Epidemiology and Risk Factors for Superficial Surgical Site Infections after Appendectomy for Acute Appendicitis: A Secondary Data Analysis.

Background

The identification of risk factors for superficial surgical site infections (SSSIs) associated with appendectomy is paramount in the management of patients with acute appendicitis (AA).

Methods

This study was a secondary data analysis from a prospective multi-center observational study. It included all consecutive hospitalized patients with AA who underwent appendectomy and were monitored for complications at 30 days after the intervention. A case-control approach was used to evaluate risk factors associated with the occurrence of SSSI.

Results

Among 2,667 patients, 156 (5.8%) developed an SSSI. The series included 1,449 males (54.3%) and 1,218 females with a median age of 29 years (interquartile range [IQR] 20-45 years). Antimicrobial therapy within the previous 30 days was reported by 170 patients (6.4%), and a C-reactive protein concentration (CRP) >50 mg/L was observed in 609 (22.8%). A total of 960 patients (36.0%) underwent open surgery, 1,699 (63.7%) laparoscopic surgery, and 8 (0.3%) another surgical intervention. In 2,575 patients (95.6%), a pathological appendix was detected during the operation. In 776 patients (29.1%), an intra-operative abdominal drain (IAD) was placed; 125 patients (4.7%) were admitted to the intensive care unit. The median hospital length of stay was 3 days (IQR 2-5 days). The overall mortality rate was 0.11%. Multinomial logistic regression analysis of risk factors demonstrated that statistically significant risk factors independently associated with the occurrence of SSSIs were antimicrobial therapy within the previous 30 days, CRP >50 mg/L, open surgical procedures, presence of IAD, and intra-operative findings of complex appendicitis.

Conclusions

Knowledge of five easily recognizable variables, assessable at hospital admission or as soon as the surgical intervention is concluded, might identify patients with a greater risk of developing an SSSI.