Faculty Bibliography

Higher PJI rates may be related to identifiable risk factors, which may or may not be modifiable. Identifying risk factors preoperatively provides opportunities for modification and potentially decreasing the incidence of PJI. The purposes of this study were to: (1) retrospectively identify and quantify risk factors for PJI following primary TKA, and (2) to classify those significant risk factors as either non-modifiable or modifiable for intervention prior to surgery. Optimization of modifiable risk factors such as Staphylococcus aureus colonization, and tobacco use prior to primary TKA may decrease the incidence of periprosthetic joint infection after primary TKA, thereby reducing morbidity and the costs associated with treating those infections.

Accurate documentation of the use of invasive devices, such as urinary and central line catheters, is important to track potential catheter-associated infections. Real-time identification of device infections allows practitioners to initiate timely apparent-cause analyses, therefore allowing rapid improvement of practice. For this reason, it was crucial to ensure our institution's mechanism to capture possible catheter-associated infections is validated after the adoption of a new electronic medical record system.

The routine use of amoxicillin antibiotic prophylaxis prior to dental procedures for patients with total joint prostheses in place remains controversial. This analysis shows that the practice may not be cost-effective for patients in whom the risk of infection with dental work is low. However, specific data quantifying the risk and the impact prophylactic antibiotics can have is needed. Patients and physicians will need to continue to consider their use on an individual basis and should consider the risk of infection as well as the risk of adverse drug reaction when making treatment decisions.

BACKGROUND: Periprosthetic joint infections (PJIs) are associated with increased morbidity and cost. It would be important to identify any modifiable patient- and surgical-related factors that could be modified before surgery to decrease the risk of PJI. QUESTIONS/PURPOSES: We sought to identify and quantify the magnitude of modifiable risk factors for deep PJIs after primary hip arthroplasty. METHODS: A series of 3672 primary and 406 revision hip arthroplasties performed at a single specialty hospital over a 3-year period were reviewed. All deep PJIs were identified using the Centers for Disease Control and Prevention case definitions (ie, occurs within 30-90 days postoperatively, involves deep soft tissues of the incision, purulent drainage, dehiscence and fever, localized pain or tenderness). Univariate and multivariate analyses determined the association between patient and surgical risk factors and PJIs. For the elective patients, the procedure was performed on the day of admission ("same-day procedure"), whereas for the fracture and nonelective patients, the procedure was performed 1 or more days postadmission ("nonsame-day procedure"). Staphylococcus aureus colonization, tobacco use, and body mass index (BMI) were defined as patient-related modifiable risk factors. RESULTS: Forty-seven (1.3%) deep PJIs were identified. Infection developed in 20 of 363 hips of nonsame-day procedures and 27 of 3309 same-day procedures (p = 0.006). There were eight (2%) infections in the revision group. After controlling for confounding variables, our multivariate analysis showed that BMI >== 40 kg/m2 (odds ratio [OR], 4.13; 95% confidence interval [CI], 1.3-12.88; p = 0.01), operating time > 115 minutes (OR, 3.38; 95% CI, 1.23-9.28; p = 0.018), nonsame-day surgery (OR, 4.16; 95% CI, 1.44-12.02; p = 0.008), and revision surgery (OR, 4.23; 95% CI, 1.67-10.72; p < 0.001) are significant risk factors for PJIs. Tobacco use and S aureus colonization were additive risk factors when combined with other significant risk factors (OR, 12.76; 95% CI, 2.47-66.16; p = 0.017). CONCLUSIONS: Nonsame-day hip and revision arthroplasties have higher infection rates than same-day primary surgeries. These characteristics are not modifiable and should be categorized as a separate cohort for complication-reporting purposes. Potentially modifiable risk factors in our patient population include operating time, elevated BMI, tobacco use, and S aureus colonization. Modifying risk factors may decrease the incidence of PJIs. When reporting deep PJI rates, stratification into preventable versus nonpreventable infections may provide a better assessment of performance on an institutional and individual surgeon level. LEVEL OF EVIDENCE: Level IV, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

INTRODUCTION: The indications for vancomycin prophylaxis to prevent Methicillin-resistant Staphylococcus aureus (MRSA) surgical site infections are increasing. The recommended dose of vancomycin has traditionally been 1 gram intravenous. However, the increasing prevalence of obesity in our population coupled with increasing resistance of MRSA to vancomycin has resulted in recent recommendations for weight-based dosing of vancomycin at 15mg/kg. We hypothesize that the standard one gram dose of vancomycin is inadequate to meet the recently recommended dosage of 15mg/kg. METHODS: We performed a retrospective chart review on 216 patients who were screened positive for MRSA prior to undergoing elective total joint or spine surgeries between January 2009 to January 2012. All patients were given 1 gram of vancomycin within an hour prior to surgical incision as prophylaxis. Using the revised dosing protocol of 15mg/kg of body weight for vancomycin, proper dosage was calculated for each patient. These values were then compared to the 1 gram dose given to the patients at time of surgery. Patients were assessed as either underdosed (a calculated weight-based dose >1 gram) or overdosed (a calculated weight-based dose <1 gram). Additionally, we used actual case times and pharmacokinetic equations to determine the vancomycin (VAN) levels at the end of the procedures. RESULTS: Out of 216 patients who tested positive for MRSA, 149 patients (69%) were determined to be underdosed and 22 patients (10%) patients were determined to be overdosed. The predicted VAN level at the end of procedure was <15 mg/L in 60% of patients with 1 gram dose compared to 12% (p=0.0005) with weight base dose. Six patients developed post-operative MRSA surgical site infections (SSI). Of these six patients; four had strains of MRSA with vancomycin minimum inhibitory concentration of >1.0mg/L. Based on 1g dosing, 5/6 patients with MRSA positive SSIs had wound closure levels of <15 mg/L and all six were <20 mg/L. CONCLUSION: In settings such as hospitals, where the risk for resistant bacteria, especially MRSA, is high, it is becoming increasingly important to accurately dose patients who require vancomycin. In order to avoid incorrect dosing of vancomycin health care providers must use weight-based dosing.

Piperacillin-tazobactam (PTZ) is frequently used as empirical and targeted therapy for Gram-negative sepsis. Time-dependent killing properties of PTZ support the use of extended-infusion (EI) dosing; however, studies have shown inconsistent benefits of EI PTZ treatment on clinical outcomes. We performed a retrospective cohort study of adult patients who received EI PTZ treatment and historical controls who received standard-infusion (SI) PTZ treatment for presumed sepsis syndromes. Data on mortality rates, clinical outcomes, length of stay (LOS), and disease severity were obtained. A total of 843 patients (662 with EI treatment and 181 with SI treatment) were available for analysis. Baseline characteristics of the two groups were similar, except for fewer female patients receiving EI treatment. No significant differences between the EI and SI groups in inpatient mortality rates (10.9% versus 13.8%; P = 0.282), overall LOS (10 versus 12 days; P = 0.171), intensive care unit (ICU) LOS (7 versus 6 days; P = 0.061), or clinical failure rates (18.4% versus 19.9%; P = 0.756) were observed. However, the duration of PTZ therapy was shorter in the EI group (5 versus 6 days; P < 0.001). Among ICU patients, no significant differences in outcomes between the EI and SI groups were observed. Patients with urinary or intra-abdominal infections had lower mortality and clinical failure rates when receiving EI PTZ treatment. We did not observe significant differences in inpatient mortality rates, overall LOS, ICU LOS, or clinical failure rates between patients receiving EI PTZ treatment and patients receiving SI PTZ treatment. Patients receiving EI PTZ treatment had a shorter duration of PTZ therapy than did patients receiving SI treatment, and EI dosing may provide cost savings to hospitals.

BACKGROUND: Treatment of Staphylococcus aureus colonization before surgery reduces risk of surgical site infection (SSI). The regimen of nasal mupirocin ointment and topical chlorhexidine gluconate is effective, but cost and patient compliance may be a barrier. Nasal povidone-iodine solution may provide an alternative to mupirocin. METHODS: We conducted an investigator-initiated, open-label, randomized trial comparing SSI after arthroplasty or spine fusion in patients receiving topical chlorhexidine wipes in combination with either twice daily application of nasal mupirocin ointment during the 5 days before surgery or 2 applications of povidone-iodine solution into each nostril within 2 hours of surgical incision. The primary study end point was deep SSI within the 3 months after surgery. RESULTS: In the modified intent-to-treat analysis, a deep SSI developed after 14 of 855 surgical procedures in the mupirocin group and 6 of 842 surgical procedures in the povidone-iodine group (P = .1); S. aureus deep SSI developed after 5 surgical procedures in the mupirocin group and 1 surgical procedure in the povidone-iodine group (P = .2). In the per protocol analysis, S. aureus deep SSI developed in 5 of 763 surgical procedures in the mupirocin group and 0 of 776 surgical procedures in the povidone-iodine group (P = .03). CONCLUSIONS: Nasal povidone-iodine may be considered as an alternative to mupirocin in a multifaceted approach to reduce SSI. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01313182.

Led by the federal government, the payers of health care are enacting policies designed to base provider reimbursement on the quality of care they render. This study evaluated and compared patient experiences and satisfaction with nasal decolonization with either nasal povidone-iodine (PI) or nasal mupirocin ointment (MO). A total of 1903 patients were randomized to undergo preoperative nasal decolonization with either nasal MO or PI solution. All randomized patients were also given 2% chlorhexidine gluconate topical wipes. Patients were interviewed prior to discharge to assess adverse events and patient experience with their assigned preoperative antiseptic protocol. Of the 1903 randomized patients, 1679 (88.1%) were interviewed prior to discharge. Of patients receiving PI, 3.4% reported an unpleasant or very unpleasant experience, compared with 38.8% of those using nasal MO (P<.0001). Sixty-seven percent of patients using nasal MO believed it to be somewhat or very helpful in reducing surgical site infections, compared with 71% of patients receiving PI (P>.05). Being recruited as an active participant in surgical site infection prevention was a positive experience for 87.2% of MO patients and 86.3% of PI patients (P=.652). Those assigned to receive PI solution preoperatively reported significantly fewer adverse events than the nasal MO group (P<.01). Preoperative nasal decolonization with either nasal PI or MO was considered somewhat or very helpful by more than two-thirds of patients.

The aging baby boomer generation will soon start using tremendous orthopedic surgical resources. This group has also been identified as a group at high risk for having undiagnosed hepatitis C virus (HCV) infection. We conducted a study to assess the prevalence of HCV among orthopedic surgery patients at our institution-using their demographic data to determine whether they represent a unique cohort at high risk for having undiagnosed HCV. We estimated that we operated on as many as 233 patients with undiagnosed HCV in 2011. A cost-effective, universal preoperative HCV screening program may reduce the risk for occupational exposure in orthopedic surgery and significantly benefit public health by bringing undiagnosed patients to treatment. A robust screening program requires several ethical considerations. By offering routine screening to patients, orthopedic surgeons have an opportunity to maintain intraoperative safety and improve the health of the public.