L.-P Kamolz

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.

Burn treatment in the elderly

The population of elderly patients is expected to rise continuously over the next decades due to global demographic changes. The elderly seem to be most vulnerable to burns and their management remains undoubtedly a challenge. A clear age margin for elderly patients is not yet defined, but most studies adhere to the inclusion of patients 65 years and above, but the general condition and social situation must be taken into account. The understanding of the physiological basis of aging and its related pathophysiological changes has only marginally influenced treatment and decision making in elderly burn patients. When looking at treatment regimens currently applied in elderly burn patients, the discussion of standards in intensive care as well as surgical strategies is ongoing. However, trends towards a moderate, non-aggressive resuscitation approach and careful inclusion of key parameters like physiological age, pre-burn functional status and premorbid conditions, seem to be useful guidelines for interdisciplinary treatment decisions. Once ordered for surgical treatment, the amount of body surface area operated in one session should be adapted to the general status of the patient. Even if older burn victims have a reported higher mortality rate than younger patients, improved therapeutic options have contributed to a reduced mortality rate even in the elderly over the last decades. As a result of improved outcome, more attention has to be given to a comprehensive rehabilitation program. This review will give an overview of the current literature and will draw attention to specific topics related to this important subpopulation of burn patients.

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.

Hydrocortisone improved haemodynamics and fluid requirement in surviving but not non-surviving of severely burned patients

Recent studies have shown that administration of hydrocortisone may lead to a reduction of catecholamines and to an improved outcome in septic patients. However, there are no data on the use of hydrocortisone in burn patients although in these patients reduction of vasopressors might be even more crucial for outcome due to improvement of skin perfusion. This study presents the first results on the impact of hydrocortisone administration in norepinephrine dependent severely burned patients. In a prospective cohort study fourteen consecutive severely burned patients received, 12h after norepinephrine dependency, a hydrocortisone bolus of 100mg followed by 0.18mg/(kgh) hydrocortisone. The course of the necessary norepinephrine dose, as well as the fluid balance was documented 12h prior and after the first dosage of hydrocortisone. Statistical analysis showed an unexpected increase of the required norepinephrine dosage. A statistical post hoc evaluation of surviving and non-surviving patients revealed a significant increase of norepinephrine in non-survivors whereas in survivors it was possible to reduce norepinephrine significantly. Furthermore, the median fluid requirement of surviving patients could be significantly reduced whereas in the group of non-survivors there was no change of volume needed. Our data suggests that hydrocortisone might be useful in selected patients with severe burn injuries. However, patients not responding to hydrocortisone administrations seem to have a poor prognosis. Our findings are in contrast to previously published data on septic patients, in whom hydrocortisone administration resulted in a reduction of norepinephrine. In burned patients the severity of trauma seems to have more profound influence on the pathophysiological mechanism of sepsis. Due to the high number of non-responders, the potential immune suppression and impaired wound healing caused by the side effects of hydrocortisone, further selection criteria seem to be necessary. A short ACTH-test might be considered prior to hydrocortisone administration to select patients who might benefit from this therapy. In summary, further prospective controlled studies will be necessary to establish hydrocortisone in the routine therapy of severely burned patients.

The axillary vein central venous catheter in severely burned patients

In severely burned patients the approach to the central vein is often difficult due to concomitant edema, but also due to the fact that the skin area, where commonly used approaches are performed, is burned as well, whereas the axillary region is often not involved. In order to perform an axillary approach to the central vein as an alternative to the commonly used approaches in patients, an anatomical dissection in fresh human cadavers was carried out. Considering the anatomical landmarks which were found during dissection of the axillary region, the axillary approach to the central vein was used in 35 patients in our intensive burn care unit with unaffected axillary skin. In three cases the only complication observed was an occasional puncture of the axillary artery without major hematoma. The infection rate of the catheters was similar to the commonly used puncture sites. This approach to the central venous line in severely burned patients can be recommended.

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.