EVALUATION AND TREATMENT

IMMEDIATE PROPHYLACTIC MEASURES

U.S. Service Members should routinely receive tetanus toxoid and single-dose IV antibiotic (typically Ancef) for war wounds. Host nation patients or those with unclear vaccination histories should receive toxoid, Ancef and tetanus immune globulin. (Refer to Infection Prevention in Combat-Related Injuries CPG).

DEBRIDEMENT

Thorough inspection of the wounds with liberal use of surgical enlargement (i.e. wide surgical exposure) is necessary to inspect all levels of tissue, including examination of fascial planes and the integrity of neurovascular structures. This may require extension to outside the zone of trauma. When extending the wound into healthy tissue, consideration should be given to how this could potentially affect future reconstructive or closure options.4 In general, extremity wounds should be extended in a longitudinal manner (parallel with the bone) and truncal wounds should be extended along Langer’s lines (see figure below). Wound configuration and need for additional vascular exposure must be considered and this may at times violate all of the above precepts.

It is critical that the wartime surgeon has an appreciation for the phenomenon of wound evolution and weapon ballistics. Military assault rifles and proximity blasts cause large areas of cavitation because the kinetic energy transfer exceeds the area of tissue destruction by the projectile..5 Such wounds are known to appear viable or questionably viable but progress to necrosis over the subsequent 24-72 hours from microvascular thrombosis and ischemia. Blast wounds are heavily contaminated with environmental debris and, sometimes, foreign tissue from other blast victims. Furthermore, regional vascular injury, tourniquet use, hemorrhagic shock, and persistent critical illness also diminish the capacity for wound healing and lead to disappointing evolution of the war wound. Therefore, avoid closure of wounds after the first washout or within the first 48 hours. Premature wound closure causes severe morbidity from necrotizing infection, often invisible on external exam until late in the process. Appendix A outlines the injury patterns and resulting physiology from weapons of war.

Surgeons should anticipate the need to frequently re-inspect and perform serial D&I on extensive soft tissue wounds.3 While there is not a strict guideline defining the time sequence of repeat D&I, a general rule is frequent inspections in the operating room (every 24 hours) until all non-viable tissue has been debrided while all other tissues are confidently viable. This prevents overly aggressive removal of questionably viable tissue at the early debridements while still aggressively addressing progression of necrosis. Once such wounds have stabilized with absence of nonviable tissue, inspections can be separated in time by 2 days or more until a final wound closure strategy is identified. Strategies include healing by secondary intent, delayed primary closure, split thickness skin graft, or tissue transfer. Patient movement decisions should be adapted to the requirements of surgical management – not the converse. When possible, ensure that a planned D&I is done within 24 hours prior to patient movement to ensure the receiving team has adequate time to assess and schedule follow-on wound care. In general, leave the wound open until arrival at the definitive care facility.

It is recognized that unstable blast injury patients with multiple fragmentation injuries over much of their bodies may not be able to undergo thorough debridement of all wounds at initial operation; this can be due to instability, lack of resources, lack of personnel, or urgency of transfer. It is therefore important that extent and adequacy of what debridement has been done is documented to guide further treatment at receiving facilities.

Sharp surgical debridement is the mainstay of care for war wounds; irrigation is an adjunct, but in no way replaces debridement for removal of non-viable tissue in wounds. Meticulous sharp debridement using a scalpel and/or scissors should be a starting point for most wartime wounds. Assurance of hemostasis and removal of all nonviable skin, fat, fascia, muscle, and bone are essential to reduce the load of contamination and necrotic tissue prior to dressing application.4

The need for repeat serial inspection and wound debridement cannot be over-emphasized. Unstable blast injury patients with multiple fragmentation injuries may not receive thorough debridement of all wounds at initial operation due to resuscitation needs, lack of resources, lack of personnel, or urgency of transfer. Always document the extent and adequacy of debridement performed as well as debridements still required. When receiving a patient from a forward role of care within the first 24 hours of injury, urgent operative re-exploration of all wounds is a best practice. Pre-operative CT scan is an important adjunct to identify areas of radiopaque debris or soft tissue air. These serve as a signal for areas of occult injury, residual contamination or necrosis that guides the next debridement.

IRRIGATION

There are several acceptable devices available for wound irrigation. Simple bulb syringe irrigation and gravity irrigation are the preferred methods. Large bore gravity-fed tubing is favored for irrigations requiring large fluid volumes, such as those associated with contaminated open fractures. Cystoscopy tubing connected to a 3 liter saline bag is ideal for gravity irrigation of large or multiple wounds. Pulsatile jet lavage irrigation using a battery powered system is not associated with improved outcomes but increases expense, weight, and space.6,7 All methods of wound irrigation are adjuncts and not substitutes to sharp surgical debridement.

The current recommendations for volume of irrigation are as follows:

- 1-3 liters for small volume wounds.
- 4-8 liters for moderate wounds.
- 9 or more liters for large wounds or wounds with evidence of heavy contamination.

This takes into account that bacterial loads drop logarithmically with increasing volumes of irrigation. Depending on the environment and medical logistics support, the volume of sterile fluids may not be available. Normal saline, sterile water and potable tap water all have comparable efficacy and safety as irrigation solutions.8,9 The inclusion of irrigation fluid additives such as iodine, bacitracin or antibiotics is without proven benefit.7