番茄社区

ORLANDO -- Patients with diabetes, immunosuppression, and renal insufficiency are at increased risk of nasal colonization with Staphylococcus aureus and surgical site infection following joint replacement, a retrospective study showed.

The rate of diabetes among patients with nasal colonization with S. aureus was 25.36% compared with 17.61% in uncolonized patients (P=0.04), according to , a second-year resident at Mount Sinai Medical Center in New York City.

And the rates of immunosuppression for colonized patients and uncolonized patients were 12.32% versus 6.48% (P=0.02), while the rates of renal insufficiency were 6.52% and 2.43%, respectively (P=0.03), she reported at the here.

"About 20% to 30% of the U.S. population has positive nasal swabs for S. aureus preoperatively in both the orthopedic and non-orthopedic literature, and this is an established risk factor for postoperative surgical site infection," she said.

"Furthermore, it's been well documented that preoperative screening and decolonization as appropriate reduce the number of surgical site infections."

However, the risk factors for colonization have not been fully characterized, so she and her colleagues conducted a retrospective review of patients at their institution who underwent total hip or knee replacement during the years 2011 to 2015, identifying 716 who had nasal swab results.

The overall rate of S. aureus nasal colonization was 19.27%, and the rate of colonization for other organisms was 11.70%.

Immunosuppression was defined as being on chronic immunosuppressive therapy for a solid organ transplant or on chronic corticosteroids for an autoimmune disease. Renal insufficiency was defined as either chronic kidney disease or end stage renal disease.

In a bivariate analysis, predictors of nasal colonization with S. aureus were diabetes (P=0.04), renal insufficiency (P=0.03), and immunosuppression (P=0.02), while predictors for colonization with other bacteria were smoking (P=0.02) and immunosuppression (P=0.001).

In multivariate analysis, independent predictors for S. aureus colonization were immunosuppression (OR 1.95, 95% CI 1.03-3.71, P=0.04) and renal insufficiency (OR 2.49, 95% CI 1.01-6.18, P=0.04), Walsh and colleagues found.

And independent predictors for colonization with other organisms were smoking (OR 1.77, 95% CI 1.10-2.88, P=0.02) and immunosuppression (OR 2.95, 95% CI 1.45-5.86, P=0.01), she reported.

In conclusion, patients with diabetes, immunosuppression, and renal insufficiency are at increased risk of S. aureus colonization and therefore should be screened preoperatively. "This is particularly important because these population subsets are more predisposed to infection and also have a harder time fighting off infection," she said. "While this might not make a difference for clinicians who are globally screening all of their patients, it certainly might encourage people who don't screen all to at least screen these subsets."

One of her co-authors, , chief of adult reconstruction and joint replacement at Mount Sinai Hospital, added: "The main message of the study is that staph screening and decolonizing is an important infection-prevention modality.

"We realize that not all surgeons who perform joint replacement have the resources to do this on every patient, but this study has identified high-risk patients where the focus on screening and decolonization should be emphasized," he told 番茄社区.

Walsh said that in the future, it might be worthwhile to think about how these comorbidities and risks for S. aureus might influence bundled interventions: "Should we take this into account? And how can we make this work to our advantage from a cost-effectiveness standpoint?"

Limitations of the study were its retrospective design and single-center setting. "However, our institution is a large, urban academic medical center with a very diverse patient population," she noted.

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