Lung ultrasoundin the critically ill patient

BASICS

Rohit Patel, MDUniversity of Florida Health

Director, Critical Care Ultrasound Surgical ICUCenter for Intensive Care

Gainesville, Florida

Sunday, August 14, 16

IntroductionLearning ObjectivesIdentify and interpret ‘signs’ found in lung ultrasoundBe able to identify presence or absence of ‘lung sliding’Use ‘signs‘ found in lung ultrasound to evaluate respiratory failure in algorithm

Overlooked?Basic terminology -- was a free field, made sure no terms were used elsewhere

Sunday, August 14, 16

Critical Care UltrasoundA lines Bat sign B lines

B3 lines B7 lines BLUE protocol

BLUE points Comet tails Sinusoid sign

Jellyfish sign Lung point Merlin's space

PLAPS Point Quad sign Seashore sign

Shred sign Stratosphere sign

Tissue like sign Z lines

Sunday, August 14, 16

What can I find?

Pneumothorax

Hemothorax

Other pleural effusions

Alveolar consolidation

Pulmonary edema and/or extravascular lung water

Pulmonary embolism?

Sunday, August 14, 16

What are the questions?

Focused assessment with sonography in trauma

Focused abdominal sonography in trauma

Shock, hypoxia, oligoanuria, fever, etc.?

Sunday, August 14, 16

Principles of lung ultrasoundA simple, 2-d apparatus is the most appropriate

Most sophisticated are for cardiac, usually big, image resolution, start up time, probe shape, high cost all hinders

Sunday, August 14, 16

Principles of lung ultrasoundThe lung is the largest organ in the body

17% of body skin projection

Where to apply the probe? Same place as stethoscope?

BLUE points: similar to ECG or partitions of abdomen

Sunday, August 14, 16

Principles of lung ultrasoundAnterior zone = "BLUE hands"

Lateral zone

Posterior zone

Lichtenstein. Textbook. Whole body ultrasonography in the critically ill.Sunday, August 14, 16

Upper BLUE point: between third and fourth finger of BLUE hand, at palmar insertion

Lower BLUE point: middle of palm of lower BLUE hand; allows for avoidance of heart in most cases

Phrenic line: continuation of this line locates the lateral place

PLAPS point: "posterior and/or lateral alveolar and/or pleural syndrome" -- intersection between the posterior axillary line and the transversal line continuing posteriorly to the lower BLUE point; also can have extended PLAPS points

Sunday, August 14, 16

Principles of lung ultrasoundStage 1: anterior wall

Stage 2: adds lateral wall from anterior to posterior axillary line

Stage 3: external part of the posterior wall; aim from back towards sky; no visual control of probe so need to hold with whole hand; can depress bed if need to

Stage 4: patients must be positioned laterally or sitting; can also study the apex

Sunday, August 14, 16

Principles of lung ultrasoundUpper and Lower BLUE points

Phrenic point

PLAPS point

Lichtenstein. Textbook. Whole body ultrasonography in the critically ill.Sunday, August 14, 16

How to hold the probeLike a fountain pen

Decreases fatigue

Minimizes pressure placed (important for vascular structures and optic nerve)

Operators hand must remain still especially with dynamic evaluations

Don't hold the probe too tight --> can fatigue you (another person should be able to withdraw it from your grip)

May confuse when evaluating lung artifacts with your own movement if not stable

Sunday, August 14, 16

Sunday, August 14, 16

Principles of lung ultrasoundAll signs arise from the pleural line

Rib shadows

A line

Pleural line

This pattern: bat sign

Sunday, August 14, 16

Principles of lung ultrasoundThe pleural line indicates the interface between the soft tissues (rich in water) and lung tissue (rich in air); parietal pleura in all cases and visceral pleura only when no pneumothorax

Lung sliding indicates inspiratory descent of the visceral pleura against the parietal pleura, and the expiratory ascent

Observation of the pleural line shows this to and fro dynamic (glittering, shimmering, sparkling, twinkling)

Better seen with longitudinal scans and hand must be motionless; M mode useful for data recording

Sunday, August 14, 16

Principles of lung ultrasound

The main normal artifact: the A lineRepetition of the pleural line, roughly horizontal hyperechoic from the pleural line

Comes from air blocking the ultrasound beam

Distance between the pleural line and A line is equal to the skin-pleural line difference

Sunday, August 14, 16

Sunday, August 14, 16

Sunday, August 14, 16

A line

Sunday, August 14, 16

A line

Sunday, August 14, 16

Sunday, August 14, 16

Principles of lung ultrasound

B lines arise from fluid air artifacts and give hyperechoic patterns and up to a completely diffuse white pattern called Birolleau variant

Conclude that fluids traditionally described as anechoic make hyperechoic tones when small and surrounded by air

Sunday, August 14, 16

Principles of lung ultrasoundB line B7 lines B3 lines

Birolleau Variant

Sunday, August 14, 16

Principles of lung ultrasoundB line video

Sunday, August 14, 16

Principles of lung ultrasoundB line video

Sunday, August 14, 16

Sunday, August 14, 16

Sunday, August 14, 16

Sunday, August 14, 16

IntroductionLearning ObjectivesIdentify and interpret ‘signs’ found in lung ultrasoundBe able to identify presence or absence of ‘lung sliding’Use ‘signs‘ found in lung ultrasound to evaluate respiratory failure in algorithm

Overlooked?Basic terminology -- was a free field, made sure no terms were used elsewhere

Sunday, August 14, 16