Sensitivity of Murphy's Sign in Acute Cholecystitis
Murphy's sign has a sensitivity of 63-86% for diagnosing acute cholecystitis, making it a useful but imperfect clinical finding that should never be relied upon in isolation. 1, 2
Diagnostic Performance Characteristics
Murphy's sign demonstrates moderate sensitivity with the following performance metrics:
- Sensitivity ranges from 63% to 86% across prospective studies, meaning it misses approximately 14-37% of acute cholecystitis cases 1, 2
- Specificity is relatively low at 35-94%, with most studies showing specificity around 35-50%, resulting in many false positives 1, 2
- Positive predictive value is only 43-73%, indicating that a positive Murphy's sign alone is insufficient for diagnosis 1, 2
- Negative predictive value is stronger at 82-91%, meaning its absence is somewhat more reliable for excluding disease 1, 2
The World Society of Emergency Surgery meta-analysis reported a positive likelihood ratio of only 2.8 (95% CI 0.8-8.6), with confidence intervals that include 1.0, demonstrating limited diagnostic power 3.
Critical Clinical Limitations
Murphy's sign has several important pitfalls that significantly limit its clinical utility:
- Prior pain medication administration invalidates the reliability of a negative Murphy's sign, making timing of examination crucial 3, 4
- The sign may be absent in elderly, diabetic, or immunocompromised patients despite severe gallbladder disease 5
- Low specificity means it cannot reliably differentiate acute from chronic cholecystitis when used alone 2
- The large number of false positives limits its standalone diagnostic value 2
Optimal Diagnostic Approach
No single clinical sign or laboratory test has sufficient diagnostic power to establish or exclude acute cholecystitis 3, 5. The most accurate diagnostic strategy combines multiple modalities:
Recommended Diagnostic Triad
When Murphy's sign is combined with elevated neutrophil count and ultrasound showing cholelithiasis or cholecystitis, diagnostic accuracy improves substantially:
- Sensitivity: 74% 6
- Specificity: 62% 6
- Positive predictive value: 80% 6
- Negative predictive value: 53% 6
This combination approach is significantly more accurate than Murphy's sign alone 5, 6.
Clinical Algorithm
- Elicit Murphy's sign during physical examination (maximal tenderness over the gallbladder during deep inspiration) 5
- Obtain complete blood count focusing on neutrophil elevation 6
- Perform ultrasound as first-line imaging (96% accuracy for gallstones, remains initial test of choice) 3, 5
- If ultrasound is negative but clinical suspicion remains high, proceed to hepatobiliary scintigraphy (97% sensitivity, 90% specificity) or CT with IV contrast 3, 4
Comparative Diagnostic Performance
The Tokyo Guidelines diagnostic criteria (which incorporate Murphy's sign along with other findings) demonstrate 84.9% sensitivity and 50.0% specificity for definitive acute cholecystitis, significantly outperforming Murphy's sign alone 7. This validates the necessity of using Murphy's sign as part of a comprehensive diagnostic algorithm rather than as an isolated finding 7.
Alternative Physical Examination Technique
Indirect fist percussion of the liver demonstrates 60% sensitivity for hepatobiliary infection, which is comparable to or better than Murphy's sign (30-33% in comparative studies), with 85% specificity 8. This technique may serve as a useful adjunct when Murphy's sign is equivocal 8.