THE IMPACT AND COST ANALYSIS OF PROPHYLACTIC INTRANASAL PHOTODYNAMIC DISINFECTION THERAPY (NPDT) AND CHLORHEXIDINE GLUCONATE (CHG) BODY WIPES ON SURGICAL SITE INFECTION IN ADULT SPINE SURGERY

A surgical site infection (SSI) following instrumented spine surgery is a devastating complication. Antibiotic nasal decolonization is primarily used to prevent SSIs. This therapy lacks compliance and leads to microbial resistance. To examine the effectiveness of intranasal photodisinfection therapy (nPDT) combined with chlorhexidine body wipes (CHG) for the prophylaxis of SSIs in adult patients undergoing spine surgery. Prospective observational surveillance data was collected from January 1st, 2006 to December 31st, 2019 including patient demographics, surgical variables and cases of SSIs confirmed by our institutional SSI surveillance program. SSI data was segmented into three regions: pre-rollout (2006 to 2010); nPDT/CHG rollout (2010 to 2014); and post-rollout (2015 to 2019). Pearson correlation was used to test for historical changes across individual patient and surgical variables. An interrupted time series analysis using segmented regression adjusted for patient and surgical variables was used to estimate the effect of the nPDT/CHG rollout on SSI incidence rates per region. Two models were developed to estimate the cost of nPDT/CHG to prevent one additional SSI per year and determine the mean cumulative institutional cost savings. A total of 13,493 patients underwent spine surgery over the study period, with a mean of 964 surgical cases per calendar year. Mean age, mean charlson comorbidity index (CCI) and mean surgical spine invasiveness index (SSII) increased from 48.4 to 58.1 years; 1.7 to 2.6 and 15.4 to 20.5 over the study period (p < 0.001). Unadjusted analysis identified a significant decrease in the mean number and mean incidence of SSIs per year from 74.6 to 26.8 and 7.98% to 2.67% between pre-rollout and post-rollout (p < 0.001). Segmented regression demonstrated an absolute percent reduction of 3.36% in SSI incidence per year during the nPDT/CHG rollout adjusted for mean age, CCI and SSII. The cost of nPDT/CHG to prevent one SSI was $1,350 to $1,650 CAD per year. The mean cumulative institutional cost savings was $2,484,856 to $2,495,016 CAD per year. No AEs were reported with the use of nPDT/CHG. Preoperative nPDT/CHG is an effective preoperative preventative strategy for reducing the incidence and cost of SSIs following spine surgery. Given the demonstrated success and the potential cost savings, we recommend the routine use of nPDT/CHG for SSI prevention in adult spine surgery.