Lung ultrasound in the management of acute decompensated heart failure

Abstract

Once thought impracticable, lung ultrasound is now used in patients with a variety of pulmonary processes. This review seeks to describe the utility of lung ultrasound in the management of patients with acute decompensated heart failure (ADHF). A literature search was carried out on PubMed/Medline using search terms related to the topic. Over three thousand results were narrowed down via title and/or abstract review. Related articles were downloaded for full review. Case reports, letters, reviews and editorials were excluded. Lung ultrasonographic multiple B-lines are a good indicator of alveolar interstitial syndrome but are not specific for ADHF. The absence of multiple B-lines can be used to rule out ADHF as a causative etiology. In clinical scenarios where the assessment of acute dyspnea boils down to single or dichotomous pathologies, lung ultrasound can help rule in ADHF. For patients being treated for ADHF, lung ultrasound can also be used to monitor response to therapy. Lung ultrasound is an important adjunct in the management of patients with acute dyspnea or ADHF.

Fig. (1)

The white arrowheads indicate B-lines. They arise from the pleural line (white arrow), are narrow, and extend vertically to the edge of the screen eliminating any horizontal lines.

Fig. (2)

The white arrows indicate horizontal A-lines. They represent reflection artifacts between the pleura and the surface of the chest wall, and are present in normal lung.

Fig. (3). (a)

Multiple B-lines with equidistant separation of 7 mm, seen in septal syndrome.

Fig. (3). (b)

Confluence of multiple B lines, appearing as two distinct bands outlined by the white double-headed arrows.

Fig. (3). (c)

Confluence of multiple B lines into what appears as the hyperechoic ‘white lung’.

Fig. (4). (a)

The right chest wall is divided into anterior and lateral, upper and lower halves for four zones per side. The margins delineating the anterior chest are the parasternal and anterior axillary lines, while the lateral chest are defined by the anterior and posterior axillary lines.

Fig. (4). (b)

The right chest is divided into anterior, lateral and posterolateral zones. Again, this can be further subdivided into upper and lower halves for a total of six zones per side. The patient is usually slightly turned to expose zone 3, which is beyond the posterior axillary line.

Fig. (4). (c)

Fixed locations on the anterior and lateral chest walls are placed along the parasternal, mid-clavicular, anterior axillary and middle axillary lines, from the second to the fifth intercostal space on the right chest, and from the second to the fourth intercostal space on the left chest, for a total of 28 scan sites.

Fig. (5)

(Video Clip) Reduced lung sliding is seen in a patient with bilateral pneumonia.

Fig. (6a)

With M mode ultrasound, regular small movements (white arrowheads) can be seen under conditions with reduced lung sliding. These are known as lung pulses, which are due to tiny movements between the parietal and visceral pleura created by transmission of cardiac pulsations to the lung.

Fig. (6b)

The heart rate can be calculated by measuring the intervals between the lung pulses.