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Biomedical subjects

R A Matthay

Publications and source records attributed to R A Matthay.

At least 55 records · Page 3Linked to original sources
PubMed1987

Lack of association of pleural effusion with chronic pulmonary arterial and right atrial hypertension.

Right atrial hypertension has been considered to have a major physiologic influence on the formation of transudative pleural effusions. Since pleural fluid is thought to be cleared primarily by the parietal pleural lymphatic vessels that empty into the systemic veins, systemic venous hypertension secondary to right atrial hypertension should decrease the lymphatic drainage of the pleural space. We retrospectively studied nine patients and prospectively studied 18 patients with long-term right atrial or pulmonary arterial hypertension (or both). All patients had stable respiratory symptoms, and none had a significantly elevated pulmonary arterial wedge pressure. Our purpose was to determine the relationship of right atrial and pulmonary arterial hypertension to the development of transudative pleural effusions. Posteroanterior and bilateral decubitus chest roentgenograms and ultrasound were used to detect pleural effusions. Pleural effusions were not identified in any of the 27 patients, even in four patients with right atrial pressures greater than 20 mm Hg. We conclude that chronic elevation of right atrial pressure or pulmonary arterial pressure (or both) alone is not a cause of pleural effusion. In contrast, elevation of left atrial and pulmonary arterial wedge pressures is associated with the formation of transudative pleural effusions in man. Thus, if pleural effusions are detected in patients who have cor pulmonale, a search should be made for coexisting left heart failure or a primary cause of pleural inflammation, such as pulmonary emboli or infection.

Blood Pressure↗
PubMed1987

Timing of oral anticoagulation therapy in the treatment of angiographically proven acute pulmonary embolism.

The optimal time to begin oral anticoagulation therapy with warfarin sodium in the treatment of acute pulmonary embolism has not been defined. To evaluate the relative cost, efficacy, and safety of early initiation of warfarin therapy, we reviewed the medical records of 38 patients with angiographically proven pulmonary embolism. Patients were divided into two groups: those who received warfarin early (less than or equal to 3 days after initial heparin sodium bolus, n = 17) and those who were treated late (greater than 3 days after initial heparin bolus, n = 21). After three months of follow-up, there was a similar incidence of mortality, recurrent pulmonary embolism, and bleeding complications in both treatment groups. Length of hospitalization was substantially less in the early group (9.6 +/- 2.0 vs 11.8 +/- 2.1 days). Early warfarin therapy in the treatment of acute pulmonary embolism appears to be both cost-effective and safe. A prospective multicenter controlled trial should be performed.

Administration, Oral↗
PubMed1987

Pulmonary tumor embolism: a critical review of clinical, imaging, and hemodynamic features.

Pulmonary tumor embolism is a common finding at autopsy but is generally perceived as a difficult diagnosis to make ante mortem. After a retrospective review of 164 reported cases of pulmonary tumor embolism, we identified a typical profile of clinical, laboratory, and imaging features that may permit confident clinical diagnosis in most patients with this condition. The clinical features include a documented or suspected underlying malignancy, acute to subacute onset of dyspnea, and signs of cor pulmonale. Supportive laboratory features are hypoxemia or increased alveolar-arterial oxygen gradient, and invasive or noninvasive evidence of pulmonary artery hypertension. Typical imaging findings are normal chest radiographs; multiple, subsegmental, peripheral perfusion defects on ventilation-perfusion lung scans; and delayed filling with or without subsegmental filling defects but without a thrombus on pulmonary angiogram. Radiolabeled monoclonal antibody imaging and pulmonary microvascular cytology sampling techniques are promising diagnostic tests for early diagnosis of pulmonary tumor embolism.

Adult↗
PubMed1986

Theophylline improves global cardiac function and reduces dyspnea in chronic obstructive lung disease.

Theophylline has been utilized widely as a bronchodilator, but only in recent years have its positive cardiovascular effects been recognized in patients with chronic obstructive pulmonary disease. After intravenous administration of aminophylline, pulmonary artery pressures and pulmonary vascular resistance are reduced, and both right and left ventricular ejection fraction are increased. Similar short- and long-term enhancement of biventricular performance is produced by orally administered long-acting theophylline. Possible mechanisms for this theophylline-induced improvement in right and left ventricular systolic pump performance include enhanced ventricular inotropy and reduced ventricular afterload. A recent study has established that orally administered theophylline also reduces dyspnea in patients with chronic obstructive pulmonary disease. Accordingly, in patients with chronic obstructive pulmonary disease theophylline may be useful for reducing pulmonary artery pressure and pulmonary vascular resistance, treating right or left heart failure, reducing dyspnea, and partially reversing airway obstruction.

Dyspnea↗
PubMed1986

Imaging techniques for assessing cardiovascular performance in chronic obstructive pulmonary disease.

A variety of imaging techniques are now available for evaluating cardiovascular function. Plain chest radiographs, radionuclide angiocardiography, 201Tl myocardial imaging, and M-mode and two-dimensional echocardiography have been used to detect pulmonary hypertension, right ventricular enlargement, and occult ventricular performance disturbances in patients with chronic obstructive pulmonary disease (COPD). Furthermore, radionuclide angiocardiography and echocardiography combined with hemodynamic measurements have been used to assess short- and long-term cardiovascular effects of such therapeutic agents as theophylline, beta-adrenergics, vasodilators, digitalis, and oxygen. This review evaluates these imaging techniques and their application to COPD patients.

Cystic Fibrosis↗
PubMed1986

Drug-induced pulmonary disease. Part 1: Cytotoxic drugs.

Numerous pharmacologic agents used in the treatment of cancer have been linked to pulmonary toxic side effects. Mechanisms of damage by these drugs include direct pulmonary toxicity and indirect effects through enhancement of inflammatory reactions. Risk factors for development of pulmonary damage have been elucidated for some agents but they remain unclear for others. Clinical features are similar for most categories of cytotoxic agents, and the most common associated clinical syndrome is chronic pneumonitis/fibrosis. Treatment and outcome vary with each particular agent. In Part 1 of this review, clinical aspects and pathogenic mechanisms of cytotoxic drug-induced pulmonary disease are discussed.

Aging↗
PubMed1986

Drug-induced pulmonary disease. Part 2: Noncytotoxic drugs.

Nonchemotherapeutic drugs may also cause pulmonary parenchymal alterations. Mechanisms of pulmonary damage by these agents are diverse and may involve alterations of pulmonary homeostasis. Clinical features of noncytotoxic, drug-induced pulmonary disease are more heterogeneous than those associated with cytotoxic drugs, and several clinical syndromes are equally represented. Treatment and outcome vary with each individual drug and clinical presentation. In part 2, clinical and pathogenic aspects of noncytotoxic, drug-induced pulmonary disease are discussed.

Anti-Arrhythmia Agents↗
PubMed1986

Acute effects of passive smoking on lung function and airway reactivity in asthmatic subjects.

We studied the acute effects of one hour of passive cigarette smoking on the lung function and airway reactivity of nine young adult asthmatic volunteers. At the time of this study, the subjects were asymptomatic and had normal or nearly normal lung function. Passive smoking produced no change in expiratory flow rates. However, there was a small decrease in nonspecific bronchial reactivity, as assessed by methacholine inhalation challenge testing (p = 0.022). Pharmacologically active substances present in cigarette smoke, such as nicotine, may explain the observed change in airway reactivity. Although the finding of decreased airway reactivity might suggest that passive smoking produces a "protective" effect on the underlying asthma, the observed change in reactivity was slight and of uncertain clinical significance. We conclude that passive smoking presents no acute respiratory risk to young asymptomatic asthmatic patients.

Adult↗
PubMed1986

Enlarging, atypically located pericardial cyst. Recent experience and literature review.

Pericardial cysts frequently are recognized when they present in a cardiophrenic angle, but may not be suspected when they occur elsewhere in the chest. To highlight the unusual presentations of pericardial cysts, we present two patients with cysts in the upper mediastinum and review the reported experience with similar lesions. Our patients' cysts are particularly instructive because one cyst enlarged over 23 months and because the other did not appear cystic on a computerized tomographic scan. Because percutaneous aspiration may be an attractive alternative to surgical resection when a pericardial cyst is suspected, clinicians should include pericardial cyst in the differential diagnosis of upper mediastinal masses.

Adult↗
PubMed1986

Pulmonary sequelae and lung repair in survivors of the adult respiratory distress syndrome.

The high in-hospital mortality of ARDS has not diminished over the past 10 years, despite improvements in supportive intensive care. Much of the mortality arises from infections, particularly sepsis and pneumonia, and from organ failure, especially kidney failure. The rapid advances in understanding the interlocking pathophysiologic mechanisms of ARDS have not yet been translated into therapeutic trials of new methods for diminishing the injury or for stimulating normal repair. In part, this is because it is difficult to predict which high-risk patients will develop ARDS and then intervene early in the injury process. Patients in whom the risk for ARDS is extremely high have a very high mortality even without ARDS, thereby making efficacy of an early or prophylactic therapy quite difficult to prove. In spite of severe pathologic abnormalities, including fibrosis, early in the course of ARDS, most survivors return to almost normal pulmonary function. The few cases that have been studied with serial biopsies demonstrate resolution of fibrosis. This amazing recovery poses many fascinating questions about how the lung repairs itself. Given the heterogeneous causes of ARDS and the large number of structural, cellular, and biochemical abnormalities described, one can postulate that any one of numerous factors is important in normal repair. Most promising of these are the degree of basement membrane damage, the control of type II cell proliferation and differentiation, the control of collagen synthesis, the anatomic localization of fibrosis, and the control of collagenase action. These interactions of epithelial and mesenchymal tissues probably recreate the process of lung development in the injured adult lung. At a clinical level, the role of oxygen toxicity remains a significant issue. Oxygen acting as an oxidant may be partially responsible for the small airways disease seen in approximately one quarter to one third of survivors. The mortality data stress the need for better ways of preventing and diagnosing lung infections. Better definition of the clinical factors that put survivors at risk for persistent loss of lung function is also needed, and could define a subgroup in which trials of agents designed to improve repair would be most worthwhile. More information about the long-term pathologic course, though difficult to obtain, would also be very important. Perhaps some registry of ARDS survivors would permit closer follow-up and make available more late autopsy pathology when these people die of other causes. The rapid time course of ARDS provides an ideal testing ground for agents designed to either decrease lung injury or stimulate repair.(ABSTRACT TRUNCATED AT 400 WORDS)

Humans↗
PubMed1986

Chronic obstructive pulmonary disease.

Morbidity and mortality associated with chronic airway disease are expected to continue to rise over the coming years. Accordingly, increased attention will need to be directed toward the diagnosis and treatment of COPD in the elderly population. Cessation of cigarette smoking should be pursued in all patients regardless of age. The goals of bronchodilator therapy are to reduce respiratory symptoms and to improve functional capacity without causing adverse effects. In addition, supplemental oxygen, phlebotomy for polycythemia, general exercise training, and specific respiratory muscle training may further augment exercise tolerance. Complications of COPD, such as upper respiratory infections and right heart failure, should be recognized early and treated appropriately. Implementation of a pulmonary rehabilitation program, as discussed in the next article, should complement medical therapy in the treatment of elderly patients with COPD.

Adrenal Cortex Hormones↗
PubMed1986

Lung cancer in the elderly.

Lung cancer is the most common malignancy in the elderly population and was responsible for greater than 125,000 deaths in 1985. Although advances have been made in the areas of diagnosis and staging, the long-term outlook for the disease remains poor, primarily because of dissemination of disease prior to diagnosis. Despite this, several studies suggest that lung cancer in the elderly is a more indolent disease process, which should be treated in the same manner as it is in the young population.

Adult↗
PubMed1986

Intratumoral Bacillus Calmette-Guérin immunotherapy prior to surgery for carcinoma of the lung: results of a prospective randomized trial.

A prospective randomized trial of preoperative intratumoral therapy with Bacillus Calmette-Guérin (BCG) was conducted in non-small cell lung cancer patients. Eighty-eight patients (48 BCG-treated and 40 control subjects) were entered into the study; three control subjects were removed from data analysis because histology revealed pathology other than non-small cell lung cancer. There were no differences between BCG-treated and control patients in sex, age, cigarettes smoked per day, pack-years of cigarette smoking, white blood cell count, or number of peripheral blood lymphocytes. Toxicity of BCG was limited to transient malaise and fever (average peak temperature, 38.7 degrees C). There was no significant difference in outcome (recurrence or survival) between BCG-treated and control groups with Stage I or Stage III tumors; there were too few Stage II tumors for separate statistical analysis. Outcome was not affected within or between the two treatment groups by tuberculin skin test status. Combining both treatment groups, Stage III patients had a worse outcome than did Stage I-II patients, non-squamous cell tumor patients (large cell and adenocarcinoma) had worse outcomes than did squamous cell tumor patients, and men had a worse outcome than women. We conclude that, although preoperative intratumoral BCG therapy is safe, it does not lengthen disease-free interval or prolong survival in patients with non-small cell lung cancer.

Bacterial Vaccines↗
PubMed1985

Volumetric responses of right and left ventricles during upright exercise in normal subjects.

We evaluated the volumetric responses of the right and left ventricles to upright exercise using two noninvasive methods, first-pass radionuclide angiocardiography and the CO2 rebreathing technique, in nine normal subjects. Right (RV) and left (LV) ventricular ejection fractions, heart rate, and cardiac index were determined at rest and during steady-state exercise on the bicycle ergometer at 50% of maximal O2 consumption. From these data, stroke volume index (SVI), end-diastolic volume index (EDVI), and end-systolic volume index (ESVI) were derived. SVI increased from 40 +/- 7 ml/m2 at rest to 59 +/- 13 ml/m2 with exercise (P less than 0.001). RVEDVI increased significantly from 82 +/- 16 ml/m2 at rest to 95 +/- 21 ml/m2 during exercise (P = 0.008), while there was no significant change in RVESVI with exercise. Changes in LVEDVI and LVESVI during upright exercise were similar to the right ventricle. The increase in systolic blood pressure during exercise, along with no change in LVESVI, indicated enhanced ventricular contractility. The normal augmentation in SVI during submaximal exercise was due to both the Frank-Starling mechanism and an increased contractile state. Application of these or similar techniques may be useful in evaluating ventricular performance in patients with cardiorespiratory dysfunction.

Blood Pressure↗
PubMed1985

Sustained-release theophylline reduces dyspnea in nonreversible obstructive airway disease.

Although orally administered theophylline has been prescribed widely in patients with nonreversible airway obstruction, symptomatic benefit has not been established. To assess the effects of orally administered theophylline on dyspnea, we performed a randomized, double-bind, crossover, placebo-theophylline clinical trial in 12 ambulatory male patients with moderate to severe nonreversible airway obstruction. Dyspnea was rated using 2 clinical indexes based on 3 components affecting breathlessness: functional impairment, magnitude of task that evokes dyspnea, and the associated magnitude of effort. Dyspnea and physiologic parameters were measured on 4 occasions: at baseline, 4 wk after initial treatment, a second baseline after a 2-wk washout period, and 4 wk after the second medication. For the 12 patients, mean age (+/- SD) was 60 +/- 7 yr, forced expiratory volume in one second was 1.36 +/- 0.67 L (mean, 40% of predicted), and arterial oxygen tension was 71 +/- 10 mmHg. During the treatment phase, all patients had a therapeutic theophylline blood level (range, 12 to 19 micrograms/ml). Theophylline significantly decreased the components of functional impairment (p = 0.02) and magnitude of task (p = 0.02) relating to dyspnea, as well as the overall dyspnea rating (p = 0.01). There were no significant differences between placebo and theophylline therapy for spirometry, arterial blood gas tensions, and the 12-min walking distance. Thus, sustained-release theophylline significantly reduced dyspnea in these ambulatory patients with moderate to severe nonreversible airway obstruction without altering lung function, gas exchange, or exercise performance.

Administration, Oral↗