摘要:

The formation and sustainability of burn edema require substantial change in net microvascular forces. We directly measured interstitial hydrostatic pressure (Pi) and total interstitial absorptive pressure (Pi +IIi), in dermis of anesthetized sheep, before and after a 70% to 85% total body surface area scald and during fluid resuscitation. The most rapid change occurred in Pi in the burn wound, which rapidly decreased from its baseline value of approximately −2 mm Hg to −11 mm Hg in the first 5 minutes, and thereafter increased but remained approximately −4 mm Hg through 4 hours of resuscitation. Pi in nonburned skin slowly increased from its preburn level −2 mm Hg, to become positive +1 mm Hg after 4 hours of resuscitation. The total interstitial absorptive pressure, Pi +IIi, slowly declined similarly from 15 to 16 mm Hg to approximately 10 to 11 mm Hg over 6 hours of resuscitation in both burned and nonburned dermis. Taken together, these data suggest that the rapid formation of burn edema is the result of development of a negative Pi in the burn wound, and its sustainability is the result of a large increase in interstitial compliance. Edema in nonburned skin did not start until after fluid resuscitation was initiated, and then developed as the plasma oncotic pressure declined from 21 to 10 mm Hg.

ISSN:0273-8481    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Regrowth of cutaneous nerves after thermal injury was examined in rat hairy skin with use of protein gene product 9.5, which has been shown to label nerves in skin preparations. Tissue biopsies were obtained from injured and control skin at postburn days 1, 7, 14, 28, and 120, fixed in 4% paraformaldehyde, cryoprotected, sectioned, and immunostained with rhodamine conjugated goat anti-rabbit immunoglobulin G. Immunoreactivity for protein gene product 9.5 was intense and illustrated the process of nerve regrowth in rat skin after thermal injury. No nerve growth was detectable in 1- and 7-day preparations. Variable regeneration was noted in 14-day preparations. The 28- and 120-day groups produced nerve counts that were similar to control sections. Results suggest that rat hairy skin has a capacity for nerve regrowth after thermal injury. Nerves were noted to regenerate from beneath the scar. Burn wounds in rats demonstrated vigorous cutaneous nerve regeneration.

ISSN:0273-8481    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0273-8481    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Parameters of bromine injury were studied in vitro with die use of full-thickness human skin (HS) specimens—discards from various surgical procedures. The morphology of in vitro-treated HS resembled that of in vivo-injured skin. The damage was pronounced in the epidermis (destruction of the stratum corneum, and extensive vacuolation of keratinocytes) and the dermis (collagen coagulation), depending on die bromine concentration, exposure time, and application method. A decreased viability of epidermal cells, assayed by dye exclusion, was observed as well. Permeation parameters of bromine via abdominal HS were determined by quantitating bromine concentration in die donor and receiving compartments. The amount of bromine that permeated HS was inversely related to die concentration gradient applied. This in vitro study suggests that prompt treatment and early medical intervention may be required for successful healing of both severe and mild cases of bromine injuries.

ISSN:0273-8481    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

We sought to ascertain whether an in vitro assay could be as reliable as an in vivo assay in determining the viability of human skin stored at 4° C. Allografts from six human donors were stored in RPMI 1640 tissue culture medium at 4° C. At fixed intervals during the storage period, all skin specimens were tested concurrently by two different viability assays: (1) transplantation onto surgically created defects on nude mice, and (2) intracellular enzyme activity with use of a 4-hour semiquantitative micromethod system activity (API ZYM; Biomerieux Vitek Inc., Hazelwood, Mo.). Human graft survival on the nude mice was 100% for the first 15 days of storage, and then declined to 50% on storage day 30. The API ZYM assay showed a comparable progressive decrease in enzyme activity over skin storage time. The API ZYM assay is a simple, rapid system that produces reproducible results and is cost-effective when compared to the biologic model.

ISSN:0273-8481    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0273-8481    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Although small areas of exposed calvaria commonly occur in seriously burned children, these wounds are generally straightforward management problems. In contrast, management of the nearly completely exposed calvaria is an extraordinarily difficult problem—but is fortunately rare. Over the past 15 years, we have treated 119 children with full-thickness calvarial wounds requiring grafting. Four (3.4%) of these patients (average age, 2.9 years; range, 22 months to 5.5 years) had massive exposure of nonviable calvaria, denned as 75% or more of the surface area of the calvaria. These wounds were open an average of 28 months (range, 6 to 45 months). We have concluded that optimal management involves staged debridement of the desiccated outer table with a high-speed drill, taking appropriate precautions to avoid air embolism or inadvertent dural injury in the area of sutures or fontanelles. The resulting wounds quickly granulate and can be autografted.

ISSN:0273-8481    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

We previously have reported on the enhanced cosmetic and functional outcome with the use of sheet autografts. The recent goal has been to cover larger surface areas with sheet grafts, or for patients with larger burns, covering the hands and face with sheet grafts, if possible. To evaluate the use of sheet grafts in burns of more than 30% total body surface area (TBSA), the percentage covered with sheet and meshed autograft was reviewed in 105 patients admitted between January 1, 1990, and August 30,1994. Results were that 18 patients (17%), with a mean of 44.3% TBSA burns, had all of their full-thickness wounds (mean, 36.5% ± 2.2%; range, 20% to 55.5%) covered with sheet grafts (Group 1). Seventeen patients (16%), with mean burn size of 64.3%, had their wounds (mean, 35.1% ± 4.4%; range, 15% to 79%) covered solely with mesh graft (Group 2). The lower percentage covered by mesh alone was skewed by the high mortality rate (53%) in this group. Seventy patients, 58.4% ± 19% (range, 30% to 92%) TBSA burn, had their full-thickness wounds covered with a combination of mesh and sheet graft (Group 3). In Group 3, the mean percentage of TBSA covered by sheet grafts was 15.0% ± 1.4% (range, 1% to 42.5%) and that covered by meshed grafts was 39.4% ± 2.6% (range, 4% to 93%). Three quarters (73%) of patients in this group had sheet grafts placed on the face, whereas 63% had them placed on the hands. Extremities and the trunk were more often grafted with mesh graft. Sheet grafts were the sole coverage in patients with burns up to 55.5%. With even larger burns, sheet grafts were used to cover the face and hands. Because of its superior cosmetic and functional outcome, sheet autografting should be considered for covering moderately sized burns. Sheet autografting should be considered for more important cosmetic and functional areas, such as the face and hands, for massive burns.

ISSN:0273-8481    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Pigmentation changes after superficial burn injuries are often difficult to predict. We analyzed a sample of patients with burn injuries, looking for clinical indicators of predictable color changes in burn wounds. A sample of 50 children, predominantly those with pigmented skins, who had sustained superficial partial-thickness, (second degree) thermal, scald, or friction burns, were retrospectively grouped. Chemical and electric burns, and those needing skin grafts were excluded. Forty-one patients returned for interview and examination, an average of 63 months after injury (range, 3 to 276 months). All patients had their skin color graded in terms of the Fitzpatrick scale—a numeric scale that combines innate skin color plus reported history of skin response to sun exposure, to assign a value from 1 to 6, where white skin that reddens but does not tan on sun exposure is 1 and heavily pigmented black skin is 6. The burn site, as well as unburned areas of control skin, were tested for reflectance and luminance with use of a well-validated spectrophotometric technique. As an addendum, clinical photographs of a further 50 patients were similarly analyzed. During the first 3 years after injury, burn site color changes were variable. Subsequently, there was cumulative hyperpigmentation at the burn site, provided that the melanocyte-bearing deep dermis had not been destroyed. Hyperpigmentation correlated significantly with skin color, as quantified by the Fitzpatrick scale (p<0.01), and with time after injury (p<0.05).

ISSN:0273-8481    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Deep partial-thickness burn injury was induced in the abdominal skin of anesthetized rats. Dermal perfusion was assessed by laser Doppler flowmetry. In the first set of experiments, one group of rats (n=15) was topically treated with a lidocaine-prilocaine cream 5% (25 mg of each in 1 g) for 6 hours, starting 5 minutes after inducing the burn injury. In one control group (n=14), the thermal injury was treated with placebo cream. Results showed a markedly reduced perfusion in the skin of the control animals within the first hour after burn injury, with further decrease during the following 5 hours of observation. In animals treated with the lidocaine-prilocaine cream, skin perfusion in the burned area was significantly increased during the first 30 minutes after the burn injury compared to before the burn (p<0.01), followed by a decrease to a level below the preburn stage but significantly higher than that of control animals during the first hour after burn injury (p<0.05). As opposed to burned control animals, skin perfusion gradually recovered toward preburn levels at the end of the experiment in local anesthetic-treated animals. In the second experimental set, four groups of animals were burned and subsequently treated with a bolus dose of lidocaine intravenously (2 mg/kg), followed by continuous intravenous lidocaine infusions at a rate of 50 (n=10), 100 (n=11), or 150 (n=10) μg · kg-1· min-1. The infusions were started 5 minutes after the burn injury and lasted for 6 hours. Corresponding volumes of saline solution were given to burned control animals (n=10). Results showed a significantly improved skin perfusion in the lidocaine-treated group in a dose-response fashion as compared to control annuals. A maximum improvement of dermal perfusion in the burned area was induced by intravenous lidocaine at an infusion rate of 150 μg · kg-1· min-1as compared to burned controls treated with isotonic saline solution infusions (p<0.01). Results showed that topical or systemic administration of local anesthetics can prevent progressive dermal ischemia after thermal injury.

ISSN:0273-8481    

出版商:OVID    

年代:1998

数据来源: OVID