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Biomedical subjects

L F Muscarella

Publications and source records attributed to L F Muscarella.

22 records · Page 2Linked to original sources
PubMed1986

Pressure pulse transmission into vascular beds.

Observations at the microcirculatory level have revealed that (a) the pressure pulse reaches the smallest vessel, and (b) the pulse wave velocity alters from a value in the order of meters/second in large arteries to a value in the order of centimeters/second in the microvessels. We investigate, herein, whether these experimental findings are consonant with linear pulse wave transmission theory in a branching system of vessels. Our computations, utilizing available data, show that this is indeed the case. For low frequency (1 Hz), cumulative attenuation is such that about one-third of the pulse, originating at the heart, reaches the capillary. A 10-Hz pulse, however, is virtually completely attenuated by the time the capillary is reached. Transmission time for a pulse, from heart to capillary, is also frequency dependent, with higher frequencies propagating more rapidly. Vasoconstriction, at the arteriolar level in the absence of reflection, can also strongly attenuate the pulse remnant at that site.

Blood Pressure↗
PubMedDate not supplied

Biopsy forceps: disposable or reusable?

Current debate surrounds the cost-effectiveness of disposable and reusable biopsy forceps. Although a complex and arduous task, performing a cost analysis may be necessary to determine which forcep type is more cost-effective. Costs associated with disposable biopsy forceps include their initial cost as well as storage and disposal costs. In addition to initial cost, costs associated with reusable biopsy forceps include reprocessing, maintenance, and repair costs. Estimating the number of times forceps are likely to be reused is also essential to evaluating the cost-effectiveness of reusable biopsy forceps. In general, once a reusable biopsy forcep performs a threshold number of procedures, it becomes more cost-effective than a disposable forcep. While reusable biopsy forceps may be more suitable and cost-effective for larger gastrointestinal endoscopy centers that perform many procedures per day, the convenience of disposable biopsy forceps may make them the more appropriate choice for centers that are smaller and perform only a few procedures each day. Due to significant decreases in the initial cost of disposable biopsy forceps, the cost-effectiveness of reusable biopsy forceps is waning. This article reviews the various issues associated with disposable versus reusable biopsy forceps and provides readers with guidelines for evaluating the appropriateness of both forcep designs in their unique practice setting.

Biopsy↗
PubMedDate not supplied

Current instrument reprocessing practices. Results of a national survey.

In June 1998, a questionnaire was mailed to approximately 2,900 healthcare professionals to assess current instrument reprocessing and infection control practices and determine whether they have changed during the past decade. Surveys were returned from 146 respondents whose facilities performed gastrointestinal endoscopy. Most respondents were registered nurses and almost all worked in healthcare facilities located in the United States. More than 75% of the respondents reported that infection control practices in endoscopy have improved during the past 10 years. Most respondents used glutaraldehyde to reprocess flexible endoscopes. Immersing endoscopes for 20 minutes at room temperature was commonly practiced. Almost 75% of respondents used an automated device to reprocess flexible endoscopes. Most respondents terminally rinsed the endoscope's channels with 70% alcohol followed by forced-air drying. Few respondents outsourced instruments to a commercial reprocessing company and almost 50% reused disposable items. While some practices in endoscope reprocessing have changed during the past several years, others have not. In general, infection controls appear to have improved during the past decade, with the possible exception of a trend to reuse single-use items.

Disposable Equipment↗