ID Consult

Appendicitis, antibiotics, and surgery: An evolving trilogy


 

Appendicitis is the most common surgical emergency in children. It is seen at all ages; however, it is less common in infants and toddlers younger than 4 years of age and peaks at an incidence of 25/100,000 in children 12- to 18-years-old. Fortunately, appendicitis is rarely fatal but can be associated with significant morbidity, especially in young children in whom the diagnosis is often delayed and perforation is more common. Reducing morbidity requires early diagnosis and optimizing management such that perforation and associated peritonitis are prevented.

The classical signs and symptoms of appendicitis are periumbilical pain migrating to the right lower quadrant, nausea, and low-grade fever. Presentation may vary if the location of the appendix is atypical, but primarily is age associated. In young children, abdominal distension, hip pain with or without limp, and fever are commonplace. In older children, right lower quadrant abdominal pain that intensifies with coughing or movement is frequent. Localized tenderness also appears to be age related; right lower quadrant tenderness and rebound are more often found in older children and adolescents, whereas younger children have more diffuse signs.

Dr. Stephen I. Pelton

Dr. Stephen I. Pelton

When I started my career, abdominal x-rays would be performed in search of a fecalith. However, such studies were of low sensitivity, and clinical acumen had a primary role in the decision to take the child to the operating room. In the current era, ultrasound and CT scan provide reasonable sensitivity and specificity. Ultrasound criteria include a diameter greater than 6 mm, concentric rings (target sign), an appendicolith, high echogenicity, obstruction of the lumen, and fluid surrounding the appendix.

As the pathogenesis of appendicitis represents occlusion of the appendiceal lumen, followed by overgrowth or translocation of bowel flora resulting in inflammation of the wall of the appendix, anaerobes and gram-negative gut flora represent the most important pathogens. In advanced cases, necrosis and gangrene of the appendix result with progression to rupture and peritonitis.

The traditional management was early surgical intervention to reduce the risk of perforation and peritonitis with acceptance of high rates of negative abdominal explorations as an acceptable consequence. Today, the approach to management of appendicitis is undergoing reevaluation. Early antimicrobial treatment has become routine in the management of nonperforated, perforated, or abscessed appendicitis. However, the question being asked is, “Do all children with uncomplicated appendicitis need appendectomy, or is antibiotic management sufficient?”

P. Salminen et al. reported on the results of a randomized clinical trial in 530 patients aged 18-60 years, comparing antimicrobial treatment alone with early appendectomy. Among 273 patients in the surgical group, all but 1 underwent successful appendectomy, resulting in a success rate of 99.6% (95% CI, 98.0%-100.0%). In the antibiotic group, 186 of 256 patients (70%) treated with antibiotics did not require surgery; 70 (27%) underwent appendectomy within 1 year of initial presentation for appendicitis (JAMA. 2015 Jun 16;313[23]:2340-8). There were no intraabdominal abscesses or other major complications associated with delayed appendectomy in patients randomized to antibiotic treatment. The authors concluded that among patients with CT-proven, uncomplicated appendicitis, antibiotic treatment did not meet the prespecified criterion for noninferiority, compared with appendectomy. However, most patients randomized to antibiotics for uncomplicated appendicitis did not require appendectomy during the 1-year follow-up period.

J.A. Horst et al. reviewed published reports of medical management of appendicitis in children (Ann Emerg Med. 2015 Aug;66[2]:119-22). They concluded that medical management of uncomplicated appendicitis in a select low-risk pediatric population is safe and does not result in significant morbidity. The arguments against a nonoperative approach include the risk of recurrent appendicitis, including the anxiety associated with any recurrences of abdominal pain, the risk of antibiotic-related complications, the potential for increased duration of hospitalization, and the relatively low morbidity of appendectomy in children. Factors associated with failed antibiotic management included fecaliths, fluid collections, or an appendiceal diameter greater than 1.1 cm on CT scan. The investigators concluded such children are poor candidates for nonsurgical management.

The bottom line is that antimicrobial therapy, in the absence of surgery, can be effective. Certainly in remote settings where surgery is not readily available, antimicrobial therapy with fluid and electrolyte management and close observation can be used in children with uncomplicated appendicitis with few failures and relatively few children requiring subsequent appendectomy. In more complicated cases with evidence of fecalith, or appendiceal abscess or phlegm, initial antimicrobial therapy reduces the acute inflammation and urgent need for surgery, but persistent inflammation of the appendix is often observed and appendectomy, either acutely or after improvement following antimicrobial therapy, appears indicated. Many different antimicrobial regimens have proven effective; ceftriaxone and metronidazole are associated with low rates of complications, offer an opportunity for once-daily therapy, and are cost effective, compared with other once-daily regimens.

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