Lung ultrasound in the critically ill patient BASICS

Transcription

1 Lung ultrasound in the critically ill patient BASICS Rohit Patel, MD University of Florida Health Director, Critical Care Ultrasound Surgical ICU Center for Intensive Care Gainesville, Florida

2 Introduction Learning Objectives Identify and interpret signs found in lung ultrasound Be 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

3 Critical Care Ultrasound A 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

4 What can I find? Pneumothorax Hemothorax Other pleural effusions Alveolar consolidation Pulmonary edema and/or extravascular lung water Pulmonary embolism?

5 What are the questions? Focused abdominal sonography in trauma Focused assessment Shock, hypoxia, oligoanuria, fever, etc.? with sonography in trauma

6 Principles of lung ultrasound A 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

7 Principles of lung ultrasound The 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

8 Principles of lung ultrasound Anterior zone = "BLUE hands" Lateral zone Posterior zone Lichtenstein. Textbook. Whole body ultrasonography in the critically ill.

9 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

10 Principles of lung ultrasound Stage 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

11 Principles of lung ultrasound Upper and Lower BLUE points Phrenic point PLAPS point Lichtenstein. Textbook. Whole body ultrasonography in the critically ill.

12 How to hold the probe Like 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

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14 Principles of lung ultrasound All signs arise from the pleural line This pattern: bat sign Rib shadows Pleural line A line

15 Principles of lung ultrasound The 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

16 Principles of lung ultrasound The main normal artifact: the A line Repetition 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

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19 A line

20 A line

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22 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

23 Principles of lung ultrasound B line Birolleau Variant B7 lines B3 lines

24 Principles of lung ultrasound B line video

25 Principles of lung ultrasound B line video

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29 Introduction Learning Objectives Identify and interpret signs found in lung ultrasound Be 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