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Biomedical subjects

M E Charlson

Publications and source records attributed to M E Charlson.

At least 37 records · Page 2Linked to original sources
PubMed1996

Severity of aortic atheromatous disease diagnosed by transesophageal echocardiography predicts stroke and other outcomes associated with coronary artery surgery: a prospective study.

Advanced atheromatous disease of the thoracic aorta identified by transesophageal echocardiography (TEE) is a major risk factor for perioperative stroke. This study investigated whether varying degrees of atherosclerosis of the descending aorta, as assessed by TEE, are an independent predictor of cardiac and neurologic outcome in patients undergoing coronary artery bypass grafting (CABG). Intraoperative TEE of the descending aorta was performed on 189 of 248 patients participating in a randomized controlled trial of low (50-60 mm Hg) or high (80-100 mm Hg) mean arterial pressure during cardiopulmonary bypass for elective CABG. Aortic atheromatous disease was graded from I to V in order of increasing severity by observers blinded to outcome. Measured outcomes were death, stroke, and major cardiac events assessed at 1 wk and 6 mo. Nine of the 189 patients with TEE examinations had perioperative strokes by 1 wk. At 1 wk, no strokes had occurred in the 123 patients with atheroma Grades I or II, while the 1-wk stroke rate was 5.5% (2/36), 10.5% (2/19), and 45.5% (5/11) for Grades III, IV, and V, respectively (Fisher's exact test, P = 0.00001). For 6-mo outcome, advancing aortic atheroma grade was a univariate predictor of stroke (P = 0.00001) and death (P = 0.03). By 6 mo there were one additional stroke, three additional deaths, and one additional major cardiac event. Atheromatous disease of the descending aorta was a strong predictor of stroke and death after CABG. TEE determination of atheroma grade is a critical element in the management of patients undergoing CABG surgery.

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PubMed1995

Cognitive effects after epidural vs general anesthesia in older adults. A randomized trial.

OBJECTIVE: To compare the effect of epidural vs general anesthesia on the incidence of long-term cognitive dysfunction after total knee replacement surgery in older adults. DESIGN: Randomized controlled clinical trial. SETTING: Orthopedic specialty academic hospital. PATIENTS: A total of 262 patients undergoing elective primary total knee replacement with a median age of 69 years; 70% women. INTERVENTION: Random assignment to either epidural or general anesthesia. MAIN OUTCOME MEASURES: A thorough neuropsychological assessment was performed preoperatively and repeated at 1 week and 6 months postoperatively. Cognitive outcome was assessed by within-patient change on 10 tests of memory, psychomotor, and language skills. Prospective standardized surveillance for cardiovascular complications was performed to allow simultaneous assessment of anesthetic effects on cognitive and cardiovascular outcomes. RESULTS: The two groups were similar at baseline in terms of age, sex, comorbidity, and cognitive function. There were no significant differences between the epidural and general anesthesia groups in within-subject change from baseline on any of the 10 cognitive test results at either 1 week or 6 months. Overall, 5% of patients showed a long-term clinically significant deterioration in cognitive function. There was no difference between the anesthesia groups in the incidence of major cardiovascular complications (3% overall). CONCLUSIONS: The type of anesthesia, general or epidural, does not affect the magnitude or pattern of postoperative cognitive dysfunction or the incidence of major cardiovascular complications in older adults undergoing elective total knee replacement. This is the largest trial of the effects of general vs regional anesthesia on cerebral function reported to date, with more than 99% power to detect a clinically significant difference on any of the neuropsychological tests.

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PubMed1995

Improvement of outcomes after coronary artery bypass. A randomized trial comparing intraoperative high versus low mean arterial pressure.

BACKGROUND: The objective of this randomized clinical trial of elective coronary artery bypass grafting was to investigate whether intraoperative mean arterial pressure below autoregulatory limits of the coronary and cerebral circulations was a principal determinant of postoperative complications. The trial compared the impact of two strategies of hemodynamic management during cardiopulmonary bypass on outcome. Patients were randomized to a low mean arterial pressure of 50 to 60 mm Hg or a high mean arterial pressure of 80 to 100 mm Hg during cardiopulmonary bypass. METHODS: A total of 248 patients undergoing primary, nonemergency coronary bypass were randomized to either low (n = 124) or high (n = 124) mean arterial pressure during cardiopulmonary bypass. The impact of the mean arterial pressure strategies on the following outcomes was assessed: mortality, cardiac morbidity, neurologic morbidity, cognitive deterioration, and changes in quality of life. All patients were observed prospectively to 6 months after the operation. RESULTS: The overall incidence of combined cardiac and neurologic complications was significantly lower in the high pressure group at 4.8% than in the low pressure group at 12.9% (p = 0.026). For each of the individual outcomes, the trend favored the high pressure group. At 6 months after coronary bypass for the high and low pressure groups, respectively, total mortality rate was 1.6% versus 4.0%, stroke rate 2.4% versus 7.2%, and cardiac complication rate 2.4% versus 4.8%. Cognitive and functional status outcomes did not differ between the groups. CONCLUSION: Higher mean arterial pressures during cardiopulmonary bypass can be achieved in a technically safe manner and effectively improve outcomes after coronary bypass.

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PubMed1995

Does recollection error threaten the validity of cross-sectional studies of effectiveness?

New cross-sectional studies have been designed to evaluate therapeutic effectiveness of medical and surgical treatments. The extent to which error in recollection may threaten the validity of conclusions reached in these studies has not been determined. The purpose of this research was to evaluate the impact of recollection error by comparing patients' prospectively acquired reports about their condition before total hip replacement with their recollections of their preoperative condition obtained several years after surgery. A total of 104 patients prospectively completed the Hip Rating Questionnaire (HRQ), a valid, reproducible, responsive, disease-specific scale composed of four domains (pain, walking, function, and impact of hip arthritis on overall health). These same patients then completed the HRQ several years after surgery by recalling their preoperative condition. Current postoperative condition was also obtained several years after surgery with the HRQ. Patient characteristics include: 55% were women, mean age was 67 years, 90% had osteoarthritis, 78% had no prognostically significant comorbid disease, and the mean time interval between surgery and recall was 2.5 years. Comparison of prospective and recalled responses with the weighted kappa and intraclass correlation coefficients showed poor to fair agreement in three domains, and moderate agreement in the fourth domain. Overall, the directions of the recollection errors were toward patients' recalling more pain, better walking, better function, and worse impact of hip arthritis on health than they reported before surgery. When the data were stratified to determine if there were systematic biases among major patient subgroups, there were discrepancies in the percentage of patients within each subgroup who had recollection error for the different domains, as well as differences in the magnitudes and directions of the recollection errors. These results indicate that relying on patients' recollections does not provide an accurate measure of preoperative state, and that attempting to adjust data is not feasible because the directions and magnitudes of recollection error vary for major subgroups of patients. In addition, when outcome was assessed using postoperative HRQ responses, the cross-sectional data overestimated the effectiveness of total hip replacement in 68% of patients. It is concluded that cross-sectional data do not accurately portray baseline preintervention condition and therefore can lead to overestimating, as in this instance, or to underestimating effectiveness.

Adult↗
PubMed1994

Cerebral emboli detected during bypass surgery are associated with clamp removal.

BACKGROUND AND PURPOSE: Transcranial Doppler ultrasonography detects embolic signals during coronary artery bypass surgery. The relationship between embolization and specific events of bypass surgery is unclear. METHODS: With this technique, 20 patients undergoing bypass surgery were continuously monitored from inception to discontinuation of bypass. RESULTS: Embolic signals were detected in all patients. Of all embolic signals, 34% were detected as aortic cross-clamps were removed, and another 24% as aortic partial occlusion clamps were removed. Only 5% were detected at inception of bypass. Rates for embolization were 15.15 embolic signals per minute at cross-clamp removal, 10.9 embolic signals per minute at partial occlusion clamp removal, and fewer than 3 embolic signals per minute at other times. Correlation was found between the number of emboli, severity of aortic atheromatosis, and neurocognitive deterioration. CONCLUSIONS: The majority of emboli detected during coronary artery bypass grafting are associated with the release of clamps. Clamp manipulation may lead to release of aortic atheromatous debris. These emboli may be relevant to neurocognitive outcome.

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PubMed1994

Preoperative autonomic function abnormalities in patients with diabetes mellitus and patients with hypertension.

BACKGROUND: This study was done to assess whether or not autonomic function abnormalities identified patients with diabetes mellitus as being at risk for postoperative cardiac arrest or death. STUDY DESIGN: We prospectively studied 74 patients with diabetes mellitus and 118 patients with hypertension without diabetes mellitus undergoing elective noncardiac operation. The study was done at an academic medical center between 1982 and 1985. Patients were evaluated preoperatively, monitored intraoperatively by an independent observer and had daily follow-up evaluation for seven days postoperatively, according to a standard surveillance protocol. Outcomes were judged by assessors unaware of the preoperative status and intraoperative course. Patients were interviewed at three and five years postoperatively. RESULTS: Patients with diabetes mellitus with two or more abnormal autonomic function test results did not experience more intraoperative hypotension, nor did they require more intraoperative pressor agents than patients with diabetes mellitus with one or no abnormalities. Seven percent of the patients with diabetes mellitus experienced postoperative cardiorespiratory arrest or death. All of these patients had more than two abnormal autonomic function test results as well as a previous history of either myocardial infarction or cardiomegaly. CONCLUSIONS: While this study obviously requires confirmation in a larger population, the data are sufficiently strong to warrant close postoperative monitoring of all patients with diabetes mellitus who have two or more autonomic abnormalities.

Autonomic Nervous System↗
PubMed1993

An organizational model for developing multidisciplinary clinical research in the academic medical center.

OBJECTIVE: To assess the impact of a new organizational model designed to stimulate multidisciplinary clinical research. METHODS: We conducted a prospective, 3 1/2-year followup of a research training program for residents, fellows, faculty, nurses, and allied health professionals in rheumatology and orthopedic surgery. Program components included a multidisciplinary clinical research conference, a clinical research methods curriculum, consultations, a patient registry, and regular meetings of a Research Methodology Core group. Measures included participation in each program component and the number of new investigators who developed funded clinical research projects. RESULTS: The multidisciplinary clinical research conference was attended by 369 new health professionals; 218 professionals participated in at least one of the courses; and 280 consultations were provided to 108 professionals. Thirteen new investigators developed 17 new grant proposals, of which 14 were externally funded. Investigators who successfully procured funding for new projects demonstrated significantly more participation in program components compared with those who did not (P < 0.001 overall). CONCLUSION: Participation in the program was significantly correlated with the development of new prospective patient-based studies. We conclude that our model has the potential to foster such research in other settings.

Academic Medical Centers↗
PubMed1993

Femoral neck bone density. Direct measurement and histomorphometric validation.

The purpose of this study was to develop a method for directly measuring bone density of femoral neck sections. Three types of density were measured. Real density equals wet weight divided by the actual volume of bone tissue (real volume). Apparent density equals wet weight divided by the total volume occupied by the bone plus the pore spaces (total sample volume). Ash density equals the ash weight divided by the real volume. Corticocancellous cross-sections of the femoral neck were analyzed for density at two levels: level 1, proximal neck and level 3, distal neck. Density measurements were compared with histomorphometric measurements performed on cross-sections at the midportion of the femoral neck (level 2) and with a clinical radiographic measure of bone density (cortical index 3 cm below the lesser trochanter). No correlation was found between apparent density and either real (r = .12, P = .62) or ash density (r = -.09, P = .72) within a given femoral neck section. There was, however, a strong correlation between real and ash density (r = .93, P = .0001). This was expected because real and ash densities are both reflections of bone mineralization. Apparent density showed better correlation, when comparing level 1 with level 3 sections (r = .76, P = .0001), than did ash (r = .57, P = .01) or real density (r = .55, P = .01). There was no correlation between either real or ash density with any histomorphometric parameter. Apparent density was moderately correlated with total bone area expressed as a percentage of cross-sectional area (r = .66, P = .008). This finding tends to validate the direct measurement of apparent density in that both apparent density and total bone area are measurements of the concentration of bone in space. No significant correlation was found between any of the density measurements and the cortical index at 3 cm. This underscores the necessity for precisely qualifying any definition or discussion of bone quality. The success or failure of hip implants may be at least partially determined by the ability of the bone to withstand the insult of implantation of the prosthesis and to adapt successfully to the new mechanical environment. This study represents an early phase of defining parameters that may have prognostic value in long-term implant fixation.

Adult↗
PubMed1992

Supervised fitness walking in patients with osteoarthritis of the knee. A randomized, controlled trial.

OBJECTIVE: To assess the effect of a program of supervised fitness walking and patient education on functional status, pain, and use of medication in patients with osteoarthritis of the knee. DESIGN: An 8-week randomized, controlled trial. SETTING: Inpatient and outpatient services of an orthopedic hospital in an academic medical center. PATIENTS: A total of 102 patients with a documented diagnosis of primary osteoarthritis of one or both knees participated in the study. Data were obtained on 47 of 51 intervention patients and 45 of 51 control patients. INTERVENTIONS: An 8-week program of supervised fitness walking and patient education or standard routine medical care. MEASUREMENTS: Patients were evaluated and outcomes assessed before and after the intervention using a 6-minute test of walking distance and scores on the physical activity, arthritis impact, pain, and medication subscales of the Arthritis Impact Measurement Scale (AIMS). RESULTS: Patients randomly assigned to the walking program had a 70-meter increase in walking distance relative to their baseline assessment, which represents an improvement of 18.4% (95% Cl, 9.8% to 27.0%). In contrast, controls showed a 17-meter decrease in walking distance relative to their baseline assessment (P less than 0.001). Improvements in functional status as measured by the AIMS physical activity subscale were also observed in the walking group but not in the control group (P less than 0.001); patients assigned to the walking program improved 39% (Cl, 15.6% to 60.4%). Although changes in scores on the arthritis impact subscale were similar in the two groups (P = 0.093), the walking group experienced a decrease in arthritis pain of 27% (Cl, 9.6% to 41.4%) (P = 0.003). Medication use was less frequent in the walking group than in the control group at the post-test (P = 0.08). CONCLUSIONS: A program of supervised fitness walking and patient education can improve functional status without worsening pain or exacerbating arthritis-related symptoms in patients with osteoarthritis of the knee.

Adult↗
PubMed1992

Using faculty consensus to develop and implement a medical ethics course.

This report describes the development and implementation of a new required course in medical ethics for second-year medical students at the Cornell University Medical College, 1988-89 and 1989-90. The course was specifically designed to teach students who had not yet started their clinical clerkships to think critically and systematically about ethical issues faced by practicing physicians. The goals, structure, and content of the course were developed using an innovative technique, a planning model involving faculty consensus. The faculty members found the planning sessions intellectually challenging and enjoyable, and reported that the sessions added greatly to their teaching of the course. The students' evaluations over the first two years of the course (with 188 of the 201 students--94%--responding) documented the students' satisfaction with the content and the structure of the course, and their belief that the course had achieved its goals. The authors conclude that the faculty's participation in the planning process was crucial to the success of the course.

Consensus↗
PubMed1992

Health services research in arthritis musculoskeletal disease.

This paper reviews recent studies in national patterns of disability related to arthritis, longitudinal studies of outcome in arthritis, the effects of the prospective payment system on outcomes of hip fracture patients, and recent studies of geographic variation in treatment of arthritis and musculoskeletal disease. It also reviews recent papers on clinimetric issues and advances in measuring disease activity.

Arthritis↗
PubMed1992

Post-operative delirium: predictors and prognosis in elderly orthopedic patients.

OBJECTIVE: To compare the effect of post-operative analgesia using epidural versus intravenous infusions on the incidence of delirium after bilateral knee replacement surgery in elderly patients. Additional risk factors and impact on post-operative recovery were also assessed. DESIGN: Prospective randomized controlled trial. SETTING: Urban referral hospital specializing in elective orthopedic surgery. PATIENTS: 60 consecutive patients undergoing bilateral knee replacement surgery with epidural anesthesia were approached; 51 patients were eligible and consented. The mean age was 68, 55% were women, and there was a high prevalence of comorbid medical disease. No patient was demented pre-operatively. INTERVENTION: Random allocation to either continuous epidural infusion of bupivacaine and fentanyl or continuous intravenous infusion of fentanyl. Infusions were initiated at the first complaint of pain and continued through the 36- to 48-hour stay in the recovery room. MAIN OUTCOME MEASURE: Acute post-operative delirium defined using an algorithm based on DSM III criteria. RESULTS: The overall incidence of acute delirium was 41%, with no difference between types of post-operative analgesia. Predictors of delirium were age, gender, and pre-operative alcohol use. All cases resolved within 1 week, and length of stay and achievement of physical therapy goals were the same for delirious and non-delirious patients. CONCLUSIONS: There is a high incidence of post-operative delirium in elderly non-demented patients following bilateral knee replacement, regardless of whether post-operative analgesia is administered by the epidural or intravenous route.

Age Factors↗
PubMed1992

Geographic variations in the rates of elective total hip and knee arthroplasties among Medicare beneficiaries in the United States.

We analyzed the variations in the rates of elective total hip and total knee arthroplasties for 1988 in the United States to determine whether the rates correlated with the numbers of surgeons. There were 56,204 total hip arthroplasties and 68,491 total knee arthroplasties, performed in the home states of the patients among all of the Medicare beneficiaries. Medicare beneficiaries include most people who are more than sixty-five years old in the United States and a small proportion of younger people who are eligible for Medicare for other reasons. Seventy-nine per cent of the patients who had had a total hip arthroplasty and 89 per cent of those who had had a total knee arthroplasty had been managed with the operation because of osteoarthrosis. Both operations were most common in the seventy to seventy-four-year age-group. We calculated the rate of operations per 100 beneficiaries for each state and age-adjusted the results. Across all of the states, bilateral procedures constituted 1.6 per cent of the total hip arthroplasties and 4.8 per cent of the total knee arthroplasties. The in-hospital rates of mortality were 0.72 per cent for total hip arthroplasties and 0.45 per cent for total knee arthroplasties. The destinations after discharge from the hospital were similar for the two groups of patients, with more than 65 per cent of the patients being discharged directly to their homes. There were no significant differences among states in terms of the length of stay in the hospital or reimbursement of the hospital.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1992

A self-administered hip-rating questionnaire for the assessment of outcome after total hip replacement.

The hip-rating questionnaire was developed for the assessment of the outcome of total hip replacement. The purpose of this study was to evaluate its reproducibility, validity, and responsiveness. The questionnaire uses a 100-point scale in which equal weight is given to the domains of global or over-all impact of arthritis, pain, walking, and function. Ninety-eight patients were enrolled in the prospective study and have been followed for at least three months; sixty-two patients have been followed for six months; and forty-two patients have been followed for one year. Reproducibility was tested with the use of the kappa statistic in fifty patients whose condition was stable clinically, and it was found to be good or excellent both for individual questions and for the total score. The validity of the questionnaire was assessed by comparison with the scores from a six-minute walking-distance test and arthritis impact-measurement scales. The result of the six-minute walking-distance test correlated with the patient's response concerning walking distance on the hip-rating questionnaire. The score for pain from the hip-rating questionnaire correlated well with the score for pain from the arthritis impact-measurement scales, and the total score from the hip-rating questionnaire correlated well with the total score from the arthritis impact-measurement scales. The score on the hip-rating questionnaire was responsive to the change in the clinical condition of the patient, as indicated by a favorable index of responsiveness. The results of the questionnaire were sensitive enough to demonstrate differences among treatment groups with relatively small sample sizes. This questionnaire has the characteristics of a useful instrument for assessment of outcomes, such as that after an operation.

Activities of Daily Living↗
PubMed1992

Predicting postoperative pulmonary complications. Is it a real problem?

To identify predictors of postoperative pulmonary complications, a population of 278 patients, mainly hypertensive and diabetic patients undergoing elective general surgery was studied; 60% of the patients underwent abdominal surgery. Of the 278 patients, 6% had postoperative pulmonary complications: 3% had radiographic evidence of infiltrates or segmental atelectasis and 3% had clinical evidence of atelectasis. Among the two thirds of patients undergoing abdominal surgery, only patients with underlying asthma or chronic bronchitis were at increased risk. Generally, patients with better exercise tolerance by self-report, walking distance, or cardiovascular classification had lower rates. Pulmonary function tests did not help to delineate patients at higher risk of postoperative pulmonary complications. Simple clinical information provided as much data about the patients' risk as pulmonary function tests. Many of these complications occurred in patients who sustained other types of postoperative morbidity, suggesting that predicting and preventing postoperative cardiac morbidity may be the best approach to reducing postoperative pulmonary morbidity.

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PubMed1991

Relating patient characteristics at the time of admission to outcomes of hospitalization.

In clinical practice, physicians informally address patient characteristics such as illness severity, comorbidity, functional status and stability when considering prognosis and diagnostic or therapeutic interventions. These same attributes, more formally measured, have been used as measures of casemix in clinical research to classify patients into similar risk strata. To determine whether physician estimates of illness severity, function status and stability were predictive of morbidity, mortality, length of stay and average daily ancillary charges, a cohort of 604 patients was studied. The predictive ability of the patient characteristics were found to be outcome specific. Illness severity was a significant predictor of in-hospital morbidity and mortality, length of stay and charges (p less than 0.001). Functional status was predictive of in-hospital morbidity and mortality, 1 year mortality, length of stay and charges (p less than 0.01). Physician estimates of stability were predictive only of morbidity (p less than 0.01) and comorbidity was only a preditor of 1 year mortality (p less than 0.001). Stratifying patients on the basis of specific clinical characteristics determined at the time of admission will be useful in studies of patient outcomes and resource utilization.

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