Mary Nicholson RN, BSN CIC The Christ Hospital Cincinnati, Ohio Preoperative Staphylococcus aureus Nasal Screening: Impact on Reducing Staphylococcus aureus Associated Surgical Site Infections Mary Nicholson RN, BSN CIC The Christ Hospital Cincinnati, Ohio

TCH stats 555 bed tertiary care hospital 25,840 admissions/year 44 ICU beds; ADC of 36 Services: Cardiac surgery (CVS), Orthopedic, Oncology, Neurosurgery, OB-Gyn, Renal Transplant, Medicine, and Pulmonary Internal Medicine Residency Program US News and World Report rankings (2008) Endocrinology (29) Heart & Heart Surgery (26), Neurology & Neurosurgery (34) Respiratory Disorders (38)

Introduction There are approximately 470,000 cardiovascular surgeries performed annually in the US. The incidence of surgical site infections (SSI) is generally low at 1% to 8%, with an associated mortality rate of 14-47% Complications and consequences associated with surgical site infections (SSI) are: Increased morbidity and mortality Prolonged hospitalizations Increased health care costs – sometimes greater than 2.8 times the cost of an uncomplicated postoperative CVS patients Jakob (2000) demonstrated the frequency of wound infections in CVS patients to be 1.9% to 15% with S aureus infections varying from 12% to 36.9% of the infections.

Coronary Artery Bypass Surgery                                                                                                                                        Coronary Artery Bypass Surgery Bypass surgery consists of grafting veins or arteries from the aorta (a major artery that carries blood from the heart to the rest of the body) to the coronary artery, bypassing areas that are blocked.

Sternal Wound Infections

Sternal/Leg Wound Infections                                                        

Treatment of Sternal Wounds Medical Therapy: The use of a vacuum-assisted closure (VAC) device, allows for either sole therapy for sternal wound closure or adjunctive therapy in preparation for muscle flap closure. The principles of adequate wound debridement, treatment of infection, and closure of dead space still predominate as initial management decisions in treating sternal wounds. Radical Sternectomy With significant osteomyelitis of the sternum, fixing the sternum is impossible. The persistent infection results in a recurring sinus tracts and infectious drainage unless the infected bone and hardware are removed.

Rectus Abdominus Flap Rectus abdominus muscle and 8th intercostal perforator for coverage of sternal defects

Staphylococcus aureus The most common pathogen causing SSI is Staphylococcus aureus (S. aureus). S.aureus is endogenous to the human body with the primary site of colonization the anterior nares (Herwaldt 2003) Weinstein (1959) noted there was a correlation between S.aureus and all types of SSI. Kluytmans et al (1996) showed in a study that preoperative nasal carriage was the most important risk factor of surgical infections.

Studies have determined ~ 25-30% of the population may be colonized at any given time with S.aureus Carriers of S aureus are 2-9 times more likely as non- carriers to have SSI Jakob also demonstrated 28.1% of his CVS patients showed nasal colonization of S aureus preoperatively with 16% developing SSI, whereas the 71% patients with normal flora in their nares only 7.7% developed an SSI. Ursy et al (2002) found in a CVS study over a 2 year period the SSI rate was 2.6% with S aureus accounting for 79.4% of that grouping

Mupirocin Usage Perl, et. al, (2002) conducted a randomized double blinded placebo controlled trial to determine whether intranasal mupirocin reduces the rate of S. aureus infections at surgical sites and prevents other nosocomial infections 4030 patients were enrolled who underwent CVS, general surgery, neurosurgery, gynecologic procedures. 891 patients who had S aureus in their anterior nares, 444 received mupirocin and 447 placebo Among the patients with S aureus nasal carriage 4.0% who received mupirocin had nosocomial S.aureus infections as compared with the 7.7% who received placebo Concluded mupirocin significantly reduced the rate of nosocomial infections due to S aureus, specifically among patients with nasal carriage of S aureus, the group expected to be at increased risk

CVS TCH STATS At this hospital S.aureus accounted for 80% of the SSI in CVS population During the preceding 16 month period (Jan 02 –April 03) the overall CVS SSI rate was 1.89% (18 infs/per 954 procedures performed) MRSA non-surgical isolates occurred in ~ 11 patients each year Study reviews found using prophylactic mupirocin ointment applied to the nares decreased the incidence of S. aureus associated nosocomial infections 2002 Quality control hospital statistics found the average cost to treat a deep sternal infection was $ 42,700.00

Study Purpose The objective of this study was to show that, with performing prescreening nasal cultures and with both pre- and postoperative treatment with mupirocin, there would be a significant decreases in SSI in CVS patients.

Cost Impact The cost impact of starting the project was estimated to be ~ $45,000 for approximately 900 patients $12 for the S aureus screening nasal culture ~ $38 for a 1 week supply of mupirocin Based upon the 2002 costs of a deep sternal infection, if one infection was prevented it would pay for the cost of the project.

Culture Protocol All patient’s nares were cultured preoperatively using the Oxoid Penicillin Binding Protein Latex agglutination test before the patient skin was prepped in the operating room. This screening test selects for S.aureus and reports both methicillin sensitive and resistant strains After the nasal culture was obtained, each patient received an intranasal mupirocin application to each nares The mupirocin application was continued every 12 hours until the culture results were available. If the culture returned positive for S. aureus, mupirocin was continued for a total of 14 doses If the culture returned negative, mupirocin was stopped

CVS Procedures April 2003 - September 2004 1077 patients were studied

Nasal screening results April 2003 – September 2004 Approximately, 22% of the patients were identified as nasal carriers

Infections: Pre and Post Mupirocin

SSI Results 33% reduction in overall infections 75% decrease in S. aureus associated infections (p < 0.006) 90% decrease in deep sternal S.aureus infections ( p<0.0087) Elimination of MRSA non-surgical isolates in this population and no incidences of MRSA pneumonia, UTIs or bacteremias

Cost Impact of Deep SSI Pre vs. Post Mupirocin Post mupirocin costs include the $42k start up costs

Total Joint Surgery Patients

Total Joint Prosthesis

Complications Second to loosening of the prosthesis, infection is the most common complication of orthopedic implant procedures Gram positive organisms such as S aureus and Coagulase negative staphylococcus are the predominant organisms in prosthetic joint infections and have occurred at a rate of 0.6 – 2.0% per 100 procedures

Infection Pathways Introduction of microorganisms during the operative procedure, contiguous spread of post-op wound infection or colonization by hematogenous seeding The freshly implanted biomaterial is highly susceptible to infection – colonization by even small numbers of bacteria can lead to joint sepsis During the early post-op period, when superficial infections can develop, the fascial layers have not healed and the deep periprosthetic tissue is not protected by usual physical barriers Any factor that delays wound healing increases the risk such as: ischemic necrosis, hematoma, wound sepsis or suture abscesses

Treatment Options Joint irrigation with antibiotics Antibiotic therapy without removal of prosthesis 2 stage implant exchange Prosthesis removal (infected bone, soft tissue and joint linings- called a synovectomy) Followed by irrigation and implantation of an antibiotic implanted spacer Treated with 6-8 week course of antibiotics Once infection is cleared, joint is re-implanted Arthrodesis- the surgical immobilization of a joint until the bone has healed

Antibiotic Impregnated Joint

TCH Ortho Stats At TCH over 500 total joint surgeries are performed each year The associated SSI rate had averaged 0.86% per 100 procedures over the previous 2 year period. S. aureus had accounted for 50% of the SSIs SSI rate 2002 = 1.2% SSI rate 2003 = 0.6%

Hospital Stats In 2004, there was an increase in total joint SSIs with an associated rate of 1.49% (8/453). Upon further investigation 5/8 of the SSI were caused by S.aureus (with 3/5 isolates were MRSA) The patients and OR team underwent nasal cultures to rule out S. aureus nasal colonization 4 patients and 1 OR team member was identified as S. aureus nasal carriers

All S. aureus isolates were sent to the Ohio Department of Health for DNA pulse field gel electrophoresis typing (PFGE). This included 5 patients and 1 OR team member’s nasal isolate Six (6) different strains of S. aureus were identified None of the strains were linked epidemiologically One patient’s daughter was also hospitalized with MRSA sepsis and both patient and daughter shared the same strain of MRSA

Protocol Beginning in December 2004, all total joint patients when reporting for Pre Admission Testing (PAT) Nasal cultures were obtained to rule out S. aureus Cultures are sent to LabOne of Ohio using the Oxoid penicillin binding protein Latex agglutination test Culture results would generally be available within 48 hours and before patient was admitted to hospital for surgery In those cases where cultures had not been collected PTA, SDS are to send a nasal screening culture and begin intranasal mupirocin before surgery

Treatment of Carriers S.aureus sensitive carriers To receive intranasal mupirocin BID for 7 days IV cephazolin or clindamycin is to be administered as the pre-operative surgical antimicrobial Mupirocin is to be continued during hospitalization if not completed pre-operatively Follow-up culture to be obtained in surgeon’s office

Treatment of Carriers Methicillin resistant carriers To receive intranasal mupirocin BID for 7 days IV vancomycin is administered as the pre-operative surgical antimicrobial Patients are instructed to shower with CHG soap Patients are placed into Contact isolation upon admission to the hospital and continued until culture negative Mupirocin is continued during hospitalization if not completed pre-operatively Follow-up culture is obtained in surgeon office

Total Joint Procedures Dec 04 - Dec 2005 Figure 1

Nasal Culture Results (Dec 04 – Dec 05) 27% of patients were identified as S aureus carriers at the time of PAT

Findings 27.3% (119/435) of total joint procedure patients were identified as S aureus nasal carriers at the time of pre-admission testing. 16.8% (20/119) of S aureus nasal isolates were MRSA strains. Zero (0) deep infections occurred during the post mupirocin treatment study period. There was one superficial SSI. There were no deep infections associated with S. aureus. The SSI rate post mupirocin, was 0.19% (1 infection / 534 procedures). There was an 82% reduction in overall SSIs in historical group (16/1467) to the treated group (p < 0.03).

Infections Pre-mupirocin and Post-mupirocin

Pre-op nasal screening results

CVS screening results thru June 08

Total Joint screening results

Orthopedic spinal procedures

Pre-op nasal screening impact on SSI Service Total screened Reductions in SA/MRSA SSI CVS 3933 90% Total Joints 2614 75% Spinal 1069 70%

Application of project and future directions Pre-operative nasal screening may be applied to other services if S. aureus is a frequent source of SSIs To be successful, efforts should be coordinated with surgeon offices, microbiology labs and hospitals Obtaining a culture pre-operatively, eliminates the need to prophylactically treat all patients with a 7 day course of mupirocin; and should reduce the risks of drug resistance Targeting vancomycin usage for MRSA carriers should minimize the risks of drug resistance

MRSA stats at TCH

MRSA surveillance at TCH Patients identified with MRSA – are placed in Contact isolation and records are “flagged”; so that when readmitted - placed in isolation until cultures return negative

Recommendation from ICC Continue pre-operative nasal screening for SAS/MRSA colonization Expand the pre-op screening to include patients with other implantable devices (e.g. vascular grafts, ICD, etc). Support the initiation of a surveillance study in MICU to determine baseline prevalence rate of MRSA nasal carriage (medical residents) Continue to place all MRSA patients in Contact isolation until follow-up cultures return negative Do not recommend MRSA hospital wide surveillance at this time.

Awards and Publication 2004 Sodexho Health Care Services : Honorable Mention: Spirit of Excellence Award for Quality Nicholson, MR and Huesman LA. Controlling the usage of intranasal mupirocin does impact the rate of Staphylococcus aureus deep sternal wound infections in cardiac surgery patients. Am J Infect Control 2006; 34(1):44-48. Midwest Nursing Research Society Annual Meeting, Milwaukee April 2006 Poster presentation: Limiting the Usage of Intranasal Mupirocin Does Impact the Rate of Staphylococcus aureus Deep Sternal Wound Infections APIC Blue Ribbon Abstract Award 2006 – Tampa, June 2006: Poster Presentation: Pre-operative Staphylococcus aureus Nasal Screening does Reduce Total Joint Surgical Site Infections American College of of Orthopedic Surgeons – Poster presentation- February 2007: Screening for S. aureus does Reduce Total joint SSI. Anthem’s Hospital Quality Meritorious Award March 2007 Poster and Oral presentations at National Orthopedic Nursing Association May 2007 and 2008.  

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