Tuesday, June 16, 2015

Antibiotics for acute appendicitis?

- Kenny Lin, MD, MPH

Until recently, the most well-studied clinical questions about acute appendicitis have been how to efficiently diagnose it using the history and physical examination and laboratory and imaging tests. Once appendicitis was identified, the next step was to perform an appendectomy, using a laparoscopic or open surgical approach. However, a recent review discussed evidence that some cases of acute appendicitis resolve spontaneously rather than leading to perforation. A 2011 Cochrane review of five randomized, controlled trials found that three-quarters of patients with acute appendicitis who were initially treated with antibiotics rather than surgery recovered completely within two weeks and did not experience a recurrence within one year. Due to the small sizes and other limitations of these trials, the American College of Surgeons has continued to recommend surgery as the "standard" treatment for acute appendicitis.

A study published in this week's JAMA may change a few minds about the utility of antibiotics for this condition. Dr. Paulina Salminen and colleagues randomized 530 Finnish adults aged 18 to 60 years with CT-confirmed uncomplicated acute appendicitis to a 10-day course of intravenous followed by oral antibiotics versus open appendectomy. 73 percent of patients in the antibiotic group did not need an appendectomy within 1 year; the rest, who underwent delayed appendectomies for signs of progressive or recurrent infections, did not develop intra-abdominal abscesses or other major complications as a result of waiting. Although the antibiotic "failure rate" of 27 percent exceeded the authors' pre-specified non-inferiority margin of 24 percent (compared to a 0.4 percent failure rate for initial surgery), the results confirm the viability of a medical approach to acute appendicitis.

A few issues would need to be addressed before antibiotics for acute appendicitis could be routinely implemented in American clinical practice. Unlike in Europe, most appendectomies in the U.S. are laparoscopic, which may make surgery more appealing to some patients. Children and adults older than age 60, who were not included in the JAMA study, may be at higher risk for complications from delayed surgery. Since acute appendicitis is common, we don't know if treatment with broad-spectrum antibiotics could worsen the problems of antibiotic resistance and Clostridium difficile infection. Finally, the lack of consensus on the "clinically important" difference needed to choose antibiotics over surgery may favor a shared decision making approach, which could be a challenge to carry out in the acute care setting.