Biomedical subjects

M A Hutcheon

Publications and source records attributed to M A Hutcheon.

24 records · Page 2Linked to original sources

PubMed1983

Usefulness of transbronchial biopsy in immunosuppressed patients with pulmonary infiltrates.

In a retrospective study of thirty-one immunosuppressed patients with new pulmonary infiltrates transbronchial biopsy provided a specific diagnosis in 11 of the 31 (36%) patients. In a further five patients, whose biopsy showed non-specific interstitial pneumonitis, a specific diagnosis was established by other means. Overall a specific diagnosis was obtained in 52% of patients. Twelve patients were left with a diagnosis of non-specific interstitial pneumonitis. In three out of 31 (10%) patients insufficient tissue was obtained. The seven patients who had metastatic carcinoma of the lung did poorly. The nine with other specific diagnoses did better in that five of them were alive after more than 11 months of follow-up. Patients with non-specific pneumonitis did well; eight out of 12 (67%) were alive after an average follow-up of 13.4 months. In 27 of the 31 (87%) patients the procedure was felt to have influenced therapeutic decisions. This was true whether the biopsy yielded a specific or a non-specific diagnosis. In our series making a specific diagnosis did not improve the patients' survival. Those with non-specific pneumonitis who were treated empirically did well, as did patients with specific diagnoses other than metastatic carcinoma of the lung.

Adult↗

PubMed1983

A systematic controlled study of pulmonary abnormalities in rheumatoid arthritis.

We have conducted a prospective comparison of 155 rheumatoid patients and 95 control subjects. Both groups were selected without regard to respiratory status, but were comparable in age, sex and smoking experience. The prevalence of respiratory symptoms, of past respiratory illnesses and of pulmonary function findings of airway obstruction was similar in both groups. However, the rheumatoids showed an increased frequency of chest crackles and abnormal chest radiographs, and had pulmonary function changes suggestive of a restrictive ventilatory defect. These pulmonary abnormalities were associated with smoking, the presence of nonpulmonary extraarticular features, the level of rheumatoid disease activity and treatment with oral corticosteroid or gold.

Adult↗

PubMed1981

Upper airway occlusion induced by diaphragm pacing for primary alveolar hypoventilation: implications for the pathogenesis of obstructive sleep apnea.

This report describes a patient with primary alveolar hypoventilation who, after 2 yr of successful treatment with nocturnal oxygen, developed severe hypoxemia and hypercapnia during sleep, morning headaches, and daytime fatigue. Sleep studies demonstrated prolonged periods of hypoventilation and apnea without evidence of upper airway occlusion. Therefore, a phrenic nerve stimulator was implanted to allow pacing of the diaphragm during sleep. However, diaphragm pacing was accompanied by paradoxical movement of the rib cage and upper airway occlusion during sleep, and was unsuccessful in maintaining adequate ventilation. Therefore, the patient underwent a tracheostomy after which diaphragm pacing maintained adequate nocturnal ventilation; however, paradoxical movement of the rib cage persisted. The induction of upper airway occlusion as a result of diaphragm pacing, in contrast to the absence of occlusion during spontaneous breathing, highlights the importance of the normal temporal coordination of inspiratory activation of the upper airway muscles and diaphragm. The findings have important implications for the pathogenesis of obstructive sleep apneas in general.

Adult↗

PubMed1980

Effect of layoff and rehire on respiratory variables of grain elevator workers.

A group of 77 grain elevator workers was examined at monthly intervals over a 7-month period. Approximately half of the workers were temporarily laid off for several months of this period, during which those who were steadily employed were involved in processing a reduced throughput of grain. The men who were laid showed a transient decrease in some respiratory symptoms during the months of layoff, followed by an increase after rehire. Those who were steadily employed showed a corresponding increase in these symptoms during the period of reduced grain movement, which did not change when the elevator returned to full activity. All of them demonstrated the greatest maximal expiratory flow rates during the midportion of the period of reduced work status, and the lowest values after either rehire or the restoration of full elevator activity. These longitudinal changes in respiratory variables are largely consistent with the effects of grain dust exposure, which may be at least partially reversible.

Absenteeism↗

PubMed1977

Effect of breathing helium-oxygen on static lung volumes and lung recoil in normal man.

Static lung volumes and static elastic recoil pressure (Pel) were measured in normal subjects breathing air and 80% helium plus 20% oxygen (He+O2). In 22 subjects, He+O2 produced small but significant increases in total lung capacity (TLC) (mean 0.11 liter, P less than 0.001) and residual volume (mean 0.10 liter, P less than 0.01) without change in vital capacity or functional residual capacity. The mechanisms for this change are obscure. In 10 subjects, breathing He+O2 had no significant effect on Pel (paired t-test) at any lung volume measured (50-80% TLC). In one subject, Pel at 70 and 80% TLC was significantly higher on air than on He+O2 (unpaired t-test, P less than 0.05). Because changes in lung volumes and lung recoil were small, we concluded that these effects do not negate the clinical utility of He+O2 flow-volume curves.

Adult↗

PubMedDate not supplied

Computed tomographic diagnosis of pulmonary sequestration.

Two cases of pulmonary sequestration demonstrated by CT scans of the chest are described. In one, CT demonstrated the anomalous artery. This finding may obviate the need for angiography when surgery is not contemplated.

Adult↗