This study retrospectively followed 148 patients with extensive burns of over 25% between 2002-2009, of whom 76 received treatment with allografts. Moreover, during 2010-2011, 47 new patients enrolled, of whom 13 were treated with allografts.
After the burn event, the patient had to be transported to a specialized unit as fast as possible with great care, while respecting the measures of asepsis.
Intensive Care Unit (I.C.U.) management of extensive burns (over 25% TBSA)
Crystalloids are the main solution used for fluid resuscitation (Natrium chloride and Lactated Ringer's solution). The volumes required vary greatly, with a mean value of about 4 ml per kilogram multiplied by the percentage of body-surface area burned. Fluid requirements are greater if resuscitation has been delayed and in patients with smoke inhalation. Large volumes are needed because only 20 to 30 percent of the crystalloid administered remains with the vascular system. About half the fluid must be given during the first eight hours after the injury, in the same period of rapid edema formation. In most patients, the hourly rate of urine flow, a reasonable indicator of organ perfusion, is the principal guide used to alter the rate of fluid administration (about 1ml/min=60 ml/hour). Abrupt weight gains of 30 percent or more of the body weight can result from resuscitation in patients with massive injury; early endotracheal intubation and multiple limb and truncal escharotomies are commonly required in these circumstances. Pulmonary-artery catheters are not routinely used but are helpful in elderly patients and in those with limited cardiac reserves. Survival after near-total burns is no longer uncommon, provided that early organ failure is avoided [17
]. The crystalloid requirement during the second day of treatment is about half that of the first day. Within 48 to 72 hours after the burn injury, the hematocrit begins a progressive fall due to factors such as intravascular resorption of edema, lysis of thermally injured cells, and the onset of the anaemia that is characteristic after a burn injury. Crystalloid administration should be discontinued at the earliest possible time. A reasonable goal is for the patient to have returned to his or her pre-injury weight within one week after the burn [17
Resuscitation by using fluids containing solutes with plasma-like oncotic properties has an intuitive appeal, since these fluids resemble what is being lost and protein sieving is still at least partially operative in unburned tissues. Nevertheless, the adjunctive use of colloid in burn shock has decreased, mainly because the controlled trials that have been done have shown no clear advantage to its use [17
Colloid administration for 12 to 24 hours after the injury (use of HES solution -4 mg/kg body weight) — a time when capillary permeability has partially returned to normal but plasma volume may be subnormal. This practice has no demonstrated clinical benefit, however, and recent data suggest that it may be deleterious. The administration of albumin to patients in stable condition after 24 hours of clinically satisfactory crystalloid resuscitation resulted in a significant decrease in the glomerular filtration rate, below the normal range, despite an increase in plasma volume [17
The administration of crystalloid with a sodium concentration of 250 mmol per litre can reduce volume requirements, presumably by mobilizing water from cells that are over-hydrated as a consequence of the injury [17
]. This therapy is useful in patients with limited cardiopulmonary reserves but demands careful monitoring and clearly has a much narrower therapeutic margin than does the use of isotonic crystalloid [17
]. Systemic antimicrobial therapy is not mandatory from the start (it is used only if the antibiogram shows the presence of microbial cultures or if there are increased values of fibrinogen or leukocytosis); early antimicrobial therapy does not influence the prognosis. We insist on prophylactic measures on venous, arterial and urine catheters.
The algorithm for intensive burn resuscitation also includes the assurance of the function of the enterocyte through early enteral nutrition.
Surgical treatment of severe burns
At the admission: adequate local debridement with Betadine scrub or Chlorhexidine solutions; also decompression incisions (where these are required); dressing with Flamazine or Flammacerium (the last one, applied in the first post burn hours, is blocking the release of lipoproteins responsible for the cytokines storm leading to SIRS).
The surgical treatment can be considered after the patient has surpassed the acute stage, usually after 3-5 days, and is done either by early excision and grafting or by assisted detersion, which aims to obtain a granular wound surface that will eventually lead to healing.
For deep burns that are too extensive to be closed in one procedure, wound excisions can be staged — typically at intervals of about one week — as sufficient autologous skin grafts become available to close the excised wound. Alternatively, the burns can be completely excised within the first several days after the injury, and a temporary skin substitute used to close the wound remaining after all available autologous skin has been harvested and grafted.
We have to establish a prioritisation of the areas that we want o excise. First, we have to think about the functional areas such as the hands, and then the 3rd degree burns of the thorax, where the allograft has a better chance. For the extensive burns, we often have to consider the use of allografts at this stage, because there is a lack of uninjured skin that could be used for an autograft.
Fresh or cryopreserved allogeneic skin from cadavers is the most reliable wound cover, although its use has a small risk of disease transmission.
In our clinic, we used skin from honorific donors who were usually relatives or friends of the patient. It was of paramount importance to obtain complete and accurate medical information about the potential donor to ensure the safety of the tissue for transplantation). This required a comprehensive medical and social history of the donor, a physical examination of the potential donor, and a panel of serologic screening tests for viral diseases (HIV-1/2, Hepatitis B and C). It was imperative that skin banks performed microbial cultures before the release for transplantation.
The donors also had to sign a specific informed consent by which they agreed to donate skin, knowing the risks of donating organs and/or tissues/cells, according to the legal status for these procedures, understanding this gesture as being purely humanitarian, without being pressured in any way or expecting a material reward.
Split-thickness skin grafts were removed by using an electric dermatome with a thickness of 0.012 to 0.018 inches.
We applied the allograft as a simple graft meshed 1,5:1 or 3:1 or as a sandwich graft which implied the covering of the wound with a widely meshed autograft (6:1). This layer was covered with a 1,5:1 or 3:1 expanded mesh allograft.
Another common use of the allograft was to test a questionable wound bed, in excisions that were carried down near tendons, bone, or fascia of questionable viability. If the allograft needed it, the wound bed usually will also take an autograft [2
The allograft was rejected in an interval of time that varied between 14-21 days, but in this period of time the more shallow burns will heal and provide material for autograft.
In these situations, we had to use every resource of skin that was available, so that we had to consider taking skin from unusual sites as the soles of the feet or the scalp.