What is the diagnosis and treatment for appendicitis (inflammation of the appendix)?

From the Guidelines

Appendicitis requires prompt surgical attention, and the standard treatment is an appendectomy, which can be performed laparoscopically or as an open procedure, with laparoscopic appendectomy conferring superior outcomes compared with open appendectomy for adult and pediatric patients with acute appendicitis 1. The diagnosis of appendicitis typically involves a physical examination, blood tests to check for infection, and imaging studies such as ultrasound or CT scan.

• Clinical scoring systems can be used as a basis for structured management in adult patients with suspected appendicitis, but may not be sufficient for pediatric patients 1.
• Serum biomarkers may play a role in evaluating adult and pediatric patients presenting with clinical features evocative of acute appendicitis, but their role is still being researched 1.
• The optimum pathway for imaging in adult and pediatric patients with suspected acute appendicitis is still being debated, but ultrasound and CT scans are commonly used 1. In some cases of uncomplicated appendicitis, non-operative management with antibiotics may be considered, but surgery remains the definitive treatment in most cases.
• Non-operative management with or without antibiotics can be a safe and effective treatment option for adult and pediatric patients with uncomplicated acute appendicitis, but the best approach is still being researched 1. The use of antibiotics in the treatment of appendicitis is crucial, and preoperative antibiotic therapy is recommended for patients with acute appendicitis 1.
• Postoperative antibiotics may not always be indicated in adult and pediatric patients following appendectomy, and the decision to use them should be made on a case-by-case basis 1.

From the FDA Drug Label

Piperacillin and Tazobactam for Injection is indicated in adults and pediatric patients (2 months of age and older) for the treatment of appendicitis (complicated by rupture or abscess) and peritonitis caused by beta-lactamase producing isolates of Escherichia coli or the following members of the Bacteroides fragilis group: B. fragilis, B. ovatus, B. thetaiotaomicron, or B. vulgatus.

Piperacillin-tazobactam is indicated for the treatment of appendicitis, specifically complicated cases (by rupture or abscess), in adults and pediatric patients (2 months of age and older) 2.

• The treatment is effective against beta-lactamase producing isolates of Escherichia coli and certain members of the Bacteroides fragilis group.
• The recommended dosage for adults with indications other than nosocomial pneumonia is 3.375 grams every six hours, totaling 13.5 grams (12.0 grams piperacillin and 1.5 grams tazobactam) per day, administered by intravenous infusion over 30 minutes 2.
• The usual duration of treatment is from 7 to 10 days 2.

From the Research

Definition and Incidence of Appendicitis

• Appendicitis is the most common abdominal surgical emergency in the world, with an annual incidence of 96.5 to 100 cases per 100 000 adults 3.
• It affects 96.5 to 100 people per 100 000 adults per year worldwide 3.

Symptoms and Diagnosis of Appendicitis

• Classic symptoms of appendicitis include vague periumbilical pain, anorexia/nausea/intermittent vomiting, migration of pain to the right lower quadrant, and low-grade fever 3.
• The clinical diagnosis of acute appendicitis is based on history and physical, laboratory evaluation, and imaging 3.
• The diagnosis of acute appendicitis is made in approximately 90% of patients presenting with these symptoms 3, 4.

Treatment Options for Appendicitis

• Laparoscopic appendectomy remains the most common treatment for appendicitis 3.
• However, increasing evidence suggests that broad-spectrum antibiotics can successfully treat uncomplicated acute appendicitis in approximately 70% of patients 3.
• Antibiotic therapy can be offered as the first-line therapy to a majority of unselected patients with acute appendicitis without medical drawbacks other than the unknown risk for long-term relapse 5.
• In patients without high-risk CT findings, either appendectomy or antibiotics can be considered as first-line therapy 3.
• In unfit patients without these high-risk CT findings, the antibiotics-first approach is recommended, and surgery may be considered if antibiotic treatment fails 3.

Antibiotic Regimens for Appendicitis

• Ceftriaxone plus metronidazole (CTX/MTZ) is a cost-effective regimen for pediatric appendicitis 6, 7.
• CTX/MTZ has been shown to be effective in treating nonperforated, perforated, and abscessed appendicitis 7.
• Post-operative complication rates did not differ for children treated with CTX/MTZ versus a broader-spectrum regimen 6.

Complications and Recurrence Rates

• Recurrence rates of non-operated patients within 1 year are as high as 20-30% 4.
• Primary antibiotic treatment had fewer complications compared to primary surgery 5.
• CT findings of appendicolith, mass effect, and a dilated appendix greater than 13 mm are associated with higher risk of treatment failure (≈40%) of an antibiotics-first approach 3.