G. Meissl

Indocyanine green video angiographies help to identify burns requiring operation

The key decision in the treatment of thermal injuries is the determination of the depth of the burn wound and the resultant decision on treatment options. The trend in the treatment of deep dermal and full thickness burns is toward very early excision and grafting to reduce the risk of infection, decrease scar formation, shorten hospital stay, and thereby reducing costs. Traditionally, this has involved serial clinical examinations, which involves primarily subjective judgment. Various objective examination techniques, supplementing the clinical diagnosis, have been suggested, but none has yet achieved widespread clinical acceptance. It has frequently been postulated that the blood flow in injured tissue indicates the extent of tissue damage. In this study, the clinical and scientific impact of indocyanine green (ICG) video angiography was tested in 20 patients. A wide range of depth of injury and etiology was included and analyzed. In all cases considered, video angiography was possible. The measurements and observations correlated well with the actual burn depth, which was assessed clinically (pre- and intraoperative assessment) and histologically (biopsies). In conclusion, ICG video angiography seems to be a practical method to describe vascular patency in a burn wound. The results indicate that ICG fluorescence angiography is a practical, accurate, and effective adjunct to clinical methods for estimating burn wound depth and thereby to assist in the rational assessment of treatment options. Furthermore, it allows an objective, qualitative and quantitative observation of the dynamic changes in burn wound depth, which are observed during the acute post-burn period, thereby indicating optimal timing of the first operation.

Reduction of the mortality rate in aged burn patients

The management of elderly burn patients is time consuming for both nursing staff and physicians, and therapy remains often challenging and controversial. In a retrospective study, we analysed the outcome of two periods with different treatment modalities. An increased number of nurses, a change in the local burn wound treatment, better documentation of wound status and general conditions, and last, but not least, of nutritional aid, enabled us to reduce the mortality rate in patients over 65 years of age.

Comparison of prognostic indices for burns and assessment of their accuracy

Logistic regression was used to create four individual models of prognostic indices based on our patient population. The simplest index using only three factors, age, extent of full skin thickness burn and inhalation injury, proved to be best. These models were also compared with established indices, like Bauxs, Bulls and Rois. For a specificity below 80 per cent, Bauxs rule fits as well as Rois index does. Changes in treatment modalities and improvement in therapy will influence the accuracy of an index. Indices must be adapted to changing conditions to avoid increasing false prediction of death.

Serum cholesterol and triglycerides: potential role in mortality prediction

The present study was performed in order to evaluate the diagnostic usefulness of serial cholesterol and triglycerides measurements in patients with severe burns. One of the main objective was to find out if these parameters are clinically relevant to determine the morbidity of a burn patient and thereby the patients outcome. In 220 patients with thermal injuries, cholesterol and triglyceride concentrations were measured daily. Blood samples were drawn immediately upon admission and thereafter daily until patients discharge or death. For both parameters, a characteristic course was noted: in the group of non-survivors, a decrease of cholesterol prior to death was noted, while survivors, increased prior to discharge. The time courses of both groups (survivors-non-survivors) differed statistically significantly (P=0.0068). An increase in triglycerides was observed in all non-survivors prior to death, but in the group of survivors triglycerides remained more or less unchanged. These time courses also had statistically significant differences (P=0.0004). In our 220 patients, changes in cholesterol (P<0.0001, hazard ratio 1.02) and triglycerides (P=0.0008, hazard ratio 1.01) had comparable capability to predict the severity of a burn trauma and thereby its outcome than the established parameters in the treatment of burns (total body surface area burned, age, inhalation). We consider the serial measurements of cholesterol and triglycerides as clinically relevant to assess the morbidity of a patient and thereby to estimate the patients outcome. We think that these serial measurements provide useful information for the clinician treating patients with severe burns.

Serum cholinesterase activity reflects morbidity in burned patients

Blood samples of 200 patients with thermal injuries were drawn apparently to determine the trend of the cholinesterase activity. In relation to the severity of the injury, a characteristic decrease was noted during the first days after admission. A recovery to normal values was achieved in all survivors (150 patients) after a proportionate period of time, but in the group of non-survivors (50 patients), no complete recovery to normal levels was found. Furthermore, a significant relationship between serum cholinesterase activity and the severity of morbidity was detected, the fall of the cholinesterase activity at the very beginning was significantly higher (P<0.004) in patients who died (1.3kU/l) than in patients who survived (0.7kU/l). Already 24h after admission, the mean activity was significantly lower (P<0.003) in non-survivors (2.5kU/l) than in survivors (3.2kU/l). It seems that the serum cholinesterase is a sensitive indicator for the morbidity of patients with severe burn injuries.

The use of allogeneic cultivated keratinocytes for the early coverage of deep dermal burns - indications, results and problems.

Since 1995, keratinocytes are grown into cultures and used as allografts for the coverage of deep dermal defects in our burn unit. Donor skin samples are mostly acquired from other burn patients. In addition, special methods of skin preservation allow us the use of skin, which has been taken in redundancy for split thickness skin grafting from nonburned patients.Thirty five patients with deep partial thickness burns in the face were treated since 1996 according to the following concept: Dermabrasion or tangential excision was performed before the 5th day following trauma. If viable dermis was present, the wounds were covered with sheets of allogeneic cultivated keratinocytes. In cases of deeper defects, autologous skin grafts were applied. In 23 cases, epithelialisation was achieved within 10 days, in 8 patients, a prolonged duration until complete healing was observed. In 5 faces, coverage of residual defects with skin grafts was necessary. The mentioned problems of wound healing occurred from infection, incomplete excision of burn eschar and a depth of the wound which was retrospectively seen too deep for the treatment with keratinocytes. At follow up, patients were examined clinically and functionally with Freys faciometer®, which is an instrument for quantification of mimic movements. In cases of uncomplicated healing, a nearly complete restitution was found.Other indications include deep dermal burns in children and the coverage of early excised wounds in adults, with a reasonable amount of viable dermis remaining, both resulting in a significant reduction of donor-site morbidity. In severely burned adults with limited donor sites, it offers the possibility of immediate definite coverage of large areas.

Effects of burns on amino acid levels in rat plasma, liver and muscle

In this study the influence of a severe catabolic situation (scalding and nitrogen deprivation) on amino acid (AA) metabolism was investigated in an experimental rat model. Scalding of 25 per cent of the total body surface area (TBSA) and hypocaloric alimentation (5.6 kcal per 100 g rat per day, no nitrogen) resulted in mean daily nitrogen losses of -0.27 +/- 0.3 g. Compared to anabolic growing rats this nitrogen catabolism significantly reduced the total free AA content of muscle (-47 per cent, P less than 0.001) and liver (-39 per cent, P less than 0.001). The total plasma AA concentrations were slightly increased in catabolic rats (+10 per cent). In catabolic rats muscle glycine concentrations dropped significantly (-79 per cent, P less than 0.001), while glutamine concentrations decreased by 22 per cent, which was not significant. Branched chain AA and phenylalanine were significantly elevated both in muscle and in plasma. Scalding and nitrogen depletion in rats leads to characteristic changes in plasma, muscle and liver AA concentrations, which are comparable to the results obtained in catabolic patients. However, the low muscle glycine concentrations in burned rats differ from the clinical observations where glutamine rather than glycine concentrations in muscle tissue are reduced. The rat model seems to be well suited for studying the influence of various therapeutic approaches such as different forms of parenteral nutrition or hormonal substitution on nitrogen catabolism.

Rükcblick auf 20 Jahre Erfahrung in der Behandlung von Starkstromverbrennungen — ein Spiegelbild der Entwicklung der Wiederherstellungschirurgie

ZusammenfassungGrundlagen: In einer retrospektiven Untersuchung werden die Behandlungsstrategien und Ergebnisse von 55 Patienten, die innerhalb der letzten 20 Jahre nach einem Starkstromunfall am Wiener Verbrennungszentrum behandelt wurden, analysiert.Methodik: Das Durchschnittsalter der Patienten lag bei 28,0 Jahren, das Ausmaß der verbrannten Körperoberfläche betrug zwischen 1 und 80%, im Durchschnitt lag es bei 32,3%. Bei 34 Patienten handelte es sich um Stromdurchtrittsverletzungen, in 21 Fällen um eine reine Lichtbogenverbrennung.Ergebnisse: 3 der 55 Patienten verstarben im Laufe der Behandlung, was einer Letalität von 5,45% entspricht. Aufgrund tiefer Gewebeschädigung mußten bei 17 Patienten an 24 Gliedmaßen Amputationen vorgenommen werden, das entspricht genau 50% der Fälle von Stromdurchtrittsverletzungen. Neben den klassischen Methoden, wie Debridement, fakultativen Extremitätenamputationen und Spalthautdeckung, erbrachte die jüngere Vergangenheit auch eine deutliche Zunahme an Lappenplastiken zur Extremitätenerhaltung sowie die Anwendung innovativer Techniken, wie Keratinozytenkulturen und die Applikation eines VACTM-Systems zur Behandlung kleinerer Strommarken mit freiliegendem Knochen. In einer im Median 94 Monate nach dem Unfall durchgeführten Nachuntersuchung klagten die meisten Patienten — abgesehen von den Behinderungen durch Gliedmaßenamputationen — über Bewegungseinschränkungen durch hypertrophe Narbenbildung und ossifizierende Myositis sowie neurologische Defizite im Sinne von Parästhesien und Lähmungserscheinungen.Schlußfolgerungen: In Anbetracht der insgesamt geringeren Letalität unterstreicht die vorliegende Untersuchung die Bedeutung der Anwendung aufwendiger chirurgischer Techniken zur Minimierung der Langzeitmorbidität.SummaryBackground: The present study analyses the treatment modalities and results of 55 patients, who were admitted to the Vienna burn center after a high voltage accident.Methods: The patients’ mean age was 28.0 years, the mean total burned surface area was 32.3%. In 34 cases the current had passed through the body, 21 patients suffered from burned skin caused by a lightning arch.Results: 3 patients died, which means a mortality of 5.45%. Due to extensive deep tissue necrosis after the passing-through of current 24 limb amputations had to be done in 17 patients. Besides the classical methods of treatment such as repetitive debridements, successive amputations and skin grafting, in the recent years increasing numbers of pedicled and free flaps were used for coverage of exposed bones in limb salvage. Furthermore new alternative techniques like keratinocyte cultures and the vacuum assisted closure (VACTM) system were applied. Results after a median follow-up of 94 months showed several kinds of sequelae like impaired range of motion due to hypertrophic scars and neurological deficits.Conclusions: Due to the low mortality rate the present study emphasizes the importance of using expensive surgical techniques to minimize long-term morbidity.

Impaired cell-mediated immunity in the first week after burn injury: investigation of spontaneous blastogenic transformation, PHA, IL-2 response and plasma suppressive activity

This study investigated alterations of cell-mediated immunity induced by trauma, operative treatment and infections in a group of 19 burned patients with a mean burn size of 42 +/- 22 per cent of the body surface area. We tested peripheral mononuclear blood cells (PMBC) for spontaneous blastogenic transformation (SBT), phytohaemagglutinin (PHA) and interleukin-2 (IL-2) responsiveness. Plasma samples were also assayed for inhibition of mitogen stimulation of control PMBCs. Mean values were calculated for the acute postburn period (days 0-3) and the following 4 days, before the development of septic complications. SBT was significantly increased in all patients during the second period of investigation (days 4-7) in comparison to normal controls and during the acute phase. The response to mitogen stimulation (PHA) was significantly suppressed during days 0-7 and the plasma samples showed high suppressive activities following PHA stimulation of control lymphocytes during the course of the study. No significant differences in rates of SBT, PHA responsiveness and plasma suppressive activity were found between those patients who developed bacteraemia and those with negative blood cultures. The latter group showed higher reactivity to added IL-2 in comparison to normal controls. Surgical treatment immediately after trauma (fasciotomy; day 0 or 1) resulted in further increased immunosuppression (PHA and IL-2 response), whereas after necrectomy (days 4-7) the immunological parameters showed no significant differences. It can be concluded that neither rates of SBT nor response to PHA can be used to identify patients at high risk for infection during the first week postburn.(ABSTRACT TRUNCATED AT 250 WORDS)

Die Bedeutung der Keratinozytenzüchtung für die Behandlung von Brandverletzungen

ZusammenfassungGrundlagen: Die Kultivierung und anschließende Transplantation menschlicher Keratinozyten ist eine der wesentlichsten neuen Entwicklungen in der Behandlung schwerverbrannter Patienten. Methodik: Die Keratinozyten werden durch enzymatische Behandlung aus einem kleinen Hautstückchen herausgelöst und anschließend im Labor zu konfluenten Kulturen gezüchtet. Diese wiederum werden auf die debridierten Hautareale aufgebracht. Ergebnisse: Sowohl für die autologe als auch für die allogene Transplantation werden zufriedenstellende Heilungsraten publiziert. An den zu deckenden Wundgrund werden jedoch besondere Anforderungen hinsichtlich Vaskularität und Keimfreiheit gestellt. Schlußfolgerungen: Die Erfahrungen der Wiener Verbrennungsstation bestätigen die aus der Literatur bekannten Ergebnisse. Zukünftige Forschungsaktivitäten müssen einerseits trachten, rascher zur Verfügung stehende Transplantate zu entwickeln und die Anwendung als Allografts zu verbessern.SummaryBackground: The cultivation and grafting of human keratinocytes is an important recent development in the treatment of severely burned patients. Methods: A small piece of skin is trypsinized and a single cell culture of keratinocytes is produced. Finally the epidermal sheet is detached from the culture dish and grafted to the burn wound. Results: Cultivated keratinocytes can be used as auto- and as allografts with good results. Nevertheless a well vascularized and aseptic wound bed is required to yield good taking rates. Conclusions: The experiences made at the Vienna Burn Unit support the findings of several previous authors. Further studies must try to improve the efficacy of cultivation as well as the use of cultured keratinocytes as allografts.