EDE

Question 1

When probe is longitudinal, left side of screen is cephalad or caudad?

Answer 1

Cephalad

Question 2

When probe is transverse, left side of the screen is right or left side of the patient’s body?

Answer 2

Right

Question 3

Name the three forms of artifact

Answer 3

Refraction, Shadowing, Enhancement

Question 4

Explain refraction (form of artifact)

Answer 4

Occurs when U/S waves are deflected from their original path by passing close to a large, curved smooth walled structure - result is a shadow like image that seems to project from the edge of a curved structure

Question 5

Shadowing

Answer 5

Acoustic shadow ie. behind bone. Too lineasr to be mistaken for free fluid.

Question 6

Enhancement

Answer 6

Opposite of shadowing. When U/S waves go through an area of low resistance ie. fluid, tissues on the far side glow more brightly than the tissues beside them.

Question 7

Is AAA scan in transverse or longitudinal plane

Answer 7

transverse

Question 8

What is the landmark for the aorta?

Answer 8

Internal landmark: Spine and Acoustic Shadow, External Landmark: Xiphoid Process

Area of Interest: Outer wall of aorta

Question 9

4 criteria to identify the aorta and then two MAIN criteria

Answer 9

(1) location - aorta and IVC anterior to spine, look immediately near field to spine (2) wall thickness - aortic wall thicker than that of the IVC so more echogenic (3) non compressibility (4) lack of respiratory variability (IVC will collapse slightly when patient inspires - can exaggerate this by asking the patient to sniff quickly. Do not rely on pulsatility. Two main criteria: echogenicity and non-compressibility.

Question 10

How to improve your image if difficulty seeing abdominal aorta

Answer 10

(1) push gas away by pushing deeper (2) move to the side and then heel medially (3) flex patient knees to relax abdo muscles (4) iliac bifurcation tends to be level with the umbilicus - air in the umbilicus can cause scatter and block your view of the bifurcation - placing lots of gel in the umbilicus can help (or you can treat this air as you did bowel gas) **special note - sniff test will be negative (IVC will not collapse if right sided pressures are high ie. tamponade)

Question 11

Initial depth for vascular access

Answer 11

5 cm

Question 12

Needle insertion pointers:

Answer 12

(1) insert needle very close to edge of probe at sharp angle - 45 degrees or greater (2) will penetrate the vein at 1.4x the depth ie. 2cm from skin will be penetrated at 2.8 cm (3) dimple skin with needle cap to see if entry point directly above the vein

Question 13

three things that help to get needle to its target with vascular access

Answer 13

(1) ring down artifact - can be used as a guide for needle location but not for depth (2) vein wall tenting and rebound - to confirm cannulation, look for tenting of anterior vein wall (3) probe slide - if you lose view of needle tip, slide probe away until you locate the needle tip again. Always advance probe first and then advance needle for safety.

Question 14

IJ line placement key features

Answer 14

(1) patient in trendelenburg (2) turn head 20-30 degrees to the left (3) transverse: probe just above the clavicle, jugular vein joins the subclavian vein at this level and becomes less round and more elongated (4) do not cannulate where the jugular and subclavian join as needle may find the nearby pleura at this level - slide probe cephalad and sway from pleura for ideal cannulations

Question 15

Femoral Line Placement Key Features

Answer 15

(1) Reverse trendelenburg to distend common femoral vein by up to 50% (2) place probe just caudad to inguinal ligament (3) leg in slight abduction and external rotation (4) cannulate common femoral between the inguinal ligament proximally and its division into superficial and deep branches distally

Question 16

Subclavian Vein Cannulation Tips

Answer 16

(1) useful in trauma when there is a collar (2) useful in hypovolemic patients as IJ and femoral can be quite flat (3) more difficult to visualize due to overlying clavicle (4) locate best spot depending on where SVC goes under clavicle - often may be confluence of IJ and SVC.

Question 17

Peripheral IV placement key features

Answer 17

(1) set depth to 2-3 cm minimum (2) arm in dependent position, place tourniquet (3) will need 2.5 inch PIV catheters (4) veins should be compressible with very little pressure

Question 18

To place a peripheral IV, a vein must be:

Answer 18

(1) visible for at least 1 cm (2) diameter more than 3 mm (3) less than 1.5 cm deep

Question 19

Best veins to look for for peripheral IV placement

Answer 19

• cephalic and basilic veins
• place probe two finger widths proximal to antecubital fossa
• slide probe to look for veins; both small and superficial
• cephalic is lateral upper arm
• basilic on medial aspect
• brachial veins are lateral to the basilic vein; avoid brachial veins due to proximity of brachial artery and median/ulnar nerves

Question 20

Additional peripheral IV tips

Answer 20

externally rotate arm if targeting basilic vein, indent skin first (use blunt end of needle cap), put local anesthetic at the site of puncture, barely touch the skin with the probe, shallow angle, can make your needle more echogenic by lightly scoring the distal shaft several times with a scalpel or scissor edge

Question 21

Cardiac EDE - reasons to use

Answer 21

(1) cardiac standstill (2) pericardial effusion

Question 22

Placement of probe and movement of probe in cardiac EDE

Answer 22

Place probe flat on abdomen just cephalad to umbilicus –> slide probe up midline of abdomen –> identify heart and center on screen –> identify pericardium –> perform anterior-posterior sweep. Near field images are inferior and far field images are superior.

Question 23

Cardiac EDE Anatomy

Answer 23

Pericardium shows up as a bright, white, thick line surrounding the heart - it surrounds the heart on three sides (there is no pericardium at the top right corner of heart as this is where the great vessels enter - this shows up as far field screen left.) Pericardial effusions will first be visible in inferior posterior area as this is the most dependent part (near field.)

Internal Landmark: Liver
External Landmark: Midline just cephalad to umbilicus

Question 24

Complete Cardiac EDE Scan

Answer 24

(1) Need to see inferior pericardium all the way to the septum (2) Need to sweep completely through the heart passing from anterior to posterior and back again watching the heart disappear at each extreme **Note - epicardial fat pad will be seen anteriorly - can figure this out based on position of probe. If probe flat and see something suspicious that disappears when you sweep posteriorly, most likely anterior epicardial fat pad. (3) must see liver

Question 25

Pericardial Effusion on EDE

Answer 25

PCEs will be appreciable at 100 mL posteriorly in systole, 100-300 mL posteriorly throughout cycle, 300 mL anteriorly and posteriorly. If acute, the normal pericardium can only accommodate 100-200 mL of fluid before hemodynamic compromise but if chronic can hold more.

Question 26

Additional tips for Cardiac EDE:

Answer 26

• inspiration to bring down diaphragm and heart for a better view (and sweep probe posteriorly)
• slide probe to patient right and heel to patients left to recenter the heart - this helps use liver as an acoustic window

Question 27

Cardiac EDE Documentation

Answer 27

PCE positive
PCE negative
PCE indeterminate

Cardiac activity good
Cardiac activity poor
Cardiac activity absent
Indeterminate