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Biomedical subjects

L Goldman

Publications and source records attributed to L Goldman.

At least 217 records · Page 12Linked to original sources
PubMed1992

Risk assessment in cancer patients with fever and neutropenia: a prospective, two-center validation of a prediction rule.

PURPOSE: The study was undertaken to validate a clinical model for predicting the medical risk of cancer patients with fever and neutropenia. PATIENTS AND METHODS: A consecutive sample of 444 cancer patients with fever and neutropenia (granulocyte count less than 500/microL) at two hospitals, a specialized cancer referral center and a university-affiliated general medical hospital, was studied to identify clinical characteristics in the first 24 hours that predict subsequent serious medical complications during the hospital stay. To control for bias, major risk factors and complications were subject to blinded review. RESULTS: Serious medical complications occurred in 34% of patients with risk factors identified in a prior study, including prior inpatient status (group I), outpatients with a serious independent comorbidity (group II), or uncontrolled cancer (group III), compared with 5% of the remaining patients (group IV) (P less than .000001). Two of the complications in group IV patients were transient asymptomatic hypotension, and the remaining three complications occurred after at least 1 week of progressive medical deterioration. These risk groups were independently significant in stepwise logistic regression analysis. Multiple complications (17%) and death (10%) were common among patients in groups I through III but did not occur in group IV patients. CONCLUSIONS: This risk assessment model accurately stratified the medical risk of these patients using only clinical information available on the first day of their course. Low-risk patients are an appropriate population in which to study less intensive treatment strategies.

Adolescent↗
PubMed1992

The association between hemoglobin and behavior problems in a sample of low-income Hispanic preschool children.

This cross-sectional study, conducted in 1988, examines the association between hemoglobin level and behavior problems in 236 Hispanic children, ages 2 to 5 years, residing in low-income census tracts in the Los Angeles area. Venous blood samples were analyzed for hemoglobin, mean corpuscular volume, free erythrocyte protoporphyrin, and lead. Family and child data were obtained through a home interview with the child's mother or guardian. Behavior problems were assessed using questionnaires modeled after Child Behavior Checklists for children ages 2 to 3 and 4 to 5 years. A significant correlation between decreasing hemoglobin values and increasing total behavior problems scores was found for girls, 2 to 3 and 4 to 5 years old. These associations remained significant in both age groups after adjusting for maternal education and marital status. Statistically significant inverse correlations also were found between hemoglobin and social withdrawal, sleep problems, and depression (internalizing subscale behaviors) in 2- to 3-year-old girls, and between hemoglobin and aggression and hyperactivity (externalizing subscale behaviors) in 4- to 5-year-old girls. The potentially negative consequences of these anemia-related behavior problems on children's development, learning ability, and parent-child relationships warrant further investigation.

California↗
PubMed1991

Prediction of major cardiac events after peripheral vascular surgery using dipyridamole echocardiography.

Patients undergoing peripheral vascular surgery are at increased risk of postoperative cardiac complications. To evaluate the role of dipyridamole echocardiography in predicting major cardiac events, 109 unselected patients undergoing elective peripheral vascular surgery were prospectively studied. Preoperative dipyridamole echocardiograms were interpreted by an echocardiographer unaware of all clinical data. Patients were followed up until hospital discharge by research physicians without knowledge of dipyridamole echocardiography results. Outcomes were classified using strict predefined criteria by reviewers unaware of other clinical and echocardiographic data. Of the 109 patients, 9 (8%) had positive studies defined as development of new regional wall motion abnormalities or worsening of preexistent wall motion abnormalities. Of these 9 patients, 7 had postoperative events, including 3 cardiac deaths, 1 nonfatal myocardial infarction, 2 with unstable angina, and 1 with pulmonary edema. Only 1 event occurred among the 100 patients with negative studies. The sensitivity and specificity of dipyridamole echocardiography for predicting cardiac events after vascular surgery were 88 and 98%, respectively; the positive and negative predictive values were 78 and 99%. The relative risk of having a cardiac event if dipyridamole echocardiography was abnormal was 78 (95% confidence interval, 11 to 564; p less than 0.0001). If these results are extended and confirmed by other investigators, preoperative dipyridamole echocardiography may be an important screening test for patients undergoing elective peripheral vascular surgery.

Aged↗
PubMed1991

Outcome of patients who were admitted to a new short-stay unit to "rule-out" myocardial infarction.

For emergency room patients with a low probability of acute myocardial infarction, we established a new short-stay coronary observation unit, a 2-bed nonintensive care unit with telemetry monitoring adjacent to the emergency room. Of 512 consecutive admissions to the coronary observation unit, 425 (83%) were discharged home without evidence of acute myocardial infarction or serious complications (mean length of stay, 1.2 days; median length of stay, 1 day); 87 (17%) were transferred to other hospital beds. The rate of acute myocardial infarction was 3%. No deaths and only 1 serious complication occurred in the coronary observation unit. At 6 month follow-up, the cardiac survival rate was 99% for patients sent home directly from this unit. It is concluded that the coronary observation unit is safe and adequate for ruling out acute myocardial infarction in a defined subset of patients. Short-stay units, however, encourage early discharges which, when premature, may miss patients who are at risk of having complications shortly thereafter. Strategies such as mandatory but expeditious predischarge stress testing to encourage early but not premature discharge may augment the efficiency of coronary observation units.

Coronary Care Units↗
PubMed1991

Predictors of event-free survival after balloon aortic valvuloplasty.

BACKGROUND: Balloon aortic valvuloplasty was developed as an alternative to aortic-valve replacement in selected elderly patients with aortic stenosis. The use of this procedure is limited, however, by a high incidence of restenosis. METHODS: Between December 1985 and April 1989, valvuloplasty was performed in 205 patients. We evaluated 40 demographic and hemodynamic variables as univariate predictors of event-free survival by Cox regression analysis and identified independent predictors of event-free survival by stepwise multivariate analysis. RESULTS: Early hemodynamic results indicated a decrease in the peak transaortic-valve pressure gradient from 67 +/- 28 to 33 +/- 15 mm Hg after valvuloplasty and an increase in aortic-valve area from 0.6 +/- 0.2 to 0.9 +/- 0.3 cm2 (P less than 0.001 for both comparisons). The rate of event-free survival (defined as survival without recurrent symptoms, repeated valvuloplasty, or aortic-valve replacement) was 18 percent over the mean (+/- SD) follow-up period of 24 +/- 12 months (range, 1 to 47). Significant predictors of event-free survival included the left ventricular ejection fraction and the left ventricular and aortic systolic pressure before valvuloplasty, and the percent reduction in the aortic-valve pressure gradient; the pulmonary-capillary wedge pressure was inversely associated with event-free survival. Although the predicted event-free survival rate for the entire patient group was 50 percent at one year (95 percent confidence interval, 43 to 57 percent) and 25 percent at two years (95 percent confidence interval, 19 to 31 percent), the probability of event-free survival at one year varied between 23 and 65 percent when patients were stratified according to three independent predictors: the aortic systolic pressure, the pulmonary-capillary wedge pressure, and the percent reduction in the peak aortic-valve gradient. CONCLUSIONS: The most important predictors of event-free survival after balloon aortic valvuloplasty were related to base-line left ventricular performance. The best long-term results after valvuloplasty were observed among patients who would also have been expected to have excellent long-term results after aortic-valve replacement.

Aortic Valve Stenosis↗
PubMed1991

Ruling out acute myocardial infarction. A prospective multicenter validation of a 12-hour strategy for patients at low risk.

BACKGROUND: Although previous investigations have suggested that 24 hours is required to exclude acute myocardial infarction in patients who are admitted to a coronary care unit for the evaluation of acute chest pain, we hypothesized that a 12-hour period might be adequate for patients with a low probability of infarction at the time of admission. METHODS: Using a Bayesian model, we developed a strategy to identify candidates for a shorter period of observation from an analysis of a derivation set of 976 patients with acute chest pain who were admitted to three teaching and four community hospitals. In the derivation set, patients whose clinical characteristics in the emergency room predicted a low (less than or equal to 7 percent) probability of myocardial infarction had only a 0.4 percent risk of infarction if they had neither abnormal levels of cardiac enzymes nor recurrent ischemic pain during the first 12 hours of hospitalization. In an independent testing set of 2684 patients from the seven hospitals, 957 admitted patients (36 percent) were classified as candidates for this 12-hour period of observation according to a previously published multivariate algorithm. Few of these patients were actually transferred from a monitored setting at 12 hours. RESULTS: Of the 771 candidates for a 12-hour period of observation who did not have enzyme abnormalities or recurrent pain during the first 12 hours, 4 (0.5 percent) were subsequently found to have acute myocardial infarction, and only 3 (0.4 percent) died after primary cardiac arrests, all of which occurred three to five days after admission. Rates of other major cardiovascular complications were low in the patients who might have been transferred from the coronary care unit after 12 hours with this strategy. In patients with a higher initial risk of infarction, the standard strategy of 24-hour observation identified all but 11 of 739 acute myocardial infarctions (1 percent). CONCLUSIONS: Emergency room clinical data can be used to identify a large subgroup of patients for whom a 12-hour period of observation is normally sufficient to exclude acute myocardial infarction. Patient-specific evaluation and treatment can then proceed without the restrictions imposed by "rule-out" protocols for myocardial infarction.

Adult↗
PubMed1991

Cost-effectiveness of HMG-CoA reductase inhibition for primary and secondary prevention of coronary heart disease.

To determine the cost-effectiveness of HMG-CoA (3-hydroxy-3-methylglutaryl coenzyme A) reductase inhibitors (such as lovastatin) for the primary and secondary prevention of coronary heart disease, we used the Coronary Heart Disease Policy Model, a computer-stimulated model that estimates the risk factor-specific annual incidence of coronary heart disease and the risk of recurrent coronary events in persons with prevalent coronary heart disease. When used for secondary prevention, 20 mg/d of lovastatin was estimated to save lives and save costs in younger men with cholesterol levels above 250 mg/dL (6.47 mmol/L) and to have a favorable cost-effectiveness ratio regardless of the cholesterol level except in young women with cholesterol levels below 250 mg/dL (6.47 mmol/L). Doses of 40 mg/d of lovastatin had favorable incremental cost-effectiveness ratios in men with cholesterol levels above 250 mg/dL (6.47 mmol/L). By comparison, primary prevention had favorable cost-effectiveness ratios only in selected subgroups based on cholesterol levels and other established risk factors. We conclude that current national recommendations regarding medication for secondary prevention are not as aggressive as our projections would suggest, while recommendations regarding the use of medications for primary prevention should consider the cost of medication as well as the risk factor profile of the individual patient.

Adult↗
PubMed1991

Contaminant blood cultures and resource utilization. The true consequences of false-positive results.

To determine whether contaminant blood cultures increase resource utilization, we studied charge and length of stay data for episodes in which blood cultures were obtained from hospitalized adults. Compared with 1097 negative episodes, 94 false-positive episodes were associated with increased subsequent length of stay (median, 12.5 vs 8 days) and subsequent total charges (median, $13,116 vs $8731), pharmacy charges (median, $1456 vs $798), and laboratory charges (median, $2057 vs $1426). In multivariate analyses, contaminants were independently correlated with 20% and 39% increases in total subsequent laboratory charges and intravenous antibiotic charges, respectively. Thus, the true costs of contaminants may greatly exceed those of the test itself. Identifying patients at very low risk of bacteremia and attention to sterile technique may reduce costs by decreasing the frequency of contaminants.

Adult↗
PubMed1991

Impact of physician experience on triage of emergency room patients with acute chest pain at three teaching hospitals.

PURPOSE: To determine whether the experience of the physician (as measured by postgraduate training level or time during the academic year) who performs the initial evaluation affects the triage of patients with acute chest pain. PATIENTS AND METHODS: Prospective data on the presenting clinical features, initial triage, final diagnosis, and complications were collected for 7,857 patients who presented to the emergency rooms of three teaching hospitals, including 1,118 (14%) with acute myocardial infarction (AMI), 2,477 (32%) with acute ischemic heart disease (AIHD) (i.e., AMI or unstable angina), and 335 (4%) with major complications. The experience of the evaluating physicians, who were in their first three postgraduate years in 93% of cases, was measured in three ways: (1) postgraduate training level, (2) month during the academic year, and (3) number of patients with acute chest pain previously evaluated. Multivariate logistic regression analyses that adjusted for hospital site and 20 clinical variables estimated the odds ratios for admission to the coronary care unit (CCU) and hospital associated with each incremental increase in physician experience. RESULTS: With more experience (as measured by postgraduate training level or time during the academic year), the sensitivity of physicians for admitting patients with AMI, AIHD, or major complications to the hospital increased. For example, each incremental increase in postgraduate training level carried a 1.4 increase in the adjusted odds ratio for admission of a patient with AIHD to the hospital (p less than 0.05), corresponding to an increase in the probability of admission from 93% to 97%. However, increasing physician experience was also associated with an elevated false-positive rate in admitting patients without these diagnoses to the CCU and hospital. Thus, each incremental increase in postgraduate training level carried a 1.2 increase in the adjusted odds ratio for admission of a patient without AIHD to the CCU and hospital (p less than 0.005), corresponding to an increase in the probability of admission from 34% to 47%. By receiver operating characteristic curve (ROC) regression analyses, these changes in triage patterns were consistent with movement along a single ROC curve, rather than a shift to a new or better ROC curve. CONCLUSIONS: As the experience of the physician who performed the initial evaluation increased, there was a lower threshold for admitting all patients with and without AMI, AIHD, or major complications to the CCU and hospital without a detectable improvement in diagnostic accuracy.

Adult↗
PubMed1991

Gating current kinetics in Myxicola giant axons. Order of the back transition rate constants.

Gating current, Ig, was recorded in Myxicola axons with series resistance compensation and higher time resolution than in previous studies. Ig at ON decays as two exponentials with time constants, tau ON-F and tau ON-S, very similar to squid values. No indication of an additional very fast relaxation was detected, but could be still unresolved. Ig at OFF also displays two exponentials, neither reflecting recovery from charge immobilization. Deactivation of the two I(ON) components may proceed with well-separated exponentials at -100 mV. INa tail currents at OFF also display two exponentials plus a third very slow relaxation of 5-9% of the total tail current. The very slow component is probably deactivation of a very small subpopulation of TTX sensitive channels. A -100 mV, means for INa tail component time constants (four axons) are 76 microseconds (range: 53-89 microseconds) and 344 microseconds (range: 312-387 microseconds), and for IOFF (six axons) 62 microseconds (range: 34-87 microseconds) and 291 microseconds (range: 204-456 microseconds) in reasonable agreement. INa ON activation time constant, tau A, is clearly slower than tau ON-F at all potentials. Except for the interval -30 to -15 mV, tau A is clearly faster than tau ON-S, and has a different dependency on potential. tau ON-S is several fold smaller than tau h. Computations with a closed2----closed1----open activation model indicated Na tail currents are consistent with a closed1----open rate constant greater than the closed2----closed1.

Animals↗