Management of Appendicitis with Alvarado Score of 5
For a patient with an Alvarado score of 5, obtain a CT scan of the abdomen and pelvis with IV contrast to confirm or exclude appendicitis, as this intermediate score indicates only 30-36% probability of appendicitis and lacks diagnostic certainty. 1
Risk Stratification at Alvarado Score 5
An Alvarado score of 5 places the patient in the intermediate risk category (scores 4-6), where approximately 30-36% of patients actually have appendicitis 1. This equivocal range has:
- Sensitivity of only 35.6% for detecting acute appendicitis 2
- Specificity of 94% 2
- The score is insufficiently specific to confirm or exclude appendicitis on clinical grounds alone 3
Recommended Diagnostic Algorithm
Primary Recommendation: CT Imaging
Obtain CT abdomen/pelvis with IV contrast immediately 1, 2. This is the strongest recommendation because:
- CT following equivocal clinical presentation has 90.4% sensitivity and 95% specificity for appendicitis 2
- Patients with intermediate Alvarado scores (4-6) derive the greatest diagnostic benefit from CT evaluation 1
- CT can distinguish complicated from uncomplicated appendicitis, which impacts management 4
Special Population Considerations
For elderly patients (≥60 years):
- The World Society of Emergency Surgery strongly recommends CT scan for all elderly patients with Alvarado score ≥5 4
- The Alvarado score is less reliable at extremes of age (0-10 years and 60-80 years) 1, 3
- Elderly patients have higher risk of perforation and atypical presentations 4
If IV contrast is contraindicated (renal disease):
- MRI is preferred if available 4
- Non-contrast CT is the alternative if MRI unavailable 4
- Ultrasound can confirm but not exclude appendicitis 4
Clinical Observation Alternative
If immediate CT is unavailable or patient refuses imaging:
- Admit for clinical observation with serial abdominal examinations 4
- Obtain CT if symptoms persist or worsen during observation 4, 1
- Do not discharge patients with intermediate scores without adequate monitoring, especially elderly patients 4
Management Based on CT Results
If CT confirms appendicitis:
- Proceed to surgical consultation for appendectomy 3
- Laparoscopic approach preferred in elderly patients (reduced morbidity, length of stay, costs) 4
If CT excludes appendicitis:
- Repeat clinical assessment can rule out appendicitis in 59% of initially equivocal cases 1
- Consider alternative diagnoses (urinary tract infection can cause symptom overlap and affect Alvarado scoring) 5
Critical Pitfalls to Avoid
- Never use Alvarado score alone to confirm appendicitis at score 5—the positive predictive value is insufficient 3
- Do not discharge without imaging or observation—35.6% of patients with scores 4-6 have appendicitis 2
- Do not rely on ultrasound alone to exclude appendicitis in this intermediate range 4
- Avoid delaying CT in elderly patients—they have higher perforation rates and atypical presentations 4
Alternative Scoring Systems
Consider using the AIR (Appendicitis Inflammatory Response) score or Adult Appendicitis Score (AAS), which outperform the Alvarado score with better sensitivity and specificity 3. However, regardless of scoring system used, CT imaging remains indicated for intermediate-risk patients 1, 2.