David M. Heimbach

Artificial dermis for major burns. A multi-center randomized clinical trial.

This communication presents an 11-center prospective randomized trial using the artificial dermis invented by Burke and Yannas. Patients with life-threatening burns who underwent primary excision and grafting within 7 days of injury had comparable sites randomized to receive either the artificial dermis (study site) or the investigators usual skin grafting material (control site). Control materials were autograft, allograft, xenograft, or a synthetic dressing. Epidermal grafts were applied to the study site during a second operation, and surviving patients were followed for 1 year after grafting. One hundred thirty-nine sites on 106 patients were studied. Mean burn size was 46.5 ± 15% mean total body surface (TBSA). Overall mortality was 13%, and mean hospital stay was 68 ± 45 days. Median artificial dermis take was 80% compared with 95% for all comparative sites, but the take was equivalent to that of all nonautograft control materials. Results with the artificial dermis improved slightly as the investigators became more familiar with the material. Donor site thickness for the study site averaged .006“ ± .002” compared to .013“ ± .018” for control (p < .0001) and the epidermal donor site healed an average of 4 days sooner (10 ± 6 vs. 14 ± 8 days) (p < .0001). As the wounds matured during the first year, both patients and surgeons felt that both sites became more comparable in appearance and function. At the completion of the study, there was less hypertrophic scarring of the artificial dermis, and more patients preferred the artificial dermis to the control graft. Artificial dermis with an epidermal graft provides a permanent cover that is at least as satisfactory as currently available skin grafting techniques, and uses donor grafts that are thinner and donor sites that heal faster.

Clinical Evaluation of an Acellular Allograft Dermal Matrix in Full-Thickness Burns

A multicenter clinical study assessed the ability of an acellular allograft dermal matrix to function as a permanent dermal transplant in full-thickness and deep partial-thickness burns. The study consisted of a pilot phase (24 patients) to identify the optimum protocol and a study phase (43 patients) to evaluate graft performance. Each patient had both a test and a mirror-image or contiguous control site. At the test site, the dermal matrix was grafted to the excised wound base and a split-thickness autograft was simultaneously applied over it. The control site was grafted with a split-thickness autograft alone. Fourteen-day take rates of the dermal matrix were statistically equivalent to the control autografts. Histology of the dermal matrix showed fibroblast infiltration, neovascularization, and neoepithelialization without evidence of rejection. Wound assessment over time showed that thin split-thickness autografts plus allograft dermal matrix were equivalent to thicker split-thickness autografts.

Hemostasis in massively transfused trauma patients.

Twenty-seven patients requiring massive transfusions were studied prospectively to determine whether administration of stored, modified whole blood induced a primary disorder of hemostasis evidenced by generalized microvascular oozing. Platelet counts fell in proportion to the number of units of blood transfused. In contrast, the levels of factors V and VIII correlated poorly with the units of blood transfused, 85% of the total variation in the levels being due to influences other than transfused blood. Levels of all other clotting factors were unrelated to the number of units of blood given. Eight patients developed abnormal bleeding. The cause appeared to be dilutional thrombocytopenia in five patients, and DIC in three. In six of the eight, bleeding was controlled with platelet concentrates alone. Two patients were given cryoprecipitate also. The most useful laboratory test for predicting abnormal bleeding was the platelet count. Fibrinogen levels should be followed as an aid in the diagnosis of DIC. The BT, PT, and PTT were not helpful in assessing the cause of bleeding, unless they were greater than 1.5 times the control value. We recommend that any patient receiving massive transfusions who develops diffuse microvascular bleeding be given platelet concentrates. Platelet counts as high as 100,000 may be required to control bleeding from surgical wounds. It is not necessary to supplement transfusions of stored, modified whole blood with fresh blood or fresh frozen plasma.

Early excision and grafting vs. nonoperative treatment of burns of indeterminant depth: a randomized prospective study.

Compared to nonoperative treatment with silver sulfadiazine cream, early excision and grafting of 22 patients with indeterminant burns of less than 20% TBSA resulted in an average shorter hospitalization, lower cost, and less time away from work than 25 patients treated nonoperatively. While early excision and grafting resulted in increased use of blood products and operating room facilities, this did not result in increased patient morbidity. Long-term followup demonstrated no difference in need for reconstruction, incidence of blisters, incidence of loss of motion, or contour irregularities. Those patients treated nonoperatively required more late grafts for closure and demonstrated more hypertrophic scarring. Those treated by early excision demonstrated more mesh graft irregularity. We conclude that in otherwise healthy patients with dermal burns of indeterminant depth less than 20% total body surface area, early excision and grafting is the preferred form of treatment.

Multicenter postapproval clinical trial of Integra dermal regeneration template for burn treatment.

The safety and effectiveness of Integra Dermal Regeneration Template was evaluated in a postapproval study involving 216 burn injury patients who were treated at 13 burn care facilities in the United States. The mean total body surface area burned was 36.5% (range, 1-95%). Integra was applied to fresh, clean, surgically excised burn wounds. Within 2 to 3 weeks, the dermal layer regenerated, and a thin epidermal autograft was placed. The incidence of invasive infection at Integra-treated sites was 3.1% (95% confidence interval, 2.0-4.5%) and that of superficial infection 13.2% (95% confidence interval, 11.0-15.7%). Mean take rate of Integra was 76.2%; the median take rate was 95%. The mean take rate of epidermal autograft was 87.7%; the median take rate was 98%. This postapproval study further supports the conclusion that Integra is a safe and effective treatment modality in the hands of properly trained clinicians under conditions of routine clinical use at burn centers.

Prophylactic platelet administration during massive transfusion. A prospective, randomized, double-blind clinical study.

Prior studies at Harborview Medical Center have suggested that dilutional thrombocytopenia is a major etiology of microvascular, nonmechanical bleeding (MVB). We undertook a prospective randomized double-blind clinical study to compare the prophylactic effects of 6 units of platelet concentrates (PLT) versus 2 units of fresh frozen plasma (FFP) administered with every 12 units of modified whole blood in patients undergoing massive transfusion (12 or more units in 12 hours). After exclusions, three of 17 patients who received PLT and three of 16 patients who received FFP developed MVB, an incidence no different from our previous findings. Regression lines of platelet counts during transfusion were no different between groups, and both groups had higher platelet counts than predicted from a standard washout equation. Only one patient had evidence of dilutional thrombocytopenia as a cause for MVB. Prophylactic platelet administration is not warranted as a routine measure to prevent MVB.

Early surgical excision versus conventional therapy in patients with 20 to 40 percent burns: A comparative study

Using the records of 72 patients treated at the University of Washington Burn Center, this study compared the results of early surgical excision (by 14 days postburn) and autografting to those of autografting after spontaneous separation and bedside debridement of burn eschar. Excised patients had shorter hospitalizations and lower rates of burn wound sepsis and serious burn wound contamination, and less use of potentially toxic antibiotics (p less than 0.05) than did the prognostically equivalent group treated before the introduction of early excision. Excised patients required more blood transfusions (p less than 0.05), but did not differ significantly from controls in rates of mortality or other inpatient complications, in the number of operations performed, or in the adjusted hospital costs. Evaluation of patients treated over the entire study period for more shallow burns indicated no concurrent change in other aspects of burn care which might account for the observed results. We conclude that early excision and grafting in young, otherwise healthy patients with 20 to 40 percent total body surface area burns that are likely to heal within 3 weeks is more effective than the more traditional management of slow wound separation and debridement.

Rates, trends, and severity of depression after burn injuries

It is commonly assumed that patients hospitalized for burn treatment will experience some level of depression. However, little is known about the trends in severity of depression over time. The purpose of this study was to determine the rates and severity of depression over a 2-year period. The Beck Depression Inventory was administered at 1 month (N = 151), 1 year (N = 130), and 2 years (N = 125) after discharge. At 1 month, 54% of patients showed symptoms of moderate to severe depression, and at 2 years, 43% of the patients responding still reported moderate to severe depression. The average correlation between scores over time was high. Women had higher depression scores than men at each time period. An interaction between gender and having a head or neck injury was also observed at 1 month and 1 year after discharge. Results suggest that routine outpatient screening for depression is warranted.

A biopsy of the use of the Baxter formula to resuscitate burns or do we do it like Charlie did it

The Baxter formula is commonly used to calculate fluid requirements. Baxter reported that 12% of patients would require more than 4.3 mL/kg per percentage of total body surface area (%TBSA). We anecdotally observed that we frequently exceeded the predictions of the formula, and we wondered if this was unique to our practice. We studied our last 11 burn-related resuscitations and collected fluid resuscitation data from US burn centers. Twenty-eight centers were queried, and 6 centers shared data. We were therefore able to study the resuscitation data of 50 adult patients. For 29 patients (58%), 4.3 mL/kg/%TBSA was exceeded compared with the 12% reported by Baxter. These findings suggest that in actual practice, fluid volumes administered are larger than the Baxter formula predicts. This survey does not explain why. Possible reasons for the larger fluid volumes are as follows: (1) the sample is not representative; (2) the formula is used improperly; (3) burns have changed and require more fluids; (4) burn care has changed.

Multispectral imaging of burn wounds: a new clinical instrument for evaluating burn depth

A real-time video imaging system called the imaging burn depth indicator (IBDI) is described; IBDI can discriminate areas of burn wounds expected to heal in three weeks or less from the day of injury from those areas not expected to heal in that time period. The analysis can be performed on or about the third day postburn on debrided burn wounds. The relative diffuse reflectivity of the burn-wound is measured in the red, green, and near-infrared wavelength bands and an algorithm established previously is used to translate this optical data into burn healing probabilities. Over 100 burn wound sites were studied. Burn sites were evaluated on day three postburn by the IBDI and by the attending physician. Overall, the IBDI was found to be more accurate in predicting burn healing than were the attending physicians.<<ETX>>