Anaesthesiology - Critical Care Medicine - POCUS

Question 1

Define different echogenicities produced by US probe

Answer 1

• Isoechoic
• Hyperechoic – e.g. stones
• Hypoechoic – e.g. lymph node
• Anechoic – e.g. fluid

Question 2

Define colours on colour flow doppler

Answer 2

Blue away, Red towards (BART)

Question 3

4 positions of cardiac imaging by POCUS

Answer 3

Question 4

Define the structures seen on PLA on cardiac POCUS

S

Answer 4

Question 5

Define the structures seen on PSA on cardiac POCUS

Answer 5

Question 6

Define the structures seen on apical 4 chambers view on cardiac POCUSS

Answer 6

Question 7

Define the structures seen on subxiphoid view on cardiac POCUS

Answer 7

Question 8

Define Cavel Index and clinical use

Answer 8

Cavel index measures respiratory variation in diameter of the inferior vena cava to predict fluid responsiveness in spontaneous breathing emergency department patients with signs of shock.

Index correlates IVC size on POCUS with CVP

Assesses volume status and guides fluid management: low caval index in a patient with signs of shock is associated with fluid unresponsiveness; high caval index is inconclusive

Question 9

What is the normal size of the right ventricle at the apical 4 chamber view?

Answer 9

right ventricle is less than 2/3 of the size of the left ventricle

Question 10

Where is pericardial effusion in relation to the descending aorta in the parasternal long axis?

Answer 10

Anterior to the descending aorta

Question 11

List applications of cardiac POCUS

Answer 11

Assess cardiac function

Valvular assessment: Valve morphology (number of leaflets, movement, rheumatic heart valves, calcifications, vegetation)

Fluid status

Pericardial effusion +/- tamponade

Acute right heart strain (e.g. acute pulmonary embolism)

Aortic dissection

Question 12

Methods to assess left heart function on POCUS

Answer 12

LeLt ventricular ejection fraction
- Assess in Parasternal long axis view
- estimate bu “eyeballing LV movement” or degree of “LV squeeze”
- Measure distance of anterior mitral valve leaflet to septum (MV slapping septum = >50% LVEF; MV not touching septum = 30-50%; MV not moving = <30% LVEF)

Question 13

Assess severity of mitral regurgitation on POCUS

Answer 13

Observe doppler colour and size of mitral regurgitation jet:

Jet <20% of LA area = mild MR
Jet 20-40% of LA area = moderate MR
Jet >40% = severe MR

Question 14

Identify pathology

Answer 14

Calcified aortic valve (bright area), with severely impaired valve opening

Question 15

Identify pathology

Answer 15

Aortic regurgitation

Jet return to LA during systole

Question 16

Identify pathology

Answer 16

Tricuspid regurgitation

Question 17

Features of Rheumatic heart disease on cardiac POCUS

Answer 17

• Mixture of valvular dysfunction
• Atrial fibrillation
• Systolic doming on anterior mitral valve leaflet with “Hockey stick” appearance
• LA dilation

Question 18

Identify pathology

Answer 18

Mitral valve calcification

Question 19

Identify pathology

Answer 19

Endocarditis with vegetation on MV

Question 20

Define position of pericardial effusion and pleural effusion to the descending aorta

Answer 20

Pericardial effusion: Anterior to descending aorta

Pleural effusion:
Posterior to descending aorta

Question 21

Cardiac tamponade
Features on cardiac POCUS

Answer 21

Early: Systolic collapse of RA

Late: Diastolic collapse of RV

Question 22

Identify pathology

Answer 22

Massive pericardial effusion

Question 23

Features of pulmomary embolism on cardiac POCUS

Answer 23

Acute right heart strain:
RV dilatation
Interventricular septum bowing during systole into LV - D-shape LV

Question 24

Aortic dissection

Features on cardiac POCUS

Answer 24

Dilated aortic root
Dissection flap visible
Aortic regurgitation

Question 25

Answer 25

Question 26

Lung POCUS - Standard views - Positions

Answer 26

R1/L1: Anterior Superior lung field for pneumothroax and/or interstitial edema - Straight linear probe - At 2nd and 3rd ICS at MCL at left and right side - Find Batwing Sign (confirm between two ribs) and Lung Sliding (visceral and parietal pleura sliding over) and A-lines (equdistant artifacts under pleural line) R2/L2: Lateral lung view - Midaxillary line at 6th-7th ICS, lateral to nipple R3/L3: Posterolateral/ Posterior- Inferior lung view - Posterior axillary line, 10th-12th ICS - Indicator towards patient's head - Find Liver (R) or spleen (L), kidney, diaphragm, spine - FInd curtain sign (aerated lung slide over organs during inspiration)

Question 27

Absent lung sliding on lung POCUS Specific signs Ddx

Answer 27

There is no lung sliding present when the parietal and visceral pleura become separated by air (pneumothorax) or fluid (pleural effusion). Furthermore, severe COPD or anything that hyperinflates the lungs can markedly reduce pleural sliding. Ddx: - Pneumothroax - Pleural effusion - Pleurodesis - Acute infectious/ inflammatory consolidation - Fibrotic lung diseases - ARDS - Mainstem intubation Absence of lung sliding can be seen using B-mode or using M-mode (stratosphere sign and barcode sign).

Question 28

Interstital edema Features on Lung POCUS

Answer 28

B-lines form when interlobular septa and lung tissue thicken or fill with fluid. * Appear ray-like, hyperechoic, and vertical (c.f. A lines that are horizontal) * Emanate from the pleural line. * Move with lung sliding. * Extend to the periphery of the far-field. * Can be associated with a thickened pleural membrane. Fluid build-up causes convergence of B-lines into “Confluent B-lines.”

Question 29

Lung consolidation Features on POCUS

Answer 29

Consolidation is fluid build-up in lungs ultrasound findings will progress from multiple B-lines, confluent B-lines, subpleural consolidation, the shred sign, to a dense consolidation, and then "hepatization of the lung" Air-trapped inside consolidations cause: - Dynamic Air Bronchograms tend to occur in pneumonia and move as the patient inhales and exhales. - Static Air Bronchograms tend to occur when air bubbles are trapped behind an obstruction, as occurs in atelectasis, and don’t move with respiration.

Question 30

Pleural effusion Features on POCUS

Answer 30

Signs: The PLAPS point is the most specific and sensitive view used to diagnose pleural effusion. * Spine Sign: sound waves can pass through the pleural fluid allowing the spine to be seen above the diaphragm. * Jellyfish sign: consolidated lung is seen floating in the pleural effusion * Sinusoid Sign: parietal and visceral pleura moving closer and further apart while the patient breathes * Quad Sign: anechoic appearance often delineated by the pleural line, the rib shadows, and the lung line * Plankton Sign: shows an exudative effusion with swirling, hyperechoic debris. * Hematocrit Sign: echogenic layering of material in a pleural effusion * Loculated Pleural Effusions

Question 31

Answer 31

Question 32

COPD or Asthma Features on POCUS

Answer 32

normal findings such as lung sliding and A-lines but the patient still has symptoms and difficulty breathing, you should consider COPD, asthma, pulmonary embolism, or nonpulmonary conditions causing the patient’s dyspnea. – Bilateral A-lines – Reduced lung sliding

Question 33

Pulmonary embolism Features on POCUS

Answer 33

– Bilateral A-Lines – Deep Vein Thrombosis in Upper or Lower Extremities – Right Ventricular Enlargement (massive/submassive PE)

Question 34

Outline diagnosis of pneumothroax by POCUS

Answer 34

First, if lung sliding is present, you can rule out pneumothorax with 100% accuracy at that ultrasound point Second, if lung sliding is ABSENT, you should not automatically assume pneumothorax. Think ddx: severe consolidation, chemical pleurodesis, acute infectious or inflammatory states, fibrotic lung diseases, acute respiratory distress syndrome, or mainstem intubation. Third, if a lung point is present, you can rule in pneumothorax with 100% accuracy. Lung point is when you can see the transition between normal lung sliding and the absence of lung sliding. This is the transition point between the collapsed lung and normal lung.