Medical Aspects of Chemical Warfare (2008) - The Black Vault

Vesicantsactivity against a broad spectrum of Gram-positive andGram-negative organisms. 139 Dakin solution must befreshly compounded to be effective. Aqueous mafenide5% solution (acetate or hydrochloride) is bacteriostaticagainst a broad spectrum of Gram-positive and Gramnegativebacteria and has strong coverage againstpathogens commonly encountered in gunshot wounds,blast injuries, open fractures, necrotizing fascitis, andFournier gangrene. 140,141 The drug is particularly activeagainst Pseudomonas and Clostridia species. 142 Theacetate salt is commercially available as Sulfamylon(Bertek Pharmaceuticals, Morgantown, WV). An isoosmolarsolution is produced by 50 g of powder mixedin 1 L of sterile water; if mixed in sterile saline, thesolution is hyperosmolar and painful on application.Mendelson points out that aqueous mafenide is anexcellent battlefield or mass casualty drug, because 5lb of powder mixed with local water sources can supplysufficient solution to provide a patient with a 50%TBSA burn with 455 dressing changes of 10% solutionor 910 dressing changes of a 5% solution. 140,143 In austereconditions, where gloves and dressing supplies areunavailable, 5% or 10% mafenide solution has beenapplied with spray bottles to wounds that are thenleft uncovered. 140,144,145Deep skin injury may be produced by exposureto liquid HD, causing coagulation necrosis. Delayedtreatment may allow progression of superficial injuryto deeper levels. Concurrent trauma or wound contaminationmay predispose the wound to infection.Infection complicating superficial HD wounds mayconvert a partial thickness injury to full thickness.Deep HD skin injuries should be washed twice dailywith a surgical detergent (chlorhexidine gluconatesolution), rinsed with saline or water, and coveredwith silver sulfadiazine cream followed by protectivegauze dressings. Wounds that are obviously full thicknessbenefit from “alternating agents,” application of11% mafenide acetate cream during the day followedby application of silver sulfadiazine cream at night.The combination of these agents provides a broaderantimicrobial spectrum, limits emergence of resistantorganisms, and has fewer side effects (neutropeniaand metabolic acidosis) than when either agent isused alone. 139 Mafenide acetate cream alone may beapplied twice daily on wounds that are very deep,heavily contaminated, or infected. Mafenide acetatecream has the best eschar penetration of any topicalagent; it is useful in situations where injuries are deepand battlefield conditions preclude proper wounddebridement or excision. Full thickness or infectedinjuries will also require surgical debridement or excision.Following excision, split-thickness autograftingwill shorten wound healing time.Wounds should be inspected periodically for signsof infection. The risk of secondary infection of HDwounds is at least as high as in thermal injury. Infectionis a significant factor in causing delayed healingof cutaneous HD injuries, although even uninfectedHD burns exhibit delayed wound healing. Infectedwounds require surgical debridement or excision. Anybiologic or synthetic dressings should be removedwhen cellulitis is present, the wounds should be debridedof any nonviable tissue, and penicillin shouldbe administered orally. Intravenous antibiotics maybe indicated for cellulitis that does not respond tooral antibiotics. There is no indication for the routineadministration of systemic antibiotics to patients withHD injury.The decision to evacuate and hospitalize an HDcasualty is based upon the magnitude and type ofexposure (vapor versus liquid); systemic, ocular, andpulmonary manifestations; and the extent and severityof skin lesions, in consideration with other injuries thatmay be present (eg, respiratory, ocular). For patientsexperiencing only cutaneous HD injuries, erythemacovering more than 5% of TBSA in noncritical areasrequires hospitalization. Erythema covering less than5% TBSA may require hospitalization, depending uponthe site of the injury (eg, face, inguinal area) and levelof impairment (eg, limitation of limb movement dueto pain, edema). Multiple or large areas of vesicationalso require hospitalization. Since blister formationmay initially be slight, the patient should be watchedfor a progression in the size and number of blisters.Topical antibacterial creams such as silver sulfadiazinecan be prescribed to patients who do not require closemedical monitoring, with instructions to apply a thinlayer to the affected area twice, four times a day. Followingapplication of the cream, the area should becovered with a loose gauze dressing such as a petrolatumgauze bandage.Development of improved therapies. Treatmentstrategies for improved and rapid healing of cutaneousHD injuries recently formulated by a workinggroup of US and UK researchers and physicians aresummarized below. 138 Research is underway to experimentallysupport these strategies and determinewhich medical devices, supplies, and pharmaceuticalsare most efficacious. The ultimate goal is to determinethe most efficacious treatment regimen to be appliedin the clinical management of HD casualties. The idealregimen should return damaged skin to optimal appearanceand normal function in the shortest time.Improved treatment will result in a better cosmeticand functional outcome for patients and enable themto return to normal activities sooner.Immediate treatment. For those patients who are281