studmed

LK-test – Evaluation of pleural effusion on the right side of the thorax

Bodytext1 Evaluation of pleural effusion corresponding to zone 3 on the right side of the thorax is performed by:

1. Placing the ultrasound transducer in the medioaxillary line at the lower limit of the right hemithorax
2. Identifying the liver
3. Moving the transducer cranially until the diaphragm is seen
4. Demonstrating or excluding the presence of a pleural effusion using:
– Presence or abscence of curtain sign?
– Presence or abscence of spine sign?

The principles for assessment of zone 5 are the same, the only difference being that the transducer is typically placed in the medioclavicular line at the posterior side of the chest

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Fact text: The video shows how to evaluate presence of pleural effusion in the right pleural space

LK-test – Normal pleura and pleural effusion on the right side

Bodytext1 The videos recorded at the lower limit of the right side of the thorax show presence and absence of pleural effusion in two different patients

In the recording from the patient without pleural effusion (right), a black area is absent above the diaphragm and during inspiration the “curtain sign” is present and the “spine” sign absent

Presence of normal lung ultrasound signs and the “curtain sign” hiding the organs below the transducer during inspiration rule out pleural effusion.

The recording in the patient with pleural effusion (left) shows a black area above the diaphragm consistent with pleural effusion

No lung ultrasound signs are visible in the costophrenic recess, and no “curtain sign” is seen

Click on the VIDEO CLIP button to view the video

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Fact text: The videos show lung ultrasound in two patients with and without pleural effusion

Observe the black area above the diaphragm in the patient with pleural effusion (left), and the normal lung ultrasound signs and the “curtain sign” coming into view on the monitor during inspiration in the patient without pleural effusion (right)

LK-test – Left diaphragm and pleural sinus

Bodytext1 A systematic approach will help:
– Place the probe beam parallel to the vertical plane

– Ensure that the OM of the transducer is oriented cranially and that the corresponding OI is placed on the left side of the screen. (In this way the cranial end of the transducer is always displayed towards the left side of the monitor)

– Find the spleen – if difficult you may rotate the transducer clockwise to get a better look in between the ribs

– Move the transducer cranially until the hyperechoic (white) line representing the diaphragm gets into sight

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Fact text: If the OM and OI are placed correctly, the left edge of the ultrasound screen (blue) correspond to the cranial part of the examined part of the body and the right side of the screen (red) corresponds with the caudal part of the examined part of the body

LK-test – Right diaphragm and pleural sinus

Bodytext1 A systematic approach will help:

– Place the beam of the probe parallel to the vertical plane

– Ensure that the OM ”notch” of the transducer is oriented cranially, and that this side of the transducer corresponds to the left side of the ultrasound screen – the OI dot must be placed on the left side of the ultrasound image on the screen

– Find the liver – if difficult you may rotate the transducer clockwise to get a better look in between the ribs

– Move the transducer until the hyperechoic (white) line representing the diaphragm is seen

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Fact text: If the OM and OI are placed correctly, the left edge of the ultrasound screen (blue) corresponds with the cranial part of the examined part of the body and the right side of the screen (red) corresponds with the caudal part of the examined part of the body

LK-test – Pleural effusion: The focused question

Bodytext1 The focused question regarding pleural effusion is:

Is fluid present in the pleural space?

The question is answered by using ultrasound imaging for detection of an anechoic (black) area above the diaphragm on either the left or the right side of the lower, posterior part of the thorax

The patient must be in supine or sitting position, preferably with elevated thorax so that the fluid is moved down/back

Beware: Patients placed in the Trendelenburg position may not show fluid due to movement of fluid into the apical area of the lung

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Fact text: The image shows pleural effusion on the right side of the body (top) and on the left side of the body (bottom)

Observe the black area above the diaphragm indicating pleural effusion

LK-test – Lung pulse

Bodytext1 Lung sliding is movement of the pleural line synchronous with the respiratory cycle

In addition, the pleural line may move in synchrony with the cardiac pulse

This movement, termed “lung pulse”, is caused by the force of the cardiac pulsation being transmitted to the lung and hence to the visceral pleura

Like lung sliding, lung pulse indicates that the visceral and parietal pleural surfaces are juxtaposed at the location of the probe

In case of pneumothorax, there will be no lung pulse

In case of failed intubation to right main bronchus there will be lung pulse on the left side but no sliding

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Fact text: The video shows pulsatile movement of the pleural line in synchrony with the cardiac pulsation – the so-called lung pulse

LK-test – Comparing ”lung sliding” and ”lung pulse”

Bodytext1 This video shows both ”lung pulse” and ”lung sliding”

Notice that ”lung pulse” is rhythmic and in synchrony with the cardiac pulsation. If in doubt it can be useful to palpate the peripheral pulse to check for synchrony

“Lung sliding” appears in synchrony with the respiratory cycle. Lung sliding is easier to see with higher tidal volumes, and disappears with apnea

Both lung signs indicate that the visceral and parietal pleural surfaces are juxtaposed at the location of probe

This is why lung sliding and lung pulse can be used to rule out the presence of air in between the two pleural sheets (i.e. pneumothorax)

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Fact text: The video shows normal lung pulse at the top and normal lung sliding at the bottom

LK-test – B-lines (Comet tails)

Bodytext1 B-line(s) is a lung artefact generated by an increased density of the underlying lung tissue. An example is when subpleural interlobular septae become edematous in cardiogenic pulmonary edema

A B-line is a hyperechoic, laser-like, vertical, reverberation artefact originating from the pleural line

B-lines are continuous from the pleural line to the bottom edge of the screen and do not fade in intensity

Few narrow B-lines can be seen in healthy persons, while multiple and wide B-lines suggest pathology

B-lines are used in emergency lung ultrasound to confirm or exclude the presence of pneumothorax and/or interstitial syndrome (ie. pulmonary edema)

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Fact text: The image shows a lung ultrasound picture obtained with an abdominal curved array probe
Rib and pleura are marked
Arrows indicate a narrow (A) and a wider (B) B-line

LK-test – B-lines – appearance with two different kinds of transducers

Bodytext1 B-lines look different dependent on the transducer type used

The images show B-lines recorded with a curved array (abdominal) transducer and an echo transducer

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Fact text: Top: Lung ultrasound image obtained with an abdominal curved array probe. Arrows indicate a narrow (A) and a wider (B) B-line

Bottom: Lung ultrasound image obtained with a phased array echo probe. Arrows point at two B-lines

LK-test – Video: B-lines

Bodytext1
In dynamic views B-lines move back and forth in synchrony with the lung sliding in real time

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Fact text: The videos display lung ultrasound recorded with an abdominal transducer
At the top, a few B-lines can be seen as vertical, hyperechoic (white), and sharply demarcated lines originating from the pleura line
At the bottom, multiple closely spaced B-lines are visible