Pleural effusion: auscultatory percussion was a useful test for ruling in and ruling out effusions.

Clinical bottom line (level 4)

  1. Auscultatory percussion may help to diagnose a pleural effusion, and if negative, made one much less likely.
Guarino et al: Journal of General Internal Medicine 1994; 9: 71-74
Expires April 2003

The study

Setting: Veterans' Affairs university affiliated hospital, USA

118 patients (aged range 32 to 96 years; mean 64, 90% male) chest radiographic evidence of pleural effusion. 175 control patients randomly selected from surgical and medical wards

Excluded if
  • if teaching cases for trainees



    • Independent blinded reference standard, applied in all patients from a consecutive inappropriate spectrum.
    Reference standard:
    • PA and lateral chest X-ray
    Diagnostic test:
    • Auscultatory percussion by attending (5) and house staff (60): With the patient sitting or standing back facing examiner the upper edge of the twelfth rib is marked on each side of the thorax. After 5 minutes upright, free pleural fluid gravitates to the base of the lung. The diaphragmatic piece of the stethoscope is placed posteriorly with its upper edge approximately 3 cm below the last rib in the midclavicular line. Direct percussion is applied with the free hand preferable by finger flicking or with the pulp of a finger, along three or more parallel lines from the apex of each hemithorax perpendicularly down toward the base
    • In the absence of pleural effusion, the percussion note perceived sounds dull and remains unchanged, but changes sharply to a loud note at the last rib, forming a horizontal baseline across the posterior hemithorax.
    • In the presence of pleural effusion, a similar sharp change to a loud percussion note occurs at the interface of air containing lung and pleural fluid, approximating a horizontal line across the posterior hemithorax clearly above the baseline at the last rib. In the absence of air in the pleural space, the fluid level is usually highest laterally towards the axilla. The distance between the level and the upper border of the last rib is measured and used as a guide for thoracentesis for estimation of fluid volume.

    The evidence


    differential diagnosis number of patients prevalence
    (95% CI)
    cause: malignancy 57 48%
    (39% to 57%)
    congestive heart failure 32 27%
    (19% to 35%)
    pneumonia 8 6.8%
    (2.2% to 11%)
    acute pancreatitis or pancreatic abscess 7 5.9%
    (1.7% to 10%)
    ascites 3 2.5%
    (0.0% to 5.4%)
    lung or subphrenic abscess 3 2.5%
    (0.0% to 5.4%)
    pulmonary infarction 2 1.7%
    (0.0% to 4.0%)
    traumatic rib fracture with haemothorax 2 1.7%
    (0.0% to 4.0%)
    empyema 2 1.7%
    (0.0% to 4.0%)


    diagnostic test pleural effusion no pleural effusion LR+
    (95% CI)    		 post-test probability LR-
    (95% CI)    		 post-test probability
    auscultatory percussion 113 9 19
    (9.8 to 35)     		93% 0.045
    (0.019 to 0.11)     		3%
    total 118 175

    Comments

    1. Examination requires training and takes five minutes to perform. As little as 50 ml of pleural effusion could be detected.
    2. Pleural effusions could be confirmed by asking a patient to lean to one side and then reassess the fluid level to see whether it had shifted. No false-positives were detected this way.
    3. All the patients with false negative results had loculated effusions.

    Citation

    1. Guarino JR, et al: auscultatory percussion: a simple method to detect pleural effusion. Journal of General Internal Medicine 1994; 9: 71-74
    Search Terms: pleural effusion in Cochrane
    Contributor: Donald Stanley and Chris Ball, April 2000
    Reviewer:

    Clinical Question.
    Patient suspected pleural effusion
    Intervention or Exposure auscultatory percussion
    Outcome diagnosis of pleural effusion