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Biomedical subjects

B Gothe

Publications and source records attributed to B Gothe.

25 records · Page 2Linked to original sources
PubMed1980

Effects of expiratory loading on respiration in humans.

We examined the effects of expiratory resistive loads of 10 and 18 cmH2O.l-1.s in healthy subjects on ventilation and occlusion pressure responses to CO2, respiratory muscle electromyogram, pattern of breathing, and thoracoabdominal movements. In addition, we compared ventilation and occlusion pressure responses to CO2 breathing elicited by breathing through an inspiratory resistive load of 10 cmH2O.l-1.s to those produced by an expiratory load of similar magnitude. Both inspiratory and expiratory loads decreased ventilatory responses to CO2 and increased the tidal volume achieved at any given level of ventilation. Depression of ventilatory responses to Co2 was greater with the larger than with the smaller expiratory load, but the decrease was in proportion to the difference in the severity of the loads. Occlusion pressure responses were increased significantly by the inspiratory resistive load but not by the smaller expiratory load. However, occlusion pressure responses to CO2 were significantly larger with the greater expiratory load than control. Increase in occlusion pressure observed could not be explained by changes in functional residual capacity or chemical drive. The larger expiratory load also produced significant increases in electrical activity measured during both inspiration and expiration. These results suggest that sufficiently severe impediments to breathing, even when they are exclusively expiratory, can enhance inspiratory muscle activity in conscious humans.

Adult↗
PubMed1978

Effects of continuous positive airway pressure after oleic acid-induced lung injury in dogs.

The physiologic effects of continuous positive airway pressure (CPAP) of 5,10,15, and 20 cm H2O during spontaneous ventilation were studied in six anesthetized dogs with simulated respiratory distress syndrome (RDS) induced by iv infusion of oleic acid and in three normal controls. After oleic acid, mean PaO2 dropped to 63.6 +/- 3.1 mm Hg while breathing 100% oxygen and mean shunt fraction was 48.3 +/- 3.0%. PaO2 and shunt fraction improved significantly at the two highest levels of CPAP (e.g.,PaO2 271.3 +/- 41.3 mm Hg and shunt fraction 17.8 +/-2.2% at 20 cm H2O CPAP). Mean mixed venous PO2 rose from 37.4 +/- 1.5 mm Hg with no CPAP TO 60.8 +/- 3.1 mm Hg at 20 cm H2O CPAP. Tissue oxygenation appeared to improve during CPAP, since cardiac output, oxygen delivery, and serum lactate were not significantly affected and mixed venous PO2 rose significantly. However, significant hypoventilation occurred at all but the lowest level of CPAP, mean PaCO2 rising from 44.1 +/- 1.8 mm Hg with no CPAP to 77.6 +/-6.8 mm Hg at 20 cm H2O CPAP. The hypoventilation during CPAP is consistent with increased work of breathing due to a combination of decreased lung compliance and increased dead space ventilation due to rapid, shallow breathing.

Animals↗
PubMedDate not supplied

Fiberoptic bronchoscopy in the diagnosis of lung cancer comparison of pre-and post-bronchoscopy sputa, washings, bruchings and biopsies.

Fiberoptic bronchoscopy (brushings, washings and biopsies) was performed and pre- and post-bronchoscopy sputum cytologies obtained on 70 patients with histopathologically proven lung cancer. Bronchoscopy, with its associated procedures performed in 52 patients with primary bronchogenic carcinoma, was diagnostic in 41 (79%). Of all the various methods of obtaining specimens, bronchial brushing and bronchial biopsy gave the highest percentage yield (67%). However, since brush specimens could be obtained from peripheral lesions under fluoroscopic guidance, a greater number of positive specimens were obtained by this procedure (34) than by forceps biopsy (25), making brushing more useful. Pre- and post-bronchoscopy sputa were positive and thus of value in two cases when brushing and biopsy were both negative. Bronchial washing did not add significantly to the yield of positives and could therefore be eliminated as an unnecessary cost-and time-consuming procedure. Fiberoptic bronchoscopy was not helpful in diagnosing mediastinal tumors (5), lung metastases (7) and bronchial adenomas (6).

Adenoma↗