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Biomedical subjects

K M Moser

Publications and source records attributed to K M Moser.

At least 91 records · Page 5Linked to original sources
PubMed1988

Doppler assessment of changes in right-sided cardiac hemodynamics after pulmonary thromboendarterectomy.

It is not known whether Doppler echocardiography can accurately follow changes in right-sided cardiac hemodynamics after a therapeutic intervention in patients with pulmonary artery (PA) hypertension. Therefore, Doppler measurements of the maximal velocity of the tricuspid regurgitant jet and the acceleration time of the PA velocity profile were obtained in 28 patients before and after pulmonary thromboendarterectomy for chronic thromboembolic PA hypertension. Doppler values were compared with hemodynamic variables obtained at cardiac catheterization. Postoperatively, decreases in mean PA pressure (50 +/- 14 to 28 +/- 8 mm Hg), transtricuspid systolic pressure difference (69 +/- 21 to 36 +/- 14 mm Hg) and Doppler measurement of the maximal velocity of the tricuspid regurgitant jet (4.1 +/- 0.7 to 2.7 +/- 0.5 m/s) were noted, while acceleration time increased (57 +/- 16 to 94 +/- 18 ms, all p less than 0.001) compared with preoperative values. For the population as a whole, the calculated systolic transtricuspid pressure difference determined from the maximal velocity of tricuspid regurgitation correlated well with the catheterization systolic transtricuspid pressure difference (r = 0.93, p less than 0.001) and the acceleration time correlated with mean PA pressure (r = -0.81, p less than 0.001). More importantly, the change in the maximal velocity of tricuspid regurgitation for postoperative patients was found to correlate with the change in catheterization systolic transtricuspid pressure difference (r = 0.82, p less than 0.001), while the change in acceleration time correlated weakly with the change in mean PA pressure (r = -0.41, p = 0.053).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Early changes of right heart geometry after pulmonary thromboendarterectomy.

To determine the changes in right heart hemodynamics and geometry early after surgery for chronic pulmonary hypertension due to large vessel thromboembolic occlusion, 30 patients were evaluated 8 +/- 8 days (mean +/- SD) before and 6 +/- 4 days after pulmonary thromboendarterectomy by two-dimensional echocardiography and right heart catheterization. Surgery resulted in an early significant improvement in hemodynamic variables including mean pulmonary artery pressure (48 +/- 12 to 28 +/- 8 mm Hg, p less than 0.001), right ventricular systolic pressure (76 +/- 20 to 47 +/- 15 mm Hg, p less than 0.001), pulmonary vascular resistance (935 +/- 620 to 278 +/- 252 dynes.s.cm-5, p less than 0.001) and cardiac index (2.0 +/- 0.5 to 2.9 +/- 0.6 liters/min per m2, p less than 0.001). Similarly, echocardiographic variables of right heart structures, which were well outside the normal range preoperatively, improved significantly early after thromboendarterectomy. These included diameters of the pulmonary artery (2.8 +/- 0.3 to 2.4 +/- 0.4 cm, p less than 0.001), inferior vena cava (2.9 +/- 0.6 to 2.2 +/- 0.4 cm, p less than 0.001) and right atrium (6.8 +/- 1.5 to 5.9 +/- 1.5 cm, p less than 0.001) as well as right ventricular short axis (4.5 +/- 0.8 to 3.7 +/- 0.8 cm, p less than 0.001) and long axis (8.7 +/- 0.9 to 8.1 +/- 0.9 cm, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

The treatment of endobronchial stenosis using balloon catheter dilatation.

Acquired bronchial stenosis has been associated with sleeve resection, tuberculosis, sarcoidosis, and prolonged intubation. Various modalities of therapy for the relief of such stenoses include surgery, cryotherapy, and laser photoresection. Several recent reports have described the use of angioplasty balloon catheters for dilatation of stenotic areas. In two patients with endobronchial stenosis, we found that balloon dilatation, using either angioplasty or valvuloplasty catheters, in combination with laser photoresection can be safely and effectively performed with alleviation of pulmonary symptoms.

Aged↗
PubMed1988

Transthoracic needle aspiration biopsy following negative fiberoptic bronchoscopy in solitary pulmonary nodules.

To evaluate the utility of transthoracic needle aspiration biopsy (TTNAB) following negative fiberoptic bronchoscopy (FOB) in a patient with a solitary pulmonary nodule (SPN), we reviewed the records from 262 patients who had undergone TTNAB over an eight-year period. Fifty-eight patients had a SPN and met the criteria for inclusion in this series. Twenty-five of these (43 percent) were diagnosed by TTNAB; 24 had malignant lesions; one had M tuberculosis. Of the remaining 33 patients, 18 went on to definitive diagnostic procedures (surgery, repeat FOB or TTNAB). Nine of these patients had a malignancy. Fifteen patients were followed long-term; one was diagnosed with carcinoma two years after the initial work-up. Carcinoma was not found in any patient under 40 years of age. A benign lesion was diagnosed by TTNAB in only two patients. We conclude that TTNAB is a valuable procedure in the evaluation of patients with a SPN and negative FOB. While a negative FOB and TTNAB do not assure that the lesion is benign, a complex of variables influences the decision regarding thoracotomy vs careful follow-up.

Adult↗
PubMed1988

Perfusion scan findings understate the severity of angiographic and hemodynamic compromise in chronic thromboembolic pulmonary hypertension.

Major vessel chronic thromboembolic pulmonary hypertension is potentially remediable by thromboendarterectomy. The diagnosis often has been delayed because a lung perfusion scan demonstrated modest defects thought to be incompatible with severe vascular obstruction. To define the relationships between perfusion scan abnormalities, angiographic findings, and hemodynamic data, we analyzed 25 consecutive patients with chronic major vessel thromboembolic pulmonary hypertension who subsequently underwent thromboendarterectomy. We found that the perfusion lung scan consistently caused us to underestimate the severity of pulmonary arterial obstruction as defined by pulmonary angiography. Furthermore, there was no significant correlation between the severity of hemodynamic compromise and the extent of obstruction defined by perfusion scan or angiogram. These findings suggest that, when pulmonary hypertension is known or suspected, the diagnosis of correctable, chronic major vessel obstruction should be pursued by angiography and hemodynamic assessment even though the perfusion scan may demonstrate only two segmental defects.

Adult↗
PubMed1988

Effect of heparin, tissue plasminogen activator, and increased intracaval pressure on the acute morbidity of Greenfield filter insertion.

The effects of anticoagulation, thrombolytic therapy, and augmented intracaval pressure on the risks of acute caval hemorrhage from Greenfield filter insertion have not been rigorously investigated. To examine these risk factors, the device was placed in three groups of five dogs. Group 1 served as controls, with filter placement only. Groups 2 and 3 received anticoagulants before surgery. Group 3 was additionally given a continuous infusion of tissue plasminogen activator begun immediately after filter insertion. Animals were killed after a 6-hour period of observation and measurement. A second phase was carried out at autopsy in group 3: intracaval pressure was augmented and its effects on caval integrity noted. During the period of observation there were no significant decrements in central venous pressure or hematocrit. At autopsy, no evidence of caval hemorrhage and no caval perforations were found. Increased intracaval pressure did not alter these findings. These results support the clinical experience with the device, and suggest that the risk of acute hemorrhage from a properly seated filter is minimal, even with concurrent use of heparin and thrombolytic agents or high caval pressures.

Animals↗
PubMed1988

Operative predictors of delirium after pulmonary thromboendarterectomy. A model for postcardiotomy delirium?

Pulmonary thromboendarterectomy is an innovative surgical technique for treating pulmonary hypertension caused by chronic thromboembolism. The procedure uses cardiopulmonary bypass but necessitates dramatically longer bypass times than coronary artery bypass grafting or valve operations. We prospectively evaluated 22 patients undergoing pulmonary thromboendarterectomy to determine the incidence of delirium and its relationship to certain preoperative and postoperative medical variables as well as to duration of cardiopulmonary bypass, deep hypothermia, and circulatory arrest. Delirium occurred in 77% of patients with a peak incidence around 72 hours postoperatively. No preoperative or postoperative medical variable distinguished delirious from nondelirious patients. Total bypass time was not associated with delirium, but deep hypothermia time and total circulatory arrest time were both strongly associated. Overall prediction of delirium was 81% when total circulatory arrest time was considered. Further analysis suggested that a total circulatory arrest time greater than 55 minutes was both sensitive to (82%) and specific for (80%) delirium. Implications for the mechanism of postcardiotomy delirium and future research directions are discussed.

Cardiopulmonary Bypass↗
PubMed1988

Perfusion lung scans provide a guide to which patients with apparent primary pulmonary hypertension merit angiography.

There is hesitancy, based on the perceived risk, to do pulmonary angiography in patients believed to have primary pulmonary hypertension. Yet pulmonary hypertension due to major-vessel, chronic thromboembolism mimics primary pulmonary hypertension clinically and on standard laboratory tests. Because thromboembolic pulmonary hypertension is potentially remediable by thromboendarterectomy and primary pulmonary hypertension is not, differentiating between these disorders is essential. Angiography is required in patients with thromboembolic pulmonary hypertension to define the anatomic location of the thrombi. In evaluating perfusion lung scans of 110 patients with pulmonary hypertension to determine whether the scan might provide a guide to selecting those patients who merit angiography, no segmentalsize perfusion defects were noted on the scans of 64 patients with primary pulmonary hypertension, whereas all 46 patients with thromboembolic hypertension had one or more defects that were segmental in size or larger. These data indicate that a perfusion lung scan should be done in patients with pulmonary hypertension of uncertain cause and that those with one or more segmental or larger defects merit pulmonary angiography before being diagnosed as having primary pulmonary hypertension.

Angiography↗
PubMed1987

Harvesting the noncirculating pool of polymorphonuclear leukocytes in rats by hetastarch exchange transfusion (HET): yield and functional assessment.

Isolation of polymorphonuclear leukocytes (PMN) provides an opportunity to study PMN activity in vitro and to label PMN for study of in vivo kinetics. However, simple phlebotomy (SP) of a small animal frequently yields too few PMN for in vitro handling, while PMN harvested from an induced-peritonitis may not accurately reflect PMN in a less stimulated state. We report a novel method of harvesting PMN from the circulation of rats, using hetastarch exchange transfusion (HET), which is both time and animal sparing. HET harvested 8-fold more PMN than SP. In vitro cell function was examined with assays of adherence, chemotaxis, bacterial killing, and superoxide generation. No significant (p less than 0.05) difference was found between PMN obtained by HET and pooled-PMN obtained by SP. In vivo function was examined following labeling with indium111-oxine. The kinetics pattern described suggested normal migratory activity when compared to previous reports. The data demonstrate that rats possess a relatively large, noncirculating pool of PMN which is readily accessible by HET.

Animals↗
PubMed1987

Management of recurrent venous thromboembolism.

We have described our current criteria for selecting those patients with acute V T-E who merit long-term protection, for accomplishing the acute to long-term transition efficiently and for deciding when such protection can be interrupted. Naturally, in individual patients, special circumstances may exist which alter these decisions. Also, it is evident that additional studies are needed so that this sequence of decision-making can be improved. Our current approach contains a number of rather arbitrary components. Furthermore, if effective thrombolytic therapy does become available, we will need to reevaluate current criteria for long-term protection from recurrence.

Anticoagulants↗
PubMed1987

Pulmonary penetration of alpha 1-proteinase inhibitor administered parenterally to dogs.

To study the penetration of alpha 1-proteinase inhibitor (A1Pl) into the lungs of healthy dogs, 83 mg/kg of active A1Pl was administered intravenously over 30 min followed by a bolus of 131I-A1Pl. Animals were lavaged 2 to 72 h after infusion, sequential gamma camera scans were acquired, and urine was analyzed for the excretion of desmosine. After a distribution phase, infused A1Pl left the bloodstream with a half-life of 103 +/- 24 h. Analysis of plasma antiprotease activity demonstrated preservation of function of the infused A1Pl. Lavage fluid A1Pl concentration and activity were significantly increased 24 h after infusion. Gamma camera scans demonstrated that lung, liver, and spleen acquired 131I-A1Pl similarly; radioactivities per gram of tissue of these organs were similar at autopsy. Excretion of desmosine did not decrease from a baseline of 157 +/- 59 nmol/24 h after A1Pl infusion, indicating no effect of A1Pl infusion on background elastolysis. These data suggest that intravenous administration of A1Pl can raise lung antiproteinase levels within 24 h despite the absence of preferential uptake by the lung of the infused protein.

Animals↗
PubMed1987

Pulmonary artery obstruction due to malignant fibrous histiocytoma.

Obstruction of the pulmonary artery can be due to a variety of conditions, including chronic thromboembolic disease, neoplasia, and fibrosing mediastinitis. Differentiation can be difficult. We report a case of malignant fibrous histiocytoma causing intravascular obstruction and include a review of the literature.

Aged↗
PubMed1987

Thromboendarterectomy for chronic, major-vessel thromboembolic pulmonary hypertension. Immediate and long-term results in 42 patients.

Since 1970, forty-two patients with pulmonary hypertension due to chronic, thromboembolic obstruction of the major pulmonary arteries have had pulmonary thromboendarterectomy at the University of California, San Diego, and the San Diego Veterans Medical Centers. Duration of symptoms before admission averaged 4.4 years, with many alternative diagnoses having been made. At admission, 29 patients had class IV disease by New York Heart Association criteria, and 12, class III. Immediately after surgery, pulmonary vascular resistance declined significantly (p less than 0.001) from 897 +/- 352 dynes/s.cm-5 to 278 +/- 135 dynes/s.cm-5. Seven patients with class IV disease died in the postoperative period. Of the 35 survivors (mean follow-up, 28 months), 16 had class I disease; 18, class II; and 1, class III. Of the 17 patients who have returned for cardiac catheterization at 4 to 12 months after surgery, a further decline (p less than 0.05) in pulmonary vascular resistance has occurred. This experience indicates that the disorder is commoner than we previously suspected and that thromboendarterectomy is feasible, even in patients with severe and protracted hemodynamic compromise.

Adult↗
PubMed1987

Do indium 111-labeled polymorphonuclear leukocytes detect neutrophil-prominent, fibrosing lung disease in rats?

The role of polymorphonuclear leukocytes (PMNs) in fibrotic lung disease remains poorly defined, but PMN prominence may predict a poor response to therapy in some patients. The bleomycin injury to rats represents a model of PMN-prominent alveolitis leading to fibrosis. We examined a method of identifying the alveolitis during its PMN-prominent phase with indium 111-labeled homologous PMNs (In-PMNs). When pairs of injured and uninjured rats were compared, greater activity was consistently found persisting in the lung images of the injured rats, both several hours (early) and a day (late) after injection of In-PMNs. Differences could likewise be identified when lung activity was normalized to activity of the injectate, the spleen, and variably the liver, as determined from organ images. These differences in gamma camera images were supported by direct measurement of activity in organs obtained by killing the animals after scanning. When groups of animals were compared, lung/spleen ratios appeared to most consistently differentiate the group of normal animals from those with alveolitis. These methods may provide a noninvasive means of identifying PMN prominence in the lung, which occurs in some fibrotic processes.

Animals↗