158: Impact of evidence based interventions on wound complications after cesarean

Abstract

Background A number of evidence-based interventions have been proposed to reduce post cesarean wound complications. Examples of such interventions include appropriate timing of preoperative antibiotics, appropriate choice of skin antisepsis, closure of the subcutaneous layer if subcutaneous depth is ≥ 2 cm, and subcuticular skin closure with suture rather than staples. However, the collective impact of these measures is unclear. Objective We sought to estimate the impact of a group of evidence-based surgical measures (prophylactic antibiotics administered prior to skin incision, chlorhexidine-alcohol for skin antisepsis, closure of subcutaneous layer, and subcuticular skin closure with suture) on wound complications after cesarean, and to estimate residual risk factors for wound complications. Study Design We conducted a secondary analysis of data from a randomized controlled trial of chlorhexidine-alcohol versus iodine-alcohol for skin antisepsis at cesarean from 2011-2015. The primary outcome for this analysis was a composite of wound complications, including surgical site infection (SSI), cellulitis, seroma, hematoma, and separation within 30 days. Risk of wound complications in women who received all four evidence-based measures (prophylactic antibiotics within 60 minutes of cesarean and prior to skin incision, chlorhexidine-alcohol for skin antisepsis with three minutes of drying time prior to incision, closure of subcutaneous layer if ≥ 2 cm of depth and subcuticular skin closure with suture) were compared to those who did not. We performed logistic regression analysis limited to patients who received all the evidence-based measures to estimate residual risk factors for wound complications and SSI. Results Of 1082 patients with follow-up, 349 (32.3%) received all the evidence-based measures and 733 (67.7%) did not. The risk of wound complications was significantly lower in patients who received all the evidence-based measures compared to those who did not (20.3% vs 28.1%; aRR 0.75, 95% CI 0.58, 0.95). The impact appeared to be largely driven by a reduction in surgical site infections. Among patients who received all the evidence-based measures, unscheduled cesarean was the only significant risk factor for wound complications (27.5% vs. 16.1%, aRR 1.71, 95% CI 1.12, 2.47) and SSI (6.9% vs. 1.6%, RR 3.74, 95% CI 1.18, 11.92). Other risk factors, including obesity, smoking, diabetes, chorioamnionitis, surgical experience, and skin incision type were not significant among patients who received all of the four evidence-based measures. Conclusion Implementation of evidence-based measures significantly reduces wound complications, but the residual risk remains high. This suggests the need for additional interventions, especially in patients undergoing unscheduled cesareans, who are at risk for wound complications even after receiving current evidence-based measures.