Parameters	Factors to Consider
Mechanism of injury	Sharp vs. blunt trauma, bite
Dirty vs. clean	Outdoors vs. kitchen sink
Time since injury	Suture up to 12 h; 24 h on face
Foreign body	Explore and obtain radiograph for metal or glass
Functional examination	Neurovascular, muscular, tendons
Need for prophylactic antibiotics	If needed, give ASAP and cover Staphylococcus aureus; irrigate well

In general, antibiotics are not needed for either wound or subacute bacterial endocarditis (SBE) prophylaxis for cutaneous procedures ¹ (see Chapter 1). Consideration should be given to coverage for Staphylococcus aureus and MRSA infection in several situations.

The following are major goals for prescribing antibiotics before or after skin surgery:

1. Prevention of a new wound infection

2. Prevention of the spread of an existing local infection

3. Treatment of an existing infection

4. Prevention of bacterial endocarditis.

The clinical decision-making process of whether or not to use antibiotics before or after skin surgery is complex. The physician must consider host factors, the anatomic location of the surgery, the sources that might contaminate the wound, and method of wound injury. The multiple factors to be considered when making a decision about antibiotic prophylaxis for skin procedures are:

Coexisting Conditions

• Diabetes mellitus

• Peripheral vascular disease

• Frail elderly patients

• Immunocompromised

• Previous radiation to the site

• Malnutrition (e.g., alcoholism, chemotherapy)

• History of previous infection or slow healing

• Chronic steroid use

• Morbid obesity.

Locations

• Axilla, mouth and anogenital areas have higher levels of bacterial colonization

• End arterial locations (fingers, toes) with diseases of vascular compromise

• Over joint spaces where there is a possibility of entering joint (e.g., metacarpal-phalangeal joints).

Contamination

• Dirty wounds, especially barnyards, meatpacking plants, etc.

• Less than optimal sterile technique (should be rare)

• Deep puncture wounds

• Bites (especially human and cat bites)

• Presence of a retained foreign body.

Method of Wound Injury

• Crush injury (10-fold increase in infection) with devitalized skin

• Penetrating injury.

The recommendations of the American Heart Association (AHA) for the prevention of bacterial endocarditis were last published in 2007 and are discussed in Chapter 1.¹ Endocarditis prophylaxis is not needed for incision or biopsy of surgically scrubbed noninfected skin no matter what endocarditis risk factors are present. The 2007 guidelines state that antibiotic prophylaxis is recommended for procedures on infected skin and skin structures for patients with underlying cardiac conditions associated with the highest risk of adverse outcome from infective endocarditis (see Chapter 1, Box 1-2 and Table 1-3).¹

Cummings et al. performed a meta-analysis of randomized studies on the use of antibiotics to prevent infection of simple wounds.² They concluded that there is no evidence in published trials that prophylactic antibiotics offer protection against infection of nonbite wounds in patients treated in emergency departments. However, prophylactic antibiotics did reduce the incidence of infection in patients with dog-bite wounds in another meta-analysis.³ The authors concluded that it may be reasonable to limit prophylactic antibiotics to patients with dog-bite wounds that are at highest risk for infection.³

Controversy exists over which bite injuries should be treated with prophylactic antibiotics. Cat- and dog-bite injuries carry the risk of infection with Pasteurella multocida, and human-bite injuries carry the risk of infection with Eikenella corrodens and S. aureus. Based on the microbiology of these wounds, amoxicillin/clavulanate provides good prophylactic coverage for the bacteria affecting most bite injuries. Alternatives include second-generation cephalosporins or clindamycin with a fluoroquinolone.

Antibiotics have a role in the treatment of many established skin infections. However, most skin abscesses are better treated with incision and drainage rather than with antibiotics. For skin procedures of infected skin, no specific evidence exists as to whether to give an antibiotic and the appropriate timing for its administration. Recommendations for timing before the procedure vary from 1 hour (which is typical timing for bacterial endocarditis prophylaxis) to within 30 minutes of the procedure. Whereas a single second dose 6 hours later was the standard in the past, it is no longer currently recommended for bacterial endocarditis prophylaxis but may be advocated for further treatment of the infection.

The best method for prevention of wound infections is to clean and irrigate traumatic wounds well, rather than relying on prophylactic antibiotics. The physician needs to weigh the benefits and the risks of antibiotic use based on the individual patient and the circumstances of the wound repair or skin surgery.

Local and Regional Anesthesia

In traumatic wounds, neurovascular integrity should be assessed prior to administration of anesthesia. The wound should then be fully anesthetized to allow for painless examination of the tissue damage, thorough irrigation, and adequate closure. Many wounds can be adequately anesthetized with 1% or 2% lidocaine. Consider using lidocaine with epinephrine to provide increased hemostasis if there are no contraindications to epinephrine use in the patient, the location, or the wound itself (see Chapter 3, Anesthesia). Topical anesthetics are effective for wounds that do not involve mucosal surfaces. A combination of lidocaine, epinephrine, and tetracaine (LET) applied with a saturated cotton ball or as a gel formulation directly into the wound provides adequate anesthesia for many wounds.^4,⁵

Regional anesthesia may be desirable in cases where the volume of locally infiltrated anesthesia might exceed the safe maximum dosage (see Chapter 3, Table 3-3) or in cosmetically important areas where a local infiltration might distort the anatomy to impair a meticulous closure. If a regional anesthetic technique is employed, lidocaine without epinephrine is the optimal choice, because epinephrine’s role as a vasoconstrictor is not needed at a site remote to the traumatic wound.

Follow these instructions to minimize the pain of injecting local anesthetic:

• Use a small-gauge needle (27 or 30 gauge).

• Inject slowly.

• Inject directly into the dermis through the open wound (not through intact skin).

• Warm anesthetic to body temperature (optional).

• Buffer the anesthetic with sodium bicarbonate (1 mL bicarbonate for .9 mL lidocaine) (optional).

Wound Preparation

After the initial assessment and administration of local or regional anesthetic, and antibiotics if indicated, wounds should be inspected thoroughly for foreign bodies, deep tissue layer damage, and injury to nerve, vessel, or tendon. Underlying bone or joint injury should be considered in wounds sustained as a result of traumatic force. A radiograph should be obtained to look for retained glass or metal in wounds sustained from broken glass or metal and to assess for joint integrity or fractures in traumatic injuries. Complex wounds or those in cosmetically important areas should be closed by a practitioner with the appropriate expertise.

Determine If the Wound Needs Intervention to Close

One study assessed the difference in clinical outcome between lacerations of the hand closed with sutures and those treated conservatively.⁶ Consecutive patients with uncomplicated lacerations of the hand (full thickness < 2 cm; without tendon, joint, fracture, or nerve complications) who would normally require sutures were randomized to suturing or conservative treatment. The mean time to resume normal activities was the same in both groups (3.4 days). Patients treated conservatively had less pain and treatment time was 14 (10 to 18) minutes shorter. The groups did not differ significantly in the assessment of cosmetic appearance on the visual analogue scale. Conservative treatment was faster and less painful.⁶