Influence of crossdrafts on the performance of a biological safety cabinet.
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A biological safety cabinet was tested to determine the effect of crossdrafts (such as those created by normal laboratory activity or ventilation) upon the ability of the cabinet to protect both experiments and investigators. A simple crossdraft, controllable from 50 to 200 feet per min (fpm; 15.24 to 60.96 m/min), was created across the face of the unit. Modifications of standardized procedures involving controlled bacterial aerosol challenges provided stringent test conditions. Results indicated that, as the crossflow velocities exceeded 100 fpm, the ability of the cabinet to protect either experiments or investigators decreased logarithmically with increasing crossdraft speed. Because 100 fpm is an airspeed easily achieved by some air conditioning and heating vents (open windows and doorways may create velocities far in excess of 200 fpm), the proper placement of a biological safety cabinet within the laboratory--away from such disruptive air currents--is essential to satisfactory cabinet performance. (+info)
Modernizing the FDA: an incremental revolution.
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The U.S. Food and Drug Administration (FDA) is responsible for protecting consumers from unsafe or ineffective drugs and medical devices. The agency's role is defined by a growing and increasingly complex set of statutes, which reflect Congress's desires, on the one hand, to prevent product hazards and, on the other, to expedite FDA review and approval of promising new medical technologies. Congress's latest attempt to calibrate regulation to achieve these goals, the 1997 Food and Drug Administration Modernization Act, endorses certain of the FDA's own innovations and changes in the agency's ways of doing business. (+info)
Managing asthma care.
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This activity is designed for physicians, medical directors, and healthcare policy makers. GOAL: To provide the reader with the tools needed to monitor and manage the care of all enrollees with asthma. OBJECTIVES: 1. Become familiar with a health maintenance organization (HMO)-wide data collection system. 2. Learn the essential elements of asthma care for patients. 3. Learn how to track the implementation of these elements in various HMO settings. (+info)
Technology assessment of medical devices at the Center for Devices and Radiological Health.
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We reviewed the Food and Drug Administration's regulatory process for medical devices and described the issues that arise in assessing device safety and effectiveness during the postmarket period. The Center for Devices and Radiological Health (CDRH), an organization within the Food and Drug Administration, has the legal authority and responsibility for ensuring that medical devices marketed in the United States are both reasonably safe and effective for their intended use. This is an enormous challenge given the diversity of medical devices and the large number of different types of devices on the market. Many scientific and regulatory activities are necessary to ensure device safety and effectiveness, including technology assessment, albeit in a manner quite different from that of conventional technology assessment. The basic approach taken at the CDRH to ensure device safety and effectiveness is to develop an understanding of the way in which a medical device works and how it will perform in clinical situations. (+info)
Role of technology assessment in health benefits coverage for medical devices.
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With the profusion of new medical technology, managed care organizations are faced with the challenge of determining which medical devices and services warrant health benefits coverage. To aid in this decision-making process, managed care companies turn to technology assessment, a process that differs from the Food and Drug Administration's review of medical devices. Health plans typically use a structured approach to implementing coverage requirements in employer group benefits contracts and use technology assessment to evaluate the scientific evidence of effectiveness to support coverage decisions. Also important is the societal context for decisions regarding coverage for new technologies and the options being considered by policy makers for accountability in technology assessment by private insurers and health plans. (+info)
Device evaluation and coverage policy in workers' compensation: examples from Washington State.
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Workers' compensation health benefits are broader than general health benefits and include payment for medical and rehabilitation costs, associated indemnity (lost time) costs, and vocational rehabilitation (return-to-work) costs. In addition, cost liability is for the life of the claim (injury), rather than for each plan year. We examined device evaluation and coverage policy in workers' compensation over a 10-year period in Washington State. Most requests for device coverage in workers' compensation relate to the diagnosis, prognosis, or treatment of chronic musculoskeletal conditions. A number of specific problems have been recognized in making device coverage decisions within workers' compensation: (1) invasive devices with a high adverse event profile and history of poor outcomes could significantly increase both indemnity and medical costs; (2) many noninvasive devices, while having a low adverse event profile, have not proved effective for managing chronic musculoskeletal conditions relevant to injured workers; (3) some devices are marketed and billed as surrogate diagnostic tests for generally accepted, and more clearly proven, standard tests; (4) quality oversight of technology use among physicians may be inadequate; and (5) insurers' access to efficacy data adequate to make timely and appropriate coverage decisions in workers' compensation is often lacking. Emerging technology may substantially increase the costs of workers' compensation without significant evidence of health benefit for injured workers. To prevent ever-rising costs, we need to increase provider education and patient education and consent, involve the state medical society in coverage policy, and collect relevant outcomes data from healthcare providers. (+info)
The limited state of technology assessment for medical devices: facing the issues.
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Medical devices are an integral part of clinical practice and account for a substantial proportion of the national health budget. Clinical testing and regulation of medical devices, however, is vastly different from and inferior to the testing and regulation of drugs. As managed care organizations begin to exert controls on device use, providers are being caught between the policies of their organizations and the demands of device manufacturers and patients, who want wider access to devices. We outline several reasons for the poor state of medical device evaluations and the dangers of using devices without adequate information, and include the recently developed device assessment and reporting guidelines created by the Task Force on Technology Assessment of Medical Devices. (+info)
High-pressure, rapid-inflation pneumatic compression improves venous hemodynamics in healthy volunteers and patients who are post-thrombotic.
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PURPOSE: Deep vein thrombosis (DVT) is a preventable cause of morbidity and mortality in patients who are hospitalized. An important part of the mechanism of DVT prophylaxis with intermittent pneumatic compression (IPC) is reduced venous stasis with increased velocity of venous return. The conventional methods of IPC use low pressure and slow inflation of the air bladder on the leg to augment venous return. Recently, compression devices have been designed that produce high pressure and rapid inflation of air cuffs on the plantar plexus of the foot and the calf. The purpose of this study is to evaluate the venous velocity response to high-pressure, rapid-inflation compression devices versus standard, low-pressure, slow-inflation compression devices in healthy volunteers and patients with severe post-thrombotic venous disease. METHOD: Twenty-two lower extremities from healthy volunteers and 11 lower extremities from patients with class 4 to class 6 post-thrombotic chronic venous insufficiency were studied. With duplex ultrasound scanning (ATL-Ultramark 9, Advanced Tech Laboratory, Bothell, Wash), acute DVT was excluded before subject evaluation. Venous velocities were monitored after the application of each of five IPC devices, with all the patients in the supine position. Three high-pressure, rapid-compression devices and two standard, low-pressure, slow-inflation compression devices were applied in a random sequence. Maximal venous velocities were obtained at the common femoral vein and the popliteal vein for all the devices and were recorded as the mean peak velocity of three compression cycles and compared with baseline velocities. RESULTS: The baseline venous velocities were higher in the femoral veins than in the popliteal veins in both the volunteers and the post-thrombotic subjects. Standard and high-pressure, rapid-inflation compression significantly increased the popliteal and femoral vein velocities in healthy and post-thrombotic subjects. High-pressure, rapid-inflation compression produced significantly higher maximal venous velocities in the popliteal and femoral veins in both healthy volunteers and patients who were post-thrombotic as compared with standard compression. Compared with the healthy volunteers, the patients who were post-thrombotic had a significantly attenuated velocity response at both the popliteal and the femoral vein levels. CONCLUSION: High-pressure, rapid-inflation pneumatic compression increases popliteal and femoral vein velocity as compared with standard, low-pressure, slow-inflation pneumatic compression. Patients with post-thrombotic venous disease have a compromised hemodynamic response to all IPC devices. However, an increased velocity response to the high-pressure, rapid-inflation compression device is preserved. High-pressure, rapid-inflation pneumatic compression may offer additional protection from thrombotic complications on the basis of an improved hemodynamic response, both in healthy volunteers and in patients who were post-thrombotic. (+info)