Sat., 10/6/12 General Interest, PAPER #100, 1:44 pm OTA-2012
Rapid Polymerase Chain Reaction Test for Methicillin-Resistant Staphylococcus aureus in Orthopaedic Trauma
Holman Chan, MD; John P. Ketz, MD; Catherine A. Humphrey, MD; Jonathan M. Gross, MD; Robert F. Betts; John T. Gorczyca, MD;
University of Rochester Medical Center, Rochester, New York, USA
Purpose: This study was conducted to (1) evaluate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonization in orthopaedic trauma patients; (2) identify risk factors for MRSA colonization in orthopaedic trauma patients; and (3) implement rapid polymerase chain reaction (PCR)-MRSA amplification to guide appropriate perioperative antibiotic prophylaxis. We hypothesized that the prevalence of MRSA colonization is higher than reported in earlier literature and that there are identifiable risk factors in patient medical, surgical, and social history that predispose this select population. We also hypothesized that rapid PCR testing can be consistently implemented to help modify perioperative antibiotic prophylaxis.
Methods: Adult patients with a surgical orthopaedic injury admitted to a Level I trauma hospital were swabbed for a nasal specimen. This was then tested for MRSA colonization via a rapid PCR-MRSA amplification test validated for its efficient turnover compared with that of bacterial culture (4 hours versus 2 days, respectively). Patients who test positive as an MRSA carrier had their perioperative antibiotic prophylaxis adjusted to treat MRSA. Medical history for each patient was reviewed for age, gender, preexisting medical/surgical conditions, recent antibiotic use, and remote history of cancer and infection. Social history was reviewed for recreational drug use and recent exposure to the institutionalized and/or to medical personnel. Multivariate binary logistic regression was performed to identify risk factors associated with MRSA colonization.
Results: 326 consecutive patients with surgical orthopaedic injuries were admitted to the Level I academic trauma center and tested with rapid PCR during the study period. Of these 326 patients, 25 patients (7.7%) tested positive as MRSA carriers. 19 of the 25 patients (76%) had their perioperative antibiotics adjusted to vancomycin. Three of five (60%) patients with previous documented MRSA infections tested positive for MRSA colonization in this study. The two most significant adjusted risk factors for MRSA colonization are current infection (odds ratio [OR] 19.5; 95% confidence interval [CI], 1.62-234) including urinary tract infections, cellulitis, and deep wound infections; and gastrointestinal conditions (OR 4.83; 95% CI, 1.31-17.8), including gastroesophageal reflex disease, gastrointestinal ulcers, and colitis. Other independent risk factors include obesity (OR 8.07; 95% CI, 1.81-36.0), previous exposure to the institutionalized and/or to medical personnel (OR 4.03; 95% CI, 1.47-11.0), chronic illness (OR 3.87; 95% CI, 1.68-8.92), diabetes mellitus (OR 3.79; 95% CI, 1.6-8.97), and the presence of medical implant such as a pacemaker, prosthetic joint reconstruction, or fracture fixation (OR 3.25; 95% CI, 1.41-7.51). Contrary to the results of certain other studies, age and recent antibiotic use did not demonstrate significant correlation with MRSA colonization in this study population.
Conclusions: The preliminary results of this study suggest a higher prevalence of MRSA colonization in orthopaedic trauma patients encountered in this institution at 7.7% relative to the documented 3% to 5% in earlier literature. Rapid PCR amplification testing for MRSA can be instituted to direct appropriate perioperative antibiotic prophylaxis.
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• The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an “off label” use). ◆FDA information not available at time of printing. Δ OTA Grant.