How should an elderly woman with new‑onset right‑sided abdominal pain be evaluated and managed acutely?

Evaluation and Management of Right-Sided Abdominal Pain in an Elderly Woman

An elderly woman with new-onset right-sided abdominal pain requires immediate CT scan with IV contrast and strong consideration for hospital admission, as this population has significantly higher mortality (up to 8%), more frequently presents with life-threatening conditions requiring surgery (22%), and often lacks typical physical examination findings despite serious pathology. 1

Immediate Diagnostic Workup

Critical Laboratory Tests

• Complete blood count to assess for leukocytosis (though 43% of elderly patients with serious pathology lack leukocytosis) 1
• Serum lactate as a marker of poor tissue perfusion, critical for detecting bowel ischemia and septic shock 1
• Procalcitonin (PCT) correlates with intestinal necrotic damage and mortality 1
• C-reactive protein (CRP) to assess severity, though elevated CRP alone cannot establish diagnosis 2
• Comprehensive metabolic panel and coagulation studies 3

Imaging Strategy

CT abdomen/pelvis with IV contrast is the mandatory first-line imaging study to detect bowel obstruction, perforation, peritonitis, ischemia, colorectal malignancy, and complications with high sensitivity and specificity. 1, 3, 4 Plain abdominal X-rays have only 50-60% diagnostic accuracy and should not delay CT imaging. 1

Critical Physical Examination Components

Mandatory Assessments

• Digital rectal examination to detect rectal mass, fecal impaction, blood, or rectal prolapse 1
• Examination of all hernia orifices to detect incarcerated hernias 1
• Assessment for abdominal rigidity which indicates perforated viscus requiring immediate surgical consultation 1
• Pain out of proportion to examination findings is the hallmark of acute mesenteric ischemia and demands immediate imaging 1

Life-Threatening Diagnoses to Consider

Right-Sided Pathology (Priority Order)

1. Acute appendicitis: Complicated appendicitis with perforation occurs in 18-70% of elderly cases versus 3-29% in younger patients, with mortality reaching 8%. 1 The typical triad of migrating right lower quadrant pain, fever, and leukocytosis is infrequently observed in elderly patients. 2

2. Bowel obstruction with ischemia: Accounts for 15% of acute abdominal pain admissions with mortality up to 8% and 22% requiring surgery. 1 Small bowel obstruction from adhesions represents 55-75% of cases, particularly with prior abdominal surgery. 1

3. Mesenteric ischemia: Carries 30-90% mortality if missed, particularly in patients with cardiovascular disease, atrial fibrillation, or recent MI. 1, 3

4. Acute cholecystitis: The most common indication for surgery in elderly patients due to age-related biliary system changes. 5

5. Colorectal cancer: Accounts for 60% of large bowel obstructions in this age group. 1, 3

6. Perforated diverticulitis: Though typically left-sided, can present atypically; only 50% present with lower quadrant pain, 17% have fever, and 43% lack leukocytosis. 1

Critical Diagnostic Pitfalls

Clinical Presentation Challenges

Do not rely on clinical signs and symptoms alone to diagnose or exclude serious pathology. 2 The guidelines strongly recommend against basing diagnosis only on clinical presentation because:

• Lower rate of correct pre-operative diagnosis compared to younger population 2
• Average time from symptom onset to admission is greater in elderly patients 2
• Physical examination can be misleadingly benign even with catastrophic conditions 5
• Typical signs of abdominal sepsis may be masked 1

Laboratory Test Limitations

Do not base diagnosis solely on elevated leukocyte count and CRP values. 2 While these tests should prompt adequate diagnostic workup, they have insufficient diagnostic accuracy for diagnosis in elderly patients. 2 However, normal values have 100% negative predictive value for excluding appendicitis. 2

Scoring System Use

Alvarado score can be used for excluding appendicitis (score <5) but not for diagnosing it in elderly patients. 2 Scores of 5-10 correspond to high risk requiring imaging. 2

Immediate Management Protocol

Resuscitation and Stabilization

• Intravenous crystalloid resuscitation with isotonic dextrose-saline and supplemental potassium 1
• Nasogastric tube placement if bowel obstruction or severe vomiting to prevent aspiration pneumonia 1
• Foley catheter to monitor urine output as perfusion marker 1
• Intravenous acetaminophen 1g every 6 hours as first-line analgesia in multimodal approach 1
• Opioids reserved for breakthrough pain only at lowest effective dose 1

Indications for Immediate Surgical Consultation

• Hemodynamic instability despite resuscitation 1
• CT evidence of perforation, closed-loop obstruction, or bowel ischemia 1
• Strangulated hernia 1
• Abdominal rigidity indicating perforated viscus 1

Disposition Decision

Hospital admission is strongly indicated for elderly patients with:

• Any concerning features on imaging 1
• Inability to exclude surgical pathology 1
• Advanced age alone with right-sided abdominal pain given the high-risk differential diagnoses 1

The combination of atypical presentations, delayed diagnosis leading to higher perforation rates, and significantly increased mortality in this population mandates aggressive evaluation and low threshold for admission. 1, 5