had a positive histamine challenge test. No relationship could be demonstrated between a clinical diagnosis of asthma, a family history of atopy, and the results of histamine challenge testing. These results question the relationship between the results of bronchial provocation tests and clinical asthma in this age group. Pediatr Pilmonol. 1989; 7:153–158.
In vitro performance of the small particle aerosol generator (SPAG‐2)
Authors: Newth C. J. L. , Clark A. R.
Published: March 2007

The anti‐viral drug ribavirin primarily used for the treatment of respiratory syncytial virus (RSV) infection in infants is delivered by continuous nebulization with the Small Particle Aerosol Generator (SPAG). Clinical data suggest that the SPAG is an efficient nebulizer for ribavirin; it is also being used for the delivery of other pulmonary agents.

The efficiency of a nebulizer can be defined in large part by delivering a major proportion of its output with a particle size of 1 to 5 μm which is small enough to penetrate the tracheobronchial tree.

We assessed both the quality and quantity of the SPAG aerosol cloud with the aid of a multistage liquid impinger, utilizing 2% ribavirin and 1% cromolyn sodium solutions. The aerosol of either solution had a mass median aerodynamic diameter (MMAD) of approximately 1.2 μm, and this seemed insensitive to solution strength and nebulization period. Of the solutions of ribavirin and cromolyn sodium 92.3% and 95.0%, respectively, by weight of delivered particles, had aerodynamic diameters less than 5 μm and about 70–75% of the aerosol particles had an aerodynamic diameter in the 1–5 μm range. This implies that the aerosol cloud is adequate for delivery through a ventilator circuit. Performance was maintained over long (16 hours), continuous periods of delivery. The SPAG could be useful for delivery of other respiratory drugs by continuous nebulization. Pediatr Pilmonol. 1989; 7:183–188.
Effects of acute viral respiratory tract infections in patients with cystic fibrosis
Authors: Hordvik Nancy L. , König Peter , Hamory Bruce , Cooperstock Michael , Kreutz Cynthia , Gayer Debra , Barbero Giulio
Published: March 2007

To determine the effects of acute viral respiratory infections (ARI) in cystic fibrosis (CF) we studied all episodes of ARI in ten patients over a 2 year period. A daily diary card was kept on which they recorded all illnesses, including specific upper and lower respiratory symptoms, antibiotic use, and daily peak flow measurements. Recording of concurrent similar illnesses in other household members aided in confirming the onset of ARI, as did a home viral culturing technique and serial serum antibody levels against specific viral types. A total of 80% of the 35 recorded onsets of ARI (1.75/yr/subject) were confirmed by one or more of these methods. Five subjects with moderate to severe pulmonary function scores at the outset of the study had significantly greater decreases in PEFR during ARI episodes (42.4%) than those with milder disease (15.4%), and it took them significantly longer to recover to their baseline measurements (22 days vs. 15 days respectively). The majority of hospital admissions for pulmonary exacerbations were preceded by viral infections (7/8). Pediatr Pulmonol 1989; 7:217–222.
Genioglossal recruitment during acute hypoxia and hypercapnia in kittens
Authors: Watchko Jon F. , Klesh Kenneth W. , O'Day Terrence L. , Weiss Marc G. , Guthrie Robert D.
Published: March 2007

We examined genioglossal and diaphragmatic EMG activities in one‐ and two‐month‐old anesthetized kittens during acute exposures to hypoxic (13% or 10% O2) and hyperoxic hypercapnic (8% CO2/50% CO2/balanced N2) gas mixtures. Phasic genioglossal EMG activity, frequently characterized by a combined inspiratory‐expiratory discharge pattern, was observed in 3 of 8 one‐month‐old vs. 7 of 7 two‐month‐old kittens during hypercapnia (Chisquare P<0.05). The percentage of kittens recruiting genioglossal activity during hypoxic exposures was similar at both ages (1 month, 75%; 2 month, 83%). Analysis of the breath‐by‐breath response during trials of hypoxia in which genioglossal recruitment was observed, however, revealed that the one‐month‐old kittens exhibited phasic genioglossal activity in only 40±27% of the stimulated breaths, compared to 63±26% for the two‐month‐old ones (P<0.05) at each level of hypoxia. In this regard, the genioglossal response to hypoxia in one‐month‐old kittens was frequently characterized by early and only transient recruitment (when diaphragmatic activity was at its peak), while genioglossal recruitment was more sustained in two‐month‐old animals. These data indicate that genioglossal activity in kittens is often recruited during exposures to hypercapnia and hypoxia, and suggest that such recruitment is more frequent with increasing postnatal age. Pediatr Pulmonol 1989; 7:235–243.
Diagnostic value of body plethysmographic parameters in healthy and asthmatic young children is not influenced by breathing frequency
Authors: Buhr Wernfrid , Jörres Rudolf , Knapp Michael , Berdel Dietrich
Published: March 2007

In 16 healthy and 16 asymptomatic asthmatic children (age range 5–8 yr; 8 girls, 24 boys) we studied the influence of breathing frequency on the results and the diagnostic value of body plethysmographic measurements. Airway resistance (Raw), specific airway resistance (SRaw), and thoracic gas volume (TGV) were measured during breathing (or breathing efforts against a closed shutter) at 0.4, 1, and 2 Hz. SRaw was computed by a simplified procedure directly from flow at the mouth vs. box volume‐curves. The diagnostic value of each parameter was assessed as the percentage of correctly classified healthy and asthmatic subjects by means of discriminant analysis. When frequency was increased from 0.4 to 1 and 2 Hz mean TGV rose by 5 and 14% in healthy children and by 11 and 21% in asthmatic children, respectively. From 0.4 to 1 Hz mean Raw decreased by 16% (P = 0.002) in healthy children and by 25% (P = 0.0004) in asthmatic children. The differences in Raw between both groups decreased with frequency (3.5, 1.8, and 1.5 cm H2O·L−1·s at 0.4, 1, and 2 Hz, respectively) and those of TGV increased (0.13, 0.21, and 0.23 L). SRaw showed similar frequency characteristics as Raw. As intra‐group variability changed in parallel with the differences the diagnostic value of the parameters remained constant with frequency. Simplified SRaw alone and TGV combined with Raw exhibited no differences in their diagnostic values (81–84% correctly classified). Our results indicate that in young healthy and asthmatic children the diagnostic value of TGV, Raw, and SRaw is not influenced by breathing frequencies (0.4–2 Hz) and that in these children the simplified computation of SRaw can be used without loss of information. Pediatr Pulmonol 1990; 8:23‐28.
Comparison of transthoracic impedance/heart rate monitoring and pulse oximetry for patients using diaphragm pacemakers
Authors: Marzocchi Mirella , Brouillette Robert T. , Weese‐Mayer Debra E. , Morrow Anna S. , Conway Linda P.
Published: March 2007

Patients using diaphragm pacemakers have several respiratory‐related problems placing them at high risk for death during sleep, including central hypoventilation, abnormal arousal responses, upper airway and/or tracheostomy obstruction, and, in the case of high quadriplegia, lack of motor response to airway obstruction. The recent death from airway obstruction of a patient using diaphragm pacemakers prompted us to re‐evaluate both the need for home monitoring and the type of monitor to prescribe. We compared the performance of a transthoracic impedance/heart rate (TI/HR) monitor with that of a pulse oximeter in six patients with central hypoventilation syndrome whose treatment included diaphragm pacing. Polygraphic recordings of airflow, ECG, Sa02, transthoracic impedance, heart rate, and breath detection were obtained during brief tracheostomy occlusion during patient sleep. Although none of 13 occlusions was detected by the TI/HR monitor, the pulse oximeter identified 13 of 13 occlusions. Three reasons for TI/HR monitor failure included 1) the breath detection circuit consistently registered a breath with each obstructed, paced diaphragmatic contraction; 2) bradycardia did not occur during any airway occlusion; and 3) pacemaker stimuli were misinterpreted as additional heart beats, increasing apparent heart rate. Thus, pulse oximetry, but not TI/HR monitoring, can detect life‐threatening airway obstruction in children using diaphragm pacemakers. Pediatr Pulmonol 1990; 8:29‐32.
Relationship between infant lung mechanics and childhood lung function in children of very low birthweight
Authors: Chan K. N. , Wong Y. C. , Silverman M.
Published: March 2007

Twenty‐seven children of very low birthweight (≤1,500 g) whose lung function had been measured on several occasions during the first year were studied at the age of about 9 years. Fifteen of the children had received neonatal intermittent positive pressure ventilation, mostly for respiratory distress syndrome. Ten of the ventilated children were still oxygen dependent at 30 days of age.

Compared to the remainder of the group, mechanically ventilated children had reduced lung compliance in early infancy and increased thoracic gas volume in the middle of their first year. These changes correlated with the level of neonatal respiratory therapy as indicated by the oxygen score. Lung compliance in early infancy, but not thoracic gas volume, correlated with forced expiratory volume at 1 second recorded at 9 years. On the other hand, reduced airway conductance showed no significant correlation with the neonatal oxygen score, but there was a strong correlation between airway conductance late in infancy and lung function at 9 years. This relationship was independent of neonatal mechanical ventilation.

We conclude that perinatal factors, which may be associated with disturbed lung mechanics early in infancy, are only weak and indirect predictors of childhood lung function. Airway conductance late in infancy, determined by constitutional factors, prematurity itself or other undetermined factors, is a good predictor of airway function at 9 years. Pediatr Pulmonol 1990; 8:74‐81.
Does lithium carbonate affect the ion transport abnormality in cystic fibrosis?
Authors: Anbar Ran D. , Lapey Allen , Khaw Kon‐Taik , Spragg Jocelyn , Strieder Denise J. , Shaw Lisa F. , Kelly Dorothy H. , Shannon Daniel C.
Published: March 2007

Lithium is known to affect several aspects of cellular regulation which may be related to ion channel function in epithelial cells. To determine whether the ion transport abnormality in cystic fibrosis (CF) is affected by lithium with resultant changes in clinical status, 36 CF patients, 12–37 years old, were enrolled in a 14 week, double‐blind, placebo‐controlled trial. Eighteen patients were randomly assigned to receive lithium carbonate for 10 weeks. At the end of therapy their average serum lithium concentration was 0.56 ± 0.06 mmol (SEM) per liter. Their sweat chloride concentration fell from 92.1 ± 4.8 mmol per liter to 87.4 ± 4.0 mmol per liter after 10 weeks of therapy (P = 0.07) and rose to 94.4 ± 3.5 mmol per liter 4 weeks after end of therapy (P < 0.001 compared to results at end of therapy). Their forced vital capacity (FVC) fell from 72 ± 5.3% of predicted to 66 ± 5.1% of predicted after 4 weeks of therapy (P < 0.01), and their forced expiratory volume in one second (FEV1) fell from 56 ± 5.5% of predicted to 51 ± 5.5% of predicted after 4 weeks of therapy (P < 0.01). In a non‐blind assessment, performed 19 weeks after the end of therapy, their FVC and FEV1 had risen and were not significantly different from baseline. Sweat chloride, FVC, and FEV1 remained unchanged in the placebo group throughout the period of study.

We conclude that in patients with CF lithium affects the function of the lungs and sweat glands, two organ systems in which the CF epithelial cell defect is well recognized. Several mechanisms could account for these lithium effects. Since pulmonary function deteriorated during short‐term lithium administration, lithium as used in this study has no therapeutic value in CF and pulmonary function must be closely monitored when lithium is used for manic‐depressive disease in patients with CF. Pediatr Pulmonol 1990; 8:82‐88.
Transcutaneous blood gas analysis during sleep and exercise in cystic fibrosis
Authors: Pradal U. , Braggion C. , Mastella G.
Published: March 2007

Forty patients with cystic fibrosis (CF) (mean age, 13 ± 2.5 years) were studied with transcutaneous (tc) blood gas monitoring (TCM) during sleep and exercise. By comparing arterial blood samples and TCM in 24 of them (27 samples), a mean bias of tc–15.91 mmHg with a precision of 8.4 mmHg was found. The mean bias of tc was 7.21 mmHg with a precision of 3.9 mmHg. A standardized submaximal exercise test (1.7 W/kg) was performed in all 40 CF patients and in 14 healthy control subjects (mean age, 13 ± 0.5 years). The typical tc trend during exercise for CF and healthy subjects was a slight increase of tc levels and tc stability. A minor decrease of tc values occurred in four CF patients (no greater than 7 mmHg). In 28 patients (mean age, 13 ± 3 years), tc and tc were recorded during sleep. In 13 of them, apparent hypoxemic episodes were noted, without relation to the degree of airway obstruction. There were simultaneous episodes of hypercapnia in ten patients. Some difficulties were encountered in analyzing long‐term recordings. Tc drifts upward and tc decreases during the recordings over several hours. The change in electrode position after 4 h of sleep modified tc and tc values. Such difficulties limit the usefulness of long‐term but not short‐term recordings. Pediatr Pulmonol 1990; 8:162‐167.
Model systems for learning pediatric flexible bronchoscopy
Authors: Wood Robert E. , Pick James R.
Published: March 2007

Considerable practice is necessary to develop the skills essential to successful and safe performance of flexible bronchoscopy, especially in pediatric patients. We review a number of model systems, both mechanical and living, for learning and maturing bronchoscopic skills. For each of the animal models (canine, feline, leporine, and simian), the relevant anatomy and anesthetic techniques as well as the relative advantages and disadvantages of each model are discussed. Pediatr Pulmonol 1990; 8:168‐171.