What are the outpatient steps for suspected acute appendicitis (inflammation of the appendix)?

From the Guidelines

For suspected appendicitis, outpatient management should be limited to early presentations with mild symptoms, and patients should be advised to go to the emergency department for evaluation, which typically includes blood tests, urinalysis, and imaging (ultrasound or CT scan) as recommended by the 2024 clinical practice guideline update by the Infectious Diseases Society of America 1.

Key Considerations

• Patients should take acetaminophen (500-1000mg every 6 hours) for pain relief, but avoid NSAIDs like ibuprofen as they may mask symptoms.
• Food and drink should be restricted to clear liquids only.
• Patients must monitor for worsening symptoms including increasing pain, fever above 101°F (38.3°C), vomiting, or dizziness, which warrant immediate medical attention.

Diagnostic Approach

• The use of intravenous contrast in CT scans is usually appropriate for adults with suspected acute appendicitis, but CT without IV contrast also has high diagnostic accuracy and may be appropriate in certain cases 1.
• Ultrasound and MRI are also reasonably accurate and may precede CT, depending on the patient and clinical circumstances.

Management

• Appendicitis typically requires surgical intervention (appendectomy), though some mild cases may be managed with antibiotics like piperacillin-tazobactam or a combination of ceftriaxone and metronidazole.
• Outpatient management is only appropriate for very select cases after thorough evaluation by a physician, as appendicitis can rapidly progress to perforation, which significantly increases complications and mortality risk.

Follow-Up

• For patients with imaging study findings negative for suspected appendicitis, follow-up at 24 hours is recommended to ensure resolution of signs and symptoms, because of the low but measurable risk of false-negative results 1.
• For patients with suspected appendicitis that can neither be confirmed nor excluded by diagnostic imaging, careful follow-up is recommended 1.

From the Research

Outpatient Steps for Suspected Appendicitis

The following steps can be taken for suspected appendicitis:

• Evaluate the patient's symptoms, including abdominal pain, nausea, vomiting, and fever 2, 3
• Perform a physical examination to assess for tenderness in the right lower quadrant 2, 3
• Order laboratory tests, such as a complete blood count and blood chemistry tests, to help diagnose appendicitis 2, 3
• Use imaging studies, such as ultrasound or computed tomography (CT) scans, to confirm the diagnosis of appendicitis 2, 3
• Consider the use of antibiotics as first-line therapy for uncomplicated appendicitis, with surgery reserved for cases where antibiotic therapy fails or is not appropriate 2, 4, 5
• For patients with complicated appendicitis, such as those with an appendiceal abscess or perforation, surgical intervention is typically recommended 3, 6

Antibiotic Therapy for Appendicitis

Antibiotic therapy can be effective in treating appendicitis, with studies showing:

• Antibiotic therapy can be used as first-line therapy for uncomplicated appendicitis, with success rates ranging from 63% to 77% 4, 5
• Broad-spectrum antibiotics, such as piperacillin-tazobactam or cefotaxime, can be effective in treating appendicitis 2, 5
• The addition of metronidazole to broad-spectrum antibiotics does not appear to provide additional benefit in treating perforated appendicitis 6

Surgical Intervention for Appendicitis

Surgical intervention is typically recommended for:

• Complicated appendicitis, such as cases with an appendiceal abscess or perforation 3, 6
• Patients who have failed antibiotic therapy or have contraindications to antibiotic therapy 2, 4, 5
• Pregnant patients or immunosuppressed patients, who are at higher risk of complications from appendicitis 3