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Biomedical subjects

D K Edwards

Publications and source records attributed to D K Edwards.

62 records · Page 4Linked to original sources
PubMed1977

Twelve years' experience with bronchopulmonary dysplasia.

A retrospective study of 299 successive infants who were ventilated for respiratory distress syndrome (RDS) showed that 62 (21%) developed radiographic stage VI bronchopulmonary dysplasia (BPD). The largest, most mature, and least ill infants tended to survive without developing BPD; the smallest, least mature, and most ill infants tended to die without developing BPD. The patients who developed BPD tended to be intermediate in terms of weight, maturity, and severity of disease; they required longer exposures to elevated oxygen and assisted ventilation than patients who did not develop BPD. The data suggest that in addition to varying individual susceptibility (primarily degree of immaturity and initial severity of disease), elevated oxygen is more important than mechanical ventilation in the pathogenesis of BPD.

Child↗
PubMed1976

Bronchopulmonary dysplasia: the pulmonary pathologic sequel of necrotizing bronchiolitis and pulmonary fibrosis.

A light and electron microscopic study was carried out in 21 infants in whom the pathologic diagnosis of bronchopulmonary dysplasia had been made. All the infants except two had the respiratory distress syndrome at birth, and all 21 had been treated with respirator and oxygen therapy for various periods of time. The pathologic alterations observed in all the infants studied were primarily damage of the bronchial and bronchiolar ciliary apparatus and mucous membranes, severe necrotizing bronchiolitis, and marked bronchiolar and alveolar fibrosis. These changes were more pronounced in infants who survived the longest period of time. Such inflammatory and fibrotic changes are known to predispose to destruction of lung tissue, emphysema, and pulmonary hypertension. Six of these 21 infants developed symptoms and signs of cardiac atrial or ventricular stress, including cor pulmonale, prior to their demise. These infants were among those that survived the longest periods of time, had the longest exposure to supplemental oxygen, and showed histopathologically severe pulmonary fibrosis and emphysema.

Bronchial Diseases↗
PubMedDate not supplied

Genitourinary malformation with calcified intraluminal meconium and pulmonary hypoplasia.

Calcified intraluminal meconium is a rare finding in newborn infants that is often associated with communication between the urinary and gastrointestinal tracts. Frequently such infants die because of respiratory problems. An illustrative case is presented, and pulmonary hypoplasia is suggested as an etiology of the respiratory difficulties observed.

Calcinosis↗
PubMedDate not supplied

Temperature measurements during ultrasound hyperthermia.

In this study the ultrasonic field distortions and the temperature measurement errors caused by temperature sensing probes were investigated. It was found that probes with diameters equal to or greater than 1/2 of the square root of the wavelength (lambda) scatter and reflect the waves, and thus distort the field significantly. Smaller probes down to lambda 1/2/5 in diameter had a detectable effect which was very local and, therefore, will probably not have a significant effect on the overall temperature distribution. When the temperature measurement errors were studied, even the smallest probes showed some self-heating artifact and its magnitude depended on the probe size, material, structure, orientation, and the operating frequency. This error was small with most of the nonultrasound absorbing probes (such as bare wires or stainless steel needle probes), but significant with plastic shielded thermocouples. The energy absorption associated with plastic coated probes can be reduced by orienting the probe parallel to the beam, by scanning the focus in such a manner that the focus is not passing on the sensor, and by inserting the probe in a stainless steel catheter. The temperature measurement error can also be reduced by covering the plastic probe with a high- (or low-) acoustical impedance material around the sensor. This would scatter the sound around the probe, thus preventing energy absorption in the plastic. This arrangement can preserve the desirable properties of plastic probes (mainly flexibility, strength, and electrical isolation from the patient) while at the same time allowing fairly absorption artifact free measurements.

Animals↗