Risk Factors and Outcomes for Sepsis after Appendectomy in Adults

Background: Sepsis is an uncommon occurrence after appendectomy, but the morbidity and mortality of patients who develop sepsis after appendectomy remains exceedingly high. The purpose of this study is to identify risk factors and adverse post-operative outcomes associated with sepsis after appendectomy in adults. Patients and Methods: The American College of Surgery National Surgical Quality Improvement Program participant user database was queried from 2012 to 2015. Patients who underwent appendectomy were identified and demographic data, intra-operative variables, and post-operative outcomes were collected. The primary outcome was post-operative sepsis after appendectomy, which was defined as the development of sepsis or septic shock post-operatively. Patients with a diagnosis of systemic inflammatory response syndrome (SIRS), sepsis, or septic shock within 48 hours prior to surgery or present at the time of surgery were excluded. Multivariable analyses (logistic and linear regression) were performed to assess for risk factors and adverse outcomes associated with sepsis. Results: Of the 72,538 patients who had appendectomies, 311 patients (0.43%) were identified as having post-operative sepsis. Of these, 17 patients (5.47%) died within 30 days. Age 60 years or more (odds ratio [OR] 1.51, 95% confidence interval [CI] 1.129-2.02), African American race (OR 1.951, 95% CI 1.399-2.722), morbid obesity (OR 1.784, 95% CI 1.264-2.516), acute renal failure or dialysis (OR 4.642, 95% CI 2.17-9.929), disseminated malignancy (OR 4.089, 95% CI 1.719-9.726), and open appendectomy (OR 2.607, 95% CI 2.003-3.393) were found to be associated with increased risk of post-operative sepsis; patients were also less likely to be female (OR 0.650, 95% CI 0.517-0.817). Patients who developed sepsis after appendectomy were more likely to return to the operating room (24.76 vs. 0.77%, p < 0.001), be re-admitted for any cause (53.38% vs. 2.70%, p < 0.0001), and die within 30 days of surgery (5.47% vs. 0.05%, p < 0.001). Conclusion: Patients who become septic after appendectomy are at risk for adverse post-operative morbidity and mortality. Age 60 years or more, African American race, morbid obesity, acute renal failure or dialysis, disseminated malignancy, and open appendectomy increase the risk for sepsis after appendectomy and sepsis-related morbidity and mortality. Given the remarkably large number of appendectomies that are performed each year, the findings of this study can assist in identifying at-risk patients, facilitate physician-patient discussion and shared decision-making, and guide appropriate care to further reduce the incidence of sepsis after appendectomy.