In a 21-year-old woman with 12 hours of right lower quadrant pain, rebound tenderness, and leukocytosis, what is the next appropriate step in management?

Next Step in Management

In this 21-year-old woman with classic acute appendicitis presentation (12 hours of right lower quadrant pain, rebound tenderness, and leukocytosis), the next appropriate step is CT abdomen and pelvis with IV contrast (Option B) before proceeding to surgery.

Rationale for CT Before Appendectomy

Even with a highly suggestive clinical presentation, preoperative imaging is essential because clinical assessment alone misdiagnoses appendicitis in 34-68% of cases. 1 The negative appendectomy rate without imaging reaches 14.7-25%, compared to only 1.7-7.7% when CT is obtained first. 1

Diagnostic Performance of CT

• CT abdomen/pelvis with IV contrast demonstrates 85.7-100% sensitivity and 94.8-100% specificity for acute appendicitis 1, 2
• CT identifies alternative diagnoses in 23-45% of patients presenting with right lower quadrant pain and classic symptoms, fundamentally changing management 1
• Common alternative diagnoses include:
  • Gynecologic pathology (21.6% of alternative diagnoses): ovarian torsion, ruptured cyst, ectopic pregnancy, pelvic inflammatory disease 1
  • Gastrointestinal conditions (46% of alternative diagnoses): right-sided diverticulitis, Crohn's disease, bowel obstruction 1
  • Genitourinary pathology: ureteral stones, pyelonephritis 1

Why Not Immediate Appendectomy?

• Classic presentation occurs in only ~50% of appendicitis cases, making clinical diagnosis unreliable 1
• Proceeding directly to surgery without imaging exposes patients to unnecessary operations when alternative diagnoses are present 1
• CT also identifies complications (perforation, abscess) that may alter surgical approach 1

Why Not Observation?

• This patient has peritoneal signs (rebound tenderness) and leukocytosis, placing her in the intermediate-to-high risk category, not low-risk 1
• Observation with IV fluids (Option D) is only appropriate for low-risk patients without rebound tenderness who can be safely discharged with 24-hour follow-up 1
• The presence of rebound tenderness indicates peritoneal irritation—a key finding in established appendicitis that warrants definitive imaging 1

Optimal CT Protocol

• Order CT abdomen/pelvis with IV contrast only (no oral contrast) for rapid acquisition without loss of diagnostic accuracy 1
• IV contrast alone provides excellent sensitivity (90-100%) and specificity (94.8-100%) 1
• Eliminating oral contrast reduces time to scan completion by approximately 23 minutes and ED length of stay by 29 minutes 3

Management Algorithm After CT

• If CT confirms appendicitis → immediate surgical consultation for appendectomy 1
• If CT shows perforated appendicitis with abscess → percutaneous drainage followed by interval appendectomy 1
• If CT reveals alternative diagnosis → manage according to specific findings 1
• If CT is negative but clinical suspicion remains high → consider diagnostic laparoscopy 1

Critical Pitfalls to Avoid

• Do not assume fever is required for appendicitis—fever is absent in approximately 50% of cases 1
• Do not delay imaging in favor of prolonged observation when peritoneal signs are present 1
• Do not proceed to appendectomy based solely on clinical findings when imaging can prevent 14.7-25% negative appendectomy rate 1
• Ensure pregnancy test is obtained before CT in all reproductive-age women due to radiation and contrast implications 4