Italian recommendations on enzymatic debridement in burn surgery

IntroductionNexobrid®, a bromelain-based type of enzymatic debridement, has become more prevalent in recent years. We present the recommendations on enzymatic debridement (Nexobrid®)’s role based on the practice knowledge of expert Italian users.MethodsThe Italian recommendations, endorsed by SIUST (Italian Society of Burn Surgery), on using enzymatic debridement to remove eschars for burn treatment were defined. The definition followed a process to evaluate the level of agreement (a measure of consensus) among selected experts, representing Italian burn centers, concerning defined clinical aspects of enzymatic debridement. The consensus involved a multi-phase process based on the Delphi method.ResultsThe consensus panel included experts from Italy with a combined experience of 1068 burn patients treated with enzymatic debridement. At the end of round 3 of the Delphi method, the panel reached 100% consensus on 26 out of 27 statements. The panel achieved full, strong consensus (all respondents strongly agreed on the statement) on 24 out of 27 statements.DiscussionThe statements provided by the Italian consensus panel represent a “ready to use” set of recommendations for enzymatic debridement in burn surgery that both draw from and complete the existing scientific literature on the topic. These recommendations are specific to the Italian experience and are neither static nor definitive. As such, they will be updated periodically as further quality evidence becomes available.     

Actinidia deliciosa (kiwifruit), a new drug for enzymatic debridement of acute burn wounds

Background

Actinidia deliciosa (kiwifruit) is used as a meat tenderizer. It acts rapidly and efficiently to soften meat, liquefying it if allowed to work for more than a few hours. Observing this effect and the lack of studies addressing this subject in the literature, the authors sought to investigate the use of this natural remedy in an animal model for eschar separation and debridement.

Methods

Thirty-five male rats were divided randomly into three groups. Under general anaesthesia, a limited standard full-thickness burn was produced on the back of each rat. For the intervention group (G1, 15 rats), the wounds were covered with fresh kiwifruit; for control groups 2 and 3 (G2, 15 rats; G3, five rats), the dressing was a neutral ointment (Emulsifier 1220). Weekly wound observations were documented for all the groups. G1 and G2 were sacrificed on Day 20, and group 3 was kept alive until complete eschar separation. The wounds of the rats in groups 1 and 2 were excised and subjected to microscopic evaluation.

Results

On Day 20, all eschars had detached and fallen off in the intervention group (G1), whereas in groups G2 and G3 the eschars were still firmly attached to the base of the wounds (except in two rats of G2); this finding was statistically significant (p < 0.001). The average wound surface area in group G1 was 212 mm² (SD = 88.80938) whereas in G2 it was 388 mm² (SD = 140.6967). Thus, the wound surface area was significantly (p < 0.001) smaller in the intervention group. The eschars in G3 separated spontaneously between days 30 and 42, while in all the rats of the kiwi-treated group, this phenomenon occurred before Day 20. The pathological study revealed no considerable differences between G1 and G2 (p < 0.05).

Conclusions

Debridement and scar contraction occurred faster in the kiwi-treated group than in the untreated group. Following rapid enzymatic debridement, healing appeared to progress normally, with no evidence of damage to adjacent healthy tissue.     

Selective debridement of burn wounds using hydrosurgery system

In recent years, hydrosurgery is a technology that has been applied more and more in debridement procedures. However, the selectivity of hydrosurgery to cutaneous necrotic tissues has not been proved. This study was designed to investigate the possible tissue selectivity of hydrosurgery in the debridement in burn wounds. Deep partial‐thickness burns were produced on the back of porcine, and 48 hours later, both burn wounds and normal skin were debrided using the hydrosurgery system. Then tissue samples were taken, and histological staining was performed and observed under microscope. Burn wound resection rates and the normal skin damaged rates were measured. Our result indicated that the burn wounds were significantly more sensitive than the normal skin when the water pressure produced by the hydrosurgery system was set between 3000 and 5000 psi (pounds per square inch), that is, the necrotic tissue portions were debrided more easily than the normal skin tissue. Based on these data, we suggest that 3000 to 5000 psi of water pressure in the hydrosurgery system has a skin tissue selectivity in burn wounds.     

Amino acid buffered hypochlorite facilitates debridement of porcine infected burn wounds

IntroductionRemoval of necrotic tissue is a vital step in the treatment of full-thickness burn wounds, with surgical debridement being the most effective method. Since minor burn wounds are typically treated on an outpatient basis where surgical capabilities can be limited there is a need for alternative treatment options. In this study we aim to evaluate the use of amino acid buffered hypochlorite (AABH) as a chemical enhancement for wound debridement in a porcine infected burn wound model.MethodA total of 60 full-thickness burn wounds, 3 cm in diameter, were created on four pigs using a standardized burn device. The wounds were inoculated with 10⁷ colony-forming units (CFU) of S. aureus. The experimental groups included wounds debrided with a plastic curette, wounds debrided after pretreatment with AABH, and control wounds wiped with gauze. Wounds were treated twice per week for three weeks. Debridement, healing, and infection parameters were evaluated over time.ResultsAfter one week, but not after two and three weeks, the curette and AABH groups had higher debrided weights compared to control (p < 0.05). Percentage of wound area adequately cleared from necrotic tissue was higher in the AABH-group compared to the curette-group and control, after one week. The earliest healing was measured in the AABH group after two weeks (5 % of wounds), which also had the most healed wounds after three weeks (55 %). In both the AABH and the curette groups, bacterial load had fallen below 10⁵ CFU/g after two weeks. No CFU were detectable in the AABH group after three weeks. The AABH-group was also the easiest to debride.ConclusionOur results indicate that AABH facilitates wound debridement and could be a helpful addition to an effective treatment modality for removal of necrotic tissue in full-thickness burns.     

A technique of haemostasis of the extremities after debridement of burn wounds.

A technique used to achieve prompt haemostasis in burned wounds of the extremities is described. After tangential debridement using a tourniquet, thrombin solution (1000 units in 1 ml of saline solution) is applied on the entire wound. Immediately after removing the tourniquet; the wound is tightly wrapped with a thin plastic film and a pressure bandage over the entire wound. The pressure bandage is kept on for approximately 10 min after removing the tourniquet. With this procedure, haemostasis of the capillary oozing can be promptly and completely achieved. Furthermore, arterial and venous haemostasis can also be achieved, with clots present at the arterial and venous haemorrhagic points. As these clots can be removed easily, ligation or electrocoagulation is necessary. This technique is especially useful for haemostasis in a wound of the extremity after tangential excision leading to decreasing blood loss.     

Effects of collagen and glucan on the healing of burn wounds in mice]

The covering of the wound is one of the important measures in the burn treatment as well as in the control of infection and hypermetabolism. Skin transplantation is the major measure in covering the wound of III degree after escharotomy, while control of the infection was of primary importance in the treatment of II degree burn. Recent studies indicate that collagen provides good frame for extension of epidermis in wound healing, and glucan, an immunoregulator, promotes wound healing by the way of activating macrophages. In the present study, the effects of normal saline, 0.5% III type collagen and 5% glucan (0.4 ml/day for 10 days respectively) on the wound healing rate (healing area/initial wound area) was evaluated in the mice with 7% II degree burn. Biopsy specimens of the wound were examined under the microscope. Results showed that the healing rate with collagen and glucan was increased in the early stage of burn as compared with that of the saline control (P less than 0.05, P less than 0.01). The healing rate was even higher in the glucan group than that in the collagen group (P less than 0.05). Microscopic examination showed that the wound was covered by epidermis, proliferation of fibrous tissue under the epidermis, transformation of fibroblast to fibrocyte and collagenization in the early stage of burn in mice treated with collagen. The healing of the glucan group was also satisfactory, and it was characterized by more macrophages and active phagocytosis of hemosiderin. The above findings suggest that collagen and glucan can promote wound healing by different ways.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bromelain‐based enzymatic debridement of chronic wounds: A preliminary report

Sharp debridement is currently considered most effective for debridement of chronic wounds; however, some patients do not have access to or cannot be treated by surgical methods. This study was designed to provide a first impression of the safety and efficacy of bromelain‐based enzymatic debridement of chronic wounds. Two consecutive single‐arm studies assessing the enzymatic debridement efficacy of a concentrate of proteolytic enzymes enriched in bromelain in chronic wounds was conducted in 2 medical centres. Patients were treated with up to 11 consecutive 4‐hour enzymatic debridement sessions and then treated until wound closure. Twenty‐four patients with chronic wounds of different aetiologies were enrolled. All wounds achieved an average of 68% ± 30% debridement in an average of 3.5 ± 2.8 enzymatic debridement 4‐hour sessions. Seventeen responding wounds (venous, diabetic, pressure, and post‐traumatic aetiologies) achieved an average 85% ± 12% debridement in 3.2 ± 2.5 applications. Seven non‐responding wounds (arterial and post‐surgical aetiologies) achieved an average 26% ± 13% debridement in 4.3 ± 3.5 applications. No treatment‐related serious adverse events were observed, and the only adverse event attributed to the enzymatic debridement was pain. These preliminary results indicate the potential safety and efficacy of bromelain‐based enzymatic debridement in chronic wounds. Larger controlled studies are needed to further investigate this indication .     

Surgical debridement of wounds

Surgical debridement is a surgical procedure which requires specific preparation. It involves a technique of surgical excision, combined with a basic procedure, lavage, to eliminate the metalloproteinases, and bleeding control.     

Preliminary evidence supporting a new enzymatic debridement product for use in chronic wounds

A new recombinant proteolytic enzyme, isolated from maggot saliva, with fibrinolytic action has been investigated through a series of non-clinical toxicology and in-vitro/in-vivo pharmacology studies to explore its potential safety and efficacy as an enzymatic debridement agent for use in chronic wounds. Studies indicate that the enzyme has a good safety profile. When locally administered, it is not detrimental to wound healing, is non-sensitising and is rapidly inactivated in the systemic circulation. Adverse effects are limited, at very high concentrations, to transient erythema at the site of application. In-vitro testing indicates that the enzyme, whilst selective for fibrin, has additional proteolytic action against collagen and elastin, with enzymatic action for all three substrates being dose dependent. In-vivo, we used an established MRSA biofilm model, in which microbiological counts were used as a surrogate for debridement efficacy. Here, we showed that higher concentrations of the enzyme in a formulated proprietary gel, significantly reduced MRSA counts over a period of 2 to 14 days, and significantly improved the vascularity of the wound at 14 days. Together, these data support the potential for this maggot-derived proteolytic enzyme as a clinically effective debriding agent.     

Effect of enzymatic debridement with two different collagenases versus mechanical debridement on chronic hard‐to‐heal wounds

A chronic ulcer is usually defined as an injury that does not spontaneously evolve towards healing and does not progress through normal healing stages such as inflammation, proliferation and remodelling. This study was designed in order to compare two types of collagenases with mechanical debridement alone. It was thus possible to evaluate their differences in terms of pain and debridement efficacy. Patients were divided into three groups: 30 patients were daily dressed using an ointment based on collagenase produced by Vibrio alginolyticus (B group), 30 patients were daily dressed using an ointment based on a collagenase preparation derived from Clostridium histolyticum (N group) and 30 patients underwent classical mechanical debridement (M group). Complete wound healing over a period of 8 weeks occurred in 24 patients (27%) out of 90;10 patients belonging to the B group, 8 patients to the N group and 6 patients to the M group. This study was performed in order to highlight the differences between two commercially available collagenase‐based ointments in comparison with mechanical debridement alone. At the final time point of week, the difference in the percentage of debridement was not statistically significant in all groups, but at 4 weeks, the debrided area in the B group was larger with respect to the N and M groups, suggesting a more rapid wound bed cleansing process. On the basis of our experience, collagenase derived from V. alginolyticus with hyaluronic acid showed chemical and physical properties that make it a product of great manageability and ensure the protection of peri‐wound skin. Moreover, less pain was experienced by the patients.     

Surgical debridement of gunshot wounds

The authors conducted experimental (130 rabbits) and clinical studies (249 persons) in gunshot wounds of the soft tissues. It was found that in 29% of cases, primary surgical debridement of the gunshot wound failed to be a radical intervention because zones of secondary necrosis of the tissues developed on days 3-4. In view of this, gunshot wounds must be examined without fail on days 3-5 to determine the indications for repeated surgical debridement. The indications for repeated surgical debridement are as follows: foci of necrotic tissues, unopened pockets, the presence of foreign bodies. Repeated surgical debridement of a gunshot wound, when indicated, reduces the number of purulent complications by 4 times and the duration of treatment by 1.5 times.