What is a positive Murphy sign?

Murphy's Sign: Definition and Clinical Significance

A positive Murphy's sign is the arrest of inspiration during deep palpation of the right upper quadrant due to pain when the inflamed gallbladder comes in contact with the examiner's fingers, and is a key physical examination finding suggestive of acute cholecystitis. 1

Clinical Technique and Interpretation

The Murphy's sign is elicited through the following procedure:

• Position the patient supine
• Place your fingers under the right costal margin at the mid-clavicular line
• Ask the patient to take a deep breath
• A positive sign occurs when the patient abruptly stops inspiration due to pain as the inflamed gallbladder descends and contacts the examiner's fingers

Diagnostic Value

• Sensitivity and Specificity: While useful, Murphy's sign has relatively low specificity for acute cholecystitis 1
• Likelihood Ratio: Positive likelihood ratio of approximately 2.8 (95% CI: 0.8-8.6) 1, 2
• Limitations: The absence of Murphy's sign is unreliable as a negative predictor if the patient has received pain medication prior to examination 1

Sonographic Murphy's Sign

The sonographic Murphy's sign is a variation performed during ultrasound examination:

• Defined as focal tenderness precisely over the sonographically localized gallbladder 1
• Used in conjunction with other ultrasound findings to differentiate acute cholecystitis from other gallbladder conditions 1
• While helpful when positive, it is relatively insensitive for accurate diagnosis of acute cholecystitis 3
• Overreliance on the sonographic Murphy's sign can result in surprisingly low diagnostic accuracy in practice 3

Clinical Context and Diagnostic Algorithm

Murphy's sign should be considered within a broader diagnostic approach for suspected acute cholecystitis:

1. Clinical presentation: Right upper quadrant pain, fever, nausea/vomiting 1
2. Physical examination: Murphy's sign, abdominal tenderness, palpable gallbladder lump (in complicated cases) 1
3. Laboratory tests: Elevated white blood cell count, C-reactive protein 1
4. Imaging: Ultrasound (first-line), CT with IV contrast, or MRCP if common bile duct stones are suspected 1

Important Caveats

• No single finding is sufficient: As no single feature has sufficient diagnostic power to establish or exclude acute cholecystitis, it is recommended not to rely solely on Murphy's sign or any other isolated clinical or laboratory finding 1
• False positives: A positive Murphy's sign can occur in other conditions, including rare cases like pericardial hematoma from right atrial tear causing right heart failure 4
• Diagnostic combination: For the diagnosis of acute cholecystitis, a combination of detailed history, complete clinical examination, laboratory tests, and imaging investigations is recommended 1

Imaging Correlation

When a positive Murphy's sign is detected, ultrasound typically reveals:

• Gallbladder wall thickening
• Pericholecystic fluid
• Distended gallbladder
• Gallstones (often impacted in cystic duct) 1, 5

The presence of these findings along with a positive Murphy's sign significantly increases the likelihood of acute cholecystitis and should prompt appropriate management according to current guidelines.