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

CT Abdomen and Pelvis with IV Contrast is the Next Step

In a 21-year-old female with 12 hours of right lower quadrant pain, rebound tenderness, and leukocytosis, you should obtain a CT abdomen and pelvis with IV contrast before proceeding to surgery. 1, 2

Why Imaging Before Surgery

Even with classic clinical presentation (RLQ pain, rebound tenderness, leukocytosis), preoperative imaging is essential because:

• Clinical assessment alone misdiagnoses appendicitis in 34-68% of cases, leading to negative appendectomy rates of 14.7-25% when surgery is performed without imaging 1, 3
• Preoperative CT reduces the negative appendectomy rate to 1.7-7.7%, dramatically improving diagnostic accuracy 1, 2
• CT identifies alternative diagnoses in 23-45% of patients presenting with classic RLQ symptoms, fundamentally changing management 4, 1
• The classic presentation occurs in only ~50% of appendicitis cases, making imaging critical even when clinical suspicion is high 1

CT Diagnostic Performance

CT abdomen and pelvis with IV contrast demonstrates:

• Sensitivity: 85.7-100% 4, 1, 2
• Specificity: 94.8-100% 4, 1, 2
• No oral contrast is needed—IV contrast alone provides excellent diagnostic accuracy with faster acquisition 1, 2

Alternative Diagnoses CT Will Detect

CT frequently identifies other surgical and non-surgical conditions that mimic appendicitis:

• Gynecologic pathology in 21.6% of alternative diagnoses (ovarian torsion, ruptured cyst, ectopic pregnancy, PID) 4, 1
• Gastrointestinal conditions in 46% of alternative diagnoses (right-sided diverticulitis 8%, Crohn's disease, bowel obstruction 3%) 4, 1
• Genitourinary pathology (ureteral stones, pyelonephritis) 4, 5

Why NOT the Other Options

Option A (Direct Appendectomy): Unacceptable Risk

• Negative appendectomy rate of 14.7-25% without imaging exposes patients to unnecessary surgery and complications 1, 3
• Female patients have 2.23 times higher risk of negative appendectomy compared to males, making imaging even more critical in this demographic 3
• Age ≤40 years increases negative appendectomy risk 2.35-fold 3

Option D (IV Fluids and 24-Hour Observation): Inappropriate

• This patient has HIGH clinical suspicion (RLQ pain, rebound tenderness, leukocytosis)—observation is only appropriate for LOW-risk patients 1
• Rebound tenderness indicates peritoneal irritation, a key finding in established appendicitis that warrants immediate diagnostic imaging 1
• Delaying diagnosis risks perforation, which carries higher morbidity and fetal loss risk (relevant for reproductive-age women) 4

Option C (Abdominal X-ray): No Diagnostic Value

• Plain radiography provides very limited sensitivity for detecting acute appendicitis and has no role in modern appendicitis diagnosis 1, 6

Practical Implementation

Order: CT abdomen and pelvis with IV contrast (no oral contrast needed) 1, 2

While awaiting CT:

• Maintain IV hydration 1
• Provide mild analgesia (avoid opioids that mask symptoms) 1
• Keep patient NPO in case surgery is needed 1

After CT results:

• If appendicitis confirmed: Immediate surgical consultation for appendectomy 1
• If perforation with abscess: Consider percutaneous drainage followed by interval appendectomy 7
• If alternative diagnosis identified: Manage accordingly 1
• If negative but high clinical suspicion persists: Consider diagnostic laparoscopy 1, 2

Critical Pitfall to Avoid

Do not assume absence of fever excludes appendicitis—fever is absent in approximately 50% of appendicitis cases 1. This patient's leukocytosis and rebound tenderness are sufficient to warrant definitive imaging regardless of temperature. 1