Mr. Smith is a 60-year-old man who recently underwent an elective open right hemicolectomy for an adenocarcinoma of the ascending colon. The case and postoperative course were unremarkable and he was discharged home on postoperative day number 4. The following day, however, he called your clinic to report subjective fevers, some increased discomfort around his incision, and new drainage from the wound. You instructed him to come to your clinic.
When he arrives, his vitals signs are T 101.4, HR 92, BP 135/85, RR 15, and O2 99% on RA. His abdominal exam is significant for a stapled midline laparotomy incision with new-onset erythema that extends approximately 3 to 4 cm laterally and inferiorly from the inferior one third of the wound. A small amount of yellow-tinged thin fluid is coming from between several of the staples. There is also a significant amount of this fluid on the dressing. Palpation reveals mildly increased superficial tenderness surrounding the inferior one third of the wound with no fluctuance or crepitus. There is no rebound tenderness and no guarding. The remainder of the physical exam is normal. You send some blood work, which reveals a white blood cell count of 11,400 cells/mm3.
1. If you know that this patient’s surgical incision was classified as “clean-contaminated,” what is the probability that he would develop a wound infection?
2. Name two other factors, besides the level of intraoperative contamination, which can modify the risk of surgical site infection (SSI)?
Postoperative Wound Complications
Wound classification is based on the degree of wound contamination. Consider the difference in exposure to bacterial load between an incision made for an inguinal hernia repair and an exploratory laparotomy for a penetrating abdominal trauma with numerous small bowel and colon injuries. In the former, proper sterile technique should essentially eliminate bacterial contamination from the surgical site. In the latter, however, bacterial contamination of the incision site secondary to gross spillage of stool into the abdomen is virtually inevitable, making the risk of postoperative wound infection considerably higher.
Wound classification is an important concept for any surgeon to understand, as it often drives clinical decision making. For example, wound classification is fundamental in deciding how or even if to close a wound at the end of a case. Additionally, classifying wounds based on their degree of contamination provides a mechanism for postoperative wound infection risk stratification. Such a tool makes it possible to maintain appropriate levels of suspicion for wound infection when evaluating a postoperative patient with a fever, leukocytosis, or peri-incisional erythema. For a description of the wound classification system most commonly used, see Table 51-1.
While the degree of contamination is one of the determining factors, it should be noted that there are multiple other factors that can influence the rate of SSIs. ...