Surgical Site Infections

• • Postoperative wound infections resulting from bacterial contamination during or after a surgical procedure

  • Infection usually is confined to the subcutaneous tissues

  • Site infections are more likely if:

  • -Excessive tissue trauma

    -Undrained hamartomas

    -Retained foreign bodies

    -Excessively tight ligatures

    -Allowing wound to become desiccated

    -Contaminated

    -Poor perfusion

    -Poor oxygenation

    -Dead space

  • Degree of intraoperative contamination can be divided into 4 categories which correlate with risk of postoperative wound infection

  • 1. Clean: No gross contamination from exogenous or endogenous sources

    2. Clean-contaminated: For example, with gastric or biliary surgery

    3. Heavily contaminated: Operations on the unprepared colon or emergency operations for intestinal bleeding or perforation

    4. Infected

  • Classification of surgical site infection:

  • -Incisional: Superficial (skin and subcutaneous tissues) and deep incisional (deep soft tissue of the incision)

    -Organ/space infection: Any part of the anatomy other than body wall

  • Wound infections usually appear between the fifth and tenth postoperative days, but they may appear as early as the first postoperative day

Epidemiology

• • Surgical site infections are the third most frequently reported nosocomial infection, accounting for 14-16% of all nosocomial infections in acutely hospitalized patients

  • Among surgical patients, surgical site infections are the most frequent nosocomial infections, accounting for 38% of the total

  • Infection rate per degree of contamination:

  • -Clean: 1.5%

    -Clean-contaminated: 2-5%

    -Heavily contaminated: 5-30%

    -Infected: 100%

  • Patient risk factors include:

  • -Diabetes mellitus

    -Nicotine use

    -Corticosteroids

    -Malnutrition

    -Poor hygiene

Symptoms and Signs

• • Fever

  • Erythema

  • Pain

  • Swelling, induration

  • Palpation of the wound may disclose an abscess

  • Palpation may reveal areas of firmness, fluctuance, crepitus, or tenderness

  • Drainage from the wound may be free flowing or expressible

Laboratory Findings

• • Leukocytosis

  • Increased ESR and C-reactive protein (CRP)

  • Bacteremia in complex deep wound infections

  • Wound culture may reveal source of infection

Imaging Findings

• • Imaging may reveal abscess, soft-tissue swelling/edema, subcutaneous air (US or CT)

• • Differential diagnosis includes all other causes of postoperative fever

  • -Atelectasis

    -Urinary tract infection

    -Deep venous thrombosis

    -Medications

  • Wound dehiscence

  • Wound herniation

  • Necrotizing infection

  • Drug reaction

Rule Out

• • Necrotizing wound infection (high fever early postoperative, crepitus)

• • Postoperative fever requires inspection of the wound

  • Palpation of the wound may disclose an abscess

  • Palpation may reveal areas of firmness, fluctuance, crepitus, or tenderness

  • Culture should be performed to help locate the source

  • Culture blood, urine, sputum to evaluate for other sources of fever and infection

  • Ensure adequate oxygenation/perfusion status

When to Admit

• • High fever, sepsis, dehydration

  • Failure to respond to opening of wound and/or oral antibiotics

  • Need for operative drainage

• • Mild superficial wound infections may be treated successfully ...