Paediatric partial‐thickness scald burns – is Biobrane the best treatment available?

Abstract

The article critically analyses the role of Biobrane, one of the widely used modern biosynthetic dressings, in paediatric partial‐thickness scald burns. Most of the studies, available in the literature, confirmed that Biobrane has significantly reduced the hospital stay, wound healing time and requirements of pain medications. However, very few studies with long‐term follow up are available. Further randomised controlled trials are required to challenge the supremacy of Biobrane in paediatric partial‐thickness burns.

Introduction

A partial‐thickness scald burn by hot water or other liquids is one of the most common causes of paediatric burns. These burns in children have been treated traditionally by daily painful tubbing, washing and cleansing of the burn wound followed by application of antimicrobial creams. The problem of this therapy is that the child has to be taken to the tub room regularly and be subjected to painful and anxiety‐prone dressings. In spite of antimicrobial therapy, some of these children can still get infections and healing problems that need to be addressed surgically. Regular exposure of the partial‐thickness burns to the environment during dressing changes predisposes patients to local infection that could convert the burns to deep dermal or full thickness. Clinicians are still searching for an ideal wound dressing for paediatric partial‐thickness burns that would provide adequate adherence, good water vapour transport, reasonable elasticity and durability. This would create a bacterial barrier with good antiseptic and haemostatic effects and lack toxicity and antigenicity. It could be easily applied and removed and have a long shelf‐life and minimal storage requirements. It would have a low cost and markedly reduce the total required treatment cost. Last, but not the least, it should limit or eliminate pain. Most of the biosynthetic dressings fit some of the above‐mentioned criteria. This review article will critically analyse the role of Biobrane, one of the widely used modern biosynthetic dressings in paediatric partial‐thickness scald burns.

The database searched included MEDLINE, CINAHL, the Cochrane Library, HealthSTAR and EMBASE. The search terms included were ‘partial thickness burns’, ‘paediatric’, ‘biobrane’, ‘dressings’, ‘scalds’ and ‘children’. The studies from 1980 to 2006 were taken into account. Studies were also identified from the reference list of the retrieved studies. All randomised controlled trials, clinical controlled trial, case series and isolated case reports were included in the review.

Trials involving Biobrane

Biobrane, introduced in 1979, is a biocomposite wound dressing consisting of an ultrathin, semi‐permeable silicone membrane mechanically bonded to a flexible knitted trifilament nylon fabric. A layer of peptides derived from the porcine dermal collagen is incorporated into both the silicone and nylon components of the dressing, which enhances its bonding to tissue fibrins at the wound surface. Biobrane can provide firm adherence, reduce the total amount of wound dressing material, protect wounds and help the patient to achieve early movement 1, 2, 3, 4. Biobrane has also been reported to achieve lower pain score with good tolerance, expedite time to healing with reduced incidence of secondary grafting and reduced hospital stay 3, 5, 6, 7, 8, 9. However, there is still lack of substantial highest level of evidence (level 1) in the form of prospective randomised controlled trials to prove the supremacy of Biobrane compared with other biological or biosynthetic dressings.

Barret et al. (6) conducted a prospective randomised trial of Biobrane versus 1% silver sulphadiazine in partial‐thickness paediatric burns in 20 children (10 in each group) recruited by significant power analysis. They have well‐defined inclusion and exclusion criteria except the fact that a wide range of total body surface area was selected (2–29%). This was reflected in the results, where a variation of the standard deviations in the study groups was noted (0·95% in the silver sulphadiazine group versus 4·9% in the Biobrane group). Patients included in both groups were otherwise comparable, and all data followed normal distribution. The study has not mentioned who was responsible for wound check and deciding the time to healing and also for assessing the pain score and whether the assessor was blinded to the intervention of the participants. Nevertheless, they concluded that Biobrane had significantly lower length of hospital stay and wound healing time and manifested decreased requirements of pain medications compared with the silver sulphadiazine group (P = 0·002).

A similar prospective randomised study reported by Gerding et al. (4) compared Biobrane with 1% silver sulphadiazine in 56 partial‐thickness burn wounds less than 10% of total body surface area. The two groups were similar in age, gender, race and extent of burn, confirming minimal group differences for important confounders. Infection and grafting rates were similar in both the groups. However, time to healing and pain scores were significantly less in the Biobrane group (P < 0·001). Compliance with the scheduled outpatient visits was improved in the Biobrane‐treated group. Idealised total treatment costs averaged $434 in the Biobrane group compared with $504 in the silver sulphadiazine group. However, the study was non blinded in design, and the investigator of the wound healing and pain scores was not clearly identified.

A prospective randomised trial was carried out recently by Cassidy et al. (9) comparing Biobrane with Duoderm, an occlusive hydrocolloid dressing in the treatment of intermediate‐thickness burns in children. They recruited 72 patients necessary for 80% power according to their strict inclusion and exclusion criteria. They recorded no significant difference in time to healing, pain scores using definite Oucher and visual analogue scale (P = 0·47 and 0·993, respectively). But the cost of treatment was statistically more expensive in the Biobrane group, regardless of the size or thickness of the dressing (P < 0·001). The study concluded that Duoderm and Biobrane provide equally effective treatment of partial‐thickness burns in the paediatric population. This study defined complete healing as ‘complete reepithelisation’ that was assessed by an experienced burn surgeon or nurse but did not mention whether the person concerned was a member of the research team, confirming a blinded assessor status. However, the subjective pain scales have been validated and shown to be clinically reliable with interrater reliability and also reproducible in the paediatric burn patients 10, 11, 12.

Another prospective randomised non blinded trial was conducted recently by Kumar et al. (8) using Biobrane, silver sulphadiazine and Transcyte, a human fibroblast‐derived temporary skin substitute consisting of a polymer membrane and neonatal human fibroblast cells cultured under aseptic conditions in vitro on a nylon mesh. They recruited 58 patients, but no preliminary power analysis was done. This is the only study that used laser Doppler imaging (LDI) as an adjunct to assessment of the depth of the burn. LDI has been shown as a valid and reliable tool for burn‐depth estimation (13). They defined 90% reepithelisation as successful healing. Their wound evaluation was scientific as the wounds were rated by two independent observers and the burn‐depth progression was recorded with the LDI at every stage. The Transcyte group had taken least time for reepithelisation, least failure rates and least dressing changes. The narcotic analgesia required during dressing changes was similar in the Transcyte and Biobrane groups and was more in the silver sulphadiazine group. The study used sound statistical tests, such as, analysis of variance with Bonferroni correction for multiple groups and Kruskal–Wallis test for the data that are not normally distributed.

Lal et al. (7) conducted a randomised trial of Biobrane versus conservative treatment with topical antimicrobials (41 in the Biobrane group and 48 in the conservative group). Biobrane was removed in 5·9% of cases of non adherence. The application of Biobrane within 48 hours of superficial burns provides for shorter hospitalisation and faster healing rates in children of all ages without increased risk of infection.

There is only one study reported in the literature involving skin substitute other than Biobrane and conservative treatment for the treatment of partial‐thickness burns (14). This is a prospective randomised comparison study of Transcyte and silver sulphadiazine with the use of paired wound sites on 14 patients. The authors reported that the time to healing was quicker in the Transcyte group (P = 0·02). Late wound evaluations were performed at 3, 6 and 12 months with Vancouver scar scale, and the results indicated that the wound sites treated with Transcyte healed better with less hypertrophic scarring than sites treated with silver sulphadiazine (P < 0·001). This study again confirmed the fact that the skin substitutes are probably overall superior to conservative dressing, and more prospective randomised trials are needed to choose between different skin substitutes, such as Transcyte and Biobrane.

Ou et al. (5) described the role of Biobrane in a case series of 106 paediatric scald burns. The average burn size was 11·4% of total body surface area, and the burns were clinically diagnosed as superficial or medium partial‐thickness burns. They separated the burn wounds into superficial partial‐thickness burns with only minimal involvement of dermis and medium deep‐thickness burns in scattered regions with small amount of dermis involved. The former group had an infection rate of 7·8% and the latter 62·1%(P < 0·01, chi‐square test). The study further highlighted the fact that accurate depth of burns is very important, if necessary with the use of LDI, as the best results of Biobrane can be obtained only on superficial partial‐thickness burns.

This observation was further supported by other case series studies 15, 16. Demling et al. (16) claimed that the infection rate in using Biobrane to manage scalds is about 5%, whereas Phillips et al. (2) cited a rate of 5·8%. However, Ou et al. (5) reported a high infection rate (22·6%). This may be due to the fact that the definition of wound infection was loose in this study, and deep partial‐thickness burn wounds were included in the study.

Beltra‐Pico et al. (17) conducted a retrospective study using Biobrane in partial‐thickness burns, covering donor sites, reinforcing meshed autografts, traumatic dermabrasions and toxic epidermal necrolysis. They found universally excellent wound healing, shorter hospital stay, reduction of pain and a higher level of satisfaction. However, the study had not highlighted whether the mechanism of healing was different in the other injuries compared with the burns. Also, the number of participants in the ‘other injuries’ group was relatively small.

Demling et al. (16) compared Biobrane with xeroform gauze in terms of pain, physical therapy and length of hospital stay. In this retrospective study, they found that the Biobrane was adherent 85% of the time. However, there is no mention of the sample size in both the groups. Except marked reduction of pain score in the Biobrane group, the study was not comparative in nature and was mainly suggestive of a case series of Biobrane describing the successful adherence, infection rates, healing time and hospital stay.

A recent retrospective clinical study conducted by Lang et al. (18) has shown that in most of the children (71 out of 84), Biobrane was adherent and without any reactions or infections. This study looked at long‐term follow up and found that in scarless healed areas, 54·3% had normopigmentation and 39·1% were hypopigmented. The quality of the scars was mostly hypopigmented with a softness between minimal and middle resistance, under 2‐mm high and of normal to pink skin colour. They concluded that when used on properly selected wounds, Biobrane is an effective and less traumatic therapy for superficial partial‐thickness burns without increasing the cost of outpatient burn care. However, the scar estimation in this study was purely clinical without the use of any validated scar assessment scale, such as, the Vancouver scale.

Yang and Tsai (19) conducted the only prospective clinical comparison of the three commercially available Biobrane preparations – regular Biobrane, thin porous Biobrane and regular porous Biobrane. Regular porous Biobrane showed superiority to the other two Biobrane products. This provided better wound adherence while maintaining wound drainage because of its porous structure. The incidence of blood or fluid accumulation was the lowest in this group (7·1%). Most of the complications, such as, infection, delayed epithelisation, pain and activity impairment, were related to fluid or blood accumulation.

Biobrane has been used for coverage of paediatric donor site, a wound similar to partial‐thickness burns (20). Housinger and Wondrely (20) reported that the chest and thighs had successful full‐term coverage in greater than 90% of cases. But the back and hip regions were the areas where Biobrane was least successful in providing donor coverage with early removal rates of 43% and 80%, respectively. These can have similar effects on the paediatric partial‐thickness burns. Selection of sites for which good success can be expected should be paramount in the decision to use this donor site material in this patient population.

Complications of Biobrane

Biobrane is well known for good tolerance with very few complications. Apart from the minor infection and non adherence, a thorough literature review could only find two anecdotal case reports of toxic shock syndrome (TSS) with the use of Biobrane in the paediatric burn. Weinzweig and Gottlieb (21) in their case report has concluded that the probable case of TSS associated with the use of Biobrane does not question its efficacy as temporary coverage of partial‐thickness thermal burns. Egan and Clark (22) reported a case of TSS in a 6‐year old boy with a 5% body surface area partial‐thickness scald burn where Biobrane was the wound dressing used initially. Children are most vulnerable to the development of TSS because of their limited prior exposure to the toxin that may be totally unrelated to the use of Biobrane. Future research should concentrate on this fatal complication, particularly looking at the role of the skin substitutes as a predisposing factor for TSS.

Fixation of Biobrane

Several methods of Biobrane fixation have been mentioned, such as sutures, fibrin glue and steristrips 2, 23. Ou et al. (5) fixed Biobrane with steristrips but later replaced them with usual paper adhesive tape with reduction of cost. The usual paper adhesive tape can be sterilised in an autoclave. They concluded that there is no difference in outcome of Biobrane adherence by using either tape.

Conclusions

While there are abundant data emerging in the literature on the continually evolving wound dressings currently being developed by biomedical companies for the treatment of partial‐thickness burns, there are few studies comparing their relative merits in a prospective manner. Biobrane seemed to be more effective than conservative treatment in terms of pain control, wound healing time and length of hospital stay in paediatric partial‐thickness burns. However, very few studies with long‐term follow up are available. Therefore, there is scanty evidence regarding the incidence of hypertrophic scarring in the Biobrane group and its comparison with other skin substitutes. The only competitor of Biobrane to date is probably Transcyte, which has been shown to be more effective in certain parameters by one prospective randomised study (8). Nevertheless, Transcyte is almost 15 times expensive as Biobrane, and the routine use of Transcyte is debatable with the current evidence available. Further randomised controlled trials are required to challenge the superiority of Biobrane in routine paediatric partial‐thickness burns.