The Nose Knows: Addressing Surgical Site Infection Prevention & Antibiotic Stewardship Through Povidone-Iodine Antiseptic Nasal Decolonization

Author: Joan Hebden, RN, MS, CIC, FAPIC, FSHEA

Decolonization is an evidence-based patient safety practice with the goal of lowering the microbial bio-burden on patient body sites to reduce the risk of infection from endogenous colonization during surgery.

Nasal decolonization has become an important strategy for reducing surgical site infections (SSIs) due to Staphylococcus aureus (S. aureus). Data from the National Healthcare Safety Network (NHSN) for 2014 reports that S. aureus is the primary pathogen responsible for SSIs, with 42.6% of S. aureus SSIs caused by methicillin-resistant S. aureus (MRSA).¹ The gold standard for nasal decolonization has been mupirocin; however, selective pressure has led to mupirocin-resistant strains of S. aureus and treatment failures. Patient compliance and satisfaction has been suboptimal, in part due to the need for multiple applications prior to surgery. As part of an overall approach to patient safety and antibiotic stewardship, investigators have looked to antiseptics, such as povidone-iodine (PVP-I), as alternatives.

An estimated 157,500 SSIs resulting in more than 8,000 deaths occur annually in the United States healthcare system.^2,3 The estimated excess length of hospital stay (LOS) for these infections is 11 days, with a cost of $20,785. If MRSA is the causative pathogen, the LOS and cost increases to 23 days and $42,300, respectively.⁴ The anterior nares are the primary reservoir for S. aureus carriage and approximately 20-30% of healthy individuals are persistently colonized.⁵ Approximately 1-3% of healthy adults are colonized with MRSA; higher carriage rates have been reported among hospitalized and long-term care patients.⁶ As S. aureus carriers are two to nine times more likely than non-carriers to have SSIs⁷, perioperative nasal decolonization has been extensively studied as an SSI prevention strategy.

The introduction in the mid-1980s of mupirocin calcium ointment, with excellent in vitro activity against staphylococci and most streptococci, led to its widespread use as the decolonization agent of choice for preventing S. aureus infection and transmission. The orthopedic and cardiothoracic surgical communities have widely adopted mupirocin decolonization protocols. A systematic review of 19 studies of orthopedic surgery patients found a range of SSI reduction from 29%-57% in total SSIs for those using mupirocin alone, 13%-81% in total SSIs, 56%-200% reductions in S. aureus SSIs, and 29%-100% reductions in MRSA SSIs for those using mupirocin and chlorhexidine.⁸ A trial involving cardiac surgery patients with an intervention of pre-operative nasal screening for Methicillin-sensitive Staphylococcus aureus,(MSSA) and MRSA, decolonization of carriers with mupirocin twice daily and chlorhexidine daily bathing for 5 days, and modification of prophylactic antibiotics to vancomycin and cefazolin for MRSA carriers, found a 42% reduction in SSIs.⁹

However, in the late 1990s, mupirocin resistance began to emerge. Recent surveillance studies have reported mupirocin-resistant (MupR) MRSA strains in up to 13% of surgical ICU patients in the absence of routine use of mupirocin¹⁰ and 23.7% MupR among MRSA clinical isolates in a facility where mupirocin was routinely used to decolonize MRSA-positive patients.¹¹ A strong association has been found between prior mupirocin use and subsequent mupirocin-resistant in MRSA.¹² Currently, mupirocin susceptibility testing is infrequently performed, and the prevalence of MupR MRSA strains is unknown in many clinical settings. Concern has also been cited regarding suboptimal patient compliance with the mupirocin regimen of twice daily application for five days and overall patient satisfaction. These concerns have led to the use of antiseptics, such as PVP-I, as alternative nasal decolonization agents.

PVP-I is a complex of polyvinylpyrrolidine and tri-iodine ions which has been used widely for cutaneous antisepsis, has rapid bactericidal activity against both mupirocin-sensitive and mupirocin-resistant strains of S. aureus, and has no reports of bacterial resistance. In two recent studies, the impact on SSI after nasal decolonization with PVP-I was assessed.

• In an open-label, randomized trial of patients undergoing arthroplasty or spine fusion procedures, deep SSI rates within 90 days were compared for those individuals receiving topical 2% chlorhexidine wipes the night before and morning of surgery in combination with either twice daily application of nasal mupirocin ointment during the 5 days before surgery or 2 applications of 5% povidone-iodine (PVP-I) solution into each nostril within 2 hours of surgical incision.¹³ In the per-protocol analysis of 763 surgical procedures in the mupirocin group and 776 surgical procedures in the PVP-I group, aureus deep SSIs developed in five patients (0.7%) who received mupirocin and zero patients (0.00%) among those who received PVP-I (p = 0.03).

• A quasi-experimental, retrospective, non-randomized trial compared a preoperative decontamination intervention—2% chlorhexidine washcloths and 0.12% chlorhexidine oral rinse the night before and morning of surgery and the use of 5% PVP-I intra-nasally once the morning of surgery—to historical controls without a decontamination protocol to evaluate the impact on SSI rates for patients undergoing elective orthopedic procedures with hardware implantation.¹⁴ Of 709 patients analyzed (344 controls and 365 patients who were decolonized), rates of SSIs were significantly lower in the intervention group than in the control group (1.1% versus 3.8%; p = 0.02). In addition to the more than 50% reduction in SSI rates, adherence to and cost of a decontamination regimen is a cardinal factor for its success. It was noted that a decolonization protocol containing PVP-I instead of mupirocin could potentially dissipate concerns regarding antibiotic resistance, broaden application beyond aureus carriers, and result in cost-savings ($35.00 per patient for the PVP-I regimen vs. $54.00 for mupirocin and chlorhexidine). A survey of 1,903 patients comparing patient experiences and satisfaction with nasal decolonization using either PVP-I or mupirocin ointment showed that significantly fewer patients assigned to receive PVP-I reported an unpleasant or very unpleasant experience (3.4% vs. 38.8%, p<0.0001). Similarly, significantly fewer patients assigned to PVP-I reported adverse effects, compared to those assigned to receive mupirocin (p<.01).¹⁵

The emergence of mupirocin-resistant S. aureus strains, suboptimal compliance and reduced patient satisfaction has led to the adoption of antiseptics for nasal decolonization. The most effective regimen for nasal decolonization to prevent SSIs should have proven efficacy against S. aureus, the major pathogen responsible for these infections, be easy to apply, have minimal adverse reactions, and be a positive experience for patients. PVP-I has rapid bactericidal activity against both mupirocin-sensitive and mupirocin-resistant strains of S. aureus, has no reports of bacterial resistance, can be applied immediately prior to surgery to suppress nasal carriage during the period of risk for bacterial contamination, has high patient satisfaction scores and is cost-effective. PVP-I offers a promising alternative to mupirocin for the prevention of SSIs.