Because a majority of SSIs are caused by Staphylococcus aureus (the leading nosocomial pathogen globally), it is important to preoperatively identify carriers of both methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). More than 80 % of healthcare-associated S. aureus infections have an endogenous origin. In one review examining infection for implantable pain therapies, S. aureus was the most commonly identified organism. Preoperative decolonization protocols for known carriers of S. aureus (both MSSA and MSRA), which include mupirocin nasal ointment and chlorhexidine soap, have been shown to reduce the risk of postoperative S. aureus infections in other populations receiving implantable devices (i.e., total joint arthroplasty).

Prophylactic antibiotic therapy with weight-based dosing (Table 5.2) has been shown to reduce the incidence of wound infection by 50 %, independent of surgery type. Weight-based dosing is important in order to achieve tissue and serum minimum inhibitory concentrations. Furthermore, failure to optimize antimicrobial therapy has been shown to increase the risk of infection by twofold to sixfold. Intravenous antibiotics should be administered within 1 h prior to surgical incision, or within 2 h when vancomycin is used. Additional studies have indicated a further reduction in SSIs when antibiotics (excluding vancomycin) are given within 30 min before incision. A study examining risk factors for infection following spinal surgery demonstrated a 3.4-fold increased risk of SSI if antibiotics were given after surgical incision.