Biomedical subjects

Robert G Castile

Publications and source records attributed to Robert G Castile.

11 recordsLinked to original sources

PubMed2005

Computed tomography in the evaluation of cystic fibrosis lung disease.

The first report of computed tomography (CT) scanning to monitor cystic fibrosis (CF)-related lung disease was published in 1986. Further publications followed, but in general there was little interest in this technique until recently. Two factors in particular have led to this increased interest. First is an increasing realization that pulmonary function tests, long the mainstay of CF evaluation, often underestimate the presence and severity of mild and moderate lung disease. Second is the need for more sensitive outcome measures to assess new therapies. This had led to new interest and a series of important publications. The goal of this article is to present the current status of CT scanning in CF.

Cystic Fibrosis↗

PubMed2005

Comparison of quiet breathing and controlled ventilation in the high-resolution CT assessment of airway disease in infants with cystic fibrosis.

BACKGROUND: Respiratory motion and low lung volumes limit the quality of HRCT examinations in infants and young children. OBJECTIVE: To assess the effects of respiratory motion and lung inflation on the ability to diagnose airway abnormalities and air trapping (AT) using HRCT in infants with cystic fibrosis (CF). MATERIALS AND METHODS: HRCT images of the lungs were obtained at four anatomical levels in 16 sedated children (age 2.4+/-1.1 years, mean+/-SD) with CF using controlled ventilation at full lung inflation (CVCT-I), at resting end exhalation (CVCT-E), and during quiet breathing (CT-B). Two blinded reviewers independently and then by consensus scored all images for the presence or absence of bronchiectasis (BE), bronchial wall thickening (BWT), and AT. RESULTS: Of the 64 images evaluated, BE was identified in 19 (30%) of the CVCT-I images compared to 6 (9%) of the CVCT-E images (P=0.006) and 4 (6%) of the CT-B images (P=0.044). AT was seen in 29 (45%) of the CVCT-E images compared to 14 (22%) of the CVCT-I images (P=0.012) and 12 (19%) of the CT-B images (P=0.012). There were no significant differences in the detection of BWT among the three methods. SUMMARY: In infants with CF, fully inflating the lung improved the ability to diagnose early BE, and obtaining motion-free images at end exhalation enhanced the detection of AT.

Airway Obstruction↗

PubMed2005

Inspiratory and expiratory CT lung density in infants and young children.

BACKGROUND: There is a lack of information on normal inspiratory and expiratory CT lung density in infants. OBJECTIVE: To describe normal regional CT lung density at end inspiratory and end expiratory lung volumes in children ages 0--5 years. MATERIALS AND METHODS: Motionless HRCT images were obtained at 25 cm (inspiratory) and 0 cm (expiratory) water pressure at apical (top of arch) and basal (2 cm above diaphragm) levels in 16 sedated children (mean age 1.5 years) who underwent CT for reasons other than respiratory disease. Density was measured at anterior-posterior and medial-lateral locations at each level in each lung. The influence of level, location, and age was quantified using analysis of variance methods. RESULTS: Lung density declined linearly in the first few years of life and thereafter approximated adult values. Beginning with the anterior-basal location, density at end inspiration (HU)=-835-(16 x age in years)+16 (if apical)+33 (if posterior)+23 (if medial)+14 (if lateral); standard error=38. At resting end exhalation =-616-(41 x age)+50 (if apical)+155 (if posterior)+74 (if medial)+46 (if lateral); standard error=68. CONCLUSION: We provide an initial basis for employing lung densitometry in infants and young children at end inspiration and resting end exhalation lung volumes.

Absorptiometry, Photon↗

PubMed2004

Pulmonary function in bronchopulmonary dysplasia.

The purpose of this study was to examine lung function and bronchodilator responsiveness in infants with a history of prematurity and bronchopulmonary dysplasia (BPD), using the raised volume rapid thoracoabdominal compression technique as well as with whole-body plethysmography. Spirometric measurements were obtained in 28 infants with a history of BPD, defined as preterm birth with O2 requirement at 36 weeks postmenstrual age (gestational age at birth, 26.4 +/- 2.1 weeks, mean +/- SD; birthweight, 898 +/- 353 g; age at study, 68.0 +/- 35.6 weeks). Fractional lung volumes were measured in 27 subjects. Values were expressed as percentage of predicted normal values. Compared to normal infants, those with a history of BPD exhibited decreases in forced expiratory flows including forced expiratory volume in 0.5 sec (76.3 +/- 19.6%), forced expiratory flow at 75% of expired forced vital capacity (FEF75; 59.5 +/- 30.7%), and FEF(25-75) (74.0 +/- 26.8%; P<0.01 for all). Functional residual capacity (107.9 +/- 25.3%), residual volume (RV, 124.5 +/- 42.7%), and RV/total lung capacity (RV/TLC, 128.2 +/- 35.3%) were increased in infants with a history of BPD (P<0.05 for each). There was no difference in TLC between groups. Seventeen infants were studied both pre- and postalbuterol, and 6 (35%) demonstrated significant bronchodilator responsiveness. Infants with recurrent wheezing showed greater expiratory flow limitation, hyperinflation, and airways responsiveness, whereas those without wheezing showed only modest airway dysfunction. We conclude that infants with a history of BPD have pulmonary function abnormalities characterized by mild to moderate airflow obstruction and air trapping.

Airway Obstruction↗

PubMed2004

Gas trapping in normal infants and in infants with cystic fibrosis.

Two different methods for estimating trapped gas volume have been described in the literature. The purpose of this study was to use both of these methods to estimate and compare trapped gas volumes in normal infants and infants with cystic fibrosis (CF). Thirty normal infants and 29 infants with CF, ages 1 month to 3 years, were studied. Pulmonary function tests, including raised volume forced expiratory flows, plethysmographic functional residual capacity (FRC(pleth)), and fractional lung volumes, were measured. Then functional residual capacity was measured by nitrogen washout (FRC(nitrogen)). Following nitrogen washout, lungs were then inflated three times to 30 cm H(2)O, using 100% oxygen. This process was repeated until no further nitrogen could be washed from the lungs. The volume of trapped gas (tg) was calculated from the total additional amounts of nitrogen expired following lung inflations. The difference between FRC(pleth) and FRC(nitrogen) provided a second estimate of trapped gas volume (delta V). Mean tg and delta V values for normal infants were 2.5 +/- 3.5 ml and 15.6 +/- 30.4 ml, respectively. Mean tg and delta V values for infants with CF were 5.8 +/- 7.7 ml and 33.2 +/- 43.8 ml, respectively. Both tg and delta V did not differ significantly between normal infants and infants with CF. Measured following raised volume forced expiratory maneuvers, delta V and tg do not distinguish infants with CF from normal infants as well as do other currently available tests of infant lung function.

Air↗

PubMed2004

Structural airway abnormalities in infants and young children with cystic fibrosis.

OBJECTIVES: To determine whether the airway structure of infants and young children with cystic fibrosis (CF) differs from that of normal children by using high-resolution computed tomography (HRCT) imaging. Study design Full-inflation, controlled ventilation HRCT images of the lungs were obtained at four anatomic levels in 34 infants with CF (age, 2.4+/-1.4 years) and 20 control infants (age, 1.8+/-1.4 years). Short axis diameters of all clearly identifiable, round airway/vessel pairs were measured to obtain airway wall thickness (AWT), airway lumen diameter (ALD), and vessel diameter (VD). RESULTS: In infants with CF, mean AWT (+/-SD) was 0.58+/-0.13 mm, ALD was 1.31+/-0.56 mm, and VD was 1.62+/-0.58 mm. In control infants, mean AWT was 0.49+/-0.13 mm, ALD was 1.07+/-0.42 mm, and VD was 1.86+/-0.64 mm. Mean AWT and ALD were greater in children with CF than in normal subjects (P<.001). ALD:VD ratios increased with age in patients with CF compared with control subjects (P=.026). CONCLUSIONS: The airways of infants and young children with CF have thicker walls and are more dilated than those of normal infants.

Analysis of Variance↗

PubMed2004

Lateral thoracic expansion for Jeune syndrome: evidence of rib healing and new bone formation.

BACKGROUND: Lateral thoracic expansion is a procedure that has been described to enlarge the thoracic cage in patients with Jeune's asphyxiating thoracic dystrophy. The procedure involves separating ribs from their periosteum and plating them together in an expanded fashion with titanium struts. We have speculated that the ribs heal in this situation, despite the absence of surrounding periosteum, and that new rib formation occurs in the liberated periosteum. METHODS: Radiographic studies of patients who have undergone lateral thoracic expansion were reviewed for evidence of rib healing or periosteal new bone formation. RESULTS: This study presents radiologic evidence that rib healing actually occurs, as does periosteal ossification. CONCLUSIONS: Lateral thoracic expansion creates additional chest wall that is formed of autologous tissue, fully healed, and not ultimately dependent on titanium struts.

Asphyxia Neonatorum↗

PubMed2004

Active and passive tobacco smoke exposure: a comparison of maternal and child hair cotinine levels.

The objective of this study was to compare tobacco smoke exposure in mothers and their healthy children less than 3 years old using hair cotinine (HC) levels as an objective long-term measure of exposure. Hair samples were obtained from mother/child pairs recruited from the Columbus Children's Hospital Primary Care Center, and were analyzed by radioimmunoassay to compare HC levels. Mothers were both self-reported smokers and nonsmokers. Contributing and confounding variables were assessed based on questionnaires completed by participants. Exclusion criteria for children were prematurity and presence of chronic cardiopulmonary disease. Hair samples and questionnaires were obtained from 104 mother/child pairs. Child and maternal HC levels were correlated for both self-reported maternal smokers (R2 = .13, p < .013) and self-reported maternal nonsmokers (R2 = .54, p < 001). Child HC levels were higher than maternal HC levels (1.18 ng/mg vs. .78 ng/mg, p < .001). Children of nonsmokers had higher HC levels than their mothers (.77 ng/mg vs. .35 ng/mg, p < .001), while HC levels of smokers and their children were no different (1.91 ng/mg vs. 1.92 ng/mg, p = .978). The relationship between child and maternal HC did not differ by child age, gender, or race. In conclusion, environmental tobacco smoke exposure in young children as reflected by HC is higher than expected based on prior studies of biomarkers and passive tobacco smoke exposure in adult nonsmokers.

Adult↗

PubMed2004

Model of forced expiratory flows and airway geometry in infants.

Early measurements of autopsied lungs from infants, children, and adults suggested that the ratio of peripheral to central airway resistance was higher in infants than older children and adults. Recent measurements of forced expiration suggest that infants have high flows relative to lung volume. We employed a computational model of forced expiratory flow along with physiological and anatomic data to evaluate whether the infant lung is a uniformly scaled-down version of the adult lung. First, we uniformly scaled an existing computational model of adult forced expiration to estimate forced expiratory flows (FEF) and density dependence for an 18-mo-old infant. The values obtained for FEF and density dependence were significantly lower than those reported for healthy 18-mo-old infants. Next, we modified the model for the infant lung to reproduce standard indexes of expiratory flow [forced expiratory volume in 0.5 s (FEV(0.5)), FEFs after exhalation of 50 and 75% forced vital capacity, FEF between 25 and 75% expired volume] for this age group. The airway sizes obtained for the infant lung model that produced accurate physiological measurements were similar to anatomic data available for this age and larger than those in the scaled model. Our findings indicate that the airways in the infant lung model differ from those in the scaled model, i.e., middle and peripheral airway sizes are larger than result from uniform downscaling of the adult lung model. We show that the infant lung model can be made to reproduce individual flow-volume curves by adjusting lumen area generation by generation.

Adult↗

PubMed2003

A comparison of the therapeutic effectiveness of and preference for postural drainage and percussion, intrapulmonary percussive ventilation, and high-frequency chest wall compression in hospitalized cystic fibrosis patients.

INTRODUCTION: Cystic fibrosis (CF) patients have abnormally viscid bronchial secretions that cause airway obstruction, inflammation, and infection that leads to lung damage. To enhance airway clearance and reduce airway obstruction, daily bronchopulmonary hygiene therapy is considered essential. OBJECTIVE: Compare the effectiveness of and patient preferences regarding 3 airway clearance methods: postural drainage and percussion (PD&P), intrapulmonary percussive ventilation (IPV), and high-frequency chest wall compression (HFCWC). METHODS: The participants were hospitalized CF patients >or= 12 years old. Effectiveness was evaluated by measuring the wet and dry weights of sputum obtained with each method. In random order, each patient received 2 consecutive days of each therapy, delivered 3 times daily for 30 minutes. Sputum was collected during and for 15 minutes after each treatment, weighed wet, then dried and weighed again. Participants rated their preferences using a Likert-type scale. Mean weights and preferences were compared using analysis of variance with repeated measures. Patient preferences were compared using Freidman's test. RESULTS: Twenty-four patients were studied. The mean +/- SD wet sputum weights were 5.53 +/- 5.69 g with PD&P, 6.84 +/- 5.41 g with IPV, and 4.77 +/- 3.29 g with HFCWC. The mean wet sputum weights differed significantly (p = 0.035). Wet sputum weights from IPV were significantly greater than those from HFCWC (p < 0.05). The mean dry sputum weights were not significantly different. With regard to overall preference and to the subcomponents of preference, none of the 3 methods was preferred over the others. CONCLUSIONS: HFCWC and IPV are at least as effective as vigorous, professionally administered PD&P for hospitalized CF patients, and the 3 modalities were equally acceptable to them. A hospitalized CF patient should try each therapy and choose his or her preferred modality.

Child↗

PubMed2002

Impaired recovery of hypothalamic-pituitary-adrenal axis function and hypoglycemic seizures after high-dose inhaled corticosteroid therapy in a toddler.

BACKGROUND: Corticosteroids are the treatment of choice for children with persistent reactive airway disease. In these patients, taper and discontinuation of systemic therapy is often facilitated by transition to high-dose inhaled corticosteroid treatment. OBJECTIVE: To report a case of impaired hypothalamic-pituitary-adrenal (HPA) axis recovery and adrenal crisis associated with prolonged high-dose inhaled therapy after long-term systemic corticosteroid treatment. METHODS: A 32-month-old child with severe airway obstruction and wheezing was treated with long-term daily systemic (intravenous and oral) corticosteroids followed by high-dose inhaled fluticasone (440 to 1,320 microg/day). This child presented in adrenal crisis, as evidenced by severe hypoglycemia and seizures, I day after receiving the influenza vaccine. After hydrocortisone replacement and a long taper of fluticasone, the child's adrenal function returned to normal. RESULTS: At the time of seizure, the serum glucose was 1 mg/dL. An electroencephalogram, computed tomographic scan, and magnetic resonance imaging of the brain were normal. Adrenal insufficiency was documented (morning serum cortisol, 0.6 microg/dL; after adrenocorticotrophic hormone stimulation, 8.4 microg/dL). Repeat evaluation 3 weeks after discontinuation of all corticosteroid therapy demonstrated normal HPA axis function. CONCLUSIONS: After treatment with long-term systemic steroids, high-dose inhaled corticosteroid therapy can impair recovery of the HPA axis and place patients at risk for adrenal crisis.

Administration, Inhalation↗