Medical instrumentation
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At 34 skin sites on anesthetized pigs, graded levels of average electrosurgical current density, J (A/cm2), at 500 kHz were delivered for specified times (t sec) to cause thermal injury. The severity of cutaneous response was determined by gross and microscopic study 56 hours later. The product J2t has been defined as the relative energy density factor, and is proportional to the delivered energy that determines skin heating. ⋯ At all 13 sites exposed to high energy density (J2t = 1.60-7.50), the maximum skin temperatures beneath the electrodes were 55-81 degrees C, and severe burns were produced with white to brownish, dry, firm, third-degree burns surrounded by peripheral rings of second-degree burns. No significant skin damage was produced with skin temperatures less than 45 degrees C (an energy density factor of 0.75). These data identify the temperature and energy density factor necessary to produce lesions on porcine skin.
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The Heimlich chest drainage valve was developed so that the process of draining the pleural cavity could be accomplished in a safe, relatively simple, and efficient manner. Replacing the cumbersome underwater drainage bottle system, the Heimlich valve connects to chest tubing and allows fluid and air to pass in one direction only. ⋯ The construction and function of the valve is easily understood by medical and nursing staffs. It is presterilized, stored in a sterile package, and readily utilized on emergency vehicles and in the operating room.
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The pathophysiology of a tension pneumothorax relates to ventilation and cardiac output. The insertion of a large-bore needle or medium-bore catheter into the affected pleural cavity rapidly accomplishes decompression. ⋯ The dart is inserted into the secondary costal space, mid-clavicular line, or the fourth intercostal space mid-axillary line. Proper identification of the indications for use of this device is often difficult in the prehospital setting.
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High technology is often erroneously implicated as a principal cause of increased medical care costs. However, thoughtful application of high technology can reduce the cost and improve the quality of medical care, especially in long-term care of the aged. The Veterans Administration rigorously evaluates various forms of high technology before incorporating them into its medical care system.