What is the recommended management for a patient with suspected acute appendicitis, presenting with right lower quadrant (RLQ) postprandial pain, diarrhea, and ultrasound findings of a dilated appendix?

Management of Suspected Acute Appendicitis Based on Ultrasound Findings

CT scan with IV contrast is the recommended next step for this patient with suspected acute appendicitis and positive ultrasound findings showing a dilated appendix measuring 1.2 cm. 1

Imaging Findings and Clinical Correlation

The patient presents with:

• Right lower quadrant (RLQ) postprandial pain
• Diarrhea
• Ultrasound showing dilated appendix (1.2 cm from outer wall to outer wall)

These findings are highly suspicious for acute appendicitis. An appendiceal diameter ≥7 mm is considered a significant finding for appendicitis, and this patient's measurement of 1.2 cm (12 mm) exceeds this threshold substantially 2.

Recommended Management Algorithm

1. Confirm diagnosis with CT scan with IV contrast

   • CT with IV contrast has the highest diagnostic accuracy for appendicitis in adults (sensitivity 90-100%, specificity 94.8-100%) 1
   • The ACR Appropriateness Criteria rates CT abdomen and pelvis with IV contrast as an 8/9 ("usually appropriate") for suspected appendicitis 1
   • CT will help confirm the diagnosis and identify any complications such as perforation or abscess formation

2. Surgical consultation

   • Once diagnosis is confirmed, prompt surgical consultation is recommended
   • Delay in surgical intervention increases risk of perforation, which occurs in 17-32% of patients with acute appendicitis 3

3. Antibiotic administration

   • Broad-spectrum antibiotics should be initiated while preparing for surgery
   • Options include piperacillin-tazobactam monotherapy or combination therapy with cephalosporins or fluoroquinolones with metronidazole 2

Rationale for CT Confirmation

While the ultrasound findings are highly suggestive of appendicitis, CT is recommended as the next step because:

1. CT has superior diagnostic accuracy compared to ultrasound alone 1
2. CT can better identify complications such as perforation or abscess 1
3. CT can identify alternative diagnoses if the appendicitis diagnosis is incorrect 4
4. CT findings (such as presence of appendicolith, mass effect, or appendix diameter >13 mm) help guide treatment decisions between surgical and antibiotic-first approaches 2

Treatment Options Following Confirmation

After CT confirmation, treatment options include:

• Laparoscopic appendectomy (standard treatment)

  • Remains the most common and definitive treatment for acute appendicitis 2
  • Preferred approach for most patients with confirmed appendicitis

• Antibiotic therapy alone (in selected cases)

  • May be considered in uncomplicated appendicitis without high-risk CT findings 2
  • Success rate approximately 70% in carefully selected patients
  • Not recommended if CT shows appendicolith, mass effect, or appendix diameter >13 mm 2

Important Considerations and Pitfalls

• Do not delay surgical consultation based solely on ultrasound findings; CT confirmation should be expedited
• Do not withhold pain medication while awaiting imaging or surgery; appropriate pain control does not mask symptoms or delay diagnosis 3
• Avoid oral contrast for CT in this setting as it may delay diagnosis without improving diagnostic accuracy 1
• Monitor for signs of perforation (increasing pain, fever, peritoneal signs) which would necessitate more urgent intervention 5

The management of acute appendicitis requires prompt diagnosis and intervention to prevent complications such as perforation, which significantly increases morbidity and mortality 5.