Leukopenia in acute thermal injury: evidence against topical silver sulfadiazine as the causative agent

Medical and Surgical Care of Critical Burn Patients: A Comprehensive Review of Current Evidence and Practice

Critically ill burn patients pose several unique challenges to care providers. The concepts of fluid resuscitation, nutritional management, organ support and wound care are rapidly evolving. There is a pressing need to review emerging evidence and incorporate these into practice for the effective management of burn patients. We have searched the PubMed and Google Scholar databases to review the current evidence on the acute care management of adult as well as paediatric burn patients. The rationales for current practices have been integrated into the review. The management of critically ill burn patients requires an in-depth knowledge of the pathophysiology of burn injury, a tailored approach for timely resuscitation, timely diagnosis of organ specific problems, and comprehensive wound care. This review will help the doctors and healthcare providers involved in the management of critical burn patients in their day-to-day practice.

A Case of Argyria and Acute Leukopenia Associated with the Use of an Antimicrobial Soft Silicone Foam Dressing

Silver has had an important role in preventing burn-related infections for decades. Relatively few side effects is one factor that has led to its wide spread use. Here, the authors present the first case of argyria, acute leukopenia, and possibly acute kidney injury associated with the use of a silver-containing soft silicone foam dressing. A 56-year-old female was transferred to the burn center with an exfoliating skin condition involving 70% TBSA diagnosed as toxic epidermal necrolysis associated with trimethoprim/sulfamethoxazole. On presentation she appeared to have clinical sepsis and was started on vancomycin and piperacillin/tazobactam. Clinical sepsis resolved within several days. Initial wound care consisted of daily topical double antibiotic and 3% bismuth tribromophenate petroleum gauze. After several days, the wounds were covered with a silver-containing soft silicone foam dressing. After 7 days, the leukocyte count declined from 18,000 to 600/cm. Silver toxicity was suspected and the dressings removed. Initial serum silver level was 190 and 249 μg/L 1 week later. The leukocyte level normalized within 7 days. Over the following days and weeks, the patient's skin began to show blue-gray coloration consistent with argyria. The patient subsequently developed acute kidney injury requiring hemodialysis and multiple organ failure. Although controversy exists about the causal relationship between silver-containing dressings and leukopenia, the authors believe that this case represents a case of acute leukopenia and argyria from the use of a silver-containing soft silicone foam dressing. It may have been a contributing factor to the development of acute kidney injury as well.

Infections in critically ill burn patients

Severe burn patients are one subset of critically patients in which the burn injury increases the risk of infection, systemic inflammatory response and sepsis. The infections are usually related to devices and to the burn wound. Most infections, as in other critically ill patients, are preceded by colonization of the digestive tract and the preventative measures include selective digestive decontamination and hygienic measures. Early excision of deep burn wound and appropriate use of topical antimicrobials and dressings are considered of paramount importance in the treatment of burns. Severe burn patients usually have some level of systemic inflammation. The difficulty to differentiate inflammation from sepsis is relevant since therapy differs between patients with and those without sepsis. The delay in prescribing antimicrobials increases morbidity and mortality. Moreover, the widespread use of antibiotics for all such patients is likely to increase antibiotic resistance, and costs. Unfortunately the clinical usefulness of biomarkers for differential diagnosis between inflammation and sepsis has not been yet properly evaluated. Severe burn injury induces physiological response that significantly alters drug pharmacokinetics and pharmacodynamics. These alterations impact antimicrobials distribution and excretion. Nevertheless the current available literature shows that there is a paucity of information to support routine dose recommendations.

Management of Burns and Anesthetic Implications

Burn injuries are highly complex and affect almost every major organ system in the body. The treatment of burn patients requires the presence of a well-organized team of caregivers who understand the multifaceted consequences of burn injuries and who are adept at coordinating care. An understanding of the multitude of abnormalities that must be addressed helps to guide therapy in these patients. Careful anesthetic and perioperative management of these patients carries special importance in this fragile patient population as a part of their often lengthy recovery and rehabilitation.

Update on the critical care management of severe burns

Care of the severely injured patient with burn requires correct diagnosis, appropriately tailored resuscitation, and definitive surgical management to reduce morbidity and mortality. Currently, mortality rates related to severe burn injuries continue to steadily decline due to the standardization of a multidisciplinary approach instituted at tertiary health care centers. Prompt and accurate diagnoses of burn wounds utilizing Lund-Browder diagrams allow for appropriate operative and nonoperative management. Coupled with diagnostic improvements, advances in resuscitation strategies involving rates, volumes, and fluid types have yielded demonstrable benefits related to all aspects of burn care. More recently, identification of comorbid conditions such as inhalation injury and malnutrition have produced appropriate protocols that aid the healing process in severely injured patients with burn. As more patients survive larger burn injuries, the early diagnosis and successful treatment of secondary and tertiary complications are becoming commonplace. While advances in this area are exciting, much work to elucidate immune pathways, diagnostic tests, and effective treatment regimens still remain. This review will provide an update on the critical care management of severe burns, touching on accurate diagnosis, resuscitation, and acute management of this difficult patient population.

Burn wound care

The goals of burn wound care are removal of nonviable tissue, prevention of infection, and facilitation of wound healing, while controlling pain and maximizing outcome. This article reviews the basic pathophysiology of burn wounds; describes the evaluation of the depth, location, and extent of the wound; and discusses the myriad of wound care products on the market including their strengths and weaknesses. This article guides the reader through wound assessment and designing the appropriate treatment plan.

A pharmacological and toxicological profile of silver as an antimicrobial agent in medical devices

Silver is used widely in wound dressings and medical devices as a broad-spectrum antibiotic. Metallic silver and most inorganic silver compounds ionise in moisture, body fluids, and secretions to release biologically active Ag(+). The ion is absorbed into the systemic circulation from the diet and drinking water, by inhalation and through intraparenteral administration. Percutaneous absorption of Ag(+) through intact or damaged skin is low. Ag(+) binds strongly to metallothionein, albumins, and macroglobulins and is metabolised to all tissues other than the brain and the central nervous system. Silver sulphide or silver selenide precipitates, bound lysosomally in soft tissues, are inert and not associated with an irreversible toxic change. Argyria and argyrosis are the principle effects associated with heavy deposition of insoluble silver precipitates in the dermis and cornea/conjunctiva. Whilst these changes may be profoundly disfiguring and persistent, they are not associated with pathological damage in any tissue. The present paper discusses the mechanisms of absorption and metabolism of silver in the human body, presumed mechanisms of argyria and argyrosis, and the elimination of silver-protein complexes in the bile and urine. Minimum blood silver levels consistent with early signs of argyria or argyrosis are not known. Silver allergy does occur but the extent of the problem is not known. Reference values for silver exposure are discussed.

Internally coated endotracheal tubes with silver sulfadiazine in polyurethane to prevent bacterial colonization: a clinical trial

OBJECTIVE

Coated medical devices have been shown to reduce catheter-related infections. We coated endotracheal tubes (ETT) with silver sulfadiazine (SSD), and tested them in a clinical study to assess the feasibility, safety, and efficacy of preventing bacterial colonization.

DESIGN

A prospective, randomized clinical trial, phase I-II.

SETTING

Academic intensive care unit (ICU).

PARTICIPANTS

Forty-six adult patients expected to need 12-24 h of intubation were randomized into two groups.

INTERVENTIONS

Patients were randomized to be intubated with a standard non-coated ETT (St-ETT, n=23; control group), or with a SSD-coated ETT (SSD-ETT, n=23).

MEASUREMENTS AND RESULTS

Coating with SSD prevented bacterial colonization of the ETT (frequency of colonization: SSD-ETT 0/23, St-ETT 8/23; p<0.01). No organized bacterial biofilm could be identified on the lumen of any ETT; however, SSD was associated with a thinner mucus layer (in the SSD-ETT secretion deposits ranged from 0 to 200 microm; in the St-ETT deposits ranged between 50 and 700 microm). No difference was observed between the two groups in the tracheobronchial brush samples (frequency of colonization: SSD-ETT 0/23, St-ETT 2/23; p=0.48). No adverse reactions were observed with the implementation of the novel device.

CONCLUSION

SSD-ETT can be safely used in preventing bacterial colonization and narrowing of the ETT in patients intubated for up to 24 h (mean intubation time 16 h).

Update on the Use of Antibiotics in Cutaneous Surgery

BACKGROUND

Antibiotics are often prescribed in perioperative settings, including dermatologic surgery. Given the continued evolution in the breadth and complexity of cutaneous procedures performed and inevitable localized or distant infections that occasionally occur, it seems prudent to periodically evaluate findings and recommendations from the literature regarding the use of antibiotics in cutaneous surgery.

MATERIALS AND METHODS

Literature review from English-language sources from the past 30 years, especially focusing on sources from the past 5 to 10 years. Data were examined for a variety of cutaneous surgical procedures, routes of antibiotic administration, and consideration of both cutaneous and distant infections.

RESULTS

The literature suggests that, for most routine skin procedures, antibiotic use is probably not warranted for the prevention of surgical wound infection, endocarditis, and late prosthetic joint infections. During prolonged Mohs procedures, delayed repairs, grafts, takedowns of interpolation flaps, or any procedure that breaches a mucosal surface, the evidence is less clear, and decisions should be made on a case-by-case basis. Topical antibiotics are probably overused, although silver sulfadiazine may have an undeserved negative reputation among dermatologists. Systemic prophylactic antibiotics for laser resurfacing and liposuction appear not to be routinely necessary, although patients with known prior herpes infection likely should receive antiviral prophylaxis. The overall reported infection rates and infectious complications remain low in dermatologic surgery, and antibiotic therapy may be prescribed excessively or inappropriately as a result. CONCLUSION.: Antibiotics continue to be widely used, and through varying routes of administration, in the setting of dermatologic surgery. Prudent use of these agents is indicated in high-risk patients, certain anatomic locations, and the presence of overt infection. Additional studies may help clarify the most appropriate indications, and in which patient populations, in the future.

Silver-Coated Dressing Acticoat Caused Raised Liver Enzymes and Argyria-like Symptoms in Burn Patient

BACKGROUND

Treatment of acute burn wounds with silver sulfadiazine (SSD) has raised concern about potential silver toxicity. Numerous adverse reactions and side effects have been reported and an increasing resistance to SSD, especially in Pseudomonas strains, have motivated researchers to search for an alternative wound dressing.

METHODS

Recently, a silver-coated wound dressing Acticoat (Smith & Nephew, Inc.) has become available for use in burn patients. It is a three-ply dressing, consisting of an inner rayon/polyester absorptive core between two layers of silver-coated, high-density polyethylene mesh. In a moist environment, the nanocrystals of silver are released and improve the microbial control in the wound.

RESULTS

After 1 week of local treatment with Acticoat in a young, previously healthy 17-year-old boy with 30% mixed depth burns, hepatotoxicity and argyria-like symptoms, a grayish discoloration of the patient's face, appeared. The silver levels in plasma (107 microg/kg) and urine (28 microg/kg) were clearly elevated, as well as the liver enzymes. As soon as the local application of Acticoat was aborted, the clinical symptoms and liver enzymes returned to the normal values.

CONCLUSIONS

This is the first report on silver toxicity in a patient with 30% burns who received Acticoat for local treatment. Due to substantial experiences with adverse SSD reactions and side effects, it is appropriate to keep the possibility of a toxic silver effect in burn patients treated with Acticoat silver-coated wound dressing in mind. The silver levels in plasma and/or urine should be monitored.

Promogran and complex surgical lesions: a case report

Surgical excision of a venous malformation on a young girl's thigh left a large and deep ulcerative wound. Treatment of the lesion with Promogran dressings suited this patient's specific needs and produced substantial healing within five weeks.

How safe is silver in wound care?

Use of silver in burns, chronic ulcers and diabetic ulcers can lead to circulatory absorption and deposits in wound sites, liver, kidney and other organs. Despite this, the risks of lasting tissue damage or functional disorders are low.

Case 40: ward management. Ward sister who failed to manage her ward appropriately

This article reviews the factors that impinge on the application of topical medications in wound care. The role of systemic and topical antibiotics in wound care is reviewed. Similarly, two antiseptics — iodine and silver, of great current interest in wound management — are scrutinized. The value of these topical agents in the management of wound bioburden should be ascertained from the perspective of understanding the advantages and disadvantages of their use and not established from what is currently the trend.

Management of burn wounds with prompt excision and immediate closure

The past 30 years have been witness to significant improvements in the overall care and prognosis of those suffering burn trauma. At the heart of this success is an aggressive approach to burn wounds. This approach, which is detailed in this review, involves early operative removal of devitalized tissue and biological coverage of resultant wounds, with particular attention to wounds in specialized areas.