Faculty Bibliography

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.

Data that can be used to guide perioperative antibiotic prophylaxis in our era of emerging antibiotic resistance are limited. We reviewed orthopedic surgeries complicated by surgical site infections (SSIs). Eighty percent of 69 arthroplasty and 80 spine fusion SSIs were infected with Gram-positive bacteria; most were staphylococcal species; and more than 25% of Staphylococcus aureus and more than 65% of coagulase-negative staphylococci were methicillin-resistant. Gram-negative bacteria were isolated from 30% of arthroplasty SSIs and 25% of spine fusion SSIs. Resistance to cefazolin was higher than 40%. A significant proportion of SSIs were caused by resistant organisms, and antibiotic guidelines were altered to provide more adequate surgical prophylaxis.

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.