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Myths in Emergency Medicine

Antibiotics for Acute Appendicitis Edging toward Mainstream Practice

Spiegel, Rory MD

doi: 10.1097/01.EEM.0000581496.39567.2e
Myths in Emergency Medicine



Appendicitis has long been considered a surgical emergency. Its pathological sequelae will lead to perforation, sepsis, and death if surgical intervention is not timely. Despite this foregone conclusion, a growing body of evidence is examining antibiotics alone in uncomplicated appendicitis.

Most of the data have found that the majority of patients treated with antibiotics alone will avoid surgery in the short term, with only about a quarter of patients requiring an appendectomy within one year of initial presentation. It is still unknown, however, what consequences such a noninvasive strategy will have in the long term. How many of these patients will require an appendectomy downstream, and more importantly, do these delays lead to any complications?

Salminen, et al., published the five-year follow-up results to the APPAC trial, a large randomized, controlled trial examining an antibiotic strategy for patients with acute uncomplicated appendicitis. (JAMA. 2018;320[12]:1259; The authors published the one-year results four years ago: A total of 530 patients presenting with CT-confirmed acute uncomplicated appendicitis were randomized to undergo an open appendectomy or three days of IV ertapenem sodium (1 g/d), followed by seven days of oral levofloxacin (500 mg once daily) and metronidazole (500 mg 3 times/day). (JAMA. 2015;313[23]:2340;

Seventy patients (27.3%; 95% CI, 22.0% to 33.2%) in the antibiotic group underwent surgical intervention within one year of initial presentation for appendicitis. Fifteen of these patients experienced failure of medical therapy during their initial presentation and required an appendectomy.

At five years, the need for appendectomy in the antibiotic group increased to 39.1 percent (95% CI, 33.1%-45.3%). The bulk of these surgeries occurred in the first few years following their initial bout of appendicitis, 35.2 percent at two years and the remaining 3.9 percent over the following three years.

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Mainstream Practice?

These results can be examined two ways. The first must consider that the failure rate of antibiotic therapy was close to 40 percent, meaning that almost half of the patients treated with this strategy will eventually require an appendectomy. Most therapeutic strategies with such a high failure rate are abandoned for clinical futility.

But when viewed from a different perspective, antibiotic therapy for acute appendicitis, prevented the need for surgery in 60 percent of the population. Forty percent of the antibiotic therapy group eventually required an appendectomy, but 99.6 percent of the surgical group underwent the very same procedure.

To argue that early appendectomy is superior, one has to demonstrate that the delay to surgery caused the patients harm, and this does not seem to be the case. No difference was seen in the number of patients with perforated appendices between the groups (2 v. 5), and in fact, the surgical group experienced a much higher rate of complications than was observed in the antibiotics-alone group. (The overall complication rate of 24.4% in the appendectomy group v. 6.5% in antibiotics group).

Certainly, much has yet to be determined before this noninvasive strategy can be considered mainstream practice. This was a small, underpowered cohort in which the participating surgeons performed primarily open laparotomies. Are there specific markers that predict patients who will go on to fail medical management? What is the ideal antibiotic regimen for these patients? Is an inpatient admission required at all?

What seems obvious, though, is that the majority of patients can be effectively managed conservatively for what was once considered an exclusively surgical disease. Despite these continued uncertainties, the long-term follow-up data continue to support the viability of a medical approach to acute appendicitis.

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Dr. Spiegelis an assistant professor of emergency medicine and critical care at Washington Hospital Center in Washington, D.C. Visit his blog at, follow him on Twitter @emnerd_, and read his past articles at

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