Silicone and pressure garment therapy for the prevention and management of post-burn scarring in children

Abstract

Background: Abnormal burn scarring can cause physical and psychological distress to children and their families. Silicone and pressure garment therapy are common burn scar interventions, used either alone or in combination. However, no definitive high quality evidence is available regarding these interventions for paediatric burn scar management. Existing evidence regarding pressure garment therapy effectiveness is confounded by the unknown level of pressure supplied by the pressure garment to the burn scar.Thesis aim: The overarching aim of this thesis was to determine the effectiveness of silicone and pressure garment therapy for the prevention and management of post-burn scarring in children. This comprised of two sub-aims, to determine the: (1) interface pressure in paediatric pressure garment therapy; (2) effectiveness of silicone versus pressure garment therapy for preventing and managing paediatric post-burn scarring.Methodology: Aim one was achieved via a pilot longitudinal cohort study. Aim two was addressed via a systematic review and randomised controlled trial (RCT). The study methods and results are presented in the order they will appear in the thesis.Systematic review: Searches of six electronic databases, grey literature and hand searches of relevant journals were completed. Eligible studies included RCT’s if they assessed the effectiveness of silicone and pressure garment therapy (alone or combined) for preventing and managing post-burn scarring in children and adults. Risk of bias was determined using the Cochrane risk of bias tool and Grading of Recommendations Assessment, Development and Evaluation. Meta-analyses were completed. The protocol was registered in PROSPERO.Pilot longitudinal cohort study: A pilot longitudinal cohort study was completed with children aged less than 18 years receiving pressure garment therapy post-burn. Test-retest reliability of the Pliance X was investigated at baseline and analysed using an Intra-Class Correlation Coefficient (ICC). Clinical utility was evaluated at baseline using criteria of appropriate, accessible, practicable and acceptable. Interface pressure was measured at first pressure garment fitting, one and three months post fitting and analysed using Linear Mixed Models.Randomised controlled trial: An RCT was completed with participants (0-18 years) referred for scar management after a new burn or following burn scar reconstruction surgery. Participants were randomised to: (1) topical silicone gel only, (2) pressure garment therapy only, or (3) topical silicone gel plus pressure garment therapy. Primary outcomes included scar thickness and scar itch intensity. Secondary outcomes included health-related quality of life (HRQoL), scar severity, adherence, adverse effects and treatment satisfaction. Outcomes were measured on up to two scar sites per person at baseline, one week post scar management commencement, three and six months post-burn or reconstruction surgery. Data were analysed using descriptive statistics and mixed effects regression.Results Systematic review: Sixteen papers were included. Unclear to high risk of bias was identified for all risk of bias categories except random sequence generation. There was insufficient data to enable meta-analysis of primary outcomes for silicone product or combined intervention investigations. Meta-analysis for pressure garment therapy (high vs low interface pressure) identified a reduction in scar thickness at one and two months post-intervention commencement, SMD (95% CI)=-0.54 (-0.89, -0.18) and -0.62 (-1.12, -0.12) respectively.Pilot longitudinal cohort study: Thirty-four children were recruited. Participants had a median (IQR) age of three (1.5, 7.5) years and 61% were male. Stationary test-retest reliability of the Pliance X was acceptable for research use (ICC=0.87, n=27). Pliance X was appropriate and acceptable for children who were not distressed. At first garment fitting, 32% of stationary and 25% of dynamic measurements were within 15 to 25mmHg. Pressure variations were recorded at one and three months with scar location (MD (95%CI)=8.06 (0.99, 15.13), p=0.03) and %TBSA (MD (95%CI)=12.46 (3.85, 21.06), p=0.01) identified as predictors of stationary interface pressure.Randomised controlled trial: Participants (n=153) had a median (IQR) age of 4.86 (1.62, 10.17) years, a median (IQR) %TBSA of 1% (0.5, 3) and 64.7% of participants were male. At six months post-burn injury, the topical silicone gel alone group had thinner scars when compared to the combined intervention group, MD (95%CI)=-0.04 (-0.07, -0.00) (p=0.05). There were less adverse effects in the topical silicone gel alone group than the pressure garment therapy alone group (MD (95% CI)=-1.36 (-2.66, -0.06), p=0.04). No statistically significant differences were identified between the intervention groups for scar itch intensity, scar severity, or HRQoL (p>0.05). Treatment satisfaction and adherence were greater when interventions were used alone.Discussion and clinical implications: A clinically useful and reliable interface pressure measuring device has been identified and recommended for use in paediatric post-burn pressure garment therapy fit and review. A combined intervention approach (topical silicone gel plus pressure garment therapy) was no more effective than individual interventions for preventing and managing paediatric post-burn scarring. If further research supports these findings, topical silicone gel or pressure garment therapy alone can be recommended considering health professional experience and family preference.