Burns: dressings

Abstract

Introduction

Burns are classified according to depth. This overview concerns the treatments for partial-thickness burns, which can be expected or have the potential to heal spontaneously (superficial partial-thickness and mid-dermal partial-thickness burns). Injuries that involve the deeper part of the dermis and require surgical treatments to achieve healing are not the focus of this overview.

Methods and outcomes

We conducted a systematic overview and aimed to answer the following clinical question: What are the effects of treatments for partial-thickness burns? We searched: Medline, Embase, The Cochrane Library, and other important databases up to January 2014 (BMJ Clinical Evidence overviews are updated periodically; please check our website for the most up-to-date version of this review).

Results

At this update, searching of electronic databases retrieved 322 studies. After deduplication and removal of conference abstracts, 193 records were screened for inclusion in the overview. Appraisal of titles and abstracts led to the exclusion of 160 studies and the further review of 33 full publications. Of the 33 full articles evaluated, two systematic reviews and two RCTs were added at this update. We performed a GRADE evaluation for 30 PICO combinations.

Conclusions

In this systematic overview, we categorised the efficacy for 10 interventions, based on information relating to the effectiveness and safety of alginate dressing, biosynthetic dressing, chlorhexidine-impregnated paraffin gauze dressing, hydrocolloid dressing, hydrogel dressing, paraffin gauze dressing, polyurethane film, silicone-coated nylon dressing, silver-impregnated dressing, and silver sulfadiazine cream.

Key Points

Superficial partial-thickness and mid-dermal partial-thickness burns can be expected, or have the potential, to heal spontaneously. Injuries which involve the deeper part of the dermis (deep partial-thickness and full-thickness burns) generally require surgical treatments to achieve healing and are not the focus of this overview.

• Most minor burns occur in the home.

• Cooling the burn for 20 minutes with cold tap water within 3 hours of the injury reduces pain and wound oedema, but prolonged cooling or use of iced water may worsen tissue damage or cause hypothermia.

This overview focuses on the effect of selected commonly used and some more recently developed types of dressings for partial-thickness burns. Although we have searched for trials comparing the individual interventions with placebo or no treatment, there is a lack of evidence for these comparisons. The basic principles of burn wound management preclude the option of no dressing treatment for all but the most minor of burns.

• We excluded sunburn, residual wounds post injury, large surface area burns, and burns to sensitive areas (i.e., specific areas that are likely to result in either functional or cosmetic impairment; e.g., face, hands, perineum).

We found insufficient evidence to draw any conclusions on the efficacy of alginate dressing, biosynthetic dressing, chlorhexidine-impregnated paraffin gauze dressing, hydrocolloid dressing, hydrogel dressing, paraffin gauze dressing, polyurethane film, silver-impregnated dressing, or silicone-coated nylon dressing in treating partial-thickness burns.

• Topical antibacterial substances, such as chlorhexidine, may be toxic to regenerating epithelial cells, and their use may delay healing in wounds that are not infected.

Silver sulfadiazine cream may prolong healing times and increase pain compared with other treatments, although the evidence is limited by small sample sizes and the heterogeneity of the patient population.

Because there is a lack of evidence to inform treatment choices, decisions on appropriate treatment in clinical practice are determined by logistical, as well as clinical, considerations. In the majority of these injuries, healing will occur in a timely fashion if infection is prevented.

Clinical context

General background

Burns are classified according to depth. The most minor burns are superficial burns (previously termed first-degree burns), such as sunburn. They involve the epidermis only and cause erythema. Generally, superficial burns do not require dressings but moisturiser only. Partial-thickness burns (previously termed second-degree burns) are divided into superficial partial-thickness and mid and deep partial-thickness dermal burns. Full-thickness burns (previously termed third-degree burns) result in destruction of the full thickness of dermis and may extend to involve injuries to subcutaneous tissue, muscular, neurovascular, or skeletal structures. Full-thickness burns require surgical treatments to achieve healing and are not the focus of this overview.

Focus of the review

This overview concerns the treatments for partial-thickness burns which can be expected, or have the potential, to heal spontaneously (superficial partial-thickness and mid-dermal partial-thickness burns). Small partial-thickness burns are common and mostly occur in the home. At present, there is a wide range of dressing for treatment options. Treatment choices have the potential to impact significantly on healing outcomes. This overview focuses on the effect of selected commonly used and some more recently developed types of dressings for partial-thickness burns.

Comments on evidence

There is a lack of evidence regarding best dressings as treatments for partial-thickness burn injuries. In part, this is due to the difficulty of objectively assessing wound depth at the time of injury and also to the logistics of determining wound healing times. Adverse events are relatively rare, which means that trials require large numbers of recruits. Reviewing the current evidence systematically can be challenging in this area due to a lack of clarity and consistency in the terminology used in studies concerning type of burn and difficulty in consistent classification of the various individual dressings. There is a lack of evidence for the comparison of individual dressing options with placebo or no treatment because the basic principles of burn wound management preclude the option of no dressing treatment for all but the most minor of burns. Also, there are few wound dressing products that differ from each other in only one feature (e.g., presence or absence of chlorhexidine) and few studies that were designed to assess the efficacy of one single characteristic of a wound dressing.

Search and appraisal summary

At this update, searching of electronic databases was performed. After deduplication and removal of conference abstracts, 193 records were screened for inclusion in the overview. Appraisal of titles and abstracts led to the exclusion of 160 studies and the further review of 33 full publications. Of the 33 full articles evaluated, two systematic reviews and two RCTs were added at this update.

Additional information

The choice of wound dressings for partial-thickness burns is rightly determined by logistical, as well as clinical, considerations. In the majority of these injuries, healing will occur in a timely fashion if infection is prevented.

About this condition

Definition

Burns are classified by depth into superficial (involving epidermis only); partial-thickness (superficial, mid and deep partial-thickness), involving part of the dermis; and full-thickness burns, in which all of the dermis is destroyed, and which may extend to involve subcutaneous tissue, muscular, neurovascular, or skeletal structures.[1] However, the depth of burn is not always static because of the various factors (e.g., inadequate tissue perfusion resulting from the injury), which may release a cascade of vaso-active and inflammatory mediators and, in turn, deepen the burn wound.[2] Superficial partial-thickness burns are caused by exposure to heat sufficient to cause damage to the epidermis and papillary dermis of the skin. Due to the exposure of sensory nerve endings in the superficial dermis, these wounds are often painful and tender. The skin is moist, pink or red, and is perfused, as demonstrated by blanching on pressure. This type of injury can result in an immediate blister response and heal within 3 weeks with minimal scarring if no infection is present.[1] Burn depth is an assessment tool undertaken by burns experts using clinical judgement; however, measuring blood flow, or its disruption, using laser Doppler imaging can also achieve the same task.[3] The severity of a superficial partial-thickness burn is usually judged by the percentage of total body surface area (%TBSA) involved, with the vast majority involving less than 10% TBSA. The population studied for this overview includes adults and children with partial-thickness burns. Our search of the literature was for adults and children with minor thermal burns, including superficial and partial-thickness burns. We found that sometimes the term 'superficial' appeared to be used to describe what we suspected to be 'superficial partial-thickness'. We excluded sunburn, residual wounds post injury, large surface area burns, and burns to sensitive areas (i.e., specific areas that are likely to result in either functional or cosmetic impairment; e.g., face, hands, perineum).

Incidence/ Prevalence

The incidence of superficial and partial-thickness burns is difficult to estimate. Generally, less than 5% of all burn injuries requiring treatment will necessitate admission to hospital.[4] [5] [6] Worldwide estimates surrounding all thermal burn injuries suggest that about 2 million people are burned, up to 80,000 are hospitalised, and 6500 die of burn wounds every year.

Aetiology/ Risk factors

The pattern of injury varies among different age groups. Men aged 18 to 25 years seem more susceptible to injury owing to a variety of causes — mainly flame, electrical, and, to a lesser extent, chemicals.[5] [6] [7] Many burn injuries in this age group are due to the inappropriate use of flammable agents, such as petrol. However, most burns occur in the home. Thermal burns, in particular scalds, are common among children as well as older adults. The kitchen is reported to be the most common place of injury for children, as is the bathroom for older people. Those with concomitant conditions or complicating factors such as motor or neurological impairment are at greater risk.

Prognosis

Superficial partial-thickness burns will heal spontaneously, with minimal hypertrophic scarring, within 2 to 3 weeks if the wound remains free of infection.[8] The capacity to heal is also dependent on the health and age of the individual, with older people and those with concomitant medical conditions prone to delayed healing. Cooling the burn, as part of the initial emergency treatment, significantly reduces pain and wound oedema if started within 3 hours of injury.[7] The optimal time to cool a wound may vary from 20 to 30 minutes, using tap water (at a temperature of 5–25°C).[9] Use of iced water or prolonged periods of cooling can deepen tissue injury and induce hypothermia, and are best avoided.[8] Cleaning solutions and dressings aim to prevent wound infection. The ideal dressing will establish an optimum micro-environment for wound healing. It will maintain the wound temperature and moisture level, permit respiration, allow epithelial migration,[10] and exclude environmental bacteria.

Aims of intervention

To promote wound healing; to prevent infection, with minimal adverse effects and discomfort.

Outcomes

Healing time to healing; quality of healing with regard to scarring, re-epithelialisation, re-pigmentation, and cosmetic results; prevention of wound infection; requirement for antibiotic treatment; requirement for surgery; number and frequency of dressing changes; quality of life during treatment regimen. Symptom severity pain; ease of dressing application and removal. Investigator/participant preference and satisfaction. Adverse effects.

Methods

Search strategy BMJ Clinical Evidence search and appraisal January 2014. Databases used to identify studies for this systematic overview include: Medline 1966 to January 2014, Embase 1980 to January 2014, The Cochrane Database of Systematic Reviews 2014, issue 1 (1966 to date of issue), the Database of Abstracts of Reviews of Effects (DARE), and the Health Technology Assessment (HTA) database. Inclusion criteria Study design criteria for inclusion in this systematic overview were systematic reviews and RCTs published in English, at least single-blinded, and containing 20 or more individuals (at least 10 in each arm), of whom more than 80% were followed up. There was no minimum length of follow-up. We excluded all studies described as 'open', 'open label', or not blinded, unless blinding was impossible. BMJ Clinical Evidence does not necessarily report every study found (e.g., every systematic review). Rather, we report the most recent, relevant and comprehensive studies identified through an agreed process involving our evidence team, editorial team, and expert contributors. The population studied for this review included adults and children with partial-thickness burns. Our search of the literature was for adults and children with minor thermal burns, including superficial and partial-thickness burns. We found that sometimes the term 'superficial' appeared to be used to describe what we suspected to be 'superficial partial-thickness'. We have used the terms as reported in the individual trials in our data tables. The interventions are types of dressing. Superficial burns do not usually require dressings other than moisturiser. We excluded sunburn, residual wounds post injury, large surface area burns, and burns to sensitive areas (i.e., specific areas that are likely to result in either functional or cosmetic impairment; e.g., face, hands, perineum). Evidence evaluation A systematic literature search was conducted by our evidence team, who then assessed titles and abstracts, and finally selected articles for full text appraisal against inclusion and exclusion criteria agreed a priori with our expert contributors. In consultation with the expert contributors, studies were selected for inclusion and all data relevant to this overview extracted into the benefits and harms section of the review. In addition, information that did not meet our predefined criteria for inclusion in the benefits and harms section, may have been reported in the 'Further information on studies' or 'Comment' section. Adverse effects All serious adverse effects, or those adverse effects reported as statistically significant, were included in the harms section of the overview. Pre-specified adverse effects identified as being clinically important were also reported, even if the results were not statistically significant. Although BMJ Clinical Evidence presents data on selected adverse effects reported in included studies, it is not meant to be, and cannot be, a comprehensive list of all adverse effects, contraindications, or interactions of included drugs or interventions. A reliable national or local drug database must be consulted for this information. Comment and Clinical guide sections In the Comment section of each intervention, our expert contributors may have provided additional comment and analysis of the evidence, which may include additional studies (over and above those identified via our systematic search) by way of background data or supporting information. As BMJ Clinical Evidence does not systematically search for studies reported in the Comment section, we cannot guarantee the completeness of the studies listed there or the robustness of methods. Our expert contributors add clinical context and interpretation to the Clinical guide sections where appropriate. Data and quality To aid readability of the numerical data in our reviews, we round many percentages to the nearest whole number. Readers should be aware of this when relating percentages to summary statistics such as relative risks (RRs) and odds ratios (ORs). We have performed a GRADE evaluation of the quality of evidence for interventions included in this review (see table). The categorisation of the quality of the evidence (high, moderate, low, or very low) reflects the quality of evidence available for our chosen outcomes in our defined populations of interest. These categorisations are not necessarily a reflection of the overall methodological quality of any individual study, because the Clinical Evidence population and outcome of choice may represent only a small subset of the total outcomes reported, and population included, in any individual trial. For further details of how we perform the GRADE evaluation and the scoring system we use, please see our website (www.clinicalevidence.com).

Table.

GRADE Evaluation of interventions for Burns: dressings.

Important outcomes	Healing, Investigator/participant preference and satisfaction, Symptom severity
Studies (Participants)	Outcome	Comparison	Type of evidence	Quality	Consistency	Directness	Effect size	GRADE	Comment
What are the effects of treatments for partial-thickness burns?
1 (59)	Healing	Alginate dressings versus silver sulfadiazine cream	4	–3	0	0	0	Very low	Quality points deducted for sparse data, lack of reporting on blinding, weak methods (randomisation/ allocation)
1 (72)	Healing	Biosynthetic dressing versus hydrocolloid dressing	4	–3	0	0	0	Very low	Quality points deducted for sparse data, unclear blinding, and weak methods (unclear randomisation/allocation)
1 (72)	Symptom severity	Biosynthetic dressing versus hydrocolloid dressing	4	–3	0	0	0	Very low	Quality points deducted for sparse data, unclear blinding, and weak methods (unclear randomisation/allocation)
3 (approx 253)	Healing	Biosynthetic dressing versus silver sulfadiazine cream	4	–3	0	0	0	Very low	Quality points deducted for no or unclear blinding, incomplete reporting of results in 2 trials, and weak methods (unclear randomisation/allocation)
3 (approx 126)	Symptom severity	Biosynthetic dressing versus silver sulfadiazine cream	4	–3	0	0	0	Very low	Quality points deducted for sparse data, no or unclear blinding, and weak methods (unclear randomisation/allocation in 1 trial; patients acting as own control in 1 trial)
2 (77)	Healing	Antimicrobial-releasing biosynthetic dressing versus silver sulfadiazine cream	4	–3	0	0	0	Very low	Quality points deducted for sparse data, unclear blinding, and weak methods (unclear randomisation/allocation/intra-individual comparisons)
1 (50)	Investigator/participant preference and satisfaction	Antimicrobial-releasing biosynthetic dressing versus silver sulfadiazine cream	4	–3	0	0	0	Very low	Quality points deducted for sparse data, unclear blinding, and weak methods (unclear randomisation/allocation/patients used as own control)
1 (34)	Healing	Chlorhexidine-impregnated paraffin gauze dressing versus hydrocolloid dressing plus silver sulfadiazine cream	4	–3	0	0	0	Very low	Quality points deducted for sparse data, unclear blinding, weak methods (randomisation/allocation), and no statistical analysis between groups
1 (34)	Healing	Hydrocolloid dressing versus chlorhexidine-impregnated paraffin gauze dressing	4	–3	0	0	0	Very low	Quality points deducted for sparse data, unclear blinding, incomplete reporting of results, and weak methods (randomisation/allocation)
1 (42)	Healing	Hydrocolloid dressing versus silver sulfadiazine cream	4	–3	0	0	0	Very low	Quality points deducted for sparse data, no blinding, incomplete reporting of results, and weak methods (randomisation/allocation)
1 (42)	Symptom severity	Hydrocolloid dressing versus silver sulfadiazine cream	4	–2	0	–1	0	Very low	Quality points deducted for sparse data, no blinding, and weak methods (randomisation/allocation); directness point deducted for unclear outcome
1 (42)	Investigator/participant preference and satisfaction	Hydrocolloid dressing versus silver sulfadiazine cream	4	–3	0	0	0	Very low	Quality points deducted for sparse data, no blinding, incomplete reporting of results, and weak methods (randomisation/allocation)
2 (127)	Healing	Hydrogel dressing versus silver sulfadiazine cream	4	–3	0	0	0	Very low	Quality points deducted for sparse data, lack of blinding, and incomplete reporting of results
1 (47)	Symptom severity	Hydrogel dressing versus silver sulfadiazine cream	4	–3	0	0	0	Very low	Quality points deducted for sparse data, lack of blinding, and incomplete reporting of results
2 (unclear)	Healing	Hydrogel dressing versus standard treatment	4	–3	0	0	0	Very low	Quality points deducted for sparse data, lack of blinding, patients acting as own control, and incomplete reporting of results
2 (unclear)	Symptom severity	Hydrogel dressing versus standard treatment	4	–3	0	0	0	Very low	Quality points deducted for sparse data, lack of blinding, patients acting as own control, and incomplete reporting of results
2 (152)	Healing	Hydrogel fibre dressing versus silver sulfadiazine cream	4	–3	0	0	0	Very low	Quality points deducted for sparse data, lack of blinding, and weak methods in 1 trial (randomisation/allocation unclear)
2 (152)	Symptom severity	Hydrogel fibre dressing versus silver sulfadiazine cream	4	–3	0	0	0	Very low	Quality points deducted for sparse data, lack of blinding, and weak methods in 1 trial (randomisation/allocation unclear)
1 (55)	Healing	Polyurethane film versus paraffin gauze dressing	4	–3	0	0	0	Very low	Quality points deducted for sparse data, lack of blinding, and incomplete reporting of results
1 (55)	Symptom severity	Polyurethane film versus paraffin gauze dressing	4	–3	0	0	0	Very low	Quality points deducted for sparse data, lack of blinding, and incomplete reporting of results
1 (55)	Investigator/participant preference and satisfaction	Polyurethane film versus paraffin gauze dressing	4	–3	0	0	0	Very low	Quality points deducted for sparse data, lack of blinding, and incomplete reporting of results
1 (51)	Healing	Polyurethane film versus chlorhexidine-impregnated paraffin gauze dressing	4	–3	0	0	0	Very low	Quality points deducted for sparse data, lack of blinding, incomplete reporting of results, and weak methods (randomisation/allocation)
1 (51)	Symptom severity	Polyurethane film versus chlorhexidine-impregnated paraffin gauze dressing	4	–3	0	0	0	Very low	Quality points deducted for sparse data, lack of blinding, incomplete reporting of results, and weak methods (randomisation/allocation)
2 (139)	Healing	Silicone-coated nylon dressing versus silver sulfadiazine cream	4	–3	0	0	0	Very low	Quality points deducted for sparse data, lack of blinding, and weak methods (randomisation/allocation)
1 (63)	Symptom severity	Silicone-coated nylon dressing versus silver sulfadiazine cream	4	–3	0	0	0	Very low	Quality points deducted for sparse data, lack of blinding, and weak methods (randomisation/allocation)
7 (unclear)	Healing	Silver-impregnated dressing versus silver sulfadiazine cream	4	–2	0	–1	0	Very low	Quality points deducted for no or unclear blinding, weak methods in 4 RCTs (unclear randomisation/ allocation, reporting on wounds rather than people, incomplete reporting of results); directness point deducted for 1 RCT studying delayed rather than acute treatment and use of variety of types of dressings impregnated with silver
5 (227)	Symptom severity	Silver-impregnated dressing versus silver sulfadiazine cream	4	–2	0	–1	0	Very low	Quality points deducted for unclear blinding and weak methods (unclear randomisation/ allocation); directness point deducted for use of variety of types of dressings impregnated with silver
1 (24)	Investigator/participant preference and satisfaction	Silver-impregnated dressing versus silver sulfadiazine cream	4	–3	0	0	0	Very low	Quality points deducted for sparse data, unclear blinding, and weak methods (unclear randomisation/ allocation)
1 (128)	Healing	Silver-impregnated dressings versus Vaseline® covered with gauze	4	–3	0	0	0	Very low	Quality points deducted for sparse data, unclear blinding, and weak methods (unclear randomisation/ allocation)
1 (32)	Healing	Silver sulfadiazine cream plus hydrocolloid dressing versus hydrocolloid dressing alone	4	–3	0	0	0	Very low	Quality points deducted for sparse data, unclear blinding, incomplete reporting of results, and weak methods (randomisation/allocation)

We initially allocate 4 points to evidence from RCTs, and 2 points to evidence from observational studies. To attain the final GRADE score for a given comparison, points are deducted or added from this initial score based on preset criteria relating to the categories of quality, directness, consistency, and effect size. Quality: based on issues affecting methodological rigour (e.g., incomplete reporting of results, quasi-randomisation, sparse data [<200 people in the analysis]). Consistency: based on similarity of results across studies. Directness: based on generalisability of population or outcomes. Effect size: based on magnitude of effect as measured by statistics such as relative risk, odds ratio, or hazard ratio.

Glossary

Polyurethane film dressing

such as Opsite or Tegaderm serves as a barrier to bacteria and water. The dressing can be left in place for several days. Film dressing is suitable for lightly exuding wounds and as secondary dressing because fluid from moderate to heavily exudating wounds may leak from this type of dressing, increasing the risk of wound contamination.[10]

Very low-quality evidence

Any estimate of effect is very uncertain.

Disclaimer

The information contained in this publication is intended for medical professionals. Categories presented in Clinical Evidence indicate a judgement about the strength of the evidence available to our contributors prior to publication and the relevant importance of benefit and harms. We rely on our contributors to confirm the accuracy of the information presented and to adhere to describe accepted practices. Readers should be aware that professionals in the field may have different opinions. Because of this and regular advances in medical research we strongly recommend that readers' independently verify specified treatments and drugs including manufacturers' guidance. Also, the categories do not indicate whether a particular treatment is generally appropriate or whether it is suitable for a particular individual. Ultimately it is the readers' responsibility to make their own professional judgements, so to appropriately advise and treat their patients. To the fullest extent permitted by law, BMJ Publishing Group Limited and its editors are not responsible for any losses, injury or damage caused to any person or property (including under contract, by negligence, products liability or otherwise) whether they be direct or indirect, special, incidental or consequential, resulting from the application of the information in this publication.