Removing bacteria via sound preoperative preparation is vitally important to help prevent postoperative infections, particularly in immunocompromised patients such as those with diabetes. A recent study in the Journal of Foot and Ankle Surgery investigates the potential of a "best evidence available" surgical preparation in this patient population.
The prospective study, the recipient of a 2006 American College of Foot and Ankle Surgeons Research Grant, involved 15 patients with diabetes undergoing elective foot and ankle surgery, and 15 patients with diabetic foot ulcerations. All patients had surgical preparation consisting of a chlorhexidine gluconate 4% scrub followed by painting with a topical solution of ethyl alcohol and 1% iodine. Researchers obtained qualitative aerobic cultures from the hallux nail fold; the second, third and fourth toe web spaces (as one culture); and the distal anterior tibia.
Prior to employing this surgical preparation, the study author cultured a total of 120 organisms. The most commonly isolated organism was methicillin-resistant Staphylococcus epidermidis (MRSE), which the study identified in 46 pre-preparation cultures (38.3 percent). The next most common organisms were methicillin-sensitive S. epidermidis (16.7 percent) and ‘‘other’’ organisms (10 percent), according to the study.
The study noted a "signi?cant reduction" in both the numbers of organisms identi?ed and positive cultures for the most commonly isolated organisms after surgical preparation. The study also noted that the surgical preparation appears to be effective for eradicating aerobic bacterial pathogens from the foot in patients with diabetes both with and without ulceration.
Thomas S. Roukis, DPM, PhD, the author of the study, notes that the study only evaluated patients with diabetes and either an intact or ulcerated/infected skin envelope. He also notes that the study only evaluated aerobic bacteria and not anaerobic bacteria, fungus, yeast or mold. Dr. Roukis says further research is required to determine if the preparation would be as efficacious in those without diabetes and for other pathogens.
Will Surgical Preparation Have To Evolve As Pathogens Evolve?
As pathogens become more resistant to antibacterials, Dr. Roukis advocates a greater emphasis on the mechanical exfoliant action of more specialized surgical brushes and a need for longer duration of the preparation to maintain effectiveness.
"The fact that this study demonstrated a high incidence of MRSE bacteria that persisted in some patients after the surgical preparation highlights the difficulty that exists in eradicating aerobic bacteria from the foot and ankle," says Dr. Roukis, who is Attending Staff at the Department of Orthopaedics, Podiatry and Sports Medicine at Gundersen Lutheran Medical Center in La Crosse, Wis.
In addition to surgical preparation, Dr. Roukis also emphasizes that surgeons follow proper hygiene practices. Routine use of a surgical preparation during outpatient or inpatient dressing changes can also decrease the development of postoperative infection and improve pedal hygiene, according to Dr. Roukis, a Fellow and member of the Board of Directors of the American College of Foot and Ankle Surgeons.