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Biomedical subjects

E Onal

Publications and source records attributed to E Onal.

50 records · Page 3Linked to original sources
PubMed1982

Periodic breathing and the pathogenesis of occlusive sleep apneas.

In order to study the relationship between sleep-induced periodic breathing and the development of occlusive sleep apneas, 6 patients with hypersomnia-sleep apnea syndrome were studied during nocturnal sleep before and approximately 1 month after therapeutic tracheostomy. Post-tracheostomy studies were performed in open and closed tracheostomy states. Sleep-induced periodic breathing resembling the pattern of Cheyne-Stokes breathing was observed in all patients before and after tracheostomy, even when tracheostomy was left open. When tracheostomy was closed all patients developed periodic hypopneas with significant oxygen desaturation, and 4 patients developed occlusive apneas at the nadir of the periodic changes. However, apnea and desaturation indexes during closed tracheostomy were significantly lower than their respective pretracheostomy values. These results indicate that sleep-induced periodic breathing, which represents an instability of respiratory control, is primary to the development of occlusive apneas, and the periodically observed is exaggerated by hypoxemia. Comparison of pre- and post-tracheostomy studies indicate a significant improvement in the underlying disorder most likely caused by the elimination of nocturnal hypoxemia and sleep fragmentation.

Cheyne-Stokes Respiration↗
PubMed1981

Diaphragmatic and genioglossal electromyogram responses to CO2 rebreathing in humans.

To assess the relationship between central control of upper airway and respiratory muscle, simultaneously recorded diaphragmatic electromyogram (EMGdi) and genioglossal EMG (EMG ge) responses to CO2 rebreathing were compared in five supine volunteers. Both EMGs were quantitated in terms of inspiratory peak moving time-average activity. In all subjects both EMGdi and EMGge increased linearly with increasing alveolar CO2 pressure (r = 0.93 +/- 0.04 and 0.87 +/- 0.07, respectively), resulting in a significantly linear EMGge vs. EMGdi relationship (r = 0.91 +/- 0.04). CO2 response slopes of both EMGs were similar and linearly related (r = 0.96, P less than 0.001) such that subjects with low EMGdi response also had a low EMGge response and vice versa. Although the onset of EMGge activity preceded that of EMGdi, and the pattern of both EMGs were different, inspiration duration of both EMGs were similar. These data indicate that in humans both diaphragm and genioglossus muscle share similar control mechanisms and suggest that upper airway function is intimately related to the regulation of breathing.

Adult↗
PubMed1981

Diaphragmatic and genioglossal electromyogram responses to isocapnic hypoxia in humans.

In order to define the relationship between central control of upper airway and respiratory muscle function, diaphragmatic electromyogram (EMGdi) and genioglossal EMG (EMGge) responses to isocapnic hypoxia were studied in 6 awake supine volunteers. Both EMGs were processed and quantitated as moving time average activity. In all subjects, EMGge showed phasic inspiratory activity synchronous with EMGdi. Increases seen in EMGdi and EMGge were linearly related to the decrease in oxygen saturation (r = 0.89 +/- 0.08 and 0.89 +/- 0.08, respectively). There was also a linear relationship between the relative responses of both EMGs to hypoxia such that a low EMGdi response was associated with a low EMGge response and vice versa (r = 0.92, p less than 0.001). These results indicated that the genioglossus muscle behaves like a respiratory muscle and suggested that central control of upper airway and respiratory muscles in humans are intimately related.

Carbon Dioxide↗
PubMed1981

Diaphragmatic EMG and transdiaphragmatic pressure measurements with a single catheter.

A single gastroesophageal catheter was used for simultaneous measurements of diaphragmatic electromyogram (EMGdi), esophageal, and gastric pressures in 10 normal volunteers. The catheter consisted of 2 polyethylene tubes, each with an outer diameter of 1.70 mm and an inner diameter of 1.19 mm, 2 platinum wire coils, and esophageal and gastric latex balloons. In all subjects studied, the increase in EMGdi, quantified as the average rate of rise of inspiratory moving average activity, and transdiaphragmatic pressure (Pdi) were linearly related to the increase in end-tidal PCO2 during CO2 rebreathing (range of r, 0.88 to 0.99 and 0.85 to 0.99, respectively). The relation between changes in EMGdi and that of Pdi, mean inspiratory flow, and occlusion pressure were also linear (range of r, 0.83-0.99, 0.73-0.99, and 0.84-0.99, respectively), indicating reliable recordings of EMGdi and Pdi during CO2 rebreathing in upright normal humans.

Carbon Dioxide↗
PubMed1980

Respiratory neuromuscular response to CO2 rebreathing with inspiratory flow resistance in humans.

The effects of inspiratory flow resistance on mouth occlusion pressure (P0.15) and diaphragmatic EMG (EMGdi) responses to CO2 rebreathing were studied in normal subjects. Occlusion pressures were measured 150 msec after onset of an inspiratory effect; EMGdi was analyzed as a moving time average and quantified in terms of peak activity and rate of rise of activity. After a control CO2 response was obtained in each subject, rebreathing was repeated 30 min later with either of two inspiratory flow resistive loads, 5 cm H2O/L/sec (IR5) and 14 cm H2O/L/sec (IR14). With IR5 (6 subjects), the P0.15 response was decreased in two subjects, unchanged in two, and increased in two; peak EMGdi was unchanged in all, while rate of rise of EMGdi response decreased in 4 of the 6 subjects. With IR14 (6 subjects, 9 runs), the P0.15 response was not decreased in any subject, remained unchanged in 4, and increased in 5; peak EMGdi response to rebreathing in all runs was, again, unchanged by this load, but rate of rise of EMGdi was decreased in 3 and unchanged in 6. The inspiratory off-switch threshold as reflected by peak diaphragmatic activity was not changed by inspiratory flow resistance, whereas inspiratory neural drive as reflected by the the rate of rise of activity was decreased in some subjects. The decrease in inspiratory drive without change in inspiratory off-switch threshold resulted in prolongation of inspiration in an attempt to effect efficient lung expansion. However, the defense of ventilation during rebreathing with both resistances appeared to mainly depend on the response of inspiratory muscle force (P0.15), since in 7 of the 7 runs in which the P0.15 response was significantly increased from control, the ventilatory response was not decreased.

Carbon Dioxide↗
PubMed1979

Effects of electrode position on esophageal diaphragmatic EMG in humans.

The effects of electrode position and gastric-balloon anchoring on esophageal diaphragmatic EMG (EMGdi) responses to CO2 rebreathing were studied in seven normal sitting humans using an esophageal catheter that consisted of four platinum wire coils enabling simultaneous recording of three EMGdi signals from three different sites in the esophagus. A gastric balloon attached to the distal end of the catheter allowed anchoring of the catheter. EMGdi signals were quantitated as a moving time average. Two rebreathing experiments were performed with and without balloon anchoring on the same day. Changes in electrode position of at least 2 cm above the site of maximum EMGdi activity caused minimal changes in the moving average EMGdi and did not significantly effect the quantitated EMGdi response to CO2 rebreathing. The maximum EMGdi activity was approximately 2 cm above the gastroesophageal junction in sitting humans. Stabilization of the catheter with an inflated gastric balloon did not improve the reproducibility of the EMGdi data. Finally, the EMGdi response to two CO2 rebreathing runs done at the same sitting showed intraindividual reproducibility.

Carbon Dioxide↗
PubMed1977

Avulsion of the ureter caused by stone basket manipulation.

A case of an iatrogenic loss of 18 cm. of the distal ureter owing to attempted basket retrieval of a lower ureteral stone is reported. The defect was bridged by mobilizing the kidney, constructing a Boari flap and fixing the bladder with a Psoas hitch. The complications of stone manipulating are reviewed and discussed.

Humans↗
PubMed1977

Nodular pulmonary sarcoidosis. Clinical, roentgenographic, and physiologic course in five patients.

Five cases of nodular pulmonary sarcoidosis are presented. That nodular infiltration represents a reversible stage of sarcoidosis is suggested by the fact that all patients demonstrated roentgenographic resolution of these infiltrates. In four of the five subjects, tests of pulmonary function showed restrictive disease which remained unchanged or worsened despite radiologic clearing, suggesting persistence of active disease or development of residual pulmonary fibrosis. Evidence of obstruction of airways that was unexplained by a history of smoking was present in all of the five subjects.

Adult↗
PubMed1976

Disseminated pulmonary blastomycosis in an immunosuppressed patient. Diagnosis by fiberoptic bronchoscopy.

A 73-year-old man with malignant lymphoma who was undergoing treatment with systemic chemotherapy presented with an acute, febrile illness associated with cough and sputum production. The patient developed bilateral, diffuse, pulmonary interstitial infiltrates with rapidly progressive respiratory insufficiency. The diagnosis was made by demonstrating Blastomyces dermatitidis in bronchial brush and transbronchial lung biopsy specimens obtained through fiberoptic bronchoscopy.

Aged↗
PubMedDate not supplied

Comparison of magnetometer and inductance plethysmography derived Konno-Mead diagrams during CO2 rebreathing.

Magnetometers measure changes in antero-posterior diameters of the rib cage and abdomen while respiratory inductance plethysmography (RIP) measures changes in chest wall cross-sectional area. We compared Konno-Mead diagrams derived from isovolume calibrated magnetometers and RIP in the DC-mode during room air and CO2 rebreathing in the sitting and supine positions. Chest wall configurations obtained during quiet tidal breathing were similar in both sitting and supine positions. During CO2 stimulated breathing, however, derived chest wall configurations were at times dissimilar. The RIP per cent rib cage contribution to tidal volume was greater than that of magnetometers during room air and CO2 rebreathing in both sitting and supine positions. Changes in end expiratory levels measured by magnetometers and RIP during CO2 rebreathing are in general proportionate to each other; however, the magnetometers usually depicted quantitatively greater decreases in abdominal end expiratory levels during rebreathing. We conclude that the qualitative and quantitative assessment of chest wall configurations and volume displacement vary depending on the method used. RIP by including lateral wall motion may more accurately reflect compartmental displacements, while magnetometers by solely measuring antero-posterior diameter may better reflect changes in abdominal volume and thus diaphragm configuration.

Adult↗