How To Prevent Postoperative Infection
Postoperative infection following elective, clean foot and ankle surgery is relatively uncommon. The Centers for Disease Control and Prevention (CDC) reports the surgical site infection (SSI) rate to be 2.1 percent for clean, uncontaminated surgery.1 However, when postoperative infection does occur, it may affect functional outcomes and the patient’s quality of life.
The incidence of infection varies from one surgical procedure to another and from patient to patient.2 Infection rates increase in complicated reconstructive surgery, types of diabetic foot surgery, open fractures and traumatic wounds.3-5 There are a few critical factors to consider when discussing SSIs and they include patient factors, pathogen factors, surgeon factors and environmental factors. Accordingly, it is important to have a strong understanding of these key factors as well as a solid grasp of techniques to help reduce the risk of postoperative infections.
There are many host factors that may potentially heighten the risk of postoperative infections.
Malnutrition, advanced age, obesity, smoking and uncontrolled diabetes are all independent risk factors for developing a postoperative infection. Malnutrition lowers host defenses and compromises the immune system, thus predisposing the patient to infection. Older patients generally have many comorbidities and researchers have shown that increased age is a factor for increased risk of postoperative SSIs.6
Research has shown that smoking significantly increases the risk of SSIs. Sorenson, et al., found the optimal abstinence period required in heavy smokers to reduce the risk of SSIs was four weeks.7 The physician should counsel patients and offer cessation treatment during the preoperative phase.
People with uncontrolled diabetes are at increased risk for SSI. Hyperglycemia negatively affects neutrophilic responses to infection and studies have shown that perioperative plasma glucose levels above 220 mg/dl increase the risk of surgical site infections.8,9 One should monitor these patients closely for glycemic control. At times, these at-risk patients may present with an ulceration preoperatively, complicating the matter even further.
Any systemic disease that compromises the host defense against a pathogen will place an individual at risk for a SSI. Recognizing at-risk patients before embarking on surgery is paramount to successful management during the perioperative period.
Recently, there has been increasing interest in various surgical techniques for the treatment of the diabetic foot. With this in mind, researchers proposed and later validated a diabetic foot surgery classification system.4,10
This classification system was designed to assist the surgeon in assessing risk when determining a rationale for foot and ankle surgery in this high-risk population. This system included class 1 (elective), class 2 (prophylactic), class 3 (curative) and class 4 (emergency) surgery. There is an increase in postoperative infection with each increasing class of foot surgery.4
What You Should Be Aware Of With Open Fractures
Open fractures carry a greater risk for infection and are considered contaminated. In these cases, antibiotic use is deemed therapeutic as opposed to prophylactic.5 Early antibiotic therapy is critical to achieving successful outcome in these patients. Physicians should direct antibiotic selection toward aerobic gram-positive cocci and increased gram-negative coverage for type II and type III fractures. Patzakis and Wilkins found that the administration of preoperative antibiotics was the most important factor in determining the rate of postoperative infection in open fractures.11
Also vital in the treatment of open fractures are adequate debridement, copious irrigation and skeletal stabilization. Strict adherence to these basic principles and guidelines can reduce the risk of complications and prevent damaging postoperative infections.