What is the proper technique for percussion of the spleen to assess for splenomegaly?

Spleen Percussion Techniques for Assessing Splenomegaly

The most effective approach combines palpation with percussion methods, specifically using Middleton's maneuver for palpation and Castell's maneuver for percussion, as this combination achieves approximately 90% specificity for detecting splenomegaly. 1, 2, 3

Patient Positioning

• Position the patient supine or in the right lateral decubitus position to optimize access to the left upper quadrant and improve diagnostic accuracy. 1
• The right lateral decubitus position allows gravity to bring an enlarged spleen forward, making it more accessible to examination. 1

Percussion Techniques

Traube's Space Percussion

• Percuss the area bounded by the sixth rib superiorly, the left midaxillary line laterally, and the left costal margin inferiorly. 4, 3
• Normal findings reveal tympany due to underlying gastric and colonic air. 4
• Dullness in this space suggests splenomegaly, though this method has moderate sensitivity (approximately 74% area under ROC curve). 3

Castell's Maneuver

• Percuss the lowest intercostal space in the left anterior axillary line during both inspiration and expiration. 3
• A change from tympany to dullness during full inspiration suggests splenomegaly. 3
• This technique demonstrates high sensitivity (85.7%) but lower specificity (31.6%), making it excellent for screening but requiring confirmation. 3

Nixon's Maneuver

• Percuss along a line from the left costal margin toward the left axilla. 3
• This method has the lowest sensitivity (66.7%) among percussion techniques and is less reliable. 3

Palpation Techniques (Complementary to Percussion)

Supine Palpation

• Palpate with the patient supine, starting in the right lower quadrant and moving toward the left costal margin. 3
• This method has highest specificity (92.1%) and positive predictive value (91.7%), making it excellent for confirming splenomegaly when positive. 3

Middleton's Maneuver

• Examine the patient in the right lateral decubitus position with hips and knees flexed. 3
• This technique achieves the highest overall accuracy (93% area under ROC curve) and sensitivity (85.7%) among all methods. 3

Grading System for Detected Splenomegaly

When splenomegaly is identified, use this standardized grading system based on palpable distance below the left costal margin:

• Score 0.5: Normal spleen (not palpable). 1
• Score 1: Spleen extends halfway between left rib cage and first quadrant line. 1
• Score 2: Spleen extends to the median line. 1
• Score 3: Spleen extends halfway between median line and right rib cage. 1
• Score 4: Spleen extends to the right rib cage. 1

Clinical Performance and Limitations

• Physical examination has low sensitivity but reasonably good specificity for detecting splenomegaly. 2, 5
• Palpation is generally more sensitive and specific than percussion alone, but combining both methods achieves the best results with approximately 90% specificity. 2
• Interobserver variability is relatively high, so findings should be interpreted cautiously. 2
• Sensitivity is greatly influenced by the degree of splenic enlargement and patient body habitus—examination is more accurate in lean patients with marked splenomegaly. 2, 3

Confirmation and Follow-up

• Abdominal ultrasonography is recommended for confirmation when physical examination suggests splenomegaly or when findings are equivocal. 6
• Physical examination is particularly unreliable in obese patients, where imaging becomes essential. 1
• Contrast-enhanced CT scan serves as the gold standard for characterizing splenic abnormalities when further evaluation is needed. 7, 8

Critical Pitfalls to Avoid

• Do not rely on percussion alone—always combine with palpation for optimal diagnostic accuracy. 2
• Castell's maneuver has high sensitivity but poor specificity, so positive findings require confirmation with other methods or imaging. 3
• In obese patients, proceed directly to ultrasonography rather than relying on physical examination, which has very poor performance in this population. 1
• A normal physical examination does not exclude mild splenomegaly, particularly in patients with higher body mass index. 2, 3