What is the appropriate management for a patient presenting with lower right quadrant pain?

Management of Lower Right Quadrant Pain

For adults presenting with lower right quadrant pain, obtain CT abdomen and pelvis with IV contrast as the initial imaging study, as this provides superior diagnostic accuracy (95% sensitivity, 94% specificity) for appendicitis while simultaneously identifying alternative diagnoses in 23-45% of cases. 1, 2

Initial Diagnostic Imaging Algorithm

Non-Pregnant Adults

• CT abdomen and pelvis with IV contrast is the first-line imaging modality for evaluating right lower quadrant (RLQ) pain in adults with fever and leukocytosis, as recommended by the American College of Radiology 1
• This approach achieves 95% sensitivity and 94% specificity for appendicitis while identifying critical alternative diagnoses including colonic diverticulitis, bowel obstruction, colorectal malignancy, gynecologic pathology, urinary tract conditions, and mesenteric ischemia 2
• IV contrast is essential for optimal diagnostic accuracy; oral contrast may be added for better bowel visualization but is not mandatory 2

Women of Reproductive Age

• Consider pelvic ultrasound (combined transabdominal and transvaginal) as initial imaging to evaluate gynecologic causes while avoiding radiation exposure 2
• However, recognize that ultrasound has significant limitations: the appendix is not visualized in 20-81% of cases, and sensitivity ranges widely from 21% to 95.7% depending on operator experience and patient body habitus 2
• If ultrasound is equivocal or non-diagnostic, proceed immediately to CT with IV contrast to avoid diagnostic delay without ultimately avoiding radiation 2

Pregnant Patients

• Begin with ultrasound abdomen, followed by MRI abdomen and pelvis without IV contrast if ultrasound is non-diagnostic 1
• MRI demonstrates superior performance in pregnancy with 100% sensitivity, 98% specificity, 89% positive predictive value, and 100% negative predictive value for appendicitis 1
• MRI visualizes the appendix in 80% of cases compared to only 7% with ultrasound, and identifies alternative pathology in 12% versus 2.6% for ultrasound 1
• Reserve CT for patients with equivocal ultrasound AND MRI findings 1

Critical Differential Diagnoses Beyond Appendicitis

In Elderly Females (High-Risk Population)

The American College of Radiology emphasizes a broad differential diagnosis in elderly females 2:

• Right-sided colonic diverticulitis - increasingly common with age and can precisely mimic appendicitis 2
• Bowel obstruction - particularly adhesive small bowel obstruction if prior abdominal surgery (85% sensitivity, 78% specificity for adhesions) 2
• Colorectal malignancy - accounts for approximately 60% of large bowel obstructions in elderly patients, especially with rectal bleeding or unexplained weight loss 2
• Mesenteric ischemia - critical time-sensitive diagnosis requiring high clinical suspicion in patients with cardiovascular disease 2
• Appendicitis with atypical presentation and higher perforation rates due to delayed diagnosis 2

General Population

Additional causes identified on CT include 3, 4:

• Inflammatory and infectious conditions of the ileocecal region 3
• Conditions affecting epiploic appendages, omentum, and mesentery 3
• Urinary tract pathology including nephrolithiasis with referred pain 5, 4
• Gynecologic conditions in females 4, 6

Immediate Management Priorities While Awaiting Imaging

The World Journal of Emergency Surgery recommends 2:

• NPO status 2
• IV fluid resuscitation 2
• Nasogastric decompression if bowel obstruction suspected 2
• Broad-spectrum antibiotics if infection suspected 2
• Surgical consultation - do not delay while awaiting imaging if clinical suspicion is high 2

Critical Pitfalls to Avoid

In Elderly Patients

• Atypical presentations are the norm - elderly patients frequently lack classic symptoms, have blunted inflammatory responses, and present later in disease course with higher complication rates 2
• Normal laboratory values do not exclude serious pathology - many tests are nonspecific and may be normal despite serious infection or perforation 2
• Consider prior abdominal surgery history, last bowel movement, rectal bleeding, unexplained weight loss, chronic constipation, and cardiovascular disease as critical historical factors 2

With Ultrasound-First Strategy

• High non-visualization rates create diagnostic uncertainty requiring subsequent CT anyway 2
• Performance varies dramatically with operator experience and patient body habitus, with false-positive rates higher in females 2
• Equivocal results necessitate CT, resulting in diagnostic delay without avoiding radiation exposure 2

In Pediatric Patients

• While ultrasound is preferred to avoid radiation, CT provides operator-independent higher diagnostic accuracy and improved patient outcomes including decreased negative laparotomy and perforation rates 7
• Complications from delayed diagnosis include abscess formation, peritonitis, sepsis, bowel obstruction, and death 7