IMPACT OF A MRSA DECOLONIZATION PROTOCOL ON ORTHOPEDIC SURGICAL SITE INFECTIONS (SSIS) IN A COMMUNITY HOSPITAL JUDY CHIN,1 JOHN MCCARTHY,1 DIANE MCCOWAN,1 MARIA CORTINAS,1 TERI PAZZULLA,1 HELEN LITVACK,1 CHRISTIANNE LANE,2 PATTY POYNTER,1 ALAN ENDO1

1Presbyterian Intercommunity Hospital, Whittier, CA ; 2University of Southern California Keck School of Medicine, Los Angeles, CA

REVISED ABSTRACTBackground:

SSIs due to S. aureus, including MRSA, are one of the most common nosocomial infections. SSIs are associated with considerable financial impact, and MRSA-colonized patients potentially have a higher risk of developing an infection. A pilot program (PP), consisting of MRSA screening (MS), empiric decolonization (ED), and antibiotic prophylaxis (AP), was implemented August 2011 to lower the risk of SSIs and prevent transmission of MRSA in adult patients undergoing elective prosthetic joint surgeries (PJS).

Methods:

A retrospective analysis was performed to evaluate SSIs and associated costs with PP. SSIs were defined according to CDC criteria. Screening was performed preoperatively by routine culture of the nares. The decolonization protocol (DP) consisted of nasal application of mupirocin three times daily and chlorhexidine daily body washes for a period of 7 days, preoperatively. Patients positive for MRSA carriage (MC), were re-screened by rapid PCR methods (of nares) and administered vancomycin prophylaxis pre- and post-operatively. Historical control patients (HCP) were identified as those who underwent PJS prior to the intervention. SSI rates were compared between the groups over an 8 month period prior to and afterwards. PP-associated costs were calculated to include laboratory supplies, nursing-associated and drug costs; and compared with SSI-associated costs. Data were collected from electronic medical records, microbiology, and pharmacy databases.

results:

304 patients were screened with 265 evaluable. 3.8% screened positive for MC (n=10) of which 70% converted to negative MC post-DP at time of surgery (n=7). PJS comprised mostly of knee arthroplasty (ART, n=171) followed by hip ART (n=70) and shoulder ART (n=24). 8-month SSI rate for the intervention group (IG) was 0.075% (n=2) compared to 2.87% (n=10) in the HCP group. The infections in IG were culture positive (n=1 MSSA and n=1 coagulase-negative staphylococci). None were MRSA SSIs compared to 4 in the HCP group (0% vs. 1.15%). Estimated cost of PP was $20288.16. The reduction in SSI rate, which also accounts for PP-associated costs, resulted in an estimated cost savings (CS) of $ 196,239.80.

conclusion:

A program consisting of MS, ED, and AP may lower orthopedic SSIs and can potentially lead to considerable CS.

� Prosthetic joint infections are one of the major complications of arthroplasty with significant morbidity, mortality, and financial burden.

� S. aureus infections are implicated in most SSIs.

� MRSA SSIs after prosthetic joint infections can prolong hospitalization and lead to mobility issues as well as lengthy antimicrobial courses.

� S. aureus is part of the endogenous flora of the skin and its ecological niche is usually found in the anterior nares.

� Patients who are colonized have a higher risk for staphylococcal infections after surgical procedures. Some studies found that nasal carriage of S. aureus correlate with wound infections.

� An intervention pilot program was implemented as part of control measures to reduce staphylococcal SSIs after prosthetic joint surgeries.

� Retrospective analysis of pilot program implemented August 1, 2012

� Duration: August 1, 2011 thru March 31, 2012

� 444-bed community acute-care hospital

� Data were collected from electronic medical records, microbiology, and pharmacy databases

Pilot PrograM (Figure 1)

� Adult patients admitted for elective prosthetic joint surgical procedures

� A preoperative visit 7 days prior to scheduled surgery was made with hospital RN

- Preoperative orders including laboratory studies

- Decolonization regimen prescribed and dispensed to patient with patient education/instruction materials

- MRSA screening of the nares performed via routine culture methodology

- Operating surgeon was notified if positive MRSA screening results – from which RN received orders for pharmacy-directed dosing of vancomycin for pre- and post-operative prophylaxis (24 hours)

- On day of surgery: patients who screened positive for MRSA carriage were re-screened again via nares by rapid PCR methodology (Cepheid Xpert MRSA Assay). Results were reported to surgical RN for isolation purposes

� Standard infection control measures were used upon confirmation of MRSA colonization (contact isolation and use of dedicated material e.g. gown, gloves, etc).

� Patients who screened negative for MRSA carriage from preoperative visit received cefazolin for pre- and post-operative prophylaxis (24 hours).

decolonization regiMen

� Topical decolonization protocol was provided to each patient

� Regimen consisted of:

- Mupirocin 2% nasal application three times daily for 7 days

- Chlorhexidine gluconate 4% daily body washes for 7 days

� SSIs were defined according to CDC’s NHSN system criteria for superficial incisional, deep incisional, and organ/organ space SSI

� Historical control patients were identified by the hospital orthopedic surgical database eight months prior to the intervention (December 1, 2010 – July 31, 2011)

� SSI incidence rate was calculated for the 8 month retrospective analysis

estiMation oF costs associated with Pilot PrograM

� Nursing and ancillary associated costs with preoperative visit: $40 per patient

� Medication costs (AWP, per patient):

- Mupirocin: $8.71

- Chlorhexidine gluconate 4%: $8.58

� Laboratory supplies and processing (per patient):

- Routine cultures: $8

- Cepheid Xpert MRSA Assay: $40

� Estimation of SSI hospital-associated costs were referenced from CDC material and figures ($25,546 per SSI)

statistical analysis

� Descriptive analysis were computed

� One-sample binomial test was utilized for comparison and significance

Four tower Pilot

Mrsa active surveillance screening PreoPerative Process

� To reduce staphylococcal, including MRSA post-operative SSIs in patients undergoing elective prosthetic joint surgeries

� To evaluate incidence of SSIs and associated costs with pilot program

� An intervention program consisting of MRSA surveillance screening, empiric decolonization, and appropriate antibiotic surgical prophylaxis can help lower total joint SSIs.

� Such a program can also potentially lead to considerable cost savings.

Part of this project was supported by NIH/NCRR SCCTSI Grant Number UL1 RR031986. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH.*

- Bode LGM and Kluytmans JAJW. Preventing surgical site infections in nasal carriers of S. aureus. NEJM

2010; 362(1): 9-17.

- Department of Health and Human Services. HHS action plan to prevent healthcare-associated infections.

US Department of Health and Human Services, DC, USA 2009.

- Hadley S, Immerman I, Hutzler L et al. S. aureus decolonization protocol decreases surgical site infections

for total joint replacement. Arthritis 2010; 2010:924518.

- Klevens RM, Edwards JR, Richards CL et al. Estimating healthcare-associated infections in U.S. hospitals,

2002. Public Health Report 2007;122:160-166.

- Kluytmans J. Reduction of surgical site infections in major surgery by elimination of nasal carriage of S.

aureus. J Hosp Infect 1998; 40: S25-29.

- Roberts RR, Scot RD, Cordell R, et al. The use of economic modeling to determine the hospital costs

associated with nosocomial infections. Clin Infect Dis 2003; 36: 1424-32.

- Stone PW, Braccia D, and Larson E. Systematic review of economic analysis of healthcare-associated

infections. Am J Infect Control 2005; 33: 501-9.

- Wenzel RP and Perl TM. The significance of nasal carriage of S. aureus and the incidence of post-

operative wound infection. J Hosp Infect 1995; 31(1): 13-24.

OBJECTIVE(S)

BACKGROUND

METHODS CONCLUSIONS

REFERENCES

RESULTS

� 304 patients were screened after implementation of intervention program

� 265 patients were evaluable for analysis

� 3.8% screened positive for MRSA carriage (n=10) and 7.2% screened positive for MSSA carriage (n=19)

� 7 of 10 patients were converted to negative MRSA carriage after undergoing the decolonization protocol for 7 days

� n=3 remained positive for MRSA carriage

� 2 SSIs were identified in the intervention group – one superficial incisional and one organ/organ space SSI.

� 349 historical control patients were identified prior to the intervention group with n=10 SSIs

� The infections in the intervention group were culture positive (n=1 MSSA and n=1 coagulase-negative staphylococci)

� The infections in the historical control patient group were mostly culture positive (n=9) with S. aureus isolated in 7 patients

� 8-month overall SSI rate for the intervention group was 0.075% compared to 2.87% in the historical control patient group (p<0.001)

� There were no MRSA SSIs in the intervention group compared to 4 in the historical control patient group (0% vs. 1.15%, p<0.001)

� Estimated costs associated with decolonization pilot program was $20,288.16

� Potential cost savings associated with reduction in SSIs was estimated at $196,239.80

Correspondence: Judy Chin, PharmD.

Judy.Chin@pihhealth.org

taBle 3Breakdown of infections in each group

Patient Age GenderPreoperative

MRSA carriage?

Intraoperative MRSA carriage if screened positive for MRSA

carriage preoperative?

Surgical procedureMicroorganism

isolated from positive cultures

SSI

Intervention Group

Case #1 56 M Yes Yes Hip arthroplastyCoagulase-negative

staphylococciSuperficial

Case #2 75 F No N/A Shoulder arthroplasty MSSA Organ/Organ space

Historical Control Patient Group

Case #1 87 M N/A N/A Hip arthroplasty MRSA Organ/Organ space

Case #2 83 F N/A N/ABilateral knee arthroplasty

Diptheroids Deep

Case #3 81 M N/A N/A Knee arthroplasty MRSA Deep

Case #4 69 F N/A N/A Hip arthroplasty MRSA Deep

Case #5 71 F N/A N/ABilateral hip arthroplasty

Diptheroids Organ/Organ space

Case #6 65 F N/A N/A Knee arthroplasty None Organ/Organ space

Case #7 55 M N/A N/A Hip arthroplasty MRSA Deep

Case #8 68 M N/A N/A Knee arthroplasty MRSA Deep

Case #9 71 F N/A N/A Hip arthroplasty MRSA Superficial

Case #10 69 F N/A N/A Knee arthroplasty MRSA Superficial

taBle 1patient characteristics

Intervention Group Historical Control Patient Group

Age ± SD (years) 70.1±10.7 70.2±10.8

Male (%) 43.4% 38.7%

Female (%) 56.6% 61.3%

Knee arthroplasty (%) 171 (64.5%) 216 (61.9%)

Hip arthroplasty (%) 70 (27.4%) 107 (30.7%)

Shoulder arthroplasty (%) 24 (9.1%) 26 (7.4%)

taBle 2surgical site infections

Intervention Group (n=265)

Historical Control Patient Group (n=349) p value

Overall SSIs (%) 2 (0.75%) 10 (2.87%) p<0.001

S. aureus SSIs (%) 1 (0.38%) 7 (2.01%) p<0.001

MSSA SSIs (%) 1 (0.38%) 3 (0.86%) p<0.001

MRSA SSIs (%) 0 4 (1.15%) p<0.001

IDSA 2012

Poster #1683