What is the most appropriate management for a 27-year-old obese woman presenting with right iliac fossa pain, anorexia, nausea, vomiting, and leukocytosis?

Management of Suspected Appendicitis in an Obese Young Woman

The most appropriate initial management is ultrasound (US) imaging, followed by CT if US is inconclusive, given that this patient is obese and imaging is essential before proceeding to surgery. 1

Diagnostic Imaging Algorithm

First-Line Imaging: Ultrasound

• US should be the initial imaging modality for all patients with suspected appendicitis, including this 27-year-old woman with classic symptoms (right iliac fossa pain, anorexia, nausea, vomiting, and leukocytosis). 1, 2
• The American College of Radiology recommends point-of-care or formal ultrasonography as the most appropriate first-line diagnostic tool when imaging is indicated based on clinical assessment. 1, 3
• US allows for swift decision-making with satisfactory sensitivity and specificity in diagnosing acute appendicitis. 1

Critical Caveat: Obesity Limitation

• In obese patients, US diagnostic performance is significantly limited, with higher false diagnosis rates compared to non-obese patients (46.2% vs 38.5% in females). 1
• Given this patient's obesity, there is a substantial likelihood that US will be inconclusive or technically limited. 1

Second-Line Imaging: CT Scan

• If US is inconclusive, negative, or technically limited (as expected in this obese patient), proceed immediately to contrast-enhanced CT abdomen and pelvis. 1, 4
• CT has become the primary diagnostic imaging modality for suspected appendicitis with high diagnostic yield: sensitivity 85.7-100% and specificity 94.8-100%. 4
• Low-dose contrast-enhanced CT provides diagnostic accuracy not inferior to standard CT while reducing radiation exposure. 1, 4
• The negative appendectomy rate with preoperative CT is only 1.7-7.7%, compared to historical rates of 14.7% without imaging. 4

Why Not Proceed Directly to Surgery?

Avoid Negative Laparotomy

• Without preoperative imaging, the negative appendectomy rate is 16.7% with clinical evaluation alone versus 8.7% with CT. 4
• Growing recognition of long-term morbidity associated with negative laparotomy has led to incorporation of preoperative imaging into clinical management algorithms. 4

Diagnostic Laparoscopy Reserved for Specific Scenarios

• Diagnostic laparoscopy should only be performed if imaging remains inconclusive but clinical suspicion remains high. 1
• Diagnostic laparoscopy has both diagnostic and therapeutic value, allowing immediate intervention if appendicitis is confirmed. 1
• However, proceeding directly to diagnostic laparoscopy without imaging bypasses the opportunity to confirm the diagnosis non-invasively and identify alternative diagnoses. 1

Practical Clinical Approach

For this specific patient (27-year-old obese woman with classic appendicitis symptoms):

1. Order US first (following guideline recommendations), but anticipate it may be limited by body habitus. 1, 2
2. Have a low threshold to proceed to CT given her obesity and the superior diagnostic performance of CT in this population. 4, 1
3. CT with IV contrast (without enteral contrast) achieves sensitivities of 90-100% and specificities of 94.8-100%, avoiding delays from oral contrast administration. 4
4. Surgical consultation follows confirmatory imaging, not before. 3

Answer: C (US) is technically correct as first-line, but B (CT) is the most practical choice given obesity. The algorithm is US → CT → Surgery/Diagnostic Laparoscopy if needed.