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In-line blood/solution warmers are used in many clinical procedures to warm refrigerated and room temperature fluids as they are infused into the patient. Warming fluids such as whole blood, blood products, intravenous (IV) solutions, and irrigation solutions helps to maintain the patient's core body temperature, thus minimizing adverse thermal reactions (e.g., hypothermia). In this study, we evaluated nine in-line blood/solution warmers from seven manufacturers. We tested these systems' performance and safety, human factors design, and quality of construction, focusing on how well the devices warm fluids over a variety of infusion rates common in clinical use. We rated each system according to the clinical application base for which it is primarily intended-routine-flow procedures (i.e., those that require low or moderate flow rates) or high-flow procedures. Of the six systems in the routine-flow category, we rated only two units Acceptable; the remaining four were rated Acceptable-Not Recommended because they could not warm fluids to the same temperature level as the Acceptable units. We rated all three of the systems in the high-flow category Acceptable. Within each of these rating groups, we ranked units according to the results of our testing, as well as the results of a life-cycle cost analysis that we performed. In the Technology Overview, we discuss the clinical need for blood/solution warming and outline the debate over whether and when in-line warming devices should be used. Also, we describe the technologies used in these devices, as well as the safety issues associated with their use. The Selection, Purchasing, and Use Guide at the end of the Evaluation provides guidance to help facilities (1) assess their blood/solution warming needs, (2) choose the systems that will best meet their needs, and (3) use these systems effectively. This study also includes the supplementary article, "Maximum Blood Warming Temperature-How Hot Is Too Hot?"

Objective: To determine the bedside accuracy of direct patient pressure monitoring when used with new and clinically used disposable blood pressure (BP) transducers., Design: Prospective study., Setting: Laboratory bench and critical care units in an adult and children's hospital., Subjects: Seventy-five bedside patient monitors (25 Marquette Electronics, 25 Spacelab Medical, and 25 Hewlett-Packard), and 100 disposable transducers (50 from Utah Medical Products and 50 from Abbott Critical Care Systems [25 new, 25 clinically used of each manufacturer]) were tested., Interventions: None., Measurements and Main Results: A +/- 2% accuracy requirement for bedside monitors and the +/- 3% American National Standards Institute accuracy standard for disposable BP transducers were used. To test the accuracy of the bedside monitors, a certified transducer simulator was used to apply 100 mm Hg to each bedside monitor. To test the accuracy of the disposable BP transducers, a very accurate (+/- 0.05%) pneumatic dead weight tester was used to apply pressures to the transducer. A digital power supply and a 6 1/2 digit voltmeter were used. The average output of the bedside monitors when 100 mm Hg was applied was 99.90 +/- 0.83 mm Hg, with the worst cases being 98 and 103 mm Hg. For all 100 disposable pressure transducers, the average output was 100.03 +/- 0.55 mm Hg, with the worst cases being 98.53 and 101.36 when 100 mm Hg was applied. There was no important difference in the accuracy of the transducers obtained from the two vendors nor whether the transducers had been used clinically., Conclusions: All disposable BP transducers tested were much more accurate than the American National Standards Institute standard for accuracy. Even the worst case transducers were twice as accurate as required by the American National Standards Institute standard. Only one bedside monitor was outside the +/- 2% accuracy range (103 mm Hg). Based on these findings, this author recommends that fixed calibration disposable transducers and fixed calibration bedside pressure monitoring systems be used. The clinical risks of air embolism and infection from the calibrating mercury manometer and the complexity of the calibration task are the overriding factors for making these recommendations.

Monopolar and concentric reusable and disposable EMG needle electrodes from several manufacturers were studied at various stages of usage. Needle tips were examined and measured microscopically, and needles were tested for spontaneous noise and resistive and capacitative characteristics at four different test signal frequencies. Resistive and capacitative characteristics were found to be frequency dependent. Needle tip areas differed by as much as 10 times among the various electrodes. The amount of noise correlated most highly with resistive characteristics. Monopolar and concentric needles differed in respect to tip area, noise, and all resistive and capacitative measures. Coaxial disposable and reusable electrodes did not differ significantly and minor differences were noted in electrical characteristics between reusable and disposable monopolar needles, even from the same manufacturer. There was considerable variability among manufacturers for both needle types. In choosing an electrode, consistent tip area is probably the most important consideration to ensure repeatable quantifiable results, but minimizing needle impedance is useful to reduce noise.

Disposable soft contact lenses are an alternative to conventional extended-wear lenses and provide an acceptable margin of safety and convenience for the wearer. The lenses are worn for one to two weeks and then discarded. Buildup of tear film deposits is minimized, and the need for cleaning and disinfecting solutions is eliminated. The long-term safety of disposable contact lenses is unknown.

The demand for health care facilities and services will remain insatiable, concludes a report by Frost and Sullivan due to be published shortly. The report on trends in the European clinical soft goods market says growth is guaranteed but that the market penetration of disposables is not.