The Effect of Silver-coated Dressing on Pain Management and Hospitalization Duration in Pediatric Partial-thickness Burns: A Retrospective, Matched Cohort Study

Objective. Daily burn wound dressing protocols elicit pain and anxiety, especially in pediatric burn patients. Novel dressing technologies reduce pain by obviating the need for frequent dressing changes. The objective of this study was to assess the effect of silver-coated dressings (SCDs) on pain management and outcomes in pediatric burn patients. Materials and Methods. A retrospective, matched cohort study compared a SCD to standard dressing protocols in admitted pediatric burn patients. Data were extracted from patient medical records. Multivariate analysis was performed to assess independent risk factors. Results. A total of 80 patients in both the control and SCD groups were matched for age (1–16 years), gender (60% males in both groups), and total body surface area (6.1% vs. 4.9%, P = .187). Mean hospitalization duration was shorter in the SCD group than the control (4.68 ± 2.96 vs. 7.05 ± 5.76 days, respectively, P = .023). Lower opiate administration and dressing change frequency were documented in the SCD group than the control (0.49 ± 0.45 vs. 1.29 ± 1.66 administrations/day, P = .004, respectively; 0.47 ± 0.44 vs. 2.04 ± 3.67 changes/day, P = .009, respectively). Conclusions. The SCD protocol led to a lower opiate consumption, fewer dressing changes, and shorter hospitalization duration than the standard dressing protocol. This should be considered when choosing appropriate topical therapies for pediatric burn patients regarding patient discomfort, nursing time resources, and hospital bed vacancy.

Burns are the third leading cause of accidental death among children in the United States, preceded only by motor vehicle and drowning incidents.¹ Approximately 1.2 million people in the United States require medical care for burn injuries each year, resulting in 51 000 hospitalizations. Up to 40% of these patients are younger than 15 years old, with an average age of 2.6 years.¹ Hot liquid scalds represent two-thirds of burn injuries in the pediatric population, with the remaining one-third consisting of flame, chemical, and electrical burns.^2,3 

Unlike superficial burns, which involve only the epidermis, partial-thickness burns extend to the upper layers of the dermis. Thermal damage to free nerve endings can cause one of the most excruciating pains known in trauma medicine.⁴ The basic local management of partial-thickness burns includes topical dressings directed towards skin healing optimization, protection against wound infection, and prevention of insensible water loss.⁵ Considered a global standard for burn dressings since the 1970s, Sulfamylon (mafenide acetate; Mylan Institutional Inc, Rockford, IL) is a sulfa-containing antibiotic solution that fulfills all of these criteria.^6,7 However, traditional treatment of burn wounds entails multiple cleansing and dressing changes each day, a process known to elicit tremendous pain and anxiety.⁸ These short spikes of procedural pain are much more intense than constant background pain at rest and have even been reported to exceed that of the original burn injury.⁹ The mainstay approach to pain control with opioids and anxiolytics during dressing changes are now recognized as insufficient, especially in young children who cannot adequately express their distress.¹⁰ 

Driven by an increased understanding of the short- and long-term psychological consequences of uncontrolled procedural pain, clinical studies in recent decades have focused on identifying pharmacologic and nonpharmacologic methods of reducing discomfort during dressing changes.^11,12 Suggested therapeutic adjuncts to opioids in children include agents of conscious sedation, such as combinations of propofol, ketamine, and midazolam,^13-15 as well as alpha-2 adrenergic agonists like clonidine and dexmedetomidine.^14,16,17 Other methods include inhaled nitrous oxide, transmucosal fentanyl citrate lollipops, and systemic lidocaine and regional nerve blocks, while general anesthesia is reserved for potentially traumatic procedures.^8,18-20 Nonpharmacologic approaches have focused on the use of hypnosis,²¹ cognitive behavioral therapy,⁸ immersive virtual reality,²² and multimodal distraction devices²³ to ease discomfort during painful procedures.

It is thus clear that the crux of past efforts centered on alleviating procedural pain rather than eliminating its source. While irrigation and debridement cannot be avoided, the advent of technologically enhanced burn dressings such as nanocrystalline silver-coated dressings (SCDs) offer a way to combat repetitive pain spikes by reducing the rate of dressing turnover. SILVERCEL (Systagenix, An Acelity Company, Gatwick, West Sussex, UK) hydroalginate antimicrobial SCD is a nonwoven pad composed of high guluronic acid alginate, carboxymethylcellulose, and nanocrystalline silver-coated nylon fibers.²⁴ An in vitro study²⁵ showed the slow release of silver ions confers antimicrobial effects that last up to 14 days. Only the outer dressing bandage is changed, ensuring redundant contact with regenerating skin is avoided. 

Objective. The authors hypothesize that the use of a SCD in treating pediatric burn patients will reduce pain and shorten hospitalization duration. Therefore, the authors’ study objective is to compare the frequency of dressing changes, analgesic administration rate, and hospital length of stay (LOS) between a SCD and the standard mafenide acetate wet-to-dry treatment protocol. 

Study design. The authors conducted a retrospective, matched cohort study. 

Setting. The study was completed at Assaf Harofeh Medical Center, Zerifin, Israel, and it was approved by the medical center’s institutional review board. 

Selection criteria. The authors retrospectively obtained patient record data from January 31, 2008, to March 30, 2013. Pediatric patients with burns under 18 years of age who suffered mainly from partial-thickness burns > 1% total body surface area (TBSA) and required hospitalization in the Pediatric Surgical Department were included. Patients were excluded if they required surgery during hospitalization, were transferred to a tertiary burn center, or received treatment different from the topical burn dressing protocols compared in the present study. Overall, 40 patients were included in the control group and 40 in the SCD group.

Variables and data measurement. Baseline variables collected from each patient’s medical record consisted of age, gender, cause of burn, location of burn, and percent TBSA (%TBSA) at admission. Group matching was done using age, gender, and TBSA. Outcome variables documented per case included daily frequency of dressing changes, analgesic administration rate, type and dosage of analgesics, duration of hospitalization, infection of burn site during hospitalization, and adverse reactions to the dressing used. Possible confounding variables used for statistical analysis included age, sex, weight, ethnicity, TBSA, and burn cause; their potential effects were examined using a multivariate analysis.

Standard dressing protocol. Standard burn treatment included burn irrigation with 0.9% normal saline. Next, wet gauze soaked in 5% mafenide acetate solution was applied directly to the wound and covered with Vaseline Petroleum Gauze (Medtronic, Dublin, Ireland). The burn irrigation, mafenide acetate, and dressing were applied twice daily. Topical Synthomycine 3% (Teva Pharmaceutical Industries, Petah Tikva, Israel), used for more delicate areas such as the face, was administered twice daily. Petroleum gauze alone was preferred for areas with superficial partial-thickness burns.

Silver-coated dressing protocol. The SCD was introduced in the authors’ medical center in 2007. It is generally placed on partial-thickness burns following initial debridement in the emergency room (ER), and then covered with a nonocclusive secondary gauze dressing. Occasionally, the SCD was not placed immediately after debridement in the ER, but rather placed 1 or 2 days into hospitalization. The dressing was left adhered for about 1 week. Patients receiving a SCD were released with their existing closed dressing. Need for continued hospitalization was assessed by a plastic surgeon on a day-by-day basis based on the patient’s vital signs, subjective pain level, clinical burn appearance, and wound dressing capacity. Following discharge, patients in each group were given a follow-up appointment at the Plastic Surgery Outpatient Clinic 3 days later, where areas of early SCD detachment were removed. The remaining adherent SCD was left untouched until it spontaneously dissociated. 

Analgesic treatment protocol. Standard burn treatment protocol included the use of analgesic medications and dressing changes for both groups. Analgesics used included acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), and opioids. Specific drugs and dosages included paracetamol 15 mg/kg, ibuprofen 10 mg/kg, oxycodone 0.1 to 0.2 mg/kg, and tramadol 1 mg/kg (max dose/6 hours did not exceed 50 mg). Generally, opioids were administered prior to dressing changes, whereas paracetamol and NSAIDs were given upon patient or parental request. Level of pain was assessed by the parents using the visual analog scale,²⁶ and the dose of analgesia was adjusted accordingly. 

Sample size calculation. Sample size was calculated using G*Power Statistical Power Analysis Version 3.1.4 (Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany). An average opiate daily dose of 0.2 mg with a standard deviation ± 0.15 mg based on previous hospitalization data was assumed. Sample size was calculated for alpha = 0.05 and power = 80%. To find a 50% decrease in average opiate daily dose, 37 cases in each group (based on the t-test) were needed. The authors added 10% for potentially unaccounted cases to the goal sample and reached 40 cases in each group.

Statistical methods. Statistical analysis was conducted using SPSS software Version 18 (SPSS Inc, Chicago, IL). Continuous variables were presented as averages and standard deviations and were compared using the independent Student’s t-test. Differences in categorical variables were calculated with Pearson’s chi-squared test or Fisher’s exact test. Multivariate analysis was performed using a linear regression model to assess independent predictors of outcome variables and control for potential confounders. 

Baseline characteristics. During the study period, 227 burn patients were admitted to the Pediatric Surgical Ward at Assaf Harofeh Medical Center. Following exclusion and group matching, 80 patients were included in the study: 40 patients were given standard mafenide acetate dressing burn management (control) and 40 patients were treated with the SCD protocol. Each group consisted of 16 girls (40%) and 24 boys (60%), with an average age of 3.8 years in the control group and 2.9 years in the SCD (eTable 1). 

In the control group, 31 patients suffered burns due to scalding, 8 from flame, and 1 from contact burn. In the SCD group, 38 patients suffered scalding, 1 patient was burned by flame, and 1 by contact burn. In regards to the extent of burn injury, the control group had an average of 6.1% TBSA (range, 1%–20%) of partial-thickness burns, while the SCD group had an average of 4.9% TBSA (range, 1%–15%) of partial-thickness burns. No significant differences were found in average TBSA of second-degree burns between both groups (P = .19).

Partial-thickness burn locations are outlined in eTable 2. Burns were most frequent in the torso and lower extremities (53.8% and 38.8%, respectively). Higher rates of upper extremity burns and lower rates of genitalia burns were documented in the SCD group as compared with the control group (35% vs. 15%, P = .039; 2.5% vs. 15%, P = .048, respectively). 

Main outcome results. Mean hospital LOS in the control group was 7.05 ± 5.76 days, while in the SCD group LOS was 4.68 ± 2.96 days (P = .023). Daily frequency of dressing changes in the SCD group was significantly lower than in the control (0.47 ± 0.44 vs. 2.04 ± 3.67, P = .009). Daily opiate administration frequency was decreased in the SCD group as compared to the control (0.49 ± 0.45 vs. 1.29 ± 1.66, P = .004). The daily paracetamol and ibuprofen administration doses were similar in both groups. No adverse reactions to treatment were encountered in either group (eTable 3). 

A multivariate analysis (eTable 4) showed that when adjusted for confounders (gender, age, weight, ethnicity, %TBSA of partial-thickness burns, and mechanism of injury), SCDs remained the driving proponent of LOS reduction (-2.06 days, 95% confidence interval [CI], -3.9 to -0.14, P = .03 [adjusted]; compared with -2.4 days, 95% CI, -4.4 to -0.34, P = .023 [unadjusted]). The %TBSA was the only other variable that had any meaningful effect on LOS; extensive %TBSA increased LOS by 0.42 days when adjusted (95% CI, 0.16–0.67, P =.002), compared with 0.51 days unadjusted (95% CI, 0.27–0.76, P < .001). Age, gender, ethnicity, weight, and mechanism of injury had negligible influence on LOS. In contrast, reduction of daily opiates was mediated by SCD use alone. The SCD decreased opiate administration by 0.8 doses per day in both the controlled and uncontrolled setting (95% CI, -1.3 to -0.2, P = .007 [adjusted]; 95% CI, -1.3 to -0.3, P = .004 [unadjusted]). Other factors, including %TBSA, were insignificant. 

Key results. This study compared a SCD with the standard mafenide acetate dressing protocol in pediatric patients with partial-thickness burns. Children treated using the SCD protocol demonstrated shorter mean hospitalization duration by approximately 2.5 days, lower frequency of dressing changes, and a lower amount and rate of opiate administration when compared with the standard dressing protocol. A multivariate analysis that controlled for possible confounding factors revealed hospital LOS was affected by SCD and %TBSA, while decreased opiate administration relied on the SCD alone. 

Interpretation. A small number of publications demonstrating the advantages of SCDs over analogous non-silver containing antimicrobial dressings in chronic, infected wounds and ulcers exist. A randomized clinical trial by Meaume et al²⁷ in 2005 compared the SCD with an alginate alone (Algosteril; Smith & Nephew, Hull, UK), finding SCD-treated wounds closed more rapidly than the control group (0.32 cm² ± 0.57 cm²/day vs. 0.16 cm² ± 0.40 cm²/day; P = .024), though other outcomes such as infection reduction and absolute decrease in wound severity were less significant (33% vs. 46%, P = .223; and -5.6 ± 3.2 vs. -4.1 ± 4.3, P = .063; respectively). Other studies^28,29 have reported similar results, but the current investigation is the first to evaluate the effect of a SCD on pain reduction in acute pediatric burns. 

There is a wider body of literature comparing other forms of a SCD with standard burn protocols.^30-35 Length of hospitalization, rate of dressing turnover, and need for opiates are often used as metrics of quality. For instance, a 2009 study³⁶ comparing AQUACEL Ag burn Hydrofiber (Convatec, Greensboro, NC) to petrolatum gauze with antibiotic ointment established the superiority of the SCD in pediatric partial-thickness burns by showing it reduced hospitalization duration (2.4 vs. 9.6 days), total number of dressing changes (2.7 vs.17.1), and intravenous narcotics administration (2.3 vs.14.4 total). Other parameters, such as subjective pain, nursing time, and time to wound epithelization, were also decreased while overall patient satisfaction with the caregiver increased twofold.³⁶ 

Similarly, Opasanon et al³⁷ showed there were significantly fewer wound dressing changes for silver dressing Askina Calgitrol Ag (silver alginate; B Braun, Melsungen, Germany) than for 1% silver sulfadiazine (2.93 ± 1.17 vs. 13.29 ± 4.19, P < .02). Abedini et al³⁸ found a two-third decrease in the number of analgesic doses, fewer days of fever, and faster wound healing with the use of SCDs when compared with silver sulfadiazine. Finally, Paddock et al³⁹ contrasted the effect of SCD with silver sulfadiazine on the hospital LOS for pediatric patients with partial-thickness burns. Mean LOS (adjusted for %TBSA burned) was longer in the sulfadiazine group (5.9 vs. 3.8 days, P = .001). 

However, controversy still exists about the optimal protocol for reducing procedural pain in partial-thickness burns. For instance, Muangman et al⁴⁰ reached opposite conclusions regarding the effectiveness of SCDs, reporting no difference in hospital LOS between patients who were treated using a SCD and patients treated with silver sulfadiazine. The discrepancy may be attributed to local policy of clinical management or other factors not mentioned in the study.

This highlights the fact that despite encouraging findings on the efficacy of SCDs, further studies are needed. A 2013 systematic review³¹ and a 2012 meta-analysis³³ demonstrated a lack of adequate clinical data and the poor quality of existing data needed to evaluate SCDs use for burn wounds.

Silver-coated dressings also present several shortcomings. First, as dressing application differs from the standard protocols, health care personnel must be educated regarding its application and removal. Second, since dressing changes are not performed daily and the dressing itself is opaque, a health care professional cannot monitor the course of wound healing. Finally, bacterial resistance to silver has been noted, and several adverse effects have been reported in patients treated topically with silver-containing products. Adverse effects mainly comprise of deterioration of periulcer skin and local burning sensation. Direct silver-induced renal toxicity, leukopenia secondary to medullary toxicity, and local argyria due to prolonged topical silver exposure have also been documented.^41,42 Yet, in the present study, no direct infections or adverse events were noted.

Due to the retrospective nature of this study, a selection bias of patients is possible due to clinician choice of treatment modality. The authors obtained a relatively small sample size, which prevented the detection of infrequent adverse reactions, and performed post hoc analysis to detect risk and protective factors to wound healing. The authors did not obtain data on important aspects of treatment outcomes such as time for definitive healing (epithelization), nursing time, re-admission rate, parent satisfaction with the treatment, and need for surgery. Because the authors mainly relied on patient data records, this study is potentially exposed to reporting bias. However, the authors can assume that if such bias exists, it affected both the control and SCD groups similarly and has minimal impact on the final outcome. The difference in frequency of dressing changes required for each treatment protocol (2x/day for mafenide acetate and 0-1 time total for SCD) may be a possible confounder, owing to the fact that the dressing protocol dictates most of the change rather than clinical wound behavior. Lastly, preference for 1 dressing protocol over another on certain body locations may have predisposed the study to a sampling bias, as areas with higher secretion rates require a greater level of hygiene (ie, more frequent dressing changes). This may explain the lower rate of SCD use in patients with genitalia burns. 

In this study, the SCD protocol was shown to be statistically superior to the standard dressing in reducing the frequency of dressing changes, thus reducing local pain and opioid use. Furthermore, SCD shortened hospital stay duration, which translates to decreased hospitalization costs and parental work absence.

In view of these properties, the authors conclude that the use of a SCD is effective, safe, and easy to use in the treatment of partial-thickness burn wounds in the pediatric population. The authors adopted the following simple treatment protocol, which they recommend. In the ER setting, the clinician should perform thorough debridement of any second-degree pediatric burn, sedate as needed, and apply a SCD and observe for 24 hours. If the SCD sheet becomes adherent to the burn wound, leave it for up to 14 days and remove free ends. If the SCD does not adhere following 24 hours, consider daily SCD application or defaulting to standard treatment.

From the Assaf Harofeh Medical Center, Zerifin, Israel; Department of Epidemiology and Public Health, Sackler School of Medicine, Tel Aviv University,Tel Aviv,  Israel; and Meir Medical Center, Kfar Saba, Israel

Address correspondence to:
Itay Wiser, MD, PhD
Assaf Harofeh Medical Center
Department of Plastic Surgery
Zerifin, Israel
wiser125@gmail.com

Disclosure: The authors disclose no financial or other conflicts of interest.