bluuebunny/crossref_metadata_2025_split huggingface dataset:
Referencing lung volume for measurements of respiratory system compliance in infants
Authors: Mortola J. P. , Hemmings G. , Matsuoka T. , Saiki C. , Fox G. 
Published: March 2007

AbstractWe propose a method for measurements of respiratory system compliance (Cm) in spontaneously breathing infants, which circumvents the potential problems introduced by the breathby‐breath oscillations in the end‐expiratory level, i.e., functional respiratory capacity (FRC). Changes in lung volume (V) and pressure at the airway opening (Pao) were measured in 10 infants breathing through a face mask. A first brief occlusion was to establish a reference V and the corresponding static Pao; a second occlusion was done at a different V. within the same expiration, or in the following breath. Both occlusions were sufficiently long for the establishment of a stable Pao value. From the V difference (Δ, where Δ was at least 20% tidal volume) and the corresponding difference in Pao (Δao) Crs was computed and averaged (Crs[REF.VOL.] = Δ/δao). Although, on average, the results were similar to those obtained by the traditional multiple occlusions technique with linear regression analysis of the Pao‐V data points (Cao[MOT]), in several infants Crs[REF.VOL] tended to be slightly higher than Crs[MOT]. Some possibilities for this discrepancy are discussed. It seems likely that breath‐tobreath oscillation in FRC may potentially lower Crs[MOT] by introducing a bias on the V measurement at low Pao. We conclude that referencing V for Crs measurements in spontaneously breathing infants is a simple approach, which does not require linear regression analysis and Circumvents the effects of oscillation in FRC. Pediatr Pulmonol. 1993; 16:248–253. © 1993 Wiley‐Liss, Inc.
Comparison of efficacy of salbutamol and sodium cromoglycate in the prevention of ticarcillin‐induced bronchoconstriction
Authors: Chua Hock Leng , Walker Sharyn L. , Lesouëf Peter N. , Sly Peter D. 
Published: March 2007

AbstractNebulized ticarcillin can cause bronchoconstriction in children with cystic fibrosis (CF). We assessed whether pretreatment with salbutamol or sodium cromoglycate (SCG) would prevent this side‐effect using a randomized, double‐blind, placebo‐controlled design. Fifteen children with CF received pretreatments of saline, SCG, or salbutamol, in random order, one on each day. Baseline lung function was measured before and after pretreatment, and after ticarcillin nebulization. On the control day (saline pretreatment), ticarcillin caused a reduction in forced expiratory volume in one second (FEV1), which was maximal 10 minutes after receiving the aerosol and persisted for 120 minutes. The mean maximal fall in FEV1, was 9%. Pretreatment with salbutamol abolished the fall in FEV, seen with ticarcillin at all time points. Pretreatment with SCG diminished the maximal fall in FEV1, at 10 minutes (mean, 4%) and resulted in the FEV, returning to baseline within 120 minutes. These data suggest that pretreatment with salbutamol is more effective in preventing ticarcillin‐induced bronchoconstriction in the doses used in routine clinical practice, than it is with SCG. Pediatr Pulmonol. 1993; 16:311–315. © 1993 Wiley‐Liss, Inc.
Cardiorespiratory effects of conventional and high frequency ventilation in rabbits with bilateral pneumothoraces and surfactant depleted lungs
Authors: Wang Chen , Nicol Margaret E. , Chakrabarti Mihir K. , Holdcroft Anita , Whitwam James G. 
Published: March 2007

AbstractWe compared high frequency ventilation (HFV) to conventional mechanical ventilation (CMV) under normoxic and normocapnic condition in surfactant depleted rabbits with bilateral pneumothoraces. We hypothesized that lower airway pressures would be required with HFV under these conditions. We applied CMV and HFV in 8 anaesthetized rabbits with a prototype ventilator at frequencies of 30, 100,200, and 300 cycles/min. A positive end‐expiratory pressure (PEEP) just below the pressure sufficient to open the air leak from the pneumothoraces was applied at all frequencies. Airway pressures, gas exchange, heart rate, and mean arterial pressure were recorded. Peak airway pressure decreased significantly from 2.50 to 2.10 kPa when the frequency of ventilation was increased from 30 to 300 cycleshnin. There were no significant changes in mean airway pressure, Pao2arterial pH, heart rate, and mean arterial pressure when HFV was compared to CMV. In conclusion, during HFV peak airway pressures measured at the mouth were decreased. Our ability to maintain adequate gas exchange in the face of ongoing pulmonary air leaks may reflect lower alveolar pressures. Pediatr Pulmonol. 1993; 16:354–357. © 1993 Wiley‐Liss, Inc.
Slow weight gain is associated with increased periodic breathing in healthy infants
Authors: Riordan Linda L. , Kelly Dorothy H. , Shannon Daniel C. 
Published: March 2007

AbstractTo investigate the hypothesis that weight gain can influence periodic breathing in healthy infants, we prospectively studied, by nocturnal pneumogram technique, respiration and heart rate in 99 full‐term infants during the first month of life. Eighty‐eight infants had a repeat study at about 2 months of age. Pneumograms were analyzed visually for percent periodic breathing (%PB), and by computer for mean respiratory rate and mean heart rate. We found a median %PB of 0.9 initially and of 0.3 at about 2 months of age. The 95th percentile was 13.5 at 2 weeks and 7.3 at 2 months, higher than previously reported. Between the two ages tested, %PB was inversely correlated with weight gain (P < 0.001, (0.03, respectively). Infants with greater weight gain had a greater fall in %PB (P < 0.03). We conclude that in the first 2 months of life, slow weight gain is associated with increased periodic breathing. Pediatr Pulmonol. 1994; 17:22–25. © 1994 Wiley‐Liss, Inc.
The effects of reversing distending pressure sequences in the neonatal piglet
Authors: Easa David , Mundie Thomas G. , Finn Kuuleialoha C. , Balaraman Venkataraman , Stevens Edward L. , Takenaka Wayne , Uyehara Catherine F. T. 
Published: March 2007

AbstractWe studied different sequences of lung inflation in ventilated newborn piglets with normal lungs in order to determine the effects of sequence, magnitude and duration of distending pressure on pulmonary function, and/or hemodynamics. End‐expiratory pressure was varied using a continuous negative extrathoracic pressure (CNEP) device. Three groups of ventilated piglets with normal lungs were exposed to 2 cmH2O increments of CNEP from −2 to −12 cmH2O and to decrements from −12 to −2 cmH2O or to only ‐6 cmH2O. Lung inflation sequence, magnitude of inflation pressure, and duration of inflation had significant effects on end‐expiratory lung volume and lung compliance at numerically equivalent pressure levels. End‐expiratory lung volume and lung compliance varied (at four and five of six inflation pressures studied) by as much as 68% and 104%, respectively. Hemodynamic effects of the lung inflation sequence were more variable; those found to be different at numerically equivalent pressure levels were associated with changes in lung compliance and ventilation. Differences in pulmonary mechanics can best be explained by the effects of lung inflation on alveolar recruitment versus overinflation. Pediatr Pulmonol. 1994; 17:97–105. © 1994 Wiley‐Liss, Inc.
Radiographic lung disease and response of persistent pulmonary hypertension to mean airway pressure and alkalosis
Authors: Deluga Karl S. , Schlesinger Alan E. 
Published: March 2007

AbstractPersistent pulmonary hypertension of the newborn (PPHN) is associated with multiple cardiopulmonary diseases. Therapy often includes hyperventilation/alkalosis despite little evidence as to its efficacy in diverse conditions. To determine (1) if part of the improvement of arterial oxygen tension (P) attributed to alkalosis is actually related to increased mean airway pressure (Paw) and (2) if the presence of radiographic pulmonary disease predicts the response to alkalosis or mean airway pressure, we reviewed records of 19 newborns with well‐documented PPHN. Arterial blood gases and corresponding ventilator settings were recorded during the first day of life. To adjust for lower F corrected P(cP) was calculated when the F < 1.0, such that cP = calculated arterial/alveolar oxygen ratio x (71 3 ‐ P/0.8). Regression equations were obtained and mean slopes of these were compared for Paw vs. cP, and pH vs. cP by one group t‐tests (with assumed population slope of zero). There was no correlation between Paw and cP (mean slope ± SD = −8.4 ± 30.8, P = 0.25), but there was a moderate correlation between p d and cP (mean slope = 333.1 ± 480.5, P = 0.007). Patients were then classified by chest radiographs as having severe or minima/no lung disease. Relationships of Paw and pH to cP were then re‐examined. No correlation was present between Paw and cP, in 11 patients with PPHN and severe radiographic disease (mean slope = −7.4 ± 26.97 P = 0.38) or in eight patients with PPHN and minima/no lung disease (mean slope = −9.8 2 37.5, P = 0.48). There was no correlation between pH and CP in patients with severe radiographic lung disease and PPHN (mean slope = 92.1 t 399.5, P 7 0.46), but patients with PPHN and minimal/no lung disease showed a strong correlation (mean slope = 664.5 ± 385.8, P = 0.002). We conclude that Paw (≤18 cm H2,O) with conventional mechanical ventilation has no apparent effect on oxygenation in patients with PPHN regardless of lung disease; however, severe radiographic lung disease may be a predominant variable predicting a poor response to alkalosis. We speculate that different diseases cause pulmonary hypertension by different mechanisms. Pediatr Pulmonol. 1994; 17:239–245. © 1994 Wiley‐Liss, Inc.
Pneumotachographic nitrogen washout method for measurement of the volume of trapped gas in the lungs
Authors: Gustafsson Per M. , Johansson Helmer J. , Dahlbäck Gunnar O. 
Published: March 2007

AbstractA computerized pneumotachometric multiple breath N,‐washout method for assessment of the volume of trapped gas in the lungs (V ) is presented. The V is measured as the volume of air mobilized from nonventilated lung spaces by five maximal breaths after a washout performed until the end‐tidal nitrogen fraction is 0.02.The method demonstrated a good instrumental precision and the reproducibility of V recordings in normal subjects was equal to that achieved with a previous V method based on gas collection in bags.It was confirmed that gas trapping occurs in normal children during tidal breathing at functional residual capacity. In normal subjects V was directly related to lung size. In 69 healthy children and adolescents V showed a good correlation with vital capacity (r = 0.85; P < 0.001), of which it comprised 1.7 ± 0.4% (mean 5 SD). Patients with bronchial asthma or cystic fibrosis investigated had pathological gas trapping with only a few exceptions; in several cases despite normal results at forced expiratory spirometry. The relative response of V (reflecting peripheral airway obstruction) and forced expiratory volume in one second (FEV1) (reflecting conditions in central airways) to beta,‐agonist inhalation among the patients with asthma was variable, indicating that bronchial obstruction is not uniformly distributed along the bronchial tree.Measurements of V can be easily performed in children from 7 years of age with the method presented. The computerized V method facilitates work and saves time for the operator and provides instant test results. V appears to be a sensitive indicator of peripheral bronchial obstruction, giving supplemental information to standard spirometry. Pediatr Pulmonol. 1994; 17:258–268. © 1994 Wiley‐Liss, Inc.
Protective effect of albuterol delivered via a spacer device (Babyhaler®) against methacholine induced bronchoconstriction in young wheezy children
Authors: Avital Avraham , Godfrey Simon , Schachter Jacob , Springer Chaim 
Published: March 2007

AbstractNine young asthmatic children aged 2–5 years underwent methacholine challenge after placebo or albuterol administered by metered dose inhaler through a spacer device (Babyhalere®)* with a face mask in a double‐blind, cross‐over, randomized study. The methacholine challenge was performed using chest auscultation to define the provocative concentration of methacholine that causes wheezing (PCW). The PCW increased from a geometric mean of 0.28 mg/mL after placebo to 3.59 mg/mL after albuterol (P < 0.0001). The protective effect of albuterol against methacholine‐induced bronchospasm was 3.7 ± 1.2 doubling doses. We conclude that administration of drugs from a metered dose inhaler through the Babyhaler® with a face mask is effective. Albuterol causes a major reduction in the bronchial hyperreactivity in young wheezy children shortly after administration. Pediatr Pulmonol. 1994; 17:281–284. © 1994 Wiley‐Liss, Inc.
Nasal response to inhaled histamine measured by acoustic rhinometry in infants
Authors: Kano Sohei , Pedersen Ole F. , Sly Peter D. 
Published: March 2007

AbstractAerosolized histamine, delivered via a face mask, is commonly used to evaluate bronchial reponsiveness in infants. To investigate nasal response to inhaled histamine we have measured nasal passage geometry in 32 infants by the use of acoustic reflections. Satisfactory data were obtained from only 17 infants (12 males, 5 females, 6.6 ± 4.4 months), because of awakening prior to completing the study in the remaining 15 infants. Acoustic rhinometry provided nasal cavity volume at 4 cm from the entrance of the nostril (VO4), the minimum cross‐sectional area (Amin), and the distance from the nostril to Amin (Dmin). Nasal geometry and lung function (maximum expiratory functional residual capacity [VmaxFRC] were measured before and immediately after a histamine challenge test using rapid thoratic compression. The histamine aerosols decreased both VO4 and Amin significantly by a mean of 17% and 13%, respectively (P < 0.001). There was a small, but significant increase (mean = 0.19 cm) of Dmin in the right side only, indicating a posterior dislocation of the narrowest site with swelling of the mucous membrane. In general, we found a dose‐response relationship in grouped data, with a greater fall in VO4 with increasing dose of histamine, but there was no correlation between percent fall in VO4 and VmaxFRC. This pilot study suggests that histamine aerosol affects nasal cavity geometry and that of acoustic rhinometry in infants and children warrants further investigation. Pediatr Pulmonol. 1994; 17:312–319. © 1994 Wiley‐Liss, Inc.
Relationship between atopy and frequent bronchial response to exercise in school children
Authors: Frischer T. , Meinert R. , Karmaus W. , Urbanek R. , Kuehr J. 
Published: March 2007

AbstractThe natural history of a bronchial response to exercise (BRE) was studied in a cohort of primary‐school children, who were followed over a 2‐year period. In 1,094 children, three free‐running tests were performed in 1 ‐year intervals. Children who responded in one of the tests were designated as “infrequent” responders (20.5%), whereas those responding at two or all three occasions were designated as “frequent” responders (7.4%). A frequent positive BRE was closely associated with atopy (defined as skin test positivity to 1 of 7 common aeroallergens) and respiratory symptom status. Compared to atopics without respiratory symptoms, an increased risk for a frequent positive BRE was seen for atopic children who were symptomatic during the whole study period [odds ratio (OR) 25.4; confidence interval (CI) 6.9–94.01, who had gained symptoms (OR, 11.0; CI, 2.8–43.2) or who had symptoms at the beginning of the study but had lost them during follow‐up (OR, 4.6; CI, 1.0–20.6). A sensitization to dust mites (OR, 8.0; CI, 4.3–15.0) but not to animal dander (OR, 2.3; CI, 1.0–5.2) or pollen (OR, 0.7; CI, 0.3–1.6) was significantly related to a frequent positive BRE. Our findings support the notion that while “children grow out of asthma,” they might maintain their bronchial hyperresponsiveness. Regarding specific sensitization, mite allergy seems to play the predominant role. Pediatr Pulmonol. 1994; 17:320–325. © 1994 Wiley‐Liss, Inc.
Measurement of chloride concentration in microvolume samples of sweat
Authors: Nathanson Ian , Tucker Marie , Jones Linda 
Published: March 2007

AbstractMeasuring sweat CI concentration requires multiple steps. Following pilocarpine iontophoresis we compared CI concentrations of sweat obtained on gauze pads to microvolumes (5 μL) collected into capillary tubes (N = 111). Chloride concentrations obtained by these two methods correlated significantly (r = 0.95; P < 0.001), indicating that CI concentration can be measured accurately and easily on small volumes. Pediatr Pulmonol. 1994; 17:340–342. © 1994 Wiley‐Liss, Inc.
Functional residual capacity and total respiratory system impedance in wheezing infants
Authors: Desager K. N. , van Bever H. P. , Willemen M. , De Backer W. , Vermeire P. A. 
Published: March 2007

AbstractAirways obstruction has been demonstrated in acutely wheezing infants. The aim of the present study was to assess functional abnormalities as detected by measurement of total respiratory system resistance (Rrs) and functional residual capacity (FRC) in infants with a history of recurrent episodes of wheezing, while not acutely ill. In 30 such infants (mean age, 10 months; range, 4–17) and in 10 healthy infants (mean age, 6 months; range, 0–14) four Rrs measurements, performed with the forced pseudo‐random noise (PRN) oscillation technique, and three FRC determinations, using the closed‐circuit helium dilution technique, were averaged. A lower than predicted FRC was demonstrated in 20/30 (66%) patients. At 16 Hz, Rrs was significantly above predicted in 3/30 (10%) patients. Specific Rrs (Rrs × FRC) at 16 Hz was increased in 5/30 (17%) patients. In conclusion, the PRN oscillation technique combined with FRC measurement by helium dilution detects lung function abnormalities in a minority of wheezing infants during symptom‐free intervals. Pediatr Pulmonol. 1994; 17:354–358. © 1994 Wiley‐Liss, Inc.
In vitro suppression of Pseudomonas cepacia after limited exposure to subinhibitory concentrations of amiloride and 5‐(N,N‐hexamethylene) amiloride
Authors: Cohn Robert C. , Rudzienski Lois 
Published: March 2007

AbstractAmiloride (A) for aerosolized therapy in cystic fibrosis (CF) is under investigation. Antipseudomonal properties of A and A analogs in vitro have recently been described. This study was performed to determine if there was suppression of P. cepacia growth after a limited 2‐hour exposure to (subinhibitory) concentrations of A ± tobramycin (T) or to the analog 5‐(N,N‐hexamethylene) amiloride (HMA) in vitro. The MIC of each drug against five different P. cepacia strains was determined. Cells were prepared in Mueller Hinton broth to [106] colony forming units (CFU)/mL and incubated at 35°C for 2 hours in the presence and absence of subinhibitory A, HMA, T, or A + T. The CFU were measured before and at 1 ‐hour intervals after dilutional removal of drug. The post‐antibiotic effect (PAE) was defined as the time (in minutes) required for the test culture counts to increase 10‐fold minus the time required for control counts to increase 10‐fold. At 400 μ/mL or 200 μ/mL, the PAE for A against five different strains was 139 ± 23 and 83 f 24 (mean 5 SD) minutes, respectively. For 100 μ/mL and 50 μ/mL HMA, the PAE was 122 ± 38 and 65 f 25 minutes. For T and A + T (200 μ/mL + 32 μ/mL) the PAE was 168 ± 30 and 258 ± 30 minutes. We conclude that A and the analog HMA in (subinhibitory) concentrations have a suppressive effect on P. cepacia after drug removal and potentiate the effect of T in vitro. Pediatr Pulmonol. 1994; 17:149–154. © 1994 Wiley‐Liss, Inc.
Management of severe congenital tracheobronchomalacia by continuous positive airway pressure and tidal breathing flow‐volume loop analysis
Authors: Reiterer Fritz , Eber Ernst , Zach Maximilian S. , Müller Wilhelm 
Published: March 2007

AbstractWe report on a now 9‐month‐old infant with severe tracheobronchomalacia associated with campomelic dysplasia. The diagnosis of tracheobronchomalacia was suggested in the neonatal period by typical changes of the tidal breathing flow‐volume loop and was confirmed by tracheobronchoscopy. Tidal breathing flow‐volume loop analysis also allowed to titrate the optimal, continuous positive airway pressure for the respiratory management of the patient. Since bedside pulmonary function testing is noninvasive and rapid, it may reduce the need for frequent bronchoscopic evaluations in the management of patients with tracheobronchomalacia. Pediatr Pulmonol. 1994; 17:401–403. © 1994 Wiley‐Liss, Inc.
Inadvertent removal of foreign body via a flexible fiberoptic bronchoscope in a 4‐year‐old boy
Authors: Akhter Javeed , Gaspar Michele , Bassuk Angel , Roberts Jack 
Published: March 2007

AbstractWe report the case of a 4‐year‐old child with an atypical presentation of an aspirated unwitnessed foreign body in the airway. During an attempt to obtain a biopsy of what appeared to be a mucosal growth, the foreign body was removed. This may be the first report of foreign body removal in a child this young, using a flexible fiberoptic bronchoscope. Pediatr Pulmonol. 1994; 18:51–52. © 1994 Wiley‐Liss. Inc.
Unilateral cervical spinal cord lesion in a term newborn, associated with ipsilateral diaphragmatic atrophy and pulmonary hypoplasia
Authors: Rotschild Avi , Ling Emily W. Y. , Wensley David F. , Norman Margaret G. , Thurlbeck William M. 
Published: March 2007

AbstractTwo major factors can interfere with normal development of the fetal lungs: mechanical constriction resulting in decreased intrathoracic space and reduced or absent fetal breathing movements. We report a unique case in which both factors contribute to the development of lethal pulmonary hypoplasia. This full‐term neonate had an isolated unilateral lesion in the cervical spinal cord resulting in ipsilateral neurogenic atrophy of the diaphragm, bilateral pulmonary hypoplasia, and lung immaturity. Evenetration of the atrophied diaphragm decreased intrathoracic space, compromising fetal lung growth. This was compounded by impaired fetal respiration due to the diaphragmatic atrophy, further aggravating pulmonary hypoplasia on the affected side. The other lung was also hypoplastic, although to a lesser degree, suggesting that its growth was also affected by either or both of these factors. Pediatr Pulmonol. 1994; 18:53–57. © 1994 Wiley‐Liss. Inc.
Brain cell membrane modification following hypercapnia and recovery in newborn piglets
Authors: Schneiderman Roy , Kubin Joanna , Mishra Om Prakash , Delivoria‐Papadopoulos Maria 
Published: March 2007

AbstractThe effect of hypercapnia on brain cell membrane structure and function was studied in anesthetized newborn piglets. Lipid peroxidation products (conjugated dienes and fluorescent compounds), Na+,K+‐ATPase activity and enzyme affinity to ATP (substrate), K+ and Na+ ions (activators), and strophanthidin (inhibitor) were measured in three groups of animals: controls, those exposed to 90 minutes of Paco2 > 80 mmHg (hypercapnia) and those exposed the same way, following restoration of normal Paco2, (recovery). Enzyme activity was unchanged by hypercapnia, but enzyme affinity was altered as indicated by an increase in ATP affinity. Affinities to Na+, K+, and strophanthidin were unchanged. Restoration of normal Paco2 resulted in an increase in conjugated dienes. The data demonstrate that hypercapnia followed by restoration of normal Paco2 in healthy term newborn piglets is associated with mild modification of brain cell membrane Na+, K+‐ATPase, possibly due to lipid peroxidation.Pediatr Pulmonal. 1994;18:81–88. © 1994 Wiley‐Liss, Inc.