bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cardiopulmonary function of cats with respiratory distress induced by n‐nitroso n‐methylurethane
Authors: Richardson Peter , Bose Carl L. , Dayton Vanessa , Carlstrom Jeffrey R. 
Published: March 2007

AbstractThe purposes of this study were to determine (1) the effects of positive end‐expiratory pressure (PEEP) and end‐expiratory lung volume on systemic blood flow, (2) whether PEEP levels yielding maximum systemic oxygen transport are associated with maximum lung compliance, and (3) the effects of end‐expiratory lung volume on pulmonary resistance to gas flow, in an animal model of respiratory distress. Twelve cats were inoculated with 12 mg/kg N‐Nitroso N‐Methylurethane (NNNMU) to induce respiratory distress. The NNNMU caused a 76% decrease in disaturated phosphatidyl‐choline of lung lavage, a 34% decrease in functional residual capacity (FRC), an 80% decrease in lung compliance, an 88% increase in pulmonary resistance to gas flow, a 43% decrease in PaO2, and a 37% decrease in oxygen consumption. Systemic blood flow and systemic oxygen transport were not significantly altered by the chemically induced respiratory distress. PEEP levels of 5.1 ± 0.8 cm H2O returned end‐expiratory lung volume to normal FRC levels. Increases in PEEP caused systemic blood flow to decrease even when end‐expiratory lung volume was below or equal to normal FRC levels but did not significantly affect systemic oxygen transport, lung compliance, or pulmonary resistance. We conclude that in cats with NNNMU‐induced respiratory distress: (1) PEEP causes decreases in systemic blood flow, (2) lung compliance and systemic oxygen transport are not clear indicators of optimal PEEP level, and (3) returning end‐expiratory lung volume to normal FRC does not significantly reduce pulmonary resistance to gas flow.
Urokinase therapy for a catheter‐related right atrial thrombus and pulmonary embolism in a 2‐month‐old infant
Authors: Zureikat George Y. , Martin Gerald R. , Silverman Norman H. , Newth Christopher J. L. 
Published: March 2007

AbstractThrombolytic therapy seems to be effective in clearins catheter‐related thrombi, allowing subsequent reuse of the Broviac catheter. We have confirmed the previously theoretical risk that thrombolytic therapy in such cases may create pulmonary emboli, but such therapy (in our very limited experience) dissolves the clot extremely quickly. This latter observation may mean that thrombolytic therapy is particularly useful for pulmonary emboli in infants and young children.
Vascular ring: Clinical and physiological assessment of pulmonary function following surgical correction
Authors: Bertrand Jean‐Marie , Chartrand Claude , Lamarre André , Lapierre Jean‐Guy 
Published: March 2007

AbstractTwelve children were evaluated 7.1 years (mean) after surgical repair of a vascular ring causing tracheal compression. Nine patients complained of persistent respiratory symptoms, mostly cough, dyspnea, and/or wheezing. Functional evaluation revealed abnormal spirometry and/or lung volumes in seven subjects. Analysis of maximal expiratory‐inspiratory flow‐volume loops suggested the presence of residual upper airway obstruction in three patients and peripheral airway obstruction in three others. Eleven patients demonstrated bronchial hyperreactivity to histamine.
Partitioning the respiratory effects of airway citric acid and normal saline in lambs
Authors: Hutchison Alastair A. , Caton Donald , Thomas Ronald G. , Bucciarelli Richard L. 
Published: March 2007

AbstractAspiration is common in the intubated human neonate. Thus, the ventilatory and blood gas responses to citric acid and saline instillation into different airway sites were studied in ten awake, unanesthetised lambs, breathing spontaneously via a tracheostomy tube. With a system of balloons, 1 ml of saline or citric acid was placed selectively into the midtrachea, the laryngeal area, or the lower trachea (lower tr). Changes in minute ventilation (V̇E), after a 30 sec baseline period, were measured 30 sec and 1 and 2 min after the challenge. Arterial blood gas changes were measured at 30 sec and 2 min. Major increases in V̇E were seen only when saline or citric acid was instilled into the lower tr, the citric acid responses exceeding saline ones. The arterial oxygen tension (PaO2) fell after lower tr saline, whereas the arterial CO2 tension (Pa) fell with midtracheal saline instillation. A rise in pH and a fall in Pa accompanied citric acid given into the lower tr. An initial rise in PaO2 after citric acid into the lower tr was followed by a return to baseline despite hyperventilation. The ventilatory and blood gas changes with saline and citric acid depend on the site of airway instillation. Pediatr Pulmonol 1987; 3:45–50.
Maximal static pressures and lung volumes in young female swimmers: One year follow‐up
Authors: Zinman Raezelle , Gaultier Claude 
Published: March 2007

AbstractThe relationship between the growth of lung volumes and the development of maximal static pressures was examined in a 1 year follow‐up study of 17 female swimmers, initially less than 12 years of age. Lung volumes were measured by body plethysmography, and maximal static inspiratory and expiratory pressures were generated near residual volume, at functional residual capacity and near total lung capacity (TLC). The results were compared to the regressions obtained from cross‐sectional data generated on 59 girls randomly selected from a local school. Height was similar in swimmers and controls. Vital capacity and total lung capacity increased during the year to exceed normal limits in 11 of 17 swimmers. The only significant increase of maximal static pressures during 1 year occurred in expiration near TLC in those swimmers initially less than 10 years of age, and all pressures fell within normal limits. We conclude that large lung volumes in swimmers cannot be accounted for by an increased ability to inflate and deflate the lung by the respiratory muscles.
Compliance of the total respiratory system in healthy preterm and full‐term newborns
Authors: Migdal M. , Dreizzen E. , Praud J. P. , Vial M. , Dehan M. , Chambille B. , Gaultier C. I. 
Published: March 2007

AbstractThe compliance of the total respiratory system (CRS) was determined by the occlusion technique during expiration in 19 preterm newborns (NB) over 31 weeks of gestational age (mean, 34 ± 1.5 SD) and in 20 full‐term NB. Postnatal age ranged from 1 to 28 days. No sedation was used during the test. In absolute terms, CRS was significantly greater (P < 0.01) in full‐term than in preterm NB (3.17 ± 0.71 ml/cm H2O vs 2.37 ± 0.81 ml/cm H2O). When normalized for body weight, length, body surface area, and the Quetelet index (body weight/length), CRS was similar in preterm and full‐term NB. These results suggest that, normalized for biometric data, passive elastic properties of the total respiratory system are similar in full‐term and preterm NB, at least in the gestation age range studied.
Effect of early furosemide administration in neonates with respiratory distress syndrome
Authors: Belik Jaques , Spitzer Alan R. , Clark Bernard J. , Gewitz Michael H. , Fox William W. 
Published: March 2007

AbstractThe effect of early furosemide‐induced diuresis was prospectively evaluated in 39 neonates less than 24 hr of age with clinical respiratory distress syndrome (RDS) who received either four doses of furosemide (1 mg/kg) or no diuretic. Measurements of Fio2 alveolararterial oxygen gradient (P[A‐a]O2), peak inspiratory pressure (PIP), and urine output as a fraction of intake (O/l) were averaged for every 8 hr. The furosemide group overall showed a significant decrease (P < 0.01) in Fio2, P[A‐a]O2, and PIP with an earlier (32 hr vs 52 hr) and more pronounced diuresis (35% greater O/l) when compared to the controls. This effect was accentuated in the subgroup with 1,000–1,500 g birth weight (significantly lower Fio2 and P(A‐a)o2 from 16 to 48 hours), while no increase in urine output was observed for the infants weighing less than 1,000 g. A significant reduction in supplemental oxygen and need for ventilatory support at 96 hr of age was observed in the furosemide‐treated, less than 1,500‐g infants. The incidence of patent ductus arteriosus was not increased following furosemide therapy, and no significant difference in echocardiographic parameters was observed in 21 infants from both groups, who were followed daily during the first week of life. This study suggests that early furosemide‐induced diuresis, particularly in infants weighing 1,000–1,500 g at birth, promotes improvement in pulmonary functions in RDS and leads to faster reduction in oxygen and ventilatory support.
Effect of pulmonary hypertension on lung compliance in newborn lambs
Authors: Caeton A. John , Goetzman Boyd W. , Bennett Stephen H. , Milstein Jay M. 
Published: March 2007

AbstractWe studied the effects of increased pulmonary arterial pressure and vascular resistance on lung compliance in 12 anesthetized newborn lambs. Lung compliance was unaffected by large changes in pulmonary artery pressure and pulmonary vascular resistance (80% increase) that were induced by either hypoxia or acidosis. We conclude that contraction of the pulmonary vascular smooth muscle in normal newborn lambs does not affect the stiffness of the lung in the parenchymal regions undergoing volume change during ventilation. Pediatr Pulmonol 1987; 3:324–327.
Lung growth and maturation in experimental oligohydramnios in the rat
Authors: Blachford Karen G. , Thurlbeck William M. 
Published: March 2007

AbstractOn day 16 of gestation the amniotic sacs of either the right or left uterine horns of timed‐pregnant Sprague‐Dawley rats were punctured with a 20‐gauge needle. The fetuses of the opposite horn served as controls. On day 21 of gestation (1 day prior to natural delivery), the fetuses were delivered by Cesarean section. Amniotic sac puncture resulted in a significant loss of amniotic fluid. Fetal growth retardation occurred. Lung growth was specifically retarded, as indicated by significantly reduced lung weight to body weight ratios and lung volume to body weight ratios following amniotic sac puncture. There appeared to be no effect on the structural units of the lung, since no differences between control and experimental fetal lungs were observed in terms of deoxyribonucleic acid, nonconnective tissue protein, total phospholipid, and disaturated phosphatidylcholine per gm dry lung weight. The ratios of disaturated phosphatidylcholine to total phospholipid and nonconnective tissue protein to deoxyribonucleic acid were unchanged. The volume proportions of saccular air, saccular wall, bronchial and bronchiolar air and nonparenchyma, peripheral airspace size, and surface‐to‐volume ratio were also unchanged. Thus loss of amniotic fluid significantly affected lung growth, more than it affected overall body growth, without having an effect on lung maturation. Pediatr Pulmonol 1987; 3:328–333.
Performance of respirators at fast rates commonly used in neonatal intensive care units
Authors: Greenough Anne , Greenall F. 
Published: March 2007

AbstractThe effect on tidal volume and airway pressure of increasing ventilator rate (30, 60, and 120/min) was tested in six commonly used neonatal ventilators. In all six ventilators increased flow was necessary to maintain mean airway pressure at the higher rates. Tidal volume decreased at rates of both 60 and 120/min in all six ventilators, associated with a change in pressure waveform. The most marked reduction in tidal volume, however, was associated with increased positive end‐expiratory pressure (PEEP). This was only demonstrated in four ventilators, all incorporating nonassisted expiratory valves. These results stress the necessity for appropriately designed ventilators if fast rates are to be used routinely in clinical practice. Pediatr Pulmonol 1987; 3:357–361.
Pulmonary vascular extraction of circulating norepinephrine in infants with bronchopulmonary dysplasia
Authors: Abman Steven H. , Schaffer Michael S. , Wiggins James , Washington Reginald , Manco‐Johnson Marilyn , Wolfe Robert R. 
Published: March 2007

AbstractAlthough the pulmonary circulation in infants with advanced bronchopulmonary dysplasia (BPD) is characterized by abnormal structure and vasoreactivity, metabolic lung functions have not been studied in these infants. To test the hypothesis that patients with severe BPD may have abnormal metabolic lung function, we assessed the pulmonary vascular extraction of circulating norepinephrine in six children with BPD during cardiac catheterization. Plasma norepinephrine levels were measured from simultaneously drawn mixed venous (main pulmonary artery) and left atrium or femoral artery samples. In comparison with four infants with mild heart disease without pulmonary hypertension, we found that infants with BPD extract proportionately less norepinephrine than non‐BPD infants [−7 ± 5% (BPD) versus + 27 ± 6% (non‐BPD); P < 0.001, t test]. Three infants with BPD had higher arterial than mixed venous concentrations of plasma norepinephrine, suggesting net production across the lung. Plasma catecholamine levels and percent extraction correlated poorly with cardiac index and systemic and pulmonary vascular resistance indices. However, this study group was characterized by a high incidence of pulmonary (6/6) and systemic (4/6) hypertension, left ventricular hypertrophy (4/6), and subsequent death (3/6). We conclude that infants with severe BPD and pulmonary hypertension have decreased pulmonary vascular clearance or net production of circulating norepinephrine, but links between altered pulmonary catecholamine metabolism and pulmonary hypertension, or other cardiovascular abnormalities associated with BPD, remain speculative.
Sequential pulmonary function measurements in very low‐birth weight infants during the first week of life
Authors: Anday Endla K. , Godart‐Wlodavar Anne , Delivoria‐Papadopoulos Maria 
Published: March 2007

AbstractSequential lung function was measured in 12 very low‐birth weight infants (≤ 1,250 g) within 14 hours of birth, and at daily intervals thereafter for the first week of life, using an esophageal balloon and pneumotachograph system. All infants were clinicaly free of respiratory distress syndrome and radiographically showed no evidence of atelectasis or pulmonary edema. The alveolar‐arterial oxygen tension gradient was high at birth and remained elevated over the period during which arterial blood gases were monitored. Increases of lung compliance and tidal volume between the first day and the end of the first week of life were not significant. Day‐to‐day determinations of lung compliance revealed an individual and group variability without a definite pattern. Lung resistance measurements indicated no clear trend for the group as a whole, but inspiratory resistance was generally lower than expiratory resistance.Possible causes, in addition to technical factors, that may account for the variability in the pulmonary mechanics of these small infants include an instability of lung volume and uneven distribution of pleural pressure due to chest wall distortion, differences in sleep‐state, and alteration in the distribution of body fluids, resulting in a change in lung water. Any or all of these mechanisms may result in an unstable lung, even in an apparently clinically stable very low‐birth weight infant.
Stimulus parameters for phrenic nerve pacing in infants and children
Authors: Brouillette Robert T. , Ilbawi Michel N. , Klemka‐Walden Linda , Hunt Carl E. 
Published: March 2007

AbstractPhrenic nerve pacing has been used since 1966 to support breathing in quadriplegics and patients with central hypoventilation syndrome (CHS). Recently, using low‐frequency, long‐inspiratory‐time (Ti) stimulation, phrenic nerve pacing has been used successfully to support breathing 24 hours per day in adults and older children. However, no similar experience exists for infants and young children. Therefore, in 27 studies in 14 infants and children we determined the effects of changing Ti and interpulse interval (the inverse of stimulus frequency) on ventilation. Diaphragmatic action potentials, airflow, tidal volume, PACO2 and SaO2 were measured during sleep. Phrenic nerve pacing proved useful in 13 of 14 patients to support breathing either during wakefulness (n = 7) or during sleep (n = 6). We found that adequate ventilation could be achieved at significantly longer interpulse intervals, 95 ± 25 (mean ± SD) ms, and shorter Ti, 580 ± 80 ms, than previously reported. At an average respiratory rate of 21 ± 8 breaths/min it was thus possible to maintain adequate ventilation despite a marked reduction in the number of phrenic nerve stimuli. Theoretically, these reductions in phrenic nerve stimulation should minimize the chance of pacing‐induced diaphragmatic damage. These results suggest that 24 hour per day phrenic nerve pacing may be a realistic goal in selected infants and children.
Relative contribution of ribcage and abdomen during augmented breaths in infants
Authors: Mathew Oommen P. , Pronske Maria L. , Clark Mark L. 
Published: March 2007

AbstractChanges in the relative contribution of ribcage and abdomen during augmented breaths were assessed in two groups of infants (<2 weeks and 4–12 weeks old). In both groups ribcage and abdominal movements increased during augmented breaths in quiet sleep. In the older infants the relative increase was greater for the ribcage (P < 0.05) when expressed either as a ribcage to abdominal movement ratio or as a percent of the respective movements during control breaths. In contrast, no significant change of the relative contribution was observed in the younger age group. During active sleep paradoxical movement of the ribcage, observed during tidal breaths, continued during the first phase of the augmented breath; however, during the second phase of inspiration, the ribcage moved outward in all but one infant. Our results show that marked increases in tidal volume are associated with greater increases in ribcage contribution in infants beyond the neonatal period. This may reflect differences in recruitment patterns of intercostal muscles during development.
Incidence and implications of false‐negative sweat test reports in patients with cystic fibrosis
Authors: Legrys Vicky A. , Wood Robert E. 
Published: March 2007

AbstractIt is well known that false‐positive sweat tests occur commonly, but since a positive test should always be repeated, such an error is likely to be discovered. False‐negative results, however, are more difficult to detect and are generally assumed to be much less frequent than false‐positive results. Diagnostic delay caused by false‐negative reports may lead to substantial morbidity. Review of the medical records of 147 unselected patients with cystic fibrosis followed in our center revealed that 17 (12%) initially had one or more sweat tests that were falsely negative (or were so reported or interpreted). In seven patients, there was diagnostic delay with adverse clinical consequences. Many factors may contribute to the incidence of false‐negative sweat tests, and negative results must not be accepted as definitively excluding cystic fibrosis if the clinical syndrome is otherwise suggestive.
Comparison of piperacillin alone versus piperacillin plus tobramycin for treatment of respiratory infections in children with cystic fibrosis
Authors: McCarty James M. , Tilden Samuel J. , Black Phillip , Craft J. Carl , Blumer Jeffrey , Waring William , Halsey Neal A. 
Published: March 2007

AbstractSeventeen patients with cystic fibrosis (CF) and pulmonary exacerbations were randomly assigned to two treatment groups: piperacillin 600 mg/kg/day (P), and piperacillin 600 mg/kg/day plus tobrarmycin (PT), in order to determine the safety and pharmacokinetics of high‐dose piperacillin and whether piperacillin alone was effective for the treatment of Pseudomonas infections. The mean half‐life of piperacillin was 0.54 hours, with a peak concentration of 232 μg/ml. No differences between P and PT groups were noted in clinical assessment, as judged by Shwachman scores, pulmonary function testing, or weight gain. However, during the course of treatment, quantitative sputum cultures decreased by greater than 102 colony‐forming units in only 5 out of 19 Pseudomonas isolates from the P group, compared with 12 of 19 isolates from the PT group (P < 0.03, Chi‐square). Although emergence of resistance was not seen, one isolate had an increase in minimum inhibitory concentration from 8 to 128 μg/ml. There were no serious adverse reactions to piperacillin; only one patient developed fever possibly related to piperacillin. Therapy with high‐dose piperacillin was safe in children with CF. Treatment with piperacillin alone was less effective than combination therapy with gentamicin for reduction in titer of Pseudomonas in sputum. However, the role of antimicrobial agents in the treatment of CF remains undefined. A double‐blind placebocontrolled trial is indicated.
Use of bronchoalveolar lavage in immunocompromised children with pneumonia
Authors: Pattishall Edward N. , Noyes Blakeslee E. , Orenstein David M. 
Published: March 2007

AbstractBecause pneumonia in the immunocompromised host presents a diagnostic dilemma to the pediatrician, we prospectively studied the use of bronchoalveolar lavage (BAL) with flexible fiberoptic bronchoscopy in 14 immunocompromised children with pneumonia over a 5‐month period. The children received immunosuppressive agents because of organ transplants, cancer, or systemic lupus erythematosus. A diagnosis was made by BAL in 10 (71%) of the 14 children. Pathogenic organisms included Pneumocystis carinii in six, cytomegalovirus (CMV) in two, Aspergillus fumigatus in one, and a mixed infection of Candida albicans and CMV in one. There were no complications. Because BAL by flexible fiber‐optic bronchoscopy is a rapid and safe procedure and a diagnosis can be made in a majority of cases, we recommend its use in immunocompromised children with pneumonia before resorting to lung biopsy.
Tracheomalacia and bronchomalacia associated with larsen syndrome
Authors: Rock Michael J. , Green Christopher G. , Pauli Richard M. , Peters Mary Ellen 
Published: March 2007

AbstractBronchomalacia has not previously been described in association with Larsen syndrome. In this article, three children with Larsen syndrome are reported. All three patients have tracheomalacia, and one of them has diffuse bronchomalacia diagnosed at flexible fiberoptic bronchoscopy. The patients' symptoms of airway obstruction include stridor, cyanosis, apnea, and recurrent pneumonias. Recognition of these abnormalities may allow the institution of supportive therapy.
Absence of long term pulmonary sequelae after mild meconium aspiration syndrome
Authors: Stevens John C. , Eigen Howard , Wysomierski David 
Published: March 2007

AbstractTo assess residual damage from meconium aspiration syndrome (MAS), we studied 12 children, ages 6 to 9 years, an average of 7.4 years after injury. Our sample consisted of mildly affected patients, only one having required intubation and mechanical ventilation in the acute phase of illness. In each child we measured FVC, FEV1, PEFR, MMEFR, VisoV, lung volumes by plethysmography, DLCO and calculated FEV1/FVC and RV/TLC. Methacholine bronchial challenge was performed and the PD20 was calculated. These results were compared with those obtained from a group of 12 normal children studied in our laboratory.No significant difference was found for pulmonary function parameters studied, except for VisoV which was greater in MAS patients than normals (P < 0.02). Given the inherent high degree of variability with VisoV, we were not able to ascribe this isolated finding to be indicative of small airway disease in these asymptomatic patients. We conclude that patients with mild to moderate initial insult from MAS show an absence of pulmonary sequelae when tested at an average of 7.4 years of age.