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Biomedical subjects

G T Rodeheaver

Publications and source records attributed to G T Rodeheaver.

At least 163 records · Page 9Linked to original sources

Technical considerations in knot construction. Part I. Continuous percutaneous and dermal suture closure.

The purpose of this investigation was to determine the security of the square knot tied with one looped end and one free end versus the security of the square knot tied with two free ends. Size 4/0 and size 6/0 monofilament nylon, polypropylene, and Biosyn sutures were selected for this evaluation. The mechanical performance of these sutures was judged according to knot breakage force and number of throws required to attain security. Knots with one looped end and one free end require more throws to ensure knot security than do knots constructed from two single suture strands of comparable sizes and types of sutures.

Caprolactam↗

Technical considerations in knot construction. Part II. Interrupted dermal suture closure.

The purpose of this study was to identify the optimal knot construction for interrupted dermal sutures. A synthetic braided absorbable suture, sizes 3-0 and 5-0, was selected for this evaluation. With reproducible mechanical performance tests, we determined that the construction of secure knots without ears required one additional throw as compared with secure knots with 3-mm ears. The direction of applied tension did not alter knot security, with the exception of granny knots, which required an extra throw when tension was applied parallel to the suture loop. Because interrupted dermal knot construction is accomplished without knot ears and with an applied tension parallel to the wound, one additional throw must be added to the knot to ensure knot security.

Humans↗

Technical considerations in knot construction, part III. Knot asymmetry.

Lactomer and the Polyglactin 910 are coated synthetic braided absorbable sutures commonly used for dermal wound closure. Biomechanical performance tests demonstrated superior performance characteristics of the Lactomer sutures. Using narrow diameter sutures, the Lactomer sutures exhibited superior knot holding forces over the Polyglactin 910 sutures. Moreover, knot security could be reliably achieved with asymmetric and symmetric knots using the Lactomer sutures.

Biomechanical Phenomena↗

Influence of absorbable dusting powders on wound infection.

Surgical glove dusting powders are commonly used as mold-release agents and to facilitate donning. Cornstarch and CaCO3 are commonly used absorbable dusting powders. This experimental study demonstrates that these absorbable dusting powders significantly potentiate bacterial growth and enhance a wound's inflammatory response. The infection-potentiating effects of CaCO3 are significantly greater than those of cornstarch.

Animals↗

Evaluation of clinically applicable exsanguination treatments to alleviate venous congestion in an animal skin flap model.

This study compares the effectiveness of alleviating venous congestion with mechanically-made outlets or leech therapy in promoting skin flap survival. Free flaps of abdominal skin (3 x 6 cm) were raised on Sprague-Dawley rats and subjected to ischemic events, simulating venous congestion. Animals received 1) no treatment; 2) two treatments involving two 18-gauge needle-puncture outlets; or 3) two sessions of leech therapy. Flap perfusion was monitored with a scanning laser Doppler flowmeter. Photographic images of flaps at 7 days were assessed for areas of normal tissue (n = 15), and laser Doppler flowmeter data consisted of control (n = 6), outlet (n = 6), and leech (n = 7). Both the needle-puncture outlet (40.0% +/- 9.24%) and leech treated (34.6% +/- 7.34%) groups had a significantly greater surviving skin area than untreated control flaps (8.0% +/- 5.0%), with 2 of 15 flaps receiving mechanical outlets exhibiting > 90% surviving area. After 7 days, laser Doppler flowmeter data showed greater mean perfusion in the outlet (71.7% +/- 16.8%) and leech (92.6% +/- 17.2%) treated groups, compared to controls (15.2% +/- 10.2%). There was a significant increase in perfusion in the outlet (13.3% +/- 6.2%) and leech (9.1% +/- 1.1%) treated groups from the end of secondary ischemia to day 7 (p < 0.05) compared to controls. The results suggest that two spatially separated outlets are as effective as one leech in increasing the area of surviving skin in venous congested flaps.

Analysis of Variance↗

Ischemia-reperfusion injury in chronic pressure ulcer formation: a skin model in the rat.

Most animal models of chronic pressure ulcers were designed to study only the role of ischemic injury in wound formation, often using single applications of constant pressure. The purpose of this study was to develop and characterize a reproducible model of cyclic ischemia-reperfusion injury in the skin of small un-anesthetized animals using clinically relevant pressures and durations. Ischemia-reperfusion injury was created in a 9 cm2 region of dorsal skin in male rats by periodically compressing skin under a pressure of 50 mm Hg using an implanted metal plate and an overlying magnet. We varied the total number of ischemia-reperfusion cycles, examined the effect of varying the frequency and duration of ischemic insult, and compared ischemia-induced injury to ischemia-reperfusion-induced injury with this model. Tissue injury increased with an increasing number of total ischemia-reperfusion cycles, duration of ischemia, and frequency of ischemia-reperfusion cycles. This model generates reproducible ischemia-reperfusion skin injury as characterized by tissue necrosis, wound thickness, leukocyte infiltration, transcutaneous oxygen tension, and wound blood flow. Using this model, the biological markers of ischemia-reperfusion-induced wound development can be studied and therapeutic interventions can be evaluated in a cost-effective manner.

Animals↗

Comparative evaluation of aztreonam in therapy for experimental bacterial meningitis and cerebritis.

Aztreonam (SQ 26,776), a new monocyclic beta-lactam agent, was compared with several frequently used antibiotics in therapy for three types of experimental meningitis in rabbits and for experimental Escherichia coli cerebritis in rats. Aztreonam was highly active against common gram-negative meningeal pathogens in vitro (all minimal bactericidal concentrations less than or equal to 0.125 microgram/ml), including ampicillin-sensitive and ampicillin-resistant strains of Haemophilus influenzae, E. coli, and meningococci. In both rabbits and rats, serum concentrations of all antibiotics evaluated closely approximated concentrations found in humans receiving standard parenteral regimens. The percent penetration of aztreonam into purulent rabbit cerebrospinal fluid was 23%. In experimental meningitis, aztreonam was more rapidly bactericidal than ampicillin in meningitis due to ampicillin-sensitive H. influenzae, than ampicillin or chloramphenicol in meningitis due to ampicillin-resistant H. influenzae, and than gentamicin in meningitis due to E. coli. Aztreonam also reduced concentrations of E. coli in rat brain as rapidly as did gentamicin during therapy for experimental cerebritis, the early stage of brain abscess formation.

Ampicillin↗

Modern concept for a new, improved microporous skin-closure tape.

A new improved skin-closure tape, Proxi-Strip, has been developed. It has unique performance and handling characteristics that are ideally suited for wound closure. Most importantly, its adhesive provides a strong level of shear adherence to the skin. Its backing is extensive under low forces to accommodate swelling of the underlying tissue. Its great air porosity and water transmission rates augur well for the presence of dry skin under the tape. An antistatic compound has been added to the tape that maintains its flat configuration and facilitates its application to skin. On the basis of these unique performance and handling characteristics, Proxi-Strip skin-closure tape is recommended for wound closure.

Adhesiveness↗

Influence of Biobrane construction on adherence.

Biobrane (standard adherence) and Biobrane L (light adherence) were compared for their degree of adherence to donor site wounds on rabbits at 1, 4, 7, and 9 days. Biobrane, which has more nylon fabric exposed to the wound surface, had significantly greater adherence levels to the wound at all time periods when compared with Biobrane L, which has less nylon fabric exposed to the wound.

Animals↗

Pilot study of a unique film dressing for the treatment of donor site wounds.

The clinical benefits of using the VENTEX Wound Dressing System (VWDS) (The Kendall Co.) in the management of donor site wounds were evaluated in this pilot study involving 10 informed and consenting patients. The study was a prospective, randomized, controlled study in which one donor site wound was managed with VWDS, and the other donor site wound on the same patient was managed by our standard of care, which involved the use of Xeroform gauze (The Kendall Co.). Each donor site wound was independently assessed daily for pain, rate of reepithelialization, adverse reactions, and ease of dressing use while patients were hospitalized. Quality of scar was assessed during regularly scheduled follow-up visits. The use of VWDS eliminated donor site pain and accelerated reepithelialization compared with Xeroform gauze. There were no adverse reactions associated with the use of VWDS. In contrast, there were two cases of suspected infection at the donor sites treated with Xeroform gauze. The VWDS was more complicated to apply and use compared with Xeroform gauze. There were no differences observed in scar quality of donor sites treated with these dressings.

Adolescent↗

Comparison of continuous vs intermittent tube feedings in adult burn patients.

In an effort to determine an optimal method of utilizing the gastrointestinal tract to meet the nutritional need of burn patients, a comparison was made between continuous and intermittent delivery of lactose-free tube-fed diets in similar groups of burn-injured patients. It was found that significantly less stool frequency and time required to achieve the nutritional goal occurred in patients treated with continuous pump tube feeding over those fed intermittently.

Adolescent↗

Pressure ulcer assessment and management.

A pressure ulcer is an area of localized tissue destruction directly related to prolonged pressure. The loss of skin integrity produces significant consequences not only for the individual, but also for the community, with reported costs of $8.5 billion for pressure-ulcer care. Because of these costs, health care providers should be seeking prevention programs that identify high-risk individuals and implement preventive measures before the ulcer begins. Once the individual develops an ulcer, assessment of healing is critical to determine the appropriate treatment. Successful treatment depends on the principles of debridement, cleansing, bacterial control, wound dressing, and occasionally, surgical intervention.

Algorithms↗

Technical considerations in the use of external condom catheter systems.

Since the advent of rehabilitation engineering new advances have been made that have revolutionized condom catheter drainage systems (CCDS). An innovative CCDS has been designed that ensures unobstructed urine flow. Its condom catheter has several unique design features. It has a double row of convolutions near the catheter tip that prevent kinking and twisting so that the pathway remains open. The condom catheter features a unique inner flap that fits snugly on the glans to prevent backflow of urine on the shaft. This condom catheter is connected to a vented leg bag that eliminates the development of a partial vacuum in the connecting tube. This vacuum can create siphoning, which in turn interferes with urine flow into the leg bag. In addition, a new rechargeable battery-operated clipper has been developed that makes nick-free hair removal from the genitals exceptionally easy. This atraumatic hair removal eliminates the pubic hair that becomes trapped under the condom catheter. The clinical impact of these new advances in CCDS requires further investigation.

Hair Removal↗

Evaluation of automatic disposable rotating cartridge skin staplers.

Burn surgeons commonly employ skin staples for the application of skin grafts and to secure dressings on donor site dressings and over skin grafts. Disposable skin staplers with rotating cartridges are ideally suited for wound closure because the position of their cartridges can be manually adjusted to facilitate placement of their staples. In response to the burgeoning interest in disposable automatic skin staplers with rotating cartridges, three different models are now commercially available. This report describes the design configuration and mechanical performance of these disposable automatic staplers and their staples. Mechanical performance of these staplers and staples has been assessed by standardized tests that can be replicated in any research laboratory. On the basis of these objective design and performance parameters, the Premium stapler is recommended for wound closure. This stapler provides maximal visualization of the wound as well as the staple during its formation. It delivers the staple into the skin or wound in a manner that the cross member of the staple is above the skin or wound surface. In addition, the Premium stapler has a prepositioning mechanism that can be controlled by the surgeon with minimal force. This mechanism allows the stapler to hold its staple securely, even when its pointed legs extend beyond the delivery end of the stapler. Force required to form its staples is so low that the surgeon can staple repetitively without fatigue. Finally, the Premium stapler delivers a staple that has a uniform geometry and sharp points that can easily penetrate tissue.

Adult↗

A new porous cohesive support bandage.

A new support bandage has been developed that is cohesive, sticking only to itself without adhering to the skin. It is warpknit product, impregnated with an acrylic compound, that consists of individual panels connected by a hinge stitch. It exhibits moderate extensibility under low loads which allows the health professional to apply the bandage so that it gives firm support to the underlying tissue without constriction. Its macroporous structure permits sufficient water vapor transmission to allow the underlying skin and/or wound to remain dry.

Adhesiveness↗

Guidelines for supervised wound care by emergency nurse practitioners.

Nearly 10 million patients with traumatic lacerations are treated annually in Emergency Departments in the United States. Since these wounds do not usually pose a threat to the patient's life, they assume a lower level of priority than emergent conditions. Consequently, treatment of patients with lacerations is often delayed until the emergent patient is resuscitated. In the event that wound care is inadvertently delayed, bacteria may proliferate to levels that result in infection. In selected patients, supervised wound care by an emergency nurse practitioner (ENP) can safely eliminate this delay in treatment. During their graduate training in the University of Virginia Nursing School, the ENPs are instructed to treat traumatic wounds with physician supervision. The criteria for patient selection and care are outlined in comprehensive guidelines reported herein. The bases for these treatment guidelines were clinical and experimental studies conducted at our medical center which examined the influence of various therapeutic decisions on the ultimate fate of the wound.

Asepsis↗