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Biomedical subjects

F A Anderson

Publications and source records attributed to F A Anderson.

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

ALS care: a resource for measuring and improving ALS outcomes.

The Amyotrophic Lateral Sclerosis Clinical Assessment, Research, and Education Project (ALS CARE) will conduct outcomes research and develop educational programs that benefit ALS patients and neurologists. An advisory board of neurologists, who are experts in ALS, will establish the policies governing this project and control the dissemination of aggregate data on ALS practices and outcomes. As a first step toward improving the care of ALS patients, a data coordinating center has been established in the Center for Outcomes Research at the University of Massachusetts Medical Center, which will manage a North American Database of ALS Outcomes. This voluntary database is designed to (1) guide the development of educational programs to improve the care of ALS patients and (2) provide a mechanism for neurologists to evaluate the impact of their diagnostic and therapeutic decisions in a manner that is timely, confidential, and objective.

Amyotrophic Lateral Sclerosis↗
PubMed1996

Physician practices in the prevention of deep vein thrombosis: the MassPRO DVT Study.

Numerous well-designed clinical trials have demonstrated that prophylaxis reduces the incidence of acute deep vein thrombosis (DVT) in high-risk surgical patients by two-thirds, with a corresponding reduction in mortality from pulmonary embolism. However, studies of clinical practices suggest that DVT prophylaxis is underused-for example, only 39% of high-risk surgical patients in 16 central Massachusetts hospitals were administered DVT prophylaxis in 1986. Subsequently, an intensive educational initiative was launched to improve utilization of DVT prophylaxis. Although some improvement was reported, the level of use was not optimal. The Massachusetts Peer Review Organization (MassPRO) DVT study was designed to gather data on recent practice patterns among Massachusetts surgeons and determine the need for additional educational and quality assurance efforts. The results indicate that there is broad compliance among orthopedic surgeons with consensus recommendations for the use of DVT prophylaxis. Nearly all patients who undergo total hip replacement in Massachusetts are protected from DVT by one or more methods of prophylaxis. These data suggest that the ongoing efforts to improve the use of DVT prophylaxis in Massachusetts since 1986 have come to fruition, at least with respect to total hip replacement.

Aged↗
PubMed1995

Asymptomatic deep venous thrombosis in the trauma patient: is an aggressive screening protocol justified?

The incidence and sequelae of deep venous thrombosis (DVT) in trauma patients are unclear because the majority of patients who develop DVT are asymptomatic. This study evaluated the incidence, risk factors, and efficacy of prophylaxis for DVT in trauma patients over a 5-year period. Trauma patients at high risk for DVT were evaluated biweekly with lower extremity venous duplex scans. The DVT prophylaxis was instituted on admission with low-dose heparin therapy and pneumatic compression. The incidence of asymptomatic DVT identified by duplex screening was 10% (45 of 458); one pulmonary embolus occurred. Five variables were significant from bivariate and multiple logistic regression analysis: age (p = 0.005), Injury Severity Score (p = 0.005), length of stay (p = 0.004), Trauma and Injury Severity Score (p = 0.01), and spinal injury (p = 0.014). This analysis documents that trauma patients with these risk factors are at increased risk for the development of asymptomatic DVT, despite prophylaxis, and warrant surveillance with venous duplex sonography.

Adult↗
PubMed1995

Venous thromboembolism. Risk factors and prophylaxis.

Most deaths from pulmonary embolism can be prevented by providing adequate prophylaxis for hospital patients who are at high risk for venous thromboembolism. Physicians, however, must be able to identify high-risk patients (including those with major trauma, hip or knee replacement, or pelvic fractures) and prescribe an appropriate prophylactic agent for each patient according to his or her level of risk. A number of prophylactic methods have been proven effective in the prevention of venous thromboembolism, including low-dose heparin, low-molecular-weight heparin, warfarin, graduated compression stockings, and intermittent pneumatic compression of the legs.

Adult↗
PubMed1994

Diagnostic tests for deep vein thrombosis. Clinical usefulness depends on probability of disease.

We review the general principles that govern the clinical utility of diagnostic tests, particularly with respect to the diagnosis of deep vein thrombosis (DVT). We stress the importance of clinical probability of disease, which strongly influences the positive predictive value (true-positive rate) and negative predictive value (true-negative rate) of all diagnostic tests. In selecting a diagnostic procedure for DVT, the physician must first consider the clinical probability of disease and then the local accuracy of the test employed and its cost-effectiveness. In 75% to 80% of patients suspected to have DVT, clinical management can be based on the results of noninvasive tests, such as ultrasonography or impedance plethysmography (IPG), rather than venography. Ultrasonography has clear advantages over venography with respect to cost and patient comfort, and it defines the anatomic extent of the thrombus. It should be considered the new diagnostic standard for symptomatic DVT. Despite recent reports of lower sensitivity than previously reported, IPG remains an acceptable alternative to ultrasonography for symptomatic DVT in selected patients. Even if the recently reported lower sensitivity proves to be accurate, the probability of adverse clinical outcomes as a result of overlooked disease is still extremely low in patients with a low probability of DVT. The negative predictive value of IPG under these circumstances approaches 99%. Impedance plethysmography is also useful in patients with a high probability of DVT, in whom the positive predictive value may be as high as 97%. When the findings of IPG (or ultrasonography) are at variance with a strong clinical impression, venography should be considered, especially when there is a high clinical probability of disease and a negative noninvasive test result.

Bias↗
PubMed1994

The epidemiology of diagnosed pulmonary embolism and deep venous thrombosis in the elderly.

BACKGROUND: There are no studies that define the basic epidemiology of pulmonary embolism (PE) and deep venous thrombosis (DVT) in the elderly. This project was undertaken to provide that information. METHODS: We obtained all Medicare claims during the period 1986 through 1989 from a random 5% sample of US Medicare enrollees. By selecting codes used for diagnoses and treatment, we identified 7174 cases of PE and 8923 cases of DVT. These cohorts were analyzed to provide incidence by age, race, sex, and geographic location; frequency of invasive treatment; frequency of PE after treatment for DVT; frequency of recurrence of PE; and survival after diagnosis. RESULTS: Annual incidence rates per 1000 at age 65 to 69 years for PE and DVT were 1.3 and 1.8, respectively. Both rates increased steadily with age to 2.8 and 3.1 by age 85 to 89 years. For PE, women had lower rates than men (adjusted relative risk, 0.86; 95% confidence interval, 0.82 to 0.90), and blacks had higher rates than whites (adjusted relative risk, 1.25; 95% confidence interval, 1.15 to 1.36). For DVT, the associations with gender and race were weaker and in the opposite direction. Pulmonary embolectomy was done in 0.2% of cases of PE; interruption of the vena cava was done in 4.4% of cases of PE and in 2% of cases of DVT. Thrombectomy was done in 0.3% of all cases. Pulmonary embolism occurred in 1.7% of patients with DVT within 1 year of hospital discharge for initial treatment. The 1-year recurrence rate for PE was 8.0%. In-hospital mortality associated with PE and DVT was 21% and 3%, respectively. One-year mortality was 39% and 21%, respectively. CONCLUSIONS: Pulmonary embolism and DVT are common problems in the elderly. Both increase with age, but the effects of race and sex are small. Current treatment patterns appear to be effective in preventing both PE after DVT and recurrence of PE. Both are associated with substantial 1-year mortality, suggesting the need to understand the role of associated conditions as well as the indications for prophylaxis and the methods of treatment.

Black or African American↗
PubMed1994

Changing clinical practice. Prospective study of the impact of continuing medical education and quality assurance programs on use of prophylaxis for venous thromboembolism.

OBJECTIVE: To determine the effect of continuing medical education (CME) with and without a quality assurance component (CME+QA) on physician practices in the prevention of venous thromboembolism. METHODS: A communitywide study was performed in 15 short-stay hospitals in central Massachusetts. The study population included 3158 patients in acute-care hospitals with multiple risk factors for venous thromboembolism. Study hospitals were randomly assigned to one of two educational strategies or to a control group that received no intervention. RESULTS: The proportion of patients at high risk for venous thromboembolism who received effective methods of prophylaxis increased significantly from 29% in 1986 to 52% in 1989 (P < .001). This increase was seen in all study groups: control hospitals, 40% to 51% (P < .001); CME hospitals, 21% to 49% (P < .0001); and CME+QA hospitals, 27% to 55% (P < .0001). The increase in prophylaxis use from 1986 to 1989 was significantly greater among patients cared for in hospitals whose physicians participated in a formal CME program (an increase of 28%) than in control hospitals (an increase of 11%) (P < .001). There was no significant difference in the use of prophylaxis in hospitals whose physicians received CME+QA interventions compared with hospitals whose physicians received CME interventions alone (identical increases of 28%). CONCLUSION: A formal CME program significantly increased the frequency with which physicians prescribed prophylaxis for venous thromboembolism. We believe the key factor in our CME interventions that motivated clinicians to change their practices was the provision of hospital-specific data demonstrating a compelling need for improvement. Despite the substantial investment by hospitals in QA, traditional QA intervention appeared to provide no additional benefit. Even after extensive CME/QA interventions, prophylaxis for venous thromboembolism remained underutilized, suggesting the need to develop new approaches to changing clinical practice.

Aged↗
PubMed1994

Free flap valvular transplantation for refractory venous ulceration.

PURPOSE: Nonoperative therapeutic approaches to chronic venous ulceration, although effective, often require prolonged dressing care and immobilization with leg elevation. Results of skin grafting, perforator ligation, and valve interpositions and reconstructions improve results of ulcer healing but have not uniformly prevented ulcer recurrence. Our hypothesis is that reconstruction of chronic venous ulcers by excision of the diseased tissue bed and replacement with a free flap containing multiple competent microvenous valves and a normal tissue microcirculation will result in long-term cure of these debilitated patients. METHODS: Six patients with chronic venous insufficiency and recurrent ulceration (class 3) underwent excision of ulcers and surrounding liposclerotic tissue beds and reconstruction with fasciocutaneous free flaps (two bilateral). Preoperative and postoperative photoplethysmography was used to assess venous refilling times. Duplex scanning was performed to assess deep venous reflux. RESULTS: There were no flap failures. Photoplethysmographic venous refilling times measured on flaps demonstrated significant immediate and long-term increases from preoperative values (all results +3 by Society of Vascular Surgery outcome grading). Long-term maintenance of tissue integrity is shown by absence of recurrent ulceration and no evidence of recurrent tissue lipodermatosclerosis in all flaps at follow-up (8 months to 7.5 years; mean 24 months). No recurrent lipodermatosclerosis was seen on flap biopsy at 2 and 7 years. Separate cadaveric injection studies, including scanning electron microscopy, revealed numerous microvenous valves directed toward the draining pedicle in the flaps used for reconstruction. CONCLUSIONS: This is the first comprehensive report providing combined laboratory and clinical evaluation, anatomic rationale, and long-term outcome of surgical rehabilitation of patients with chronic venous ulceration who have undergone microsurgical flap reconstruction.

Adult↗
PubMed1993

Experimental femoral vein reconstruction with expanded polytetrafluoroethylene grafts seeded with endothelial cells.

The effect of endothelial cell seeding on the patency of small-caliber expanded polytetrafluoroethylene (ePTFE) grafts used for venous replacements in a canine experimental model was evaluated. Grafts were implanted bilaterally in 12 dogs as femoral vein interpositions. In each animal, one graft was seeded with enzymatically derived homologous endothelial cells which had been cultivated for 3 days in vitro before implantation, whereas the contralateral graft was not seeded. In five dogs, venography was performed at 2 weeks, and grafts were then excised. In the remaining seven dogs, venography was performed at both 2 and 4 weeks, with graft excision at 4 weeks. Graft patency at 2 weeks for seeded grafts was 75% (nine of 12) compared with only 33% (four of 12) for unseeded grafts (P < 0.02). There were no new episodes of thrombotic occlusion between 2 and 4 weeks. Five dogs with thrombus in the control graft did not develop thrombus in the contralateral seeded graft. Furthermore, each dog with a patent control graft had no thrombus in the seeded graft. It is concluded that the early patency of seeded ePTFE grafts is superior to that of unseeded ePTFE grafts in the femoral vein.

Animals↗
PubMed1992

Do graduated compression stockings and pneumatic boots have an additive effect on the peak velocity of venous blood flow?

Graduated compression stockings and intermittent pneumatic compression boots reduce the incidence of deep vein thrombosis. Recent studies suggest that the simultaneous use of these devices may have a synergistic prophylactic effect; however, conflicting reports also exist. Using duplex imaging, we analyzed the effect on peak venous velocity in the superficial femoral vein produced by the individual and simultaneous use of graduated compression stockings and intermittent pneumatic compression boots. Normal volunteers and postoperative patients were examined. The use of intermittent pneumatic compression boots significantly increased the peak venous velocity relative to rest, whereas the use of graduated compression stockings did not alter the peak venous velocity. Also, the addition of graduated compression stockings to legs already being treated with intermittent pneumatic compression boots did not produce a further augmentation of peak venous velocity. This study demonstrates that the simultaneous use of graduated compression stockings and intermittent pneumatic compression boots does not produce a synergistic augmentation of peak venous velocity in the superficial femoral vein.

Bandages↗
PubMed1992

Physician practices in the management of venous thromboembolism: a community-wide survey.

Although there is a broad consensus on the optimum approach to the management of venous thromboembolism, there are few data from which to assess the extent of compliance with these recommendations. A community-wide study was therefore conducted in 16 short-stay hospitals in central Massachusetts to assess the clinical management of venous thromboembolism. Based on validated discharge diagnostic codes, there were 1231 clinically recognized cases of venous thromboembolism, 0.8% of 148,730 discharges in the 18-month period from July 1, 1988, to December 31, 1989. Eighty-one percent of study patients were admitted with signs or symptoms of acute venous thromboembolism. Ninety-seven percent of patients were treated with either heparin, warfarin, or inferior vena caval filter. Intravenous heparin was given to 89% of patients (mean bolus 6674 IU; mean duration 6.6 days). After heparin administration, there was a mean delay of 2.3 days in starting warfarin. Assuming a corresponding decrease in the length of hospital stay, appreciable cost savings could have been realized by earlier start of oral anticoagulation. An inferior vena cava filter was placed in 14% of patients. There was a clinically recognized in-hospital recurrence of venous thromboembolism during treatment in 2% of patients. Despite a slightly lower rate of compliance with recommended treatment regimens in nonteaching hospitals, and despite less frequent use of the inferior vena cava filter, there was no significant difference in the rate of in-hospital recurrence of clinically recognized venous thromboembolism in 10 nonteaching hospitals compared with six teaching hospitals.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

The prevalence of risk factors for venous thromboembolism among hospital patients.

BACKGROUND: This study provides an estimate of the prevalence of risk factors for venous thromboembolism among hospital patients. METHODS: The presence of risk factors for venous thromboembolism was determined from a retrospective review of the medical records of 1,000 randomly selected patients in 16 acute care hospitals in central Massachusetts. RESULTS: The most common risk factors for venous thromboembolism were age 40 years (59%) or more, obesity (28%), and major surgery (23%). The average number of risk factors increased with increasing age. One or more risk factors for venous thromboembolism were present in 78% of hospital patients, two or more in 48%, three or more in 19%, four or more in 6%, and five or more in 1%. CONCLUSION: Risk factors for venous thromboembolism are common among hospital patients, suggesting that prophylaxis should be widely employed. The cost-effectiveness and risk benefit of prophylaxis is well established in patients undergoing major surgery. Further studies are needed to confirm the benefit of prophylaxis in patients with nonsurgical risk factors for venous thromboembolism.

Age Factors↗
PubMed1991

Physician practices in the prevention of venous thromboembolism.

OBJECTIVE: To determine the rate of use of prophylaxis for venous thromboembolism in high-risk hospital patients. DESIGN: A retrospective medical record review. SETTING: A community-wide study in 16 short-stay hospitals in central Massachusetts. PATIENTS: A total of 2017 patients with multiple risk factors for venous thromboembolism. MEASUREMENTS AND MAIN RESULTS: On the basis of age, length of hospitalization, and the presence of at least one additional major risk factor, 17% of 151,349 discharges (25,410 patients) were identified as being at high risk for venous thromboembolism. Eight percent of these discharges were randomly selected for medical record review. Prophylaxis for venous thromboembolism was received by 32% of these high-risk patients. Prophylaxis use among the 16 study hospitals varied widely, ranging from 9% to 56%, and was higher in teaching hospitals than in nonteaching hospitals (44% compared with 19%; P less than 0.001). One or more of the following methods of prophylaxis was used: low-dose heparin (78%), intermittent calf compression (13%), warfarin (12%), and inferior vena caval filter (3%). Use of prophylaxis increased with the number of risk factors identified (P less than 0.001). CONCLUSION: Prophylaxis for venous thromboemobolism is underused, particularly in nonteaching hospitals.

Adult↗
PubMed1991

Prophylaxis against venous thromboembolism in surgical patients.

Venous thromboembolic disease is a common, potentially life-threatening, but preventable complication of surgery. Venographic studies have shown a high incidence of deep vein thrombosis in patients who do not receive prophylaxis. The long-term sequelae of deep vein thrombosis in these patients can be disabling, but the exact prevalence of post-thrombotic complications has not been well documented. Fatal pulmonary embolism has been reported in 0.5% to 1% of patients after major abdominal surgery and in 2% to 6% after total hip replacement. Several methods of prophylaxis against venous thromboembolism have demonstrated efficacy, but a surprising number of patients still do not receive prophylaxis. A medical record review in 16 hospitals recently disclosed that only 32% of high-risk patients received prophylaxis, with a range from 9% in a community hospital to 56% in a major teaching hospital. The possible reasons for this comparatively low rate of utilization are discussed. Current issues and future trends in the prophylaxis of venous thromboembolism are briefly summarized.

Humans↗