Should lung ultrasonography be more widely used in the assessment of acute respiratory disease?

Figures & data

Figure 1. The ten signs of lung ultrasound in the critically ill.

This figure shows the alphabet of lung ultrasound in the critically ill. In the right lung on top is the location of the pleural line (bat sign). The bat sign is a sort of G-key, allowing immediate recognition of the lung surface in all circumstances. Just below is the lung sliding (seashore sign in M-mode). Below is an A-line featuring horizontal repetition of the pleural line, a basic sign of air barrier. Below are the quad sign and the sinusoid sign, allowing standardized diagnosis of pleural effusion. In the left lung, on top is the typical shred sign (irregular deep border) indicating lung consolidation. Below is the tissue-like sign, another sign of consolidation. Below is the B-line, a sensitive sign: this is a comet-tail artifact arising from the pleural line, hyperechoic, long, well-defined, erasing A-lines, moving in concert with lung sliding. Several B-lines visible between two ribs are called lung rockets. See their practical relevance in the text. Below is the stratosphere sign, demonstrating abolition of lung sliding. The last image is the lung point, a sign specific to pneumothorax (the lung point corresponds to the cyclic and sudden visualization of lung signs when the collapsed lung touches the chest wall on inspiration).

Reprinted from [5] with permission from Springer Science+Business Media.

Figure 2. Practical analysis of the lung.

The left image first demonstrates one standardized point of analysis: the lower part of the anterior thorax in a supine patient (lower asterisk). Other points include one point at the upper part (upper asterisk), and one semiposterior point above the diaphragm, continuing the lower anterior point. Second, we can see the 5-MHz microconvex probe that makes critical ultrasound easy. This one in particular can analyze from 1 to 17 cm, i.e., the pleural line as well as the deep lung consolidations, and the whole body (venous network, heart, abdomen and optic nerve). This probe is smart: no time is lost changing it (meaning neither disinfecting it or purchasing it). The 8-cm probe length allows posterior analysis of critically ill patients who are in the supine position.

Reprinted from [5] with permission from Springer Science+Business Media.

Table 1. Ultrasound profiles used in the bedside lung ultrasound in an emergency protocol.

Ultrasound definitions	Diagnosis	Specificity of ultrasound using the defined profile (%)	Sensitivity of ultrasound using the defined profile (%)
B-profile (Diffuse anterior bilateral lung rockets with lung sliding)	Acute hemodynamic pulmonary edema	95	97
A-profile (Diffuse anterior bilateral A-lines with lung sliding)	Acute asthma or decompensated COPD	97	89
A-profile with deep venous thrombosis	Pulmonary embolism	99	81
A’-profile (Diffuse anterior A-lines with abolished lung sliding)	Pneumothorax	100^†	88
B’-profile (B-profile with abolished lung sliding)	Pneumonia	94	89
A/B profile (A-profile at one lung, B-profile at the other)
C-profile (Anterior lung consolidation)
A-profile plus PLAPS

^†When lung point present.

BLUE: Bedside lung ultrasound in an emergency; COPD: Chronic obstructive pulmonary disease; PLAPS: Posterolateral alveolar and/or pleural syndrome.

Data on specificity and sensitivity from [15].

Lichtenstein D. Whole Body Ultrasonography in the Critically Ill. Springer Verlag, Berlin, Germany (2010).

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Soldati G, Testa A, Sher S, Pignataro G, La Sala M, Silveri NG. Occult traumatic pneumothorax: diagnostic accuracy of lung ultrasonography in the emergency department. Chest133, 204–211 (2008).

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