Wound Infections The results of a prospective study of more than 62,000 wounds were revealing in regard to the epidemiology of wound infections (97). The wound infection rate varied markedly, depending on the extent of contamination of the surgical field. The wound infection rate for clean surgical cases (infection not present in the surgical field, no break in aseptic technique, no viscus entered) was lower than 2%, whereas the incidence of wound infections with dirty, infected cases was 40% or higher. Preoperative showers with hexachlorophene slightly lowered the infection rate for clean wounds, whereas preoperative shaving of the wound site with a razor increased the infection rate. A 5-minute wound preparation immediately before surgery was as effective as preparation for 10 minutes. The wound infection rate increased with the duration of preoperative hospital stay and with the duration of surgery. Incidental appendectomy increased the risk of wound infection in patients undergoing clean surgical procedures. The study concluded that the incidence of wound infections could be decreased by short preoperative hospital stays, hexachlorophene showers before surgery, minimizing shaving of the wound site, use of meticulous surgical technique, decreasing operative time as much as possible, bringing drains out through sites other than the wound, and dissemination of information to surgeons regarding their wound infection rates. A program instituting these conclusions led to a decrease in the clean wound infection rate from 2.5% to 0.6% over an 8-year period. The wound infection rate in most gynecologic services is lower than 5%, reﬂective of the clean nature of most gynecologic operations.
The symptoms of wound infection often occur late in the postoperative period, usually after the fourth postoperative day, and may include fever, erythema, tenderness, induration, and purulent drainage. Wound infections that occur on postoperative days 1 through 3 are generally caused by streptococcal and Clostridia infections. The management of wound infections is mostly mechanical and involves opening the infected portion of the wound above the fascia, with cleansing and debridement of the wound edges as necessary. Wound care, consisting of debridement and dressing changes two to three times daily with mesh gauze, will promote growth of granulation tissue, with gradual filling in of the wound defect by secondary intention. Clean, granulating wounds can often be secondarily closed with good success, shortening the time required for complete wound healing.
The technique of delayed primary wound closure can be used in contaminated surgical cases to lower the incidence of wound infection. This technique involves leaving the wound open above the fascia at the time of the initial surgical procedure. Vertical interrupted mattress sutures through the skin and subcutaneous layers are placed 3 cm apart but are not tied. Wound care is instituted immediately after surgery and continued until the wound is noted to be granulating well. Sutures may then be tied and the skin edges further approximated using sutures or staples.
Using this technique of delayed primary wound closure, the overall wound infection rate is decreased from 23% to 2.1% in high-risk patients (98).