Title: Lung Ultrasound in Pulmonary Edema<br/>Author: Feras Khan<br/><a href='http://umem.org/profiles/faculty/1145/'>[Click to email author]</a><hr/><ul>
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“B-Lines” can be seen in patients with pulmonary edema (see attached image below)</li>
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A “B-line” is a reverberation artifact defined by Lichtenstein as having several properties:</li>
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1. A comet-tail artifact</p>
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2. Arising from the pleural line</p>
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3. Well defined</p>
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4. Hyperechoic</p>
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5. Long (does not fade)</p>
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6. Erases A lines</p>
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7. Moves with lung sliding</p>
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A large amount of B-lines is pathologic</li>
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These artifacts are also called “comet-tails” due to their appearance</li>
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One or two B-lines can be seen in dependent lung zones in normal lungs</li>
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AIS (Alveolar interstitial syndrome) describes a group of conditions including <strong>pulmonary edema, interstitial pneumonia, and pulmonary fibrosis</strong> that show similar findings on lung ultrasonography</li>
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The most common presentation of this syndrome is from cardiogenic pulmonary edema and is characterized by B-lines in multiple lung zones</li>
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B lines correspond with interlobular septal thickening on CT scans, which represent pulmonary vascular congestion </li>
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<u><strong>Technique</strong></u></p>
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B-mode is used with the micro-convex (cardiac) probe scanning in at least 8 lung zones</li>
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Quantify the number of B-lines in each zone</li>
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A lung zone is considered to be<strong><em> “positive” when three or more B-lines</em></strong> are present in a longitudinal plane between two ribs</li>
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Two or more regions bilaterally are required to be defined as AIS</li>
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Bilateral diffuse B-lines have a specificity of 95% and a sensitivity of 97% for the diagnosis of pulmonary edema</li>
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<fieldset><legend>References</legend>
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1. Lichtenstein D, Mezie ́re G, Biderman P, et al. The comet-tail artifact. An ultra- sound sign of alveolar-interstitial syndrome. Am J Respir Crit Care Med 1997;
156(5):1640–6. </p>
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