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Biomedical subjects

K M Moser

Publications and source records attributed to K M Moser.

At least 181 records · Page 10Linked to original sources
PubMed1977

133Xenon washout patterns during diaphragmatic breathing. Studies in normal subjects and patients with chronic obstructive pulmonary disease.

Studies of the washout of radioactive 133xenon were performed in six normal subjects and six patients with chronic obstructive pulmonary disease during normal and diaphragmatic breathing. Subjects were unable to change the distribution of ventilation with diaphragmatic breathing. In all normal subjects and in three of the six subjects with chronic obstructive pulmonary disease, overall washout improved with diaphragmatic breathing. It is suggested that this change was related to the slower, deeper tidal volumes used by these subjects during diaphragmatic breathing.

Breathing Exercises↗
PubMed1977

Noninvasive assessment of left ventricular performance in patients with chronic obstructive pulmonary disease.

In patients with chronic obstructive pulmonary disease (COPD), the clinical differentiation between dyspnea due to left ventricular dysfunction and that due to pulmonary events is difficult. Invasive techniques have been the only reliable diagnostic approach. To assess the potential value of noninvasive techniques in this context, 27 patients with COPD and with clinically suspected left ventricular dysfunction were studied by echocardiography, radionuclide angiography, and right cardiac catheterization. In 20 (74%), adequate echocardiogram were obtained. Of these 20 patients, 17 had normal pulmonary arterial wedge pressures at rest and during submaximal handgrip exercise. Sixteen of these 17 had normal left ventricular performance by all three echocardiographic criteria used; in one patient, two criteria were not interpretable, but the third was normal. Results of radionuclide studies were normal in 15 patients, borderline in one, and not measurable in one. Of the three patients with abnormal wedge pressures, at least one echocardiographic criterion was abnormal in all. Radionuclide data were abnormal in two and not measurable in one. We conclude that left ventricular dysfunction is infrequently present in patients with COPD in whom such dysfunction is clinically suspected, that the two noninvasive techniques described here can be applied successfully to a high percentage of patients with COPD, and that the agreement among echocardiographic, radionuclide, and wedge pressure data is excellent.

Aged↗
PubMed1977

The role of bronchial arteriography and therapeutic embolization in hemoptysis.

A case is presented which demonstrates the value of bronchial arteriographic studies in localizing and treating hemoptysis. The patient was bleeding from an old post-tuberculous bulla and for several reasons was not a candidate for surgery. Bronchial arteriographic studies demonstrated both hypervascularity in the region of the cavity and also a mycotic aneurysm of a bronchial artery. After therapeutic embolization with gelatin (Gelfoam), the hypervascularity and aneurysm were no longer opacified. Active bleeding abruptly ceased and, except for a single mild recurrence, has not recurred during the three months since therapeutic embolization. The major theoretic risk of bronchial arteriographic study and therapeutic embolization is spinal injury. It is believed that permanent injury can almost be avoided, providing proper technique is used.

Bronchial Arteries↗
PubMed1976

Effect of hyperinflation on inspiratory function of the diaphragm.

The inspiratory efficiency of the diaphragm during unilateral and bilateral phrenic stimulation (UEPS and BEPS) with constant stimulus was studied in seven dogs from FRC to 120% TLC. Alveolar pressures (PAl) were recorded during relaxation, BEPS and UEPS at each lung volume in the closed respiratory system. From the PAl-lung volume curves, tidal volume (VT), and pressure developed by the diaphragm (Pmus) were derived. Results are summarized below. a) Hyperinflation impaired the inspiratory efficiency of the diaphragm which behaved as an expiratory muscle beyond the lung volume of 103.7% TLC (Vinef). b) The diaphragm during UEPS became expiratory at the same Vinef as during (BEPS. C) The VT-lung volume relationship was linear during BEPS, allowing simple quantitation of VT loss with hyperinflation and prediction of Vinef. d) With only one phrenic nerve stimulated, the functional loss is less pronounced in VT than in Pmus, as compared to BEPS, indicating that the respiratory system was more compliant during UEPS than BEPS. This compliance difference from UEPS to BEPS diminished with severe hyperinflation.

Animals↗
PubMed1976

Acute coccidioidal pleural effusion.

Acute coccidioidal pleural effusions were studied in 28 patients. Coccidioidal pleural effusion appeared to be secondary to direct spread of contigous parenchymal infection, rather than to hematogenous dissemination, in more than 90 per cent of these patients. Only 2 of 28 patients had the concomitant development of disseminated infection, and both patients possessed factors known to predispose to dissemination. Because of the excellent prognosis in most patients, therapy in patients with coccidioidal pleural effusion should be expectant. This is true even when substantial increases occur in complement fixation titers; such elevations were frequent in this series. Cultures of pleural biopsy specimens were the most rewarding cultural source in this series, being positive in all 8 patients in whom such biopsy specimens were cultured. Dermal hypersensitivity, including erythema nodosum and erythema multiforme, was commin in patients whose clinical course was uncomplicated.

Adolescent↗
PubMed1976

Alveolar proteinosis. Lobar lavage by fiberoptic bronchoscopic technique.

Lavage limited to an isolated lobe was performed on multiple occasions using a cuffed fiberoptic bronchoscope in a patient with alveolar proteinosis. Sequential ventilation-perfusion scintiphotoscans were used to preselect and follow the functional behavior of the lavaged lobe. Lavage led to functional improvement. The technique of fiber-optic bronchoscopic lobar lavage is simple and may find application in patients in whom lavage of an entire lung may be hazardous.

Adult↗
PubMed1976

Ventilation-perfusion alterations induced by fiberoptic bronchoscopy.

Pulmonary perfusion (Q) and ventilation (V) scintiphotography was performed in 16 patients undergoing diagnostic fiberoptic bronchoscopic examinations. Regional V/Q did not change in the majority of the patients who developed hypoxemia after bronchoscopic studies. An improvement in V/Q was detectable in the patients with a rise in arterial oxygen pressure (PaO2) after bronchoscopic examination, and this rise was associated in most with the removal of mucous plugs or extensive secretions. The data indicate that the behavior of PaO2 after bronchoscopic study is dependent upon both the extent of lavage and the yield of the procedure in terms of secretions and plugs. The results also indicate that the removal of secretions or plugs can be associated with rapid return of regional V and Q.

Bronchoscopy↗
PubMed1975

Stability in lobar ventilation distribution during change in thoracic configuration.

Stability in lobar ventilation was examined in dogs during bilateral electrophrenic respiration (BEPR) and positive pressure-assisted ventilation (PPAV). Bilateral prior ligation of the lower and middle lobe pulmonary arteries monitoring of upper lobe ventilation as alveolar minute ventilation (VA), middle and lower lobe ventilation as dead space (VD), and VD/VT ratio, both calculated by the Bohr equation. As documented by chest films, transverse and anteroposterior thoracic diameters during BEPR decreased below FRC values whereas thoracic cephalocaudal dimension greatly increased. During PPAV, all thoracic dimensions increased. Despite these dissimilar regional chest movements, VA, VD, and VD/VT ratio were comparable between PPAV and BEPR under conditions of matched tidal volume and respiratory frequency. Stability in upper lobe ventilation during BEPR was maintained by caudal displacement despite the compression of the rib cage, as documented by tantalum bronchography. Lobar-interdependence appears to be the mechanism transmitting negative pleural pressure developed by the diaphragm to the upper lobes via lower and middle lobe inflation.

Animals↗
PubMed1975

Detection of left ventricular failure in patients with adult respiratory distress syndrome.

Fourteen patients with adult respiratory distress syndrome were admitted to the medical intensive care unit and received bedside heart catheterization with the use of a balloon-tipped, flow directed catheter. Four of the 14 (29 percent) were found to have left ventricular failure (LVF), defined as a pulmonary artery wedge pressure greater than 12 mm Hg. Analysis of the standard clinical and laboratory data demonstrated no criteria which could differentiate those patients with LVF from those without. Three of the four patients indentified as having LVF responded to therapy directed toward LVF with substantial clinical improvement.

Adolescent↗
PubMed1975

Management of arterial hypoxemia induced by fiberoptic bronchoscopy.

Twenty patients undergoing fiberoptic bronchoscopy (FOB) (bronchofiberscopy) were studied with serial arterial blood gas analyses. Ten patients were managed using a 40 percent Venturi mask with a 2-cm opening cut out for the FOB; there were ten other patients, with this opening modified by a thin rubber diaphragm with a slit for insertion of the FOB. Both masks decreased the extent of hypoxemia after bronchoscopy, but the mask with the diaphragm provided significantly higher PaO2 values. A significantly higher mean FIO2 was found at the carina in the group using the diaphragm-modified mask. This study suggests that declines in PaO2 after bronchoscopy can be avoided in most patients undergoing diagnostic FOB by using a diaphragm-modified 40 percent Venturi mask during and after the procedure. However, patients with a PaO2 below 60 mm Hg before bronchoscopy may require other measure to avoid potentially hazardous degrees of hypoxemia after bronchoscopy.

Blood Gas Analysis↗
PubMed1975

Purification of human MM and ZZ alpha 1-antitrypsin.

Alpha -1-antitrypsin is the main protease inhibitor in human serum. Certain variants or phenotypes of this protein are associated with diseases of the liver and lung. The availability of purified alpha-1-antitrypsin of various phenotypes would be useful in studies exploring these associations. A two-step purification procedure is presented which involves affinity chromatography on isolubilized conconavalin A followed by preparative starch gel electrophoresis. This simple and rapid method has provided both MM and ZZ alpha-1-antitrypsin in highly pure and active form.

Chromatography, Affinity↗
PubMed1975

The current status of prostaglandins and the lungs.

The prostaglandins are a group of pharmacologically potent lipid compounds whose role in pulmonary pathophysiology remains to be defined. There is not question that these compounds can induce constriction (PGF) or relaxation (PGE) of the smooth muscle in bronchi and pulmonary vessels. There is no question that the lungs are a major site of both the synthesis and degradation. These facts make speculation about the role of the prostaglandins in pulmonary disorders a tempting exercise. However, the current paucity of clinical data prevents any valid assessment of such speculation at this time and emphasizes the need for continued investigation of the role of prostaglandins in patients with lung disease.

Animals↗
PubMed1975

Evaluation of left ventricular performance in acutely ill patients with chronic obstructive lung disease.

Among 28 patients with chronic obstructive pulmonary disease (COPD) with increasing dyspnea, the resting mean pulmonary arterial wedge pressure was elevated (greater than 12mm Hg) in 4 and became abnormal with exercise in 3 other subjects. Stroke volume index was reduced (less than 36 ml/beat/M2) in 16 of 26 patients (62 percent). The resting pre-ejection period index was prolonged (greater than 144 msec) in 17 patients (65 percent), while the left ventricular (LV) ejection time index was reduced (less than 408 msec) in 23 patients (88 percent). The ratio of the pre-ejection period to the LV ejection time was within the normal range (0.309 to 0.381) in only 3 of 26 patients (12 percent). Echocardiographic measurements of LV function were normal in nine patients, seven of whom had one or more abnormal values for systolic time intervals (STIs). These data suggest that reduced LV filing results in abnormal values for STIs in patients with COPD, and therefore that in such patients STIs are not accurate indices of LV function.

Aged↗