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Biomedical subjects

K Ryschon

Publications and source records attributed to K Ryschon.

13 recordsLinked to original sources
PubMed2000

Acute exacerbation of COPD: factors associated with poor treatment outcome.

OBJECTIVES: To determine the effect of age, severity of lung disease, severity and frequency of exacerbation, steroid use, choice of an antibiotic, and the presence of comorbidity on the outcome of treatment for an acute exacerbation of COPD. DESIGN: A retrospective chart analysis over 24 months. SETTING: A university Veterans Affairs medical center. PATIENTS: Outpatients with COPD who were treated with an antibiotic over a period of 24 months for an acute exacerbation of COPD. METHODS: Severity of an acute exacerbation of COPD was defined using the criteria of Anthonisen et al: increased dyspnea, increased sputum volume, and increased sputum purulence. Severity of lung disease was stratified based on FEV(1) percent predicted using American Thoracic Society guidelines (stage I, FEV(1) > or = 50%; stage II, FEV(1) 35 to 49%; stage III, FEV(1) < 35%). Treatment outcome was judged successful when the patient had no return visit in 4 weeks for a respiratory problem. Failure was defined as a return visit for persistent respiratory symptoms that required a change of an antibiotic in < 4 weeks. RESULTS: One-hundred seven patients with COPD (mean age +/- SD, 66.9 +/- 9.5 years) experienced 232 exacerbations over 24 months. First-line antibiotics (trimethoprim-sulfamethoxazole, ampicillin/amoxicillin, and erythromycin) were used to treat 78% of all exacerbations. Treatment failure was noted in 12.1% of first exacerbations and 14. 7% of all exacerbations, with more than half the failures requiring hospitalization. Host factors that were independently associated with treatment failure included the following: FEV(1) < 35% (46.4% vs 22.4%; p = 0.047), use of home oxygen (60.7% vs 15.6%; p < 0. 0001), frequency of exacerbation (3.8 +/- 2.0 vs 1.6 +/- 0.91; p < 0. 001), history of previous pneumonia (64.3% vs 35.1 p < 0.007), history of sinusitis (28.6% vs 8.8%; p < 0.009) and use of maintenance steroids (32.1% vs 15.2% p = 0.052). Using stepwise logistic regression analysis to identify the top independent variables, the use of home oxygen (p = 0.0002) and frequency of exacerbation (p < 0.0001) correctly classified failures in 83.3% of the patients. Surprisingly, age, the choice of an antibiotic, and the presence of any one or more comorbidity did not affect the treatment outcome. CONCLUSION: The results of our study suggest that patient host factors and not antibiotic choice may determine treatment outcome. Prospective studies in appropriately stratified patients are needed to validate these findings.

Acute Disease↗
PubMed1997

Likelihood of malignancy in a solitary pulmonary nodule: comparison of Bayesian analysis and results of FDG-PET scan.

OBJECTIVE: To compare the probability of cancer in a solitary pulmonary nodule using standard criteria with Bayesian analysis and result of 2-[F-18] fluoro-2-deoxy-D-glucose-positron emission tomographic (FDG-PET) scan. SETTING: A university hospital and a teaching Veteran Affairs Medical Center. METHODS: Retrospective analysis of 52 patients who had undergone both CT scan of the chest and a FDG-PET scan for evaluation of a solitary pulmonary nodule. FDG-PET scan was classified as abnormal or normal. Utilizing Bayesian analysis, the probability of cancer using "standard criteria" available in the literature, based on patient's age, history of previous malignancy, smoking history, size and edge of nodule, and presence or absence of calcification were calculated and compared to the probability of cancer based on an abnormal or normal FDG-PET scan. Histologic study of the nodules was the gold standard. RESULTS: The likelihood ratios for malignancy in a solitary pulmonary nodule with an abnormal FDG-PET scan was 7.11 (95% confidence interval [CI], 6.36 to 7.96), suggesting a high probability for malignancy, and 0.06 (95% CI, 0.05 to 0.07) when the PET scan was normal, suggesting a high probability for benign nodule. FDG-PET scan as a single test alone was more accurate than the standard criteria and standard criteria plus PET scan in correctly classifying nodules as malignant or benign. CONCLUSION: FDG-PET scan as a single test was a better predictor of malignancy in solitary pulmonary nodules than the standard criteria using Bayesian analysis. FDG-PET scan can be a useful adjunct test in the evaluation of solitary pulmonary nodules.

Bayes Theorem↗
PubMed1992

Ten-year experience with mitral valve replacement in the elderly.

Limited data are available on mitral valve replacement in the elderly patient. Therefore we report our 10-year experience including predictors of perioperative mortality and subsequent long-term cardiac mortality in elderly patients with mitral valve replacement compared to younger patients. Of the 126 consecutive patients with mitral valve replacement, 26 were older (77 +/- 4, group 1) and 100 were younger (62 +/- 9, group 2) than 70 years. Bioprostheses were used more frequently in patients in group 1 (65% vs 7%, p less than 0.0001). Of the 21 clinical, ECG, hemodynamic, and angiographic variables studied, patients in group 1 had higher pulmonary artery systolic pressure (57 +/- 15 vs 48 +/- 19, p less than 0.05), fascicular block on ECGs (70% vs 33%, p less than 0.005), and greater pump time on cardiopulmonary bypass (160 +/- 75 vs 120 +/- 50 minutes, p less than 0.025). A trend toward a higher perioperative mortality rate was also seen in group 1 (27% vs 12%, p = 0.058). Predictors of perioperative mortality by multivariate analysis were the presence of aortic calcification and prolonged pump time on cardiopulmonary bypass in group 1 and coronary artery disease, female sex, elevated mean pulmonary artery pressure, and postoperative complete atrioventricular block in group 2. During a mean 4-year follow-up period, cardiac mortality and total mortality rates were 42% and 54%, respectively, for group 1 compared to 24% and 35%, respectively, for group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Relation of cytogenetic abnormalities and clinical outcome in metastatic melanoma.

The value of chromosomal analysis is well established in human hematologic neoplasms. In contrast, the relation between chromosomal abnormalities and clinical outcome in solid tumors in humans has received little study. We undertook this study to determine whether chromosomal abnormalities could provide information on the survival of patients with malignant melanoma. Chromosome-banding analysis was performed on tumor-biopsy samples from 62 patients with metastatic melanoma, and recurring cytogenetic abnormalities were correlated with survival. Patients with structural abnormalities of chromosome 7 or 11 had significantly shorter survival than patients without these abnormalities. We conclude that cytogenetic analysis may provide useful prognostic information about patients with metastatic melanoma.

Chromosome Aberrations↗
PubMed1989

Long-term follow-up of patients with echocardiographically detected mitral anular calcium and comparison with age- and sex-matched control subjects.

One hundred seven patients with echocardiographically documented mitral anular calcium (MAC) and 107 age- and sex-matched control subjects without MAC were studied and followed for a mean of 4.4 +/- 2.4 (standard deviation) years. Fourteen (7%) patients were lost to follow-up. Compared with the control group, patients with MAC had higher frequency of precordial murmurs (p less than 0.0001), cardiomegaly (p less than 0.0001), left atrial enlargement (p less than 0.0001), and rhythm and conduction disturbances (p less than 0.0001). During the follow-up, patients with MAC had higher incidence of valve replacement (p less than 0.0025), permanent pacemaker implantation (p less than 0.0025), congestive heart failure (p less than 0.0001), thromboembolic cerebrovascular event (p less than 0.01), sudden death (p less than 0.001) and total cardiac death (p less than 0.0001). However, the frequencies of myocardial infarction, coronary artery bypass surgery and angioplasty, endocarditis or noncardiac death were not significantly different between patients with MAC and the control subjects. Thus, patients with MAC have higher frequencies of precordial murmurs, cardiomegaly, left atrial and ventricular enlargement, rhythm and conduction disturbances. They more frequently undergo valve replacement and permanent pacemaker implantation, develop congestive heart failure and die of cardiac causes than age- and sex-matched control subjects.

Adult↗
PubMed1987

Calcific valvular aortic stenosis with and without mitral anular calcium.

Seventy-six consecutive patients, mean age 66 +/- 9 years (+/- standard deviation), with isolated aortic valve replacement for calcific valvular aortic stenosis (AS) were studied. Mitral anular calcium (MAC) was detected by echocardiography in 45 patients (59%). Patients with MAC were older (p less than 0.01), had greater peak systolic aortic valve gradients (p less than 0.025), lower cardiac indexes (p less than 0.025) and smaller valve areas (p less than 0.05) than patients without MAC. Thirty-three percent of patients (15 of 45) with MAC required permanent pacemaker implantation after aortic valve replacement, compared with only 10% of patients (3 of 31) without MAC (p less than 0.025). During the follow-up of 7 years (mean 3.8 +/- 1.6), 27% of patients (12 of 45) with MAC died from cardiac causes, compared to only 7% (2 of 31) without MAC (p less than 0.025). Thus, patients with AS and MAC are older, have more severe AS, more frequently undergo permanent pacemaker implantation after aortic valve replacement and more frequently die of cardiac causes than patients with AS and no MAC during follow-up.

Adult↗
PubMed1984

Correlation between calcific aortic stenosis diagnosed by two-dimensional echocardiography and cardiac catheterization.

This retrospective study correlates the severity of calcific aortic stenosis determined by two-dimensional (2-D) echocardiography with the aortic valve area determined by catheterization in 57 patients. Aortic valve leaflet calcification was diagnosed by cineangiography in 50 (88%) of 57 patients and by 2-D echo in 57 (100%) of 57 patients (p less than 0.025). An agreement between severity of aortic stenosis by catheterization and 2-D echo occurred in 22 (39%) of 57 patients. Chi-square and logistic regression analyses showed no correlation between the severity of aortic stenosis and the 2-D echo variables: left ventricular wall thickness, left ventricular diastolic dimension, left ventricular systolic dimension, aortic root diameter, and left atrial dimension. We conclude that 2-D echo detects aortic leaflet calcification better than cineangiography. However, the severity of aortic stenosis determined by 2-D echo correlates poorly with the severity of aortic stenosis determined by cardiac catheterization.

Aged↗
PubMed1983

Serial ambulatory monitoring in patients with unstable angina pectoris.

We performed a prospective study by dual-channel ambulatory monitoring performed for 24 to 72 hours immediately after hospitalization for unstable angina. The incidence of ST-segment depression or elevation or ventricular tachycardia or complex premature ventricular complexes (PVCs) in 42 consecutive patients with unstable angina due to coronary artery disease (39 by coronary arteriography) was investigated. During ambulatory monitoring, 28 of 42 patients (67%) exhibited ST-segment depression or elevation, 13 of 42 patients (31%) had ventricular tachycardia or complex PVCs, and 31 of 42 patients (74%) had either ST-segment depression or elevation, ventricular tachycardia, or complex PVCs. Ventricular tachycardia or complex PVCs occurred in 10 of 20 patients (50%) with abnormal left ventricular function and in 3 of 22 patients (14%) with normal left ventricular function (p less than 0.025). We found that 72 hours of ambulatory monitoring was not more useful than 48 hours in detecting the incidence of ST-segment depression or elevation, ventricular tachycardia, or complex PVCs. Ambulatory monitoring did not help in clinically differentiating patients with left main or 3-vessel disease from 1-vessel or 2-vessel disease. In addition, ambulatory monitoring did not help in predicting which patients with unstable angina would require coronary artery surgery.

Aged↗
PubMed1983

Diagnostic and prognostic significance of exercise-induced premature ventricular complexes in men and women: a four year follow-up.

Two hundred eighty patients (197 men and 83 women) with normal rest electrocardiograms and no history of prior myocardial infarction were referred for evaluation of chest pain. It was found that exercise-induced premature ventricular complexes had a lower sensitivity, specificity, positive predictive value and negative predictive value in predicting significant coronary artery disease than exercise-induced ST segment depression greater than or equal to 1 mm. The incidence of exercise-induced premature ventricular complexes was not significantly different in patients with no significant coronary artery disease, single vessel disease or multivessel disease. The site of origin of exercise-induced premature ventricular complexes was not helpful in predicting the presence or severity of coronary artery disease. At a mean follow-up period of 47.1 months, exercise-induced premature ventricular complexes did not predict coronary events (cardiac death or nonfatal myocardial infarction) in men or women.

Adult↗
PubMedDate not supplied

Cost-minimization analysis of initial antihypertensive therapy in patients with mild-to-moderate essential diastolic hypertension.

In addition to efficacy and safety, the cost of therapy has become an increasingly important factor to consider when selecting drugs to treat patients with mild-to-moderate hypertension. However, acquisition prices alone do not determine the total cost of therapy. To better assess total costs, we conducted a systematic, retrospective, cost-minimization analysis of drugs used to treat 673 patients with newly diagnosed, mild-to-moderate (> 95 to < 110 mmHg) diastolic hypertension between the years 1985 and 1992. Patients included in the study had started antihypertensive monotherapy, and a minimum of one dose titration was required before adding another antihypertensive agent to the regimen. A patient had to have a diastolic blood pressure of < or = 90 mmHg while undergoing therapy to be included in the analysis. Drug classes included diuretics, beta-adrenergic blockers, centrally acting alpha 2-agonists, alpha 1-adrenergic blockers, calcium channel blockers, and angiotensin-converting enzyme (ACE) inhibitors. Costs, adjusted to 1992 price levels, were analyzed for 32 individual agents for each of the following five cost variables: initial drug acquisition, supplemental drug acquisition, laboratory monitoring, clinic visits, and treatment of side effects. Mean total costs per patient for all five variables by drug class were $895 for beta-blockers, $1043 for diuretics, $1165 for centrally acting alpha 2-agonists, $1243 for ACE inhibitors, $1288 for alpha 1-blockers, and $1425 for calcium channel blockers. However, costs within each class varied considerably. Acquisition cost was often a poor predictor of the total cost of treatment. Therefore, acquisition cost must be considered in conjunction with a number of outcome variables to assess the true cost of antihypertensive therapy.

Adrenergic alpha-Agonists↗