The Southwestern Surgical Congress Using antimicrobial solution for irrigation in appendicitis to lower surgical site infection rates Jeremy P. Parcells, M.D., Joan P. Mileski, Ph.D., Forrest T. Gnagy, B.S., Adriane F. Haragan, B.S., William J. Mileski, M.D.* University of Texas Medical Branch, Galveston, TX, USA Abstract BACKGROUND: The use of antimicrobial solutions for irrigation in appendicitis is controversial. Numerous antiseptic and antibiotic solutions have been suggested for use as an intraoperative irrigant. We sought to determine whether there was a difference in postoperative surgical site infections (SSIs) comparing normal saline (.9%), antiseptic solution (Dakin’s, .25%), and an antibiotic solution (imi- penem 1 mg/mL). METHODS: We performed a retrospective study of adult appendectomies from January 1997 through November 2007 at a single institution The data were evaluated by multivariate logistic regression analysis and chi-square test. The incidences of postoperative overall SSI, wound infection, and abdominal abscess were compared. RESULTS: A total of 1,063 cases were identified. Saline (n = 661) had an SSI rate of 9.8% (65/661), a wound infection rate of 7.3% (48/661), and an abdominal abscess rate of 4.2% (28/661). Dakin’s (n = 208) had an SSI rate of 20.7% (43/208), a wound infection rate of 15.9% (33/208), and an abdominal abscess rate of 9.1% (19/208). Imipenem (n = 194) irrigation had an SSI rate of .5% (1/194), a wound infection rate of .5% (1/194), and an abdominal abscess rate of .5% (1/194). CONCLUSIONS: These results suggest that abdominal irrigation with an antibiotic solution (imi- penem 1 mg/mL) is superior to both normal saline and Dakin’s solution. © 2009 Elsevier Inc. All rights reserved. KEYWORDS: Appendectomy; Antibiotics; Irrigation; Perforated appendix; Surgical complication; Surgical site infection; Wound infection; Abdominal abscess Appendectomy remains one of the most common ab- dominal operations in the United States. However, relative to other frequent abdominal operations such as cholecystec- tomy and hysterectomy, it has a high rate of postoperative infectious complications, and therefore it is an excellent model to investigate surgical site infections (SSIs) in ab- dominal operations. An area of debate regarding postoperative SSIs has been the use of intra-abdominal irrigation. There are more than 5 decades of literature on the subject. Numerous antibiotic solutions have been compared with antiseptic solutions and saline. At our institution over the past decade, 3 solutions have been used for intra-abdominal irrigation: saline (.9% normal saline), Dakin’s solution (.25% NaOCL), and imi- penem (1.0 mg/mL). We performed a chart review of the previous 10 years to see if there was a significant difference in postoperative infection rates. Methods The charts of all adult patients (18 years of age) treated for appendicitis from January 1997 to November of 2007 * Corresponding author. Tel.: +1 409 772 9066; fax: +1 409 747 7319. E-mail address: wmileski@utmb.edu Manuscript received March 19, 2009; revised manuscript September 20, 2009 0002-9610/$ - see front matter © 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.amjsurg.2009.09.002 The American Journal of Surgery (2009) 198, 875– 880