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Biomedical subjects

L Goldman

Publications and source records attributed to L Goldman.

At least 289 records · Page 16Linked to original sources
PubMed1988

Assessment of the patient with known or suspected ischaemic heart disease for non-cardiac surgery.

The perioperative care of the patient with known or suspected ischaemic heart disease requires careful co-ordination among the anaesthetist, surgeon and medical consultant. Careful preoperative evaluation can aid the identification of risk, the selection of preoperative interventions that may reduce risk, and decisions on intraoperative and postoperative monitoring. Although uncontrolled observational data suggest that such careful management allows for improved outcome, more carefully controlled studies are required to determine the precise benefits and cost-effectiveness of many of the expensive and often invasive interventions that are currently available.

Adult↗
PubMed1988

Asymmetric stratification. An outline for an efficient method for controlling confounding in cohort studies.

Confounding is usually controlled by either cross-stratification or multivariate modeling. The first approach is simple and intuitive, but it is not practical for controlling many factors. The second approach, although less intuitive, may provide a more efficient means for controlling many confounders, but its ability to control confounding depends on the appropriateness of the chosen model. Hybrid methods based on a multivariate confounder score or a propensity score combine the favorable characteristics of both methods and may be better suited for controlling many confounders. However, the resulting strata are defined by subranges of a multivariate model, and, therefore, may possess little intrinsic meaning. The authors propose the principle of asymmetric stratification to control efficiently a number of confounders in cohort studies while retaining the intuitive appeal and general framework of cross-stratification. The proposed method resembles a propensity score analysis but does not use a multivariate model to define the strata. Instead, strata are defined by the categories of only a subset of the original potential confounders. The authors also demonstrate how our proposed method can be implemented by an application of classification and regression trees (CART) (recursive partitioning), as outlined by Breiman et al. (Classification and Regression Trees. Belmont, CA: Wadsworth, 1984). Computer simulations and an actual example suggest that the proposed method is a potentially simpler alternative to the standard propensity score analysis. Specific recommendations on how the proposed method can be improved are also presented.

Aged↗
PubMed1988

3'-Azido-3'-deoxythymidine (AZT) inhibits proliferation in vitro of human haematopoietic progenitor cells.

Peripheral blood cytopenias are a serious, dose-limiting toxicity of AZT therapy in patients infected by HIV. To evaluate the mechanism by which cytopenias develop, AZT effects of haematopoietic differentiation and growth were measured in serum-free, nucleoside-depleted cultures of normal human bone marrow. In contrast to native thymidine, AZT suppressed the proliferation of erythroid, granulocyte/macrophage and primitive haematopoietic stem cells in a dose-related and time-dependent fashion. Relative progenitor sensitivity varied, with half-maximal concentrations of 1-5 microM and 20-40 microM AZT for inhibition of erythroid and nonerythroid progenitor cell growth, respectively. Inhibition was observed over full ranges of concentrations of haematopoietic tissue-specific regulators (human erythropoietin, colony-stimulating activity, interleukin-3 and lymphocyte conditioned medium) and of platelet-derived growth factor (PDGF), an agent that enhances erythropoiesis in vitro via accessory marrow stromal elements. Furthermore, suppression was similar in cultures of marrow cells that were depleted of accessory populations, suggesting that its action is directed at progenitors. Finally, when deoxythymidine was added in increasing amounts to cultures with a half-maximal concentration of AZT, inhibition was abrogated. We conclude that AZT is a potent inhibitor of haematopoiesis in vitro, and that erythroid progenitors are particularly sensitive to its action. These results may explain the marrow hypoplasia that occurs during AZT administration in vivo.

Antiviral Agents↗
PubMed1988

Proportional hazards analysis of risk factors for coronary heart disease in individuals aged 65 or older. The Framingham Heart Study.

Risk factors for coronary heart disease were examined in 2,501 individuals in the Framingham Heart Study who survived to the age of 65 without evidence of coronary artery disease. We used a proportional hazards (Cox) analysis that examined risk factors over time and included events through the 16th biennial examination. The independently significant multivariate correlates of the development of coronary heart disease after the age of 65 were sex (incidence rate ratio [RR] for males of 1.7 [95% confidence interval of 1.4,2.0]), left ventricular hypertrophy (RR = 2.4 [1.7,3.5]), systolic blood pressure (RR = 2.2 [1.4,3.3] for systolic blood pressure of 160 mmHg or higher as compared with less than 120 mmHg), casual blood glucose (RR = 2.2 [1.5,3.4] for 175 mg/dL or more as compared with less than 90 mg/dL), Metropolitan relative weight from examination 1 (RR = 1.3 [1.0,1.6] for those 130% or more of ideal weight compared with those less than 110% of ideal), and total serum cholesterol (RR = 1.8 [1.3,2.5] for cholesterol in the 90th percentile or higher compared with less than 200 mg/dL). Controlling for all these risk factors, those smoking 20 cigarettes a day or more were at slightly increased risk of coronary heart disease (RR = 1.2 [.9,1.6]) compared with nonsmokers. These analyses suggest that older persons share the same risk factors for coronary artery disease that are significant in younger populations.

Aged↗
PubMed1988

Prognostic importance of myocardial ischemia detected by ambulatory monitoring in patients with stable coronary artery disease.

To assess the relations of electrocardiographic measures of ischemia with the development of adverse coronary events, 86 patients with stable coronary artery disease and positive exercise tests for myocardial ischemia underwent ambulatory monitoring of the electrocardiogram. Monitoring was performed after withdrawal of antianginal medications, and prospective follow-up was obtained on routine medical care as prescribed by physicians who were unaware of monitor results. Forty-nine patients (57%) had a total of 426 episodes of ST segment depression; only 60 episodes (14%) were associated with symptoms of angina or an equivalent. During a mean follow-up of 12.5 +/- 7.5 months, there were two cardiac deaths, four myocardial infarctions, four hospitalizations for unstable angina, and 11 revascularization procedures required for new or worsening symptoms in 15 patients. All but one of these events (a hospitalization for unstable angina) occurred in the group of patients with ST segment depression on monitoring (p = 0.003). In multivariate analysis controlling for age, sex, and clinical descriptions of angina, the presence of ischemia on ambulatory monitoring was a significant predictor of outcome, while exercise test characteristics were not. Therefore, ischemia detected by ambulatory monitoring was common in patients with stable symptoms of coronary artery disease, and its presence identified a high-risk group for the development of subsequent unfavorable outcomes while on routine medical therapies.

Adult↗
PubMed1988

The impact of Medicare on early cancer detection in the elderly.

In an analysis of 23 sex-specific tumors in the Connecticut Tumor Registry, only seven tumors showed more than a 20 per cent increase in the ratio of localized tumors detected post-Medicare (1967-75) versus ante-Medicare (1960-65) in the 65-75 year age group compared to the 60-64 year age group. Of these seven, the information was more convincing for lung cancer in males. Overall, however, Medicare had little if any impact on early tumor diagnosis in the elderly.

Age Factors↗
PubMed1988

The coronary care unit turns 25: historical trends and future directions.

In the 25 years since the introduction of coronary care units the management of acute myocardial infarction has become oriented toward reducing infarct size and treating ongoing ischemia. The coronary care unit has been widely accepted as the standard of care for patients with acute myocardial infarction and has been considered appropriate for monitoring patients with acute chest pain until acute myocardial infarction is diagnosed or excluded. However, rising health care costs have created pressures to increase the efficiency of coronary care units. Possible strategies seek to decrease resource use by identifying low-risk patients for initial triage or early transfer to lower levels of care. The application of management algorithms and the development of intermediate care units as alternative triage sites for low-risk patients may be important future trends as a distinction is made between intensive coronary care and careful coronary observation.

Arrhythmias, Cardiac↗
PubMed1988

The medical course of cancer patients with fever and neutropenia. Clinical identification of a low-risk subgroup at presentation.

To determine whether cancer patients with fever and neutropenia differ in their medical stability, 261 medical records of 184 cancer patients who were hospitalized with fever and neutropenia and treated with conventional antibiotic therapy were studied to determine whether their presenting clinical characteristics influenced the likelihood of subsequent clinical events thought to require urgent medical attention. Overall, serious medical complications, including those without an obvious relationship to infection, occurred in 56 patient courses (21%). We distinguished three clinically determined subgroups of our study population at significantly higher risk than the remaining patient group, which seemed to be at low risk. Major complications occurred in 34 (34%) of 101 inpatients, 12 (55%) of 22 outpatients with concurrent comorbidity requiring inpatient care, and eight (31%) of 26 outpatients without concurrent comorbidity requiring inpatient care but with uncontrolled cancer. However, the remaining patients, who presented as outpatients without significant comorbidity or uncontrolled cancer, had major complications in only 2% of 112 hospitalizations. These results suggest that it may be possible to assess the medical stability of patients with fever and neutropenia based on presenting clinical features. If confirmed prospectively, these results may enable clinicians to identify groups of medically stable patients for whom conventional supportive care, including appropriately administered antibiotics, may be given safely under medical supervision of less intensity or of shorter duration than conventional treatment in the acute-care hospital setting.

Adult↗
PubMed1988

The incidence, magnitude, and time course of the amiodarone-warfarin interaction.

Eight patients concurrently treated with amiodarone and warfarin sodium were studied to characterize the interaction between these drugs. All fulfilled the following criteria: (1) stable and therapeutic prothrombin time (PT) at baseline, defined as at least two consecutive PTs obtained within two weeks before beginning amiodarone therapy that varied by less than or equal to 15%; (2) no warfarin dosage adjustment in the two weeks prior to amiodarone therapy; (3) no other drugs given that alter coagulation study results; and (4) follow-up PTs obtained 1, 2, 4, and 8 weeks after initiation of amiodarone treatment. A clinically significant change in PT was defined as greater than 15%. Mean baseline PT was 19.8 s for patients receiving 5.99 mg/d of warfarin sodium. Patients had a mean maximum increase in PT of 44% (range, 22% to 108%), which occurred during the first two weeks. In six patients, the PT returned to within 15% of baseline by week 4 or 8, and the daily warfarin requirement had decreased by 35% (range, 25% to 50%). Two patients had PTs varying by greater than 15% from baseline at week 8 despite a 33% reduction in warfarin dosage in each case. No patient in this series encountered complications of anticoagulant therapy, perhaps due to early recognition and dosage reduction. Although the mechanism remains unclear, our study indicates that amiodarone potentiation of warfarin effects occurs in all patients, occurs in the first two weeks of amiodarone therapy, variably increases PT by 22% to 108%, and lowers the warfarin requirement by 25% to 50%. We recommend a 25% prophylactic reduction of warfarin dosage and weekly measurements of PT for one month when amiodarone therapy is initiated.

Amiodarone↗
PubMed1987

Diagnostic implications for myocardial ischemia of the circadian variation of the onset of chest pain.

To determine whether the occurrence of chest pain is randomly distributed during the day and to study whether the time of onset is useful in discriminating among causes of chest pain, patients older than 30 years who presented to 7 emergency departments with a chief complaint of chest pain unexplained by trauma or chest x-ray abnormalities were studied. A total of 7,759 patients presented during the study period; of these, 3,990 presented within 6 hours of the onset of pain and were included in the primary analysis. Chest pain caused by acute myocardial infarction, unstable angina pectoris and stable angina pectoris was more likely to begin during the period from 6 AM to noon than would be expected if the onset were uniformly distributed during the day (relative risks 1.15, 1.29 and 1.32, respectively), but chest pain that was caused by nonischemic cardiac causes and by noncardiac causes was also more likely to begin during the same time period (relative risks 1.28 and 1.17). Although chest pain from coronary arterial causes had a distinct circadian variation, the time of onset of pain was not a helpful criterion for determining the cause of chest pain.

Adult↗
PubMed1987

Patient and house officer attitudes on physician attire and etiquette.

To study patient preferences on physician attire and etiquette, we interviewed 200 patients on the general medical services of teaching hospitals in Boston and San Francisco. Of these 200 patients, 65% believed physicians should wear a white coat, 27% believed physicians should not wear tennis shoes, 52% believed physicians should not wear blue jeans, 37% believed male physicians should wear neckties, and 34% believed female physicians should wear dresses or skirts. Forty percent of patients wanted physicians to address them by first name, but only 10% of patients wanted to address their physicians by first name. A concurrent mailed survey of 74 medical house staff members at the two hospitals revealed wide variability in physicians' attire and in how patients were addressed at each institution. Thus, many house officers had habits that were less formal than a substantial portion of their patients preferred.

Adult↗
PubMed1987

Current laser dentistry.

Current laser dentistry since our initial studies in 1964 is reviewed. Three areas are considered: routine dental office practice, tooth restoration, and oral surgery. For tooth restoration and oral surgery, CO2 and neodymium:YAG lasers are used and lasers are used in photodynamic therapy for oral cancer. Dental office practice today is concerned mostly with uncontrolled studies of biostimulation and requires more basic research and controlled clinical studies. The laser industry in the United States should take a more active interest in defining the applications of lasers in dentistry.

Dentistry, Operative↗
PubMed1987

A histologic study of laser-induced transmyocardial channels.

Carbon dioxide lasers are reported to provide ischemic myocardium direct access to blood within the ventricular cavity by inducing transmyocardial channels which maintain patency in long-term experiments. We have histologically examined the natural history of channels produced with this technique and compared them with transmyocardial channels created by needle puncture. Immediately after application of the laser, four concentric zones vaporization, carbonization, fixation, and transition could be distinguished along the transmyocardial path. Needle puncture channels were fully occluded within 48 hr, whereas laser-induced channels maintained partial patency for a 2-week period, after which they also became occluded. It appears likely that the instantaneous vaporization produced by the laser may delay the release of factors which mediate the healing process, but occlusion of channels was universal in this study. It remains to be determined whether or not variables such as wattage, beam diameter, or tissue temperature influence long-term channel patency.

Animals↗
PubMed1987

Identification and preliminary validation of predictors of major bleeding in hospitalized patients starting anticoagulant therapy.

Among 617 hospitalized patients who started long-term anticoagulant therapy, major bleeding developed before discharge in 28 (5 percent) and minor bleeding in another 38 (6 percent), with daily incidence rates of 0.4 and 0.5 percent, respectively. The most common site of bleeding was gastrointestinal, and one patient died from bleeding. Four independent risk factors for major in-hospital bleeding were identified and weighted using multivariate discriminant analysis in a randomly chosen group of 411 patients: co-morbid conditions other than the indication for anticoagulant therapy (specific signs of heart, liver, or kidney dysfunction, cancer, and severe anemia); the use of heparin to begin therapy in patients age 60 years or older; the intensity of therapy (measured by the maximal prothrombin time or partial thromboplastin time); and liver dysfunction that worsened during treatment. These findings were validated in an independent testing group of 206 patients; the risk factors identified 151 patients at low (1 percent) risk of major bleeding, 33 at moderate (6 percent) risk, and 22 at high (23 percent) risk. The accuracy and clinical impact of this prediction rule should be evaluated further in other hospitals.

Adolescent↗
PubMed1987

Assessing the preventability of emergency hospital admissions. A method for evaluating the quality of medical care in a primary care facility.

The quality of primary medical care was assessed by studying the events leading to 686 emergency admissions of patients from our hospital-based primary care practice. Independent physician reviewers determined that 59 (9 percent) of the admissions were potentially preventable; 40 were due to iatrogenic factors including inadequate follow-up and adverse drug reactions, 12 were due to lack of patient compliance, and seven were due to both iatrogenesis and noncompliance. Adverse drug reactions were the most common cause of iatrogenesis, and warfarin was the drug that most commonly caused an adverse reaction. Inadequate follow-up of abnormal physical findings, symptoms, and laboratory test results was also important. Patients with preventable admissions had more medical diagnoses (4.9 versus 4.1, p less than 0.01), were prescribed more medications (4.5 versus 3.7, p less than 0.01), and were older (66.5 years versus 60.2 years, p less than 0.01) than patients whose admissions were not preventable. It is concluded that a small percentage of emergency hospitalizations may be preventable and that systematic review of emergency hospitalizations may provide a means of measuring the quality of primary medical care.

Adult↗