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

Decontamination of Chemical Casualtiesfrom off-gassing from any of the chemical agents, andchemical-protective masks are not required for surgicalpersonnel. However, recent studies 58 indicate thatswine exposed to 400 µL of neat HD continue to off-gasup to 48 hours postexposure.Wound Exploration and DebridementNo single glove material protects against everysubstance. Butyl rubber gloves generally providebetter protection against chemical warfare agentsand most toxic industrial chemicals (but not all) thannitrile gloves, which are generally better than latexsurgical gloves. Surgeons and assistants are advisedto wear two pairs of gloves 44 : a nitrile (latex if nitrileis not available) inner pair covered by a butyl rubberouter pair. Thicker gloves provide better protectionbut less dexterity. Latex and nitrile gloves are generally4 to 5 mils thick (1 mil = 1/1,000 of an inch). Therecommended butyl rubber glove is 14 mils thick; ifgreater dexterity is needed a 7-mil butyl glove may beworn. A study at the US Army Soldier and BiologicalChemical Command 59 showed breakthrough times forHD and GB depended on glove material and thickness.N-Dex (Best Manufacturing, Menlo, Ga) nitrilegloves (4 mil) had a breakthrough time of 53 minutesfor HD and 51 minutes for GB. North (North SafetyProducts, Cranston, RI) butyl gloves (30 mil) had abreakthrough time of over 1,440 minutes for both HDand GB. The safety standard operating procedure atUSAMRICD 60 for working with neat agents requiresa maximum wear time of 74 minutes for HD and 360minutes for G agents and VX when wearing 7-mil butylrubber gloves over 4-mil N-Dex nitrile gloves. Wearingthis glove combination is recommended until usersascertain that no foreign bodies or thickened agentsare in the wound. Double latex surgical gloves have nobreakthrough for 29 minutes in an aqueous medium;they should be changed every 20 minutes 61 (changinggloves is especially important when bone spicules ormetal fragments can cause punctures). 56The wound should be debrided and excised as usual,maintaining a no-touch technique (explore the woundwith surgical instruments rather than with the fingers).Pieces of cloth and associated debris must not be examinedclosely but quickly disposed of in a container of5% hypochlorite. Recent studies at USAMRICD by Graham58 demonstrated significant off-gassing during laserdebridement of HD-exposed skin in swine. Removedfragments of tissue should be dropped into a containerof 5% to 10% hypochlorite. Bulky tissue such as anamputated limb should be sealed in a chemical-proofplastic or rubber bag. 56 Penetrating abdominal woundscaused by large fragments or containing large piecesof chemically contaminated cloth will be uncommon.Surgical practices should be effective in the majorityof wounds for identifying and removing the focus ofremaining agent within the peritoneum.Cooper et al 56 suggest checking a wound withan ICAM, which may direct the surgeon to furtherretained material. However, this process is slow (astable reading takes about 30 seconds; a rapid passover the wound will not detect remaining contamination)and is not effective unless vapors are emanatingfrom wound debris. A single bar reading on an ICAMwith the inlet held a few millimeters from the woundsurface indicates that a vapor hazard does not exist;more than one bar is needed to indicate a vapor hasbeen detected. 56Dilute hypochlorite solution (0.5%) should not beused to flush wounds. Isotonic saline or water may beinstilled into deep, noncavity wounds following theremoval of contaminated cloth. Subsequent irrigationwith saline or other surgical solutions should be performed.1 Saline, hydrogen peroxide, or other irrigatingsolutions do not necessarily decontaminate agents butmay dislodge material for recovery by aspiration witha large-bore suction tip. The irrigation solution shouldnot be swabbed out manually with surgical sponges;rather, it should be removed by suction to a disposalcontainer and handled like other agent-contaminatedwaste within a short time (5 min). Although the riskto patients and medical attendants is low, safe practicesuggests that any irrigation solution should be consideredpotentially contaminated. Following aspiration bysuction, the suction apparatus and the solution shouldbe decontaminated in a solution of 5% hypochlorite.Superficial wounds should be subjected to thoroughwiping with normal saline or sterile water. 1Instruments that have come into contact with possiblecontamination should be placed in 5% hypochloritefor 10 minutes before normal cleansing and sterilization.Reusable linen should be checked with the ICAM,M8 paper, or M9 tape for contamination. If found tobe contaminated, the linen should be soaked in a 5%to 10% hypochlorite solution or discarded. 1PATIENT THOROUGH DECONTAMINATIONNeedThe focus of patient decontamination is identicalthroughout the services and in the civilian sector: itis the removal of hazardous substances from the contaminatedindividual to protect that person and sub-539