Prevention of infection

All surgical procedures carry risks of infection. Thus, every operation must include all appropriate measures to reduce these risks.

For more details see a synopsis of J. Wesley Alexander, MD, ScD; Joseph S. Solomkin, MD; Michael J. Edwards, MD (2011) Updated Recommendations for Control of Surgical Site Infections. Annals of Surgery. 253(6):1082-10

• Perioperative antibiotics
• Nutritional support
• Temperature control
• Soft-tissue care
  • preservation of blood supply
  • hemostasis
  • debridement
  • tension-free wound closure

If the anticipated outcome of nonoperative treatment for a given fracture is poor enough to justify the risks of infection, and the surgeon selects operative treatment, then appropriate preventive measures must be taken. For all fracture surgery involving internal fixation, as well as exposure of the fracture site, perioperative antibiotics should be administered prior to incision, as they are an accepted means of reducing the risk of infection.
In some cases, surgery should be delayed, or modified, to address metabolic/physiologic abnormalities. In some cases, a less invasive initial, or definitive, treatment might be chosen. For instance, temporary external fixation prior to ORIF of a tibial pilon fracture (e.g.43-C). Or perhaps definitive external fixation rather than ORIF for a similar, but more severe, injury.
Lengthy operations increase the risk of infection. Preoperative planning helps the surgeon estimate surgical time and make alternative plans to reduce the duration of the procedure.
Intraoperative homeostasis (control of temperature and blood sugar, transfusion, if necessary, etc.) and postoperative support (nutrition, etc.) are additionally valuable ways of reducing chances of infection.

Open fractures need

• prompt diagnosis
• appropriate intravenous antibiotics
• meticulous debridement
• fracture stabilization
• early wound closure after debridement is adequate.

Bacterial contamination is almost always present with open fractures. Bacterial count, and infection rate, can be significantly reduced by prompt administration of intravenous antibiotics. Most infecting bacteria, except in very dirty wounds, are typical skin flora. A first generation cephalosporin (e.g. cefazolin) 1-2 grams/8 hours) is often used, except for patients with penicillin allergy. For more severe open-fracture wounds, add an aminoglycoside (e.g. gentamycin 80 mg/8-12 hours). If “barnyard” contamination is present, high-dose IV penicillin is usually added (e.g. 5 million-10 million units/24 hours).
Antibiotics for open fractures are an adjunct to debridement. They should begin as soon as the open fracture is diagnosed, but need be continued for only 2-3 days.

Debridement must be complete, thorough and aggressive.
Surgical debridement is the most important part of treating an open fracture. Adequate debridement is more important than avoiding a delay of several hours.
During debridement the surgical site should be thoroughly irrigated (several liters of fluid – optimally, balanced salt solution, without antibiotics) to reduce the bacterial population.
In cases with significant amounts of dead, or possibly ischemic, tissue, reoperation for additional debridement may be necessary.

Deciding what tissue to remove and what to retain is the essential challenge of debridement. This is best learned in the operating room from senior surgeons and by practice. Typical errors are failure to remove enough compromised tissue, or to do so in a way that injures what remains.
Take an organized approach that precedes in orderly steps through tissue levels. First, enlarge the wound for adequate exposure. Only minimal non-viable wound margin need be excised. Define the depths of the wound, and examine it thoroughly. Protect blood vessels and nerves, tendon sheaths, healthy periosteum, and soft tissue attached to bone.
Next, all dead or significantly injured tissue is excised systematically according to tissue layer. At each level, leave only clearly viable tissue:

• subcutaneous tissues
• fascia
• muscle
• bone

Any free bone fragments should be removed. Contaminated or non-viable bone surfaces will also need excision with hand or power instruments.
Abundant irrigation helps to remove bacteria, bits of dead tissue and blood clot, and improves the surgeon’s ability to examine the wound.

When an open fracture communicates with a joint, special surgical tactics are required. As always, all devitalized tissue must be removed. Joint surfaces should not be allowed to become dry. If possible, the open joint itself should be closed primarily. If this is not possible, the joint must be kept clean and moist (moisture-retaining dressing). Early definitive closure should be planned.

-> Protect open joints from drying (close, or dress appropriately)

Open fractures need:

• Surgical fixation, usually external
• Consider delayed definitive ORIF

Bone stability helps the open fracture wound recover by providing the best possible setting for soft-tissue healing and resistance to infection. Surgical fixation, external, or internal, is the best way to stabilize an open fracture. This is done after adequate debridement.
For lower-grade open fractures, use fixation that would be appropriate for similar closed injuries. For severe open fractures, or wounds that need repeated debridement, external fixation is usually better.
Intramedullary nailing may be optimal fixation for femoral or tibial diaphyseal fractures. If this must be delayed (significant wound contamination, etc.), brief temporary external fixation can be used for initial stabilization.

• After debridement complete
• Delayed closure safer for contaminated wound
• Watch for infection; treat promptly

After debridement has been satisfactorily completed, in one or several procedures, consideration must be given to choosing the best means of wound closure. Excessive skin tension interferes with wound healing. Furthermore, a contaminated wound is more likely to become infected with primary closure. Temporary open wound management with delayed primary closure is thus often the safest approach for significant open fractures. However, with low-energy fractures and benign wounds, immediate wound closure can be considered.
If primary closure is chosen, the surgeon must watch carefully for signs of wound infection.
If closure is delayed, it should be completed as soon as possible to minimize the risk of nosocomial infection.

• Avoid contamination
• Avoid dessication
• Consider special dressing
  • Antibiotic bead pouch
  • Vacuum-assisted closure
• Close promptly

An open wound needs to be protected from contamination. A sealed dressing (e.g. antibiotic bead pouch or vacuum-assisted wound closure device) can be used. Vacuum-assisted wound closure helps reduce the size of an open wound and promotes granulation tissue. It may permit early split-thickness skin grafting.
Closure with local or free flaps is typically appropriate for larger and more complicated wounds, as soon as staged debridement is complete.
It is important to close a complex wound promptly rather than leave it open and risk superinfection.

Some extremity injuries are so severe that amputation is a better option than limb salvage. In fact, efforts at salvage may be doomed to failure, with risk of life-threatening complication, particularly infection.
The decision to amputate or save a severely injured limb is one of the most controversial in the field of trauma care. It is essential to begin with awareness that a truly mangled extremity is a life-threatening injury. The patient’s ability to tolerate injury and extensive treatment must be considered. Limb salvage usually requires multiple operations, prolonged hospitalizations, and frequently results in serious complications. Awareness of the risks of limb salvage helps moderate the surgeon’s desire to save a limb at any cost. Appropriate primary amputation usually results in a wound which heals satisfactorily, effectively preventing infection.

Whenever possible, options and outcomes must be discussed with the patient and/or family at an early stage, before amputation, or before setting out on a complex, prolonged and hazardous path of reconstruction.
Since prostheses are generally more functional replacements for lower than upper extremities, additional risks may be worth considering to save a severely-injured upper extremity.

Intraoperative wound contamination
A key principle of safe surgical treatment is to minimize the number of bacteria that might enter the surgical wound. Appropriate preoperative skin decontamination with washing and antibacterial agents is a mainstay for this. Similarly, use of sterile drapes, instruments and implants, and the maintenance of sterility throughout the procedure are also important. In the absence of optimal sterility, only the most limited emergency surgery should be carried out (e.g. emergency debridement of an open fracture).

Perioperative antibiotics
Intravenous antibiotics, given within the hour before surgery, significantly reduce the incidence of operative wound infection. Typically, infections are due to skin flora entering the wound. Thus the appropriate antibiotic is one that targets the typical skin flora. In many countries, a first-generation cephalosporin is selected (e.g. Cefazolin 1-2 grams, repeated during longer cases). Alternative agents may be selected to cover other bacteria, or in case of allergy.
Perioperative antibiotics should be given briefly, to avoid selection of antibiotic-resistant bacteria. A period of 24 hours, or less, is sufficient.

Poor nutrition
Nutritional supplements, vitamin supplements and other forms of nutritional support should be considered prior to elective surgery, and instituted as soon as possible after emergency surgery.
Malnourished patients have difficulty healing wounds and resist infection. Simple screening tests, such as total lymphocyte count (< 1200), or serum albumen level (less than 3.4gm/deciliter) with a careful dietary history and physical exam help to identify patients with inadequate nourishment. If possible, severe malnutrition should be corrected before elective fracture surgery.

Wound hematomas
Continued bleeding with accumulated hematoma increases the risk of infection. This is particularly true with continuing wound drainage, which may be bloody or serous. Thus the surgeon should obtain hemostasis with care, consider suction drainage of selected wounds, and observe the patient carefully for persistent drainage. Should drainage continue, wound exploration and hematoma evacuation should be considered to stop the drainage and promote wound healing. This is done in the operating room under sterile conditions. Always obtain cultures from the wound depths since bacterial colonization may have occurred and should be treated with specific antibiotics.

Impaired wound healing
If benign progressive wound healing does not occur, risk of infection steadily increases. Debridement of ischemic or necrotic skin edges and subcutaneous tissue should be done promptly, and healthy wound coverage achieved with suture closure, or flaps, as needed. Prompt closure of such a wound is the best means of avoiding infection.

Temperature control
Should a patient’s core temperature fall below normal during surgery, his risk of infection becomes greater. Thus, every effort must be made to minimize intraoperative heat loss with appropriate covers and external warming devices.

Bacterial carrier states
Some patients have skin colonization of particularly virulent and antibiotic-resistant bacteria such as methicillin-resistant S. aureus (MRSA). These are typically carried in the nares. Screening cultures permit identification of such carriers prior to elective surgery and treatment with antibacterial ointment, and skin cleansers can significantly reduce the risk of infection.
Alternatively, for patients at significant risk of MRSA colonization, consider use of vancomycin for perioperative prophylaxis.