bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of endotracheal tube size and ventilator settings on the mechanics of a test system during intermittent flow ventilation
Authors: Farstad Teresa , Bratlid Dag
Published: March 2007

The effect of varying the size of standard neonatal endotracheal tubes on delivered tidal volumes (VT), resistance (R), dynamic compliance (Cdyn), and resistive work of breathing (WOB) was measured in a test system during intermittent flow ventilation at different ventilator settings. The experiments were performed with a Sechrist infant ventilator connected to a Dräger Test Lung via standard neonatal endotracheal tubes.

R, inspiratory (Ri), and expiratory resistance (Re) as well as WOB were significantly affected by endotracheal tube size. The calculated difference in Re between endotracheal tubes of 2.5 and 3.5 mm I.D. was 93 cm H2O/L/s (mean value for all studies). Cdyn and VT were also affected by endotracheal tube size. However, although statistically significant differences were found in Cdyn (mean, 0.584 mL/cm H2O and 0.567 mL/cm H2O) and VT (mean, 13.0 mL and 12.7 mL) for the tube sizes 3.5 mm and 2.5 mm I.D., respectively, the absolute numerical differences were small. Also, ventilator settings with respect to the peak inspiratory pressure (PIP) ‐ positive end‐expiratory pressure (PEEP) difference had a significant influence on Cdyn for both tube sizes. On the other hand, flow and inspiratory time adjustments had no significant effect on ventilatory parameters. Endotracheal tube size and ventilator settings should be considered when comparing the pulmonary function tests in intubated and non‐intubated newborn infants. Pediatr Pulmonol. 1991; 11:15‐21.
Asthma in the vicinity of power stations: I. A prevalence study
Authors: Henry Richard L. , Abramson Rachel , Adler Julie A. , Wlodarcyzk John , Hensley Michael J.
Published: March 2007

Respiratory symptoms, atopy, and bronchial reactivity were measured in primary school children living in Lake Munmorah (LM), a coastal town near two power stations, and in Nelson Bay (NB), a coastal town free from any possible major sources of outdoor air pollution. A prevalence survey and longitudinal follow‐up study were performed 1 year apart. In both studies, the prevalence of ever wheezed, current wheezing, breathlessness, wheezing with exercise, diagnosed asthma, and use of drugs for asthma at LM were all approximately double the prevalence at NB (all P values < 0.01). The prevalence of bronchial reactivity was significantly greater at LM than NB (P < 0.01) at the first but not the second survey. By contrast, no significant differences were found between the two areas for skin test atopy or for parental history of allergic disease. Multivariate analysis supported the conclusion from the univariate analysis that there was more wheezing at LM compared to NB at both studies, when adjusted for atopy, smoking in the home, age, and sex. As expected, a positive skin test reaction to house dust mite was the predominant explanatory variable. Asthma was more common in the community near power stations (LM) than in the NB area. The absence of significant differences in skin test atopy and parental history of allergic disease argued against major genetic differences between the two groups. By contrast, the more common reporting of siblings' chest disease and asthma in Lake Munmorah supported an environmental cause.
Effect of airway inertance on linear regression estimates of resistance and compliance in mechanically ventilated infants: A computer model study
Authors: Turner M. J. , Macleod I. M. , Rothberg A. D.
Published: March 2007

Respiratory inertance (I) is usually ignored when resistance (R) and compliance (C) of mechanically ventilated infants are estimated by least squares linear regression. Values of I that have been reported for these patients can cause impedances whose magnitudes approximate respiratory resistance. We show theoretically that if inertance is neglected no error is expected in resistance estimates, but a positive bias in compliance can be, proportional to the inertance, the compliance, and the sinusoidal frequency at which the measurements are made. To determine the errors in parameter estimates when the pressure waveform is non‐sinusoidal, we simulated linear regression based on non‐inertive and inertive models. R, C, and I of the simulated lung were varied over the range expected in an infant intensive care unit. The ventilator was simulated as a critically damped second order system with a square pulse input. The rise time (TR) of the pressure pulse was varied over the range reported in infant ICUs. Simulated measurements confirmed that resistance is correctly estimated if inertance is neglected. Maximum error in compliance estimates (13%) occurred when TR and R were low, and C and I were high. The variation in the error in estimated compliance was consistent with the theory. Coefficients of variation of the parameters, the standard errors, and R2 of the regressions tended to deteriorate with increasing compliance error, but the relationships were not single valued. These statistics may alert investigators to possible bias in compliance caused by neglected inertance, but cannot be used to correct any bias.
Epithelioid hemangioendothelioma of the lung (intravascular bronchioloalveolar tumor) in a young girl
Authors: Rock Michael J. , Kaufman Robert A. , Lobe Thom E , Hensley Samuel D. , Moss Max L.
Published: March 2007

This report describes a 7 year old girl who presented with scoliosis and a small right hemithorax. Findings on spine roentgenographs were pleural thickening on the right and parenchymal densities. Computed tomography of the chest and abdomen revealed multiple pulmonary nodules and two hypervascular lesions within the liver. The diagnosis established by lung biopsy was intravascular bronchioloalveolar tumor (epithelioid hemangioendothelioma of the lung). This is the youngest reported case of this rare tumor.
Undetected apnea and bradycardia in infants
Authors: Graff Michael , Soriano Cecilia , Rovell Kris , Hiatt I. Mark , Hegyi Thomas
Published: March 2007

Despite routine monitoring, a number of prolonged apneic and bradycardic episodes were undetected in a group of infants in the neonatal intensive care unit (NICU). Sixty‐one infants were evaluated by 12‐hour pneumocardiograms at a post‐conceptional age of 35 ± 3 (SD) weeks. Nursing documentation failed to detect 11 infants with prolonged apnea and bradycardia. Three of these infants were not detected in spite of increased awareness following in‐service education. Such a lack of documentation may lead to improper medical management of infants at risk for pathologic apnea and suggests the need for more accurate documentation at the time of discharge.
The effect of lung mechanics on gas transport during high‐frequency oscillation
Authors: Schindler Margrid , Seear Michael
Published: March 2007

With the general aim of obtaining clinically relevant information on the use of high‐frequency oscillation (HFO), we examined the effects of altering oscillatory frequency (f), tidal volume (VT), and mean airway pressure (Paw) on gas exchange in rabbits, both before and after altering the animal's pulmonary mechanics by saline induced lung injury. Twenty‐seven combinations of f (5,8,12 Hz), VT (0.5, 1,2 mL/kg), and Paw (5, 10, 13 cm H2O) were used. Acute pulmonary injury was induced by instilling 10 mL/kg of warm saline into the lung. Gas exchange was assessed by steady‐state levels of arterial oxygen tension (Pa) and carbon dioxide tension (Pa). Arterial Pa was independent of f or VT before or after lung injury; it was independent of Paw before injury but highly dependent on Paw after lavage. The difference was presumably related to lung volume recruitment. Arterial Pa was dependent on f and VT but independent of Paw at any time. The relationship was modeled by the equation Pa ∝ fa · VTb where the exponents a = −0.4 and b = −0.6. Our technique of a standardized saline instillation gave a reproducible and stable model of lung injury. In damaged rabbit lungs the principles of HFO appear to be similar to conventional mechanical ventilation: oxygenation depends on Paw and inspired oxygen concentration, while CO2 removal is determined by f and VT.
Response to tube breathing in preterm infants with apnea
Authors: Upton C. J. , Milner A. D. , Stokes G. M.
Published: March 2007

In order to analyze the effects of maturity and apnea frequency on the respiratory control of preterm infants, we studied their responses to tube breathing using tubes equivalent to two anatomical dead spaces. Ventilation during tube breathing was expressed as a percentage above baseline and compared to an “expected” value calculated from the volume of the added tube. Twenty‐seven preterm infants (median birthweight, 1.14 kg.; and gestational age, 29 weeks) were studied on 86 occasions.

The percentage of “expected” ventilation increased with post‐conceptional age (r = 0.48, slope = 3.12, P < 0.0005), from a mean of 73% at 26 weeks up to 104% at 36 weeks. Using multiple regression analysis, neither postnatal age nor apnea frequency had any effect once allowance had been made for post‐conceptional age. Although the respiratory adaptation of the most immature infants was poor, this study suggests that infants with apnea show no gross deficit in respiratory control, compared to those without apnea.
Bronchoscopy with bronchoalveolar lavage in the evaluation of pulmonary complications of bone marrow transplantation in children
Authors: McCubbin Michael M. , Trigg Michael E. , Hendricker Connie M. , Wagener Jeffrey S.
Published: March 2007

Pulmonary complications are a frequent cause of morbidity and mortality following bone marrow transplantation. We examined the results of flexible bronchoscopy (FB) and bronchoalveolar lavage (BAL) in 27 pediatric bone marrow transplant (BMT) recipients with 29 episodes of pulmonary complications. Bone marrow transplant was performed for a variety of malignancies and hematologic disorders. Median age of BMT was 10.3 years (range, 1.7–17.6 years). Median time of FB following BMT was 60 days (range, 11–1,026 days). Routine cytologic and culture techniques were utilized to detect malignant cells, viruses, fungi, bacteria, and protozoa. Positive results were found in 15 (52%) with cytomegalovirus (CMV), the most common positive finding. In 14 (48%) episodes the results were negative. Fourteen patients had follow‐up autopsy or open lung biopsy (OLB). Based on autopsy/OLB results, there were two false negatives and no false positives, giving a diagnostic sensitvity of 75% and specificity of 100%. There was one possible complication of FB and BAL. Survival of both positive and negative patients was poor, only seven patients being alive 90 days post‐FB with BAL. We conclude that FB with BAL is a safe and accurate procedure for the diagnosis of pulmonary complications of BMT.
Flexible endoscopic intubation of the neonate
Authors: Finer Neil N. , Muzyka David
Published: March 2007

The development of the ultrathin bronchoscope has provided a means of providing flexible endoscopic intubation for the neonate and small infant. We report our experience of 26 such endoscopic intubations in 23 neonates with birth weights form 1,200 to 4,600 g and post‐conceptional ages varying from 31.5 to 60 weeks.

The most common indications for the procedure were dysmorphic airways with variable degrees of micrognathia, acquired airway lesions, and severe degrees of hydrocephalus. With the use of the current 2.2 mm and 2.7 mm diameter instruments, it is now possible to utilize this technique with 2.5 mm endotracheal tubes. There were no failed procedures and no evidence of laryngospasm, the most frequent adverse effect being a transient fall in oxygen saturation. The procedure as practiced by experienced individuals is well tolerated and is an important adjunct for intubation of neonates with dysmorphic upper airways or other disorders that prevent adequate visualization of the larynx.
Sputum cysteinyl‐leukotriene levels correlate with the severity of pulmonary disease in children with cystic fibrosis
Authors: Spencer D. A. , Sampson A. P. , Green C. P. , Costello J. F. , Piper P. J. , Price J. F.
Published: March 2007

Sputum samples from 13 children with cystic fibrosis (CF) were analyzed for leukotrienes (LTs) LTB4, LTC4, LTD4, and LTE4. Distribution of LTB4 appeared to be normal, and of cysteinyl‐LTs log normal. Total cysteinyl‐LT levels, of which on average 75% was LTE4, were nearly 10 times higher than in earlier studies. Log LTE4 and total cysteinyl‐LT levels correlated with the overall severity of pulmonary disease assessed by Chrispin—Norman chest radiograph score (Log LTE4: r = 0.701, r2 = 49.1%, P = 0.008. Log total cysteinyl‐LTs: r = 0.715, r2 = 51.1%, P = 0.006). There was no apparent relationship between LTB4 levels and Chrispin—Norman chest radiograph score, nor between the level of any of the LTs and age or organism cultured from sputum. These findings suggest that the cysteinyl‐LTs may be involved in the pathophysiology of pulmonary disease in CF. Pediatr pulmonol.1992; 12:90–94.
Variability of respiratory system compliance in mechanically ventilated infants
Authors: Muramatsu K. , Yukitake K. , Oda T.
Published: March 2007

We measured respiratory flow, volume by integrated flow, and airway pressure in four mechanically ventilated infants. Compliance of the respiratory system (Crs) was measured by the multiple occlusion method. Airway occlusion and release were achieved by a balloon in an occlusion valve between the endotracheal tube and a pneumotachometer, all connected in series with the respirator circuit. Values of Crs varied greatly due to changes in mean airway pressure (MAP). The Crs increased with the elevation of MAP on some occasions and decreased on others. Values of Crs also varied corresponding to different occlusion pressures for individual levels of MAP. Thus Crs changed continuously, even within a single respiratory cycle. The observed variability in Crs was explained by the following mechanism: a pressure‐volume (P‐V) loop of tidal ventilation moves its position within the pressure‐volume diagram and changes shape due to variations of the ventilator settings. In some infants the lungs were ventilated in the range of the linear portion of the P‐V diagram while in others they may have been ventilated on the flattened portion. Some patients had convex expiratory P‐V curves even with low pressure swings during tidal ventilation.
Respiratory mechanics in mechanically ventilated newborns: A comparison between passive inflation and occlusion methods
Authors: Storme L. , Riou Y. , Leclerc F. , Kacet N. , Dubos J. P. , Gremillet C. , Rousseau S. , Lequien P.
Published: March 2007

A passive inflation method was described for measuring total respiratory elastance and resistance during mechanical ventilation in adult patients (Rossi et al., J Appl Physiol 58:1849, 1985). We applied this method to preterm and full‐term mechanically ventilated newborn infants and we compared the results with those obtained by the occlusion method. We performed 37 tests in 16 newborn infants (B.W. 880–4,500 g; G.A. 28–42 weeks), between 1 and 45 days of postnatal age, ventilated with a Servo Ventilator 900C, set in controlled‐volume mode. Flow was measured through a pneumotachograph inserted between the endotracheal tube (ETT) and the breathing circuit, tidal volume by integration of flow and airway pressure directly at the airway opening. Flow, volume, and pressure were recorded on an X/Y plotter to obtain pressure‐volume (P/V), flow‐volume (V/V) loops, and pressure‐time curves. Occlusion was performed by using the end‐inspiratory and the end‐expiratory pause buttons of the ventilator. Analysis of P/V and V/V loops provided respiratory system compliance (Crs, infl.), resistance (Rrs, infl.), and “intrinsic positive end‐expiratory pressure” (PEEPi, infl.). These values were compared with Crs, occl., Rrs, occl., and PEEPi, occl. measured by the occlusion method. The measurements were well correlated (Crs, infl./Crs, occl.: r = 0.90; Rrs, infl./Rrs, occl.: r = 0.91; PEEPi, infl./PEEPi, occl.: r = 0.91). Rrs, infl./Rrs, occl. and PEEPi, infl./PEEPi, occl. did not differ significantly. However, Crs, occl. was 15% higher than Crs, infl. (P < 0.01). The passive inflation method is simple to use and well tolerated in preterm and full‐term ventilated newborn infants, it provides accurate results, and can be a good alternative to occlusion methods. It requires, however, a constant inflation flow and adaptation to the ventilator.
Bronchoalveolar lavage fluid cytology reflects airway inflammation in beagle puppies with acute bronchiolitis
Authors: Dambro Nancy N. , Grad Roni , Witten Mark L. , Quan Stuart F. , Sobonya Richard E. , George Ray C. , Devine Linda , Lemen Richard J.
Published: March 2007

Beagle puppies infected with both canine parainfluenza virus type 2 (CPI2) and Bordetella bronchiseptica (Bb) develop more severe acute bronchiolitis and airways hyperresponsiveness than do those infected with CPI2 or Bb alone. The aim of our study was to characterize the inflammatory response associated with airway hyperresponsiveness, and to determine whether the inflammatory cell response of bronchoalveolar lavage fluid (BALF) reflected changes in the bronchioles in this model. We investigated 25 beagle puppies (ages 76 ± 5 days, mean ± SEM) in four groups: controls (n = 6), or puppies inoculated with both CPI2 and Bb (CPI2‐Bb) (n = 11), with only CPI2 (n = 4), or only Bb (n = 4). The puppies were killed 3–4 days after inoculation, the lungs excised, the intermediate lobe lavaged, and BALF and the bronchiolar wall tissue examined for neutrophils and other inflammatory cells. Control puppies had no evidence of inflammation. However, the CPI2‐Bb puppies had developed cough and rhinitis, positive cultures for CPI2 and Bb, and a neutrophilic cellular response in both the bronchioles and the BALF. Puppies inoculated with only CPI2 or Bb had milder illnesses and no significant bronchiolar and BALF neutrophilic response. For all groups, the severity of bronchiolar wall inflammation correlated with the total number of BALF inflammatory cells, and bronchiolar wall neutrophil counts correlated with the percentage of neutrophils in the BALF. The illness and the airway hyperresponsiveness observed in the CPI2‐Bb group were associated with airway neutrophilia. Our studies support the hypothesis that neutrophils are associated with airway dysfunction in this model, and the use of BALF to study the process.
New peripherally inserted midline catheter: A better alternative for intravenous antibiotic therapy in patients with cystic fibrosis
Authors: Harwood Ivan R. , Greene Linda M. , Kozakowski‐Koch Jo Ann , Rasor Julia S.
Published: March 2007

A study was performed on outpatients with cystic fibrosis (CF) to evaluate the performance of an over‐the‐needle peripherally inserted midline catheter for the delivery of 2‐week courses of antibiotic therapy. The midline is a 7‐inch catheter inserted in the antecubital region with the tip located in the axillary region. It is made of a newly developed biomaterial that softens and expands upon contact with body fluids. The hypotheses for the study were that the midline catheter: 1) is useful for intermediate‐length therapies; 2) can prevent multiple 3‐day conventional peripheral catheter restarts; 3) can prevent or delay the use of more invasive central devices; 4) is comfortable for patients; and 5) is economical. A total of 41 midlines were inserted in 27 patients with an average age and weight of 22 years and 109 pounds, respectively. Prior to this study implanted ports and primarily conventional short peripheral catheters were used to administer I.V. therapy to these patients; fifty percent of these short peripheral catheters failed within 2.6 days. At 2 weeks of dwell, 80% of the midline catheters placed in these patients were still indwelling. Also, 80% of all midline catheter removals were for non‐catheter‐related reasons. There were no cases of midline catheter phlebitis. In contrast, the phlebitis rates published for peripherally inserted central catheters (PICCs) and conventional short peripheral catheters at 7 days of dwell are 20% and >51% respectively. The midline catheters were comfortable and well liked by most patients and became more economical than conventional peripheral catheters for therapies lasting approximately 6 days through 1 to 2 months. These data indicate that the low complication rate and the cost savings of the midline catheter make it a better alternative than conventional peripheral catheters or central devices for most I.V. antibiotic therapies lasting for 1 week or longer in patients with CF.
Allergic alveolitis in a 12‐year‐old boy: Treatment with budesonide nebulizing solution
Authors: Carlsen Kai‐håkon , Leegaard Jens , Lund Odd Due , Skjærvik Håvard
Published: March 2007

Allergic alveolitis due to bird antigens was diagnosed in a 12‐year‐old boy. He suffered from cough, dyspnea, easy fatigue, anorexia, and severe weight loss. The diagnosis was verified by a gradual improvement when he was removed from the birds, exacerbation upon re‐exposure, and the demonstration of serum precipitating antibodies against bird antigens. The patient recovered completely after a short course of oral prednisolone, treatment with inhaled nebulized budesonide for 3 months, and removal of the birds from his home.
Comparison of nap and overnight polysomnography in children
Authors: Marcus Carole L. , Keens Thomas G. , Ward Sally L. Davidson
Published: March 2007

Overnight polysomnography is the “gold standard” for diagnosing sleep‐disordered breathing. However, the limited number of resources for pediatric polysomnography make the availability of a screening test for sleep‐disordered breathing highly desirable. Therefore, we compared 1 hour daytime nap polysomnography to overnight polysomnography in 40 children [mean age, 5.4 ± 0.8 (SE) years] with sleep‐disordered breathing; 76% of children were sedated with chloral hydrate for nap polysomnography; none was sedated for overnight polysomnography. Studies were done 26 ± 4 days apart. Chest wall motion, ECG, end‐tidal PCO2 (PETCO2), arterial oxygen saturation (Sa), and electrooculogram were monitored. Nap studies had a sensitivity of 74%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 17% in predicting sleep‐disordered breathing. Significantly more children had obstructive apnea and desaturation (Sa < 90%) during overnight polysomnography. The peak PETCO2 and the Sa nadir were significantly worse during overnight polysomnography. However, the percentage of time during which abnormalities were manifested did not differ between nap and overnight polysomnography. Despite the use of sedation, nap polysomnography underestimated sleep‐disordered breathing. We conclude that sleep‐disordered breathing detected by nap polysomnography is always confirmed by overnight polysomnography and speculate that nap polysomnography may be an effective screening method for sleep‐disordered breathing. However, overnight polysomnography should be performed if nap polysomnography is inconclusive. Chloral hydrate may be used effectively to facilitate sleep for nap polysomnography in children. © 1992 Wiley‐Liss, Inc.
Efficacy of salbutamol and ipratropium bromide in decreasing bronchial hyperreactivity in children with cystic fibrosis
Authors: Avital Avi , Sanchez Ignacio , Chernick Victor
Published: March 2007

A proportion of patients with cystic fibrosis (CF) suffer from increased airway hyperreactivity but their response to bronchodilators is variable. Adrenergic agents may produce an increase, no change or a decrease in forced expiratory volume in 1 second (FEV1). We hypothesized that the variable response might be related to poor aerosol distribution caused by the presence of secretions. Therefore, in 11 children with CF and airway hyperreactivity the influence of pretreatment with either 0.9% saline, salbutamol, or ipratropium bromide on the methacholine challenge test was evaluated in a double‐blind, randomized, cross‐over study. FEV1 (mean ± S.E.) did not change following pretreatment with saline, salbutamol, or ipratropium (1.64 ± 0.22, 1.63 ± 0.16 and 1.67 ± 0.19, respectively). All patients demonstrated airway hyperreactivity with a PC20 below 8 mg/mL (geometric mean, 0.41 mg/mL) after saline pretreatment. Salbutamol inhalation significantly increased the PC20 to 1.24 mg/mL (P < 0.01), but ipratropium bromide was found to be even more effective than salbutamol (PC20 = 7.37 mg/mL) (P < 0.0001). We conclude that the variable response to bronchodilator is not secondary to impaired aerosol distribution since ipratropium bromide effectively blocked the response to methacholine. The improvement in PC20 without a change in baseline FEV1 following salbutamol suggests that the adrenergic agent altered the contractile mechanism of smooth muscle. © 1992 Wiley‐Liss, Inc.
Cardiopulmonary response to exercise in anorexia nervosa
Authors: Lands Larry , Pavilanis Alan , Charge Thomas D. , Coates Allan L.
Published: March 2007

Malnutrition is associated with a number of systemic diseases that are often accompanied by severe exercise limitation. Anorexia nervosa (AN) is a disease characterized by malnutrition due to psychological factors rather than systemic disease. Diminished exercise capacity in AN has been attributed to a loss of muscle mass, dysfunction of remaining muscle, and impaired cardiovascular responses. In order to evaluate the role of malnutrition in the cardiopulmonary response to exercise, nine adolescent girls with AN were evaluated during progressive and steady‐state exercise testing using a cycle ergometer. Nutritional status was assessed by body mass percentile (BMP) and percent ideal weight (PIWT). Cardiac output was measured by the indirect (CO2 rebreathing) Fick method. Maximum work capacity (Wmax) was expressed as a percent of predicted for sex and height, and cardiac output as a percent of predicted for oxygen consumption. To ensure that the laboratory values were comparable to the predicted values, a control group consisting of ten adolescents was studied concurrently. Wmax was below the 95% confidence interval in six of nine of the AN group (mean ± SD; 70 ± 22% predicted), whereas two of ten controls were below and one above this interval (112 ± 37%). Wmax correlated with nutritional status (BMP: r = 0.75; P < 0.001; PIWT: r = 0.8, P < 0.001). Ventilatory responses for CO2 production at steady state and for Wmax were appropriate in both groups. Cardiac output was appropriate in both the controls (103 ± 12%) and the AN group (104 ± 14%). This was accomplished in the AN group with a relatively low stroke volume (86 ± 19%) and high heart rate (107 ± 13%), both expressed as percent predicted for sex and work. With appropriate cardiac and ventilatory responses, exercise capacity in AN appears to be limited primarily by diminished muscle mass and/or dysfunction of the existing muscle. © 1992 Wiley‐Liss, Inc.
Snoring in French preschool children
Authors: Teculescu Dan B. , Caillier Isabella , Perrin Philippe , Rebstock Eve , Rauch Anne
Published: March 2007

The prevalence of habitual snoring and its associations with respiratory symptoms, personal and familial risk factors, ear, nose, and throat (ENT) abnormalities, and its influence on ventilatory function were studied in a sample of 190 children aged 5 to 6 years from nine kindergartens in Nancy (northeastern France). Nineteen (10%; 95% Cl 5.7–14.3%) of the children were habitual snorers; the prevalence was the same in boys and girls. In univariate analysis habitual snoring was significantly associated with a personal history of exercise‐induced bron‐chospasm [relative risk (RR) 4.50]; a history of adenotonsillectomy (RR, 2.56); a personal history of allergy (RR, 2.83); a sibling history of atopy (RR, 2.39); and doctor‐assessed tonsillar hypertrophy (RR, 2.51). These factors were entered into a logistic regression model that retained as independent determinants exercise‐induced asthma, personal history of allergy, sibling history of allergy, and tonsillar hypertrophy. The height‐adjusted peak expiratory flow rate was slightly, non‐significantly lower in habitual snorers as compared to non‐snorers (2.01 ± 0.32 vs 2.10 ± 0.38 L/s/m2). Due to the limited numbers in the sample, the increased risk for paternal (RR, 1.8) and maternal (RR, 1.6) smoking at home remained nonsignificant. © 1992 Wiley‐Liss, Inc.
Early treatment of respiratory distress syndrome with bovine surfactant in very preterm infants: A multicenter controlled clinical trial
Authors: Gortner L. , Bartmann P. , Pohlandt F. , Bernsau U. , Porz F. , Hellwege H. H. , Seitz R. C. , Hieronimi G. , Bremer C. , Jorch G. , Hentschel R. , Reiter H. L. , Wolf H. , Ball F.
Published: March 2007

To determine the effect of bovine surfactant (SF‐RI 1, Alveofact) administered during the first hour following birth to very premature infants [gestational age (GA). 25‐30 weeks] in a multicenter, controlled trial. Hypothesis: Survival without bronchopulmonary dysplasia (BPD; definition: ventilator dependency or FiO2 > 0.3 during spontaneous respiration) at day 28 is increased in surfactant‐treated infants (sequential analysis). Patients and methods: Thirty‐four infants [GA 28.0 ± 1.5 SD weeks, birth weight (BW), 1,048 ± 299 g] received 50 mg/kg BW surfactant, whereas 35 infants (GA, 27.6 ± 1.5 weeks, BW 969 ± 269 g) served as controls. Retreatment with surfactant (up to three identical doses) 12‐24 hours after the previous dose was permitted if FiO2 was > 0.5. Results: Survival without BPD was significantly higher in surfactant treated infants (26/34) compared to controls (14/35; P=0.003). but in the incidence of pulmonary air leaks, patent ductus arteriosus, intracranial hemorrhage, and nosocomial infections they were not different. Conclusion: Bovine surfactant treatment improves survival without BPD in very premature infants at risk for neonatal respiratory distress syndrome (RDS). © 1992 Wiley‐Liss, Inc.
Transcutaneous blood gas monitoring during salbutamol inhalations in young children with acute asthmatic symptoms
Authors: Holmgren D. , Bjure J. , Engström I. , Sixt R. , Sten G. , Wennergren G.
Published: March 2007

The effect of salbutamol inhalations on transcutaneous blood gases was investigated in 23 children (aged 11 months‐2.5 years) with asthmatic symptoms. After one salbutamol inhalation there was a mean increase in transcutaneous Po2 (tcP) of 0.5 kPa (P < 0.01); after a second dose given 30 minutes later, the mean increase was 1.2 kPa (P < 0.001). The increase in tcP, after only one dose of salbutamol was significantly correlated to age (P < 0.01). No such correlation was observed after a second dose. The overall increase in tcP after two salbutamol inhalations showed a negative correlation to the duration of the current symptomatic period (P < 0.05). We conclude that salbutamol inhalations have beneficial effects in young children with acute asthmatic symptoms, even below the age of 18 months, provided that an adequate dose reaches the lung and preferably at an early stage of obstruction. © 1992 Wiley‐Liss, Inc.
Transcutaneous and arterial blood gas monitoring during acute asthmatic symptoms in older children
Authors: Holmgren D. , Sixt R.
Published: March 2007

The relationship between transcutaneous and arterial blood gases was investigated in 14 children with asthmatic symptoms, aged 7–15 years, before and after the inhalation of salbutamol. The degree of bronchial obstruction was assessed by forced expiratory volume in one second (FEV1) and maximum expiratory flow when 25% of FVC remained to be expelled (MEF25). On average the transcutaneous Po2 (tcPo2,) was 1.3 kPa (range, 2.6–0 kPa) lower and the transcutaneous Pco2 was 0.6 kPa (range, 0–1.5 kPa) higher than the corresponding arterial values (P < 0.01). The difference between arterial and transcutaneous Po2, was the same over the whole range of values studied (7.5–14 kPa). After the inhalation of salbutamol, the relationship between transcutaneous and arterial blood gases was not significantly changed. Changes in transcutaneous Po2 correlated to changes in MEF25 (P < 0.05). indicating a common denominator, probably the conditions in the peripheral airways.

We conclude that the close relationship between transcutaneous and arterial blood gases, even after the inhalation of a beta‐2 agonist, indicates that the transcutaneous technique can be used for monitoring acute bronchial obstruction and for evaluating the effects of treatment in children of different ages. © 1992 Wiley‐Liss, Inc.
Intratracheal administration of pulmonary vasodilator agents
Authors: D'Angeli Marisa A. , Goetzman Boyd W.
Published: March 2007

We compared intravenous and intratracheal administration of histamine (0.4 and 1.6 kg/kg, respectively) and nitroglycerin (5.0 and 20.0 μg/kg, respectively) in seven hypoxemic 2 week old lambs, during right lung only perfusion, to see if intratracheal administration could limit their vasodilator action to the pulmonary vessels. The hemodynamic variables: pulmonary artery pressure (Ppa), left atrial pressure (Pla), pulmonary blood flow per kilogram (Q/kg), and aortic pressure (Pao) were measured at baseline and in each experimental state, then pulmonary vascular resistance (PVR) and systemic vascular input resistance (SVR) were determined. We found that intravenous histamine showed some pulmonary vasodilator selectivity in that it caused a 19% decrease of Ppa from baseline (P < 0.002), a 23% decrease of PVR from baseline (P < 0.002). and an 8% decrease of SVR from baseline (P < 0.05). Intratracheal histamine produced smaller effects, decreasing Ppa by 11% from baseline (P < 0.02), and PVR by 14% from baseline (P < 0.02), while SVR was unaffected. Intravenous nitroglycerin decreased cardiac output by 16% from baseline (P < 0.02), and also decreased SVR by 8% while producing a small increase in PVR. Intratracheal nitroglycerin caused a similar 17% (P < 0.01) decrease in cardiac output, and again an increased PVR but a decreased SVR. This study confirms that histamine has some intrinsic pulmonary vasodilator selectivity. Furthermore, the data suggest that intratracheal administration may accentuate pulmonary selectivity by lessening systemic effects. Nitroglycerin, on the other hand, had untoward hemodynamic effects in the presence of hypoxia. © 1992 Wiley‐Liss, Inc.
Adaptive control of inspired oxygen delivery to the neonate
Authors: Bhutani Vinod K. , Taube John C. , Antunes Michael J. , Delivoria‐Papadopoulos Maria
Published: March 2007

Adaptive adjustment of inspired oxygen (Fio2), based on a desired percent arterial hemoglobin saturation (S02) was achieved by on‐line bedside control of the oxygen concentration delivered to the neonate. Fourteen infants with bronchopulmonary dysplasia (BW, 860 ± 80 g; GA, 26 ± 1 weeks; study age, 41 ± 8 days) receiving oxygen‐air mixtures by hood were studied. The desired range of S, from 92 to 96% with a target value of 95% was determined by pulse oximetry and maintained with adjustment of Fio2 using three modes: (1) standard neonatal intensive care protocol with oxygen delivery evaluated at 20 minute intervals; (2) bedside manual control with Fio2 manipulation every 2 to 5 minutes; and (3) adaptive control with on‐line adjustment of Fio2 according to a specifically designed adaptive program. Each study period was of 40 minute duration. So2, values within a steady 94 to 96% range was achieved for 54010 of the time with standard protocol, compared to 69% (P < 0.01) with bedside manual control and 81% (P < 0.01) with adaptive control. In addition, fluctuations in So2, values and overshoots were less apparent with adaptive control of oxygen delivery. These data describe adaptive Fio2, control as an efficient alternative technique for achieving a stable desired range of oxygenation in neonates. © 1992 Wiley‐Liss, Inc.
Evaluation of the Oxford and Sheffield SIDS risk prediction scores
Authors: Brooks John G. , Fleming Peter J. , Berry Peter J. , Golding Jean
Published: March 2007

Study objective:To evaluate the clinical usefulness (sensitivity and specificity) of the Oxford and Sheffield birth scores for prospective identification of infants at high risk of SIDS.

Design:Retrospective medical record reviews of prospectively identified, autopsy‐validated SIDS and living control infants.

Study subjects:Consecutive sample of 140 infants, born between 1/1/83 and 12/31/87, who died suddenly and unexpectedly in the Avon Area Health Authority in southwest England between 1/1/84 and 12/31/88. Seventeen of the cases were excluded: 6 because they lacked adequate clinical records, 11 because they were not SIDS. The 637 control infants were comprised of every 80th delivery between 1/1/83 and 12/31/87 in the three major hospitals in the area.

Results:SIDS incidence was 2.85/1,000 live births. Using standard cut scores to define high SIDS risk (2.0 for Oxford and 500 for Sheffield), sensitivities were 0.55 and 0.35 and specificities were 0.78 and 0.89 for the Oxford and Sheffield scores, respectively. SIDS risk for infants in the high risk group was 7.3/1,000 (Oxford) and 9.3/1,000 (Sheffield).

Conclusions:Since there is no intervention with proven efficacy for SIDS prevention, and since approximately one half of SIDS cases occur in low risk groups, clinical use of these scoring systems for allocation of health care resources or personnel for the sole purpose of SIDS prevention is not justified. Pediatr Pulmonol. © 1992 Wiley‐Liss, Inc.
Delayed compliance increase in infants with respiratory distress syndrome following synthetic surfactant
Authors: Armsby David H. , Bellon Gabriel , Carlisle Kathy , Rector David , Baldwin Roger , Long Walker , Stevenson David K. , Ariagno Ronald L.
Published: March 2007

Recent research has demonstrated that Exosurf (EXSF), a newly synthesized artificial surfactant, increases survival when administered endotracheally to premature infants with RDS. This study examines the effects of EXSF on static respiratory system compliance (Crs). Thirty‐four patients received two doses of EXSF in this rescue protocol. Crs (mL/cmH2O/kg) did not significantly change within the first 4 hours after either dose. However, Crs values did increase significantly (paired Student's t‐test, P = 0.005) when data collected after the second dose (0.36 ± 0.13 mL/cmH2O/kg) were compared to first week follow‐up data (0.51 ± 0.21 mL/cmH2O/kg). Crs data collected between 2 and 4 weeks after treatments were again not significantly different from non‐concurrent control data collected at 34 weeks of life. The measurement of Crs in infants receiving EXSF may have been affected by an increase in lung inflation, which could mask an increase in Crs. We speculate that improved lung inflation may occur with less barotrauma in the first week of life due to surfactant replacement treatment and may in part explain the improved Crs seen at 1 week of age. Many investigators using different surfactants, dosing schedules, and pulmonary function methodologies to evaluate lung mechanics have reported that the improvement in compliance after surfactant treatment usually follows the clinical improvement in gas exchange. Additional studies are needed to explain the mechanism of early improvement following surfactant replacement in infants with RDS. © 1992 Wiley‐Liss, Inc.
Acoustic vs. spirometric assessment of bronchial responsiveness to methacholine in children.
Authors: Sanchez Ignacio , Avital Avi , Wong Isaac , Tal Asher , Pasterkamp Hans
Published: March 2007

To study wheezing as an indicator of bronchial responsiveness during methacholine challenge (MC) in children, we used computer analysis of respiratory sounds and compared wheeze measurements to routine spirometry. MC was performed in 30 symptomatic subjects (sympt), age 11 ± 3.1 years (mean ± SD), with suspected asthma and in 12 controls (contr), age 10 ± 3.4 years. Respiratory rate (RR), spirometry, arterial oxygen saturation (Sa, O2), and cough were registered until the concentration provoking a ≥ 20% fall in forced expiratory flow in 1 second (FEV1; PC20), or the end point (8 mg/mL) was reached. For 1 min after each inhalation, sounds over the trachea and posterior right lower lobe were recorded together with calibrated airflow. Computer analysis of respiratory sounds was used for objective wheeze quantification. Wheezing was measured as its duration relative to inspiration (Tw/Ti,) and expiration (Tw/Te,). Seventeen of the sympt group developed wheezing (sympt/W) with ≥ Tw/Ti, or ≥ 5% Tw/Te Thirteen of the sympt did not wheeze (sympt/no W). Three contr developed wheeze (contr/w) while 9 did not (contr/no W). In sympt/W, RR increased from 20 ± 6.2 per min at baseline to 25 ± 9.2 (P < 0.05) at the MC concentration provoking wheeze (PCw), and SaO2, decreased from 97.4 ± 1.2% to 95.3 ± 2.4 (P < 0.05). In contr/W, RR did not change, but SaO2, decreased from 97.3 ± 1.5% to 95.7% ± 1.2% (P < 0.05). Wheezing occurred at both recording sites and was as common during inspiration as during expiration. In subjects who had both PCw and PC20, these variables correlated well (r = 0.82, P < 0.0001). Three SW did not reach PC20 (maximum fall in FEV1 8%, 12%, and 18%). On the other hand, 6 of 13 sympt/no W and 2 of 12 contr/no W had a positive MC. Thus, wheezing during MC had a sensitivity of 68% and a specificity of 82%. Acoustic measurements were reproducible in 14 subjects who performed a second MC within 2–10 months. We conclude that wheezing during MC in children strongly suggests airway hyperresponsiveness; however, wheeze detection cannot fully replace spirometry in bronchial provocation testing. © 1993 Wiley‐Liss, Inc.
Complications following oat head aspiration
Authors: Maayan C. H. , Avital A. , Elpeleg O. N. , Springer C. , Katz S. H. , Godfrey S.
Published: March 2007

We report 5 cases of oat head aspiration in children that resulted in serious complications due to the unidirectional migration of the oat head to the periphery of the lung. The complications included pneumothorax, pneumomediastinum, recurrent hemoptysis, chronic lung disease, bronchiectasis, lobectomy, bronchopleural and bronchocutaneous fistulae, pleural effusion, empyema cavity, and, one not described before, osteomylitis of the rib. Physicians should be aware of the dangers with this particular foreign body aspiration. © 1993 Wiley‐Liss, Inc.
Effects of air pollution on the respiratory tract of children.
Authors: Schmitzberger R. , Rhomberg K. , Büchele H. , Puchegger R. , Schmitzberger‐Natzmer D. , Kemmler G. , Panosch B.
Published: March 2007

The effects of air pollution on pulmonary function and respiratory status was evaluated in 1,626 school aged children from a European Alpine region. Based on measurements of SO2, NO2 and O3 as well as infrared imaging and lichen mapping, three zones of exposure were defined. Results of standardized respiratory questionnaires, medical examinations, and lung function tests were compared among the children in the three different exposure zones. After controlling for age, sex, height, socioeconomic status, and exposure to environmental tobacco smoking, areas of increased SO2 and NO2 as well as areas of increased ozone (max. half hourly mean value, 146 ppb) were significantly associated with decrements of forced expiratory volume in 1 s (FEV1) and flow rates at 50 and 75% of vital capacity (FEF50 FEF75). In addition, areas with increased ozone had a higher prevalence of asthma In all regions, maternal smoking was associated with reduced expiratory flow rates and increased prevalence of asthma. The results provide evidence that outdoor pollution and exposure to passive smoking are risk factors for childhood respiratory health. © 1993 Wiley‐Liss, Inc.
Respiratory resistance and transcutaneous P during histamine provocation in children with bronchial asthma
Authors: Holmgren D. , Engström I. , Bjure J. , Sixt R. , Åberg N.
Published: March 2007

Bronchial reactivity was assessed in 66 children with bronchial asthma (aged 8–15 years) by provocation with histamine‐HCl during a symptom‐free period. A significant bronchial reaction to histamine was defined as a 50% increase in the resistance of the respiratory system (Rrs) determined by the forced oscillation technique. The provocative dose causing a 50% increase in the Rrs (PD50Rrs) was interpolated from the log dose‐response curve. The mean PD50Rrs was significantly lower in children with asthma (0.22 mg/mL) compared with a group of healthy children in the same age range (1.55 mg/mL) (P < 0.001). In children with clinically severe asthma, the mean PD50Rrs was lower (0.13 mg/ml) than in children with mild asthma (0.34 mg/mL) (P < 0.001). Transcutaneous Po2 (Ptco2) was monitored in 25 of the children with asthma. In this group the proportion of mild and severe asthma, the baseline lung function variables, and the PD50Rrs were not significantly different from those of the whole group of children. During the reaction, the Ptco2 fell on average by 29% of the baseline value (P < 0.001); in 88% of the children, the fall in Ptco2 was 20% or more of the baseline value. We conclude that histamine provocation tests using the forced oscillation technique and transcutaneous Po2 to assess a bronchial reaction have a good discriminatory capacity for different degrees of clinical severity of asthma in children. © 1993 Wiley‐Liss, Inc.
A nonlinear regression analysis of nonlinear, passive‐deflation flow‐volume plots
Authors: Jarriel W. Scott , Richardson Peter , Knapp Roger D. , Hansen Thomas N.
Published: March 2007

When studying lung mechanics of intubated premature infants, by the passive‐deflation technique we noted that in many flow‐volume plots the descending limb was curvilinear with a convexity toward the volume axis. By conventional linear analysis lung mechanics of these patients did not change after the administration of terbutaline, but Mead's tangent‐chord slope ratio method for quantifying the amount of curvature showed that the shape of the flow‐volume plots did change. Because of the limitations of this method, we developed a microcomputer based, reiterative regression algorithm which optimizes a nonlinear function for the best fit to any given set of data. We then studied six very low birth weight infants with clinical evidence of pulmonary gas trapping (weight at study, 1.22 ± 0.29 kg; age, 26 ± 16 days). We measured respiratory system resistance (Rrs), compliance (Crs), and expiratory time constants (TCrs), by the passive deflation technique before and after subcutaneous administration of 0.02 mg/kg of terbutaline. No effect of terbutaline in a dose sufficient to increase heart rate > 25 beatshin was observed. The same data analyzed using the nonlinear regression technique with a function based upon a two compartment model of parallel inhomogeneities revealed one compartment with relatively normal Rrs, Crs, and TCrs, values, and a second compartment with a very high Rrs. The latter fell by 50% after terbutaline. These data suggest that abnormalities of airway resistance in ventilated preterm infants are not easily identifiable by classic linear analysis of lung mechanics. We propose that in such patients the two compartment analysis of passive exhalation mechanics measurements can provide better information about Rrs. © 1993 Wiley‐Liss, Inc.