How To Address Post-Op Infections In Patients With Diabetes
Given the elevated risk of surgical site infections in patients with diabetes, increased vigilance is crucial. This author discusses risk factors that can lead to post-op infections, keys to diagnosis and pertinent pearls on effective treatment.
The successful treatment of surgical site infections (SSIs) in patients with diabetes mellitus can prove challenging to clinicians. The SSI rate following elective, clean foot and ankle surgery in the non-diabetic patient is relatively low at less than 2.1 percent, according to the Centers for Disease Control and Prevention (CDC).1 Recent study data suggests, however, that patients living with diabetes have about a fivefold increased risk for developing a severe infection postoperatively in comparison to patients without diabetes.2
This is significant. Clinicians who are involved in the surgical care of patients with diabetes must adequately understand the risks and distinctive challenges posed by this patient population.
Lower extremity infection in the patient with diabetes is a major risk factor for non-traumatic limb loss. Nearly 83 percent of all non-traumatic lower extremity amputations (LEA) in the United States are secondary to complications associated with diabetes mellitus. It has been well documented in the literature that the consequences of major LEA in patients with diabetes are severe with an estimated five-year postoperative survival rate of less than 50 percent.3 This suggests that mortality associated with diabetic LEAs exceeds that of most cancers.
Furthermore, studies have demonstrated that nearly 77 percent of the deaths of surgical patients were related to the development of SSI.3 It is vital, therefore, that clinicians involved in surgery be appropriately qualified to manage these complications to reduce potential patient morbidity and mortality.
Prior to detailed discussion regarding SSI, it is important that the clinician have a full understanding regarding the terminology utilized to describe these postoperative complications. Surgical site infections have a wide spectrum of possible clinical features and there have consequently been several attempts to classify these infections based upon salient clinical features.
Perhaps the most appropriate definitions have been proposed by the CDC following attempts to standardize data collection for the National Nosocomial Infection Surveillance (NNIS) program.1 This program classifies infection into incisional infections, which can be superficial or deep, or organ/space infections, which affect the rest of the body other than the body wall layers.
Superficial incisional infections involve skin and subcutaneous layers while deep incisional infections involve deeper structures, such as fascial and muscle layers. Organ/space infections can be either superficial or deep, and involve any anatomy, other than the incision site, which the surgeon manipulated during the surgical procedure. An example of this in lower extremity surgery would be pin site placement in the use of external fixation. Superficial incisional infections account for more than half of all SSI for all categories of surgery.1
What Are The Risk Factors For Infection?
The frequency of SSI is clearly related to the category of operation one is performing. The NNIS defines clean and low-risk operations as having the lowest rate of infection, and contaminated and high-risk operations having greater infection rates.1 In addition to the category of surgery, there are numerous factors that combine to increase the risk of postoperative infections. These factors include: