Alvarado Score (MANTRELS)
Clinical prediction rule for acute appendicitis
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Why use it
Standardized clinical assessment for suspected appendicitis. Helps guide imaging decisions (CT abdomen/pelvis). Reduces negative appendectomy rates when used alongside imaging.
About
The Alvarado score (MANTRELS mnemonic) is a clinical scoring system for the diagnosis of acute appendicitis. It uses symptoms (migration of pain, anorexia, nausea/vomiting), signs (RLQ tenderness, rebound pain, elevated temperature), and laboratory findings (leukocytosis, left shift) to estimate the likelihood of appendicitis.
When to use
- Acute abdominal pain suspicious for appendicitis
- Decision support for CT imaging in RLQ pain
- Triage tool in emergency department
Formula
Pearls & pitfalls
- MANTRELS mnemonic: Migration, Anorexia, Nausea, Tenderness RLQ, Rebound, Elevation (temp), Leukocytosis, Shift (left).
- The score is most useful for determining whether imaging is needed, not for replacing imaging.
- In women of childbearing age, always consider gynecologic causes (ectopic, ovarian torsion, PID).
- CT has higher accuracy than Alvarado alone — use both together for best decisions.
- Modified Alvarado (no left shift) scores out of 9 and is sometimes used when differential not available.
Next steps
Score 1-4: Appendicitis unlikely, consider other diagnoses. Score 5-6: Equivocal — CT abdomen/pelvis recommended. Score 7-8: Probable appendicitis — surgical consultation. Score 9-10: Very probable — urgent surgical consultation.
Evidence
Developed by Alvarado (Ann Emerg Med, 1986). Multiple validation studies show sensitivity ~68-82% and specificity ~50-75%. Best at ruling out appendicitis with low scores. CT scan remains the gold standard for diagnosis.