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R Brown

Publications and source records attributed to R Brown.

944 records · Page 53Linked to original sources
PubMedDate not supplied

High-frequency ventilation: a promising new approach to mechanical ventilation.

Adequate pulmonary ventilation can be achieved in experimental animals and in humans using tidal volumes on the order of the anatomic dead space volume applied at very high ventilatory frequencies (3-30 Hz). Classical mechanism of gas exchange cannot account for these paradoxical observations, but theories based on the concept of augmented diffusion may provide an adequate explanation for this phenomenon. Even though the exact mechanisms accounting for gas exchange are not well understood, a number of successful ventilators have been designed and tested based on the concept of small volume/high frequency ventilation. The differences among these various ventilators are compared and contrasted and possible clinical uses of the technique are discussed.

Animals↗
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The use of intraoperative fluoroscopy and spinal cord monitoring for transoral microsurgical odontoid resection.

The transoral approach to the upper cervical spine has not gained wide acceptance. A reliable intraoperative method to determine the necessary extent of dissection and degree of decompression, as well as to evaluate spinal cord function, should improve the safety and applicability of the transoral approach. Four cases of anterior cervical cord compression were successfully treated by odontoid resection employing a microsurgical transoral approach. Intraoperative fluoroscopy monitored the depth of dissection and adequacy of decompression. Somatosensory cortical evoked potentials (SSEP) allowed assessment of spinal cord function that could be correlated with surgical decompression. In addition, follow-up examination revealed that SSEP was an intraoperative prognosticator of subsequent neurologic improvement.

Adolescent↗
PubMedDate not supplied

The cost effectiveness of three programs to increase use of bicycle helmets among children.

Each year in the United States, 280 children die from bicycle crashes and 144,000 are treated for head injuries from bicycling. Although bicycle helmets reduce the risk of head injury by 85 percent, few children wear them. To help guide the choice of strategy to promote helmet use among children ages 5 to 16 years, the cost effectiveness of legislative, communitywide, and school-based approaches was assessed. A societal perspective was used, only direct costs were included, and a 4-year period after program startup was examined. National age-specific injury rates and an attributable risk model were used to estimate the expected number of bicycle-related head injuries and deaths in localities with and without a program. The percentage of children who wore helmets increased from 4 to 47 in the legislative program, from 5 to 33 in the community program, and from 2 to 8 in the school program. Two programs had similar cost effectiveness ratios per head injury avoided. The legislative program had a $36,643 cost and the community-based one, $37,732, while the school-based program had a cost of $144,498 per head injury avoided. The community program obtained its 33 percent usage gradually over the 4 years, while the legislative program resulted in an immediate increase in usage, thus, considering program characteristics and overall results, the legislative program appears to be the most cost-effective. The cost of helmets was the most influential factor on the cost-effectiveness ratio. The year 2000 health objectives call for use of helmets by 50 percent of bicyclists. Since helmet use in all these programs is less than 50 percent, new or combinations of approaches may be required to achieve the objective.

Adolescent↗