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Biomedical subjects

H B Wheeler

Publications and source records attributed to H B Wheeler.

At least 19 recordsLinked to original sources
PubMed1999

Recommendations for incorporating palliative care education into the acute care hospital setting.

This article presents recommendations for improving the education of physicians about end-of-life care in the acute care hospital setting. The authors, who have a variety of backgrounds and represent several types of institutions, formulated and reached consensus on these recommendations as members of the Acute Care Hospital Working Group, one of eight working groups convened at the National Consensus Conference on Medical Education for Care Near the End of Life in May 1997. A recently published literature review on the status of palliative care education, a summary of recent research on education about end-of-life care, and expert opinion were helpful in developing the recommendations. The authors emphasize that the acute care setting offers many opportunities for education about care at the end of life. Faculty should support learners' appreciation of the importance of end-of-life care, and convey the meaning and privilege of attending to patients and families at this difficult time. Faculty should teach students and residents to provide care that embodies attention to the control of distressing physical, physiologic, and spiritual symptoms, appropriate awareness of patients' differing cultural backgrounds and their impact upon the experience of dying, excellent communication skills, the application of bioethical principles, timely referral and smooth transition to other care settings that meet patient and family goals, and the role of the interdisciplinary team in meeting the diverse needs of dying patients and their families.

Education, Medical, Continuing↗
PubMed1998

Adenosine A2a receptors increase arterial endothelial cell nitric oxide.

BACKGROUND: Adenosine is a potent vasodilator of vascular smooth muscle. Endothelium-derived nitric oxide (NO) elicits vasodilation. We have previously reported that adenosine stimulates the production of NO from porcine carotid arterial endothelial cells (PCAEC) via a receptor-mediated mechanism. This study was to determine whether adenosine also enhances NO production from human arterial endothelium and to define the involvement of adenosine A1 and A2 receptors. MATERIALS AND METHODS: Human iliac arterial endothelial cells (HIAEC) and PCAEC were harvested and cultured in dishes. NO production was evaluated with a NO electrode sensor which measured continuously real-time NO production. RESULTS: NO content of the medium bathing HIAEC and PCAEC was significantly increased with adenosine (100 micromol/L). Ethylcarboxamidoadenosine (NECA), a nonselective adenosine receptor agonist, and carboxyethyl-phenethylamino-ethylcarboxamidoadenosine (CGS-21680), a selective adenosine A2a receptor agonist, increased NO production by HIAEC and PCAEC with respective EC50 values of 3.32 and 6.96 nmol/L for NECA and 30.97 and 29.47 nmol/L for CGS-21680. Chlorofuryl-triazolo-quinazolinamine (CGS-15943; 1 micromol/L), an adenosine A1 and A2 receptor antagonist, and aminofuryltriazolotriazinyl-aminoethylphenol (ZM-241385; 1 micromol/L), a selective adenosine A2a receptor antagonist, inhibited the effect of CGS-21680. Chlorocyclopentyl-adenosine (CCPA; 1 micromol/L), an adenosine A1 receptor agonist, significantly depressed NO production by both HIAEC and PCAEC: This effect was inhibited by cyclopentyl-dipropylxanthine (DPCPX), a selective adenosine A1 receptor antagonist. CONCLUSIONS: The results demonstrate that adenosine A2a receptors increase, and adenosine A1 receptors decrease, the production of NO by human and porcine arterial endothelial cells.

Adenosine↗
PubMed1998

Should surgical patients be screened for thrombophilia?

Genetic abnormalities that predispose a patient to venous thromboembolism (VTE) can now be identified. These genetic abnormalities include resistance to activated protein C and deficiencies of antithrombin, protein C, or protein S. Because the risk of VTE in surgical patients is well documented, the question naturally arises as to whether screening for genetic predisposition to VTE is indicated. This paper provides an outline of the need to prevent VTE in surgical patients and a brief review of current criteria for prophylaxis. This paper also provides an evaluation of the possible role for thrombophilia screening for surgical patients, based on perspectives gained from prophylaxis. At present, a small but well-defined group of patients, especially those with idiopathic VTE or a strong family history of the disease, should be screened for thrombophilia. Results from subsequent clinical trials may indicate the need to expand the role of thrombophilia screening.

Activated Protein C Resistance↗
PubMed1996

A prospective study of the incidence of deep venous thrombosis in hospitalized children.

PURPOSE: It is commonly believed that the incidence of deep venous thrombosis (DVT) in hospitalized children is less than in adults. However, it is possible that the disease is significantly underdiagnosed in children because the index of suspicion of pediatric practitioners is low, a substantial number of patients may have no symptoms, and DVT screening is not routinely performed. We therefore undertook a prospective study to define the incidence of DVT in hospitalized children with no symptoms. METHODS: Patients included in the study were those younger than 18 years of age who were hospitalized for more than 72 hours and were identified to have two or more risk factors for the development of DVT and had at least one screening duplex scan. Risk factors for the development of DVT considered were a history of DVT or pulmonary embolism, recent operation, immobilization, trauma, stroke or acute neurologic deficit, the presence of cancer, sepsis, greater than 150% ideal body weight, a hypercoagulable state, and the presence of a femoral venous catheter. RESULTS: Over the 9-month period ending December 1994, 1997 patients 17 years of age and younger were admitted to the hospital, and 59 patients including 19 girls and 40 boys were enrolled in the study. The one patient with DVT was a 17-year-old boy hospitalized after a motor vehicle accident with blunt head trauma and a neurologic deficit who underwent multiple orthopedic and neurosurgical procedures. CONCLUSIONS: The development of acute DVT in children is unusual. As a result, DVT prophylaxis and screening is unnecessary in young children with only two risk factors for the development of the disease. Young age appears to be an important protective risk factor for the prevention of DVT.

Age Distribution↗
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

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↗
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

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↗