Final- Ultrasound [7/16/24] Flashcards
1
Q
what is ultrasound?
A
the idea of “seeing” using sound waves
S3
2
Q
Where was ultrsound first used?
A
- in nature
- bats
- dolphins…. spallanzani (1794)
- in the military
- submarines
- in medicine
3
Q
- When was ultrasound first used in medicine?
- What was it popular in?
- Why was it popular?
A
- 1950’s
- Popular first in obstetrics
- It was popular because there was no ionizing radiation.
S3
4
Q
Advantages of ultrasound.
A
- Identify anatomical structures
- Relationship of the needle to tissues is visualized
- Increases accuracy
- “See” spread of LA
- May decrease time performing pain blocks/assessments
- May decrease complications
S4
5
Q
Ultrasound waves travel between what Mhz?
A
- 2-20 Mhz
- travels differently in different structures
S5
6
Q
What is the range of audible sounds?
A
- 20-20,000 Hz
S5
7
Q
What can ultrasound waves do when they encounter a surface?
A
- Transmit through the surface
- Reflect on the surface
- Something in between
S5
8
Q
The sound waves that are reflected back to crystals create ____ recorded by the computer.
A
impulse
S5
9
Q
What is the result when ultrasound waves are transmitted through fluid?
A
- No signal
- Anechoic
- Dark
S6
10
Q
What is the result when ultrasound waves are reflected on bones/stones?
A
- Lots of signals
- Hyperechoic
- Bright
S6
11
Q
What results when ultrasound waves encounter soft tissue, muscles, and fat?
A
- Iso/hypoechoic
- Shades of grade
S6
12
Q
What is echogenesis?
A
- Google: the ability to bounce an echo, e.g. return the signal in medical ultrasound examinations.
- In other words, echogenicity is higher when the surface bouncing the sound echo reflects increased sound waves.
S7
13
Q
Differentiate hyper-echoic and hypo-echoic?
A
- Hyper-echoic: solid tissues reflect sound waves…appear bright
- Hypo-echoic: soft/hollow tissues reflect less sound waves… apear dark
S7
14
Q
- Which picture represents a solid?
- Which picture represents fluid?
A
- Picture A: Solid
- Picture B: Fluid
S8
15
Q
- Piezo electric crystals are located where?
- what do they do?
A
- Location: inside head of the transducer
- change shape with electric impulse:
- startes to vibrate
- generates sound waves
S9
16
Q
these are specific to exam performed and allow you to penetrate shallower or deeper tissue
A
transducers
S10
17
Q
What are the three types of transducers used in POCUS?
A
- Linear Array
- Curve Array
- Phased Array
S10
18
Q
- Linear Array
- Frequency?
- Resolution?
- Used for?
A
- High frequency (7-15 MHz)
- Better resolution at a superficial depth
- Examples: Great to use to start a central line , IJ, IV
For things that are close to the surface of the body
S10
19
Q
Curve Array:
* Frequency?
* Resolution?
* used for?
A
- Low frequency (2-5 MHz)
- Poorer resolution
- Great for deeper tissue
- Ex: Used to look at gallbladder or stomach to assess NPO, kidney, liver, spleen, bladder rupture
S10
20
Q
- Phased Array
- Frequency?
- Used for?
A
- Lowest frequency (1-3 MHz)
- Useful for echocardiography
- windows of the ribs, subxiphoid view
S10
21
Q
What do we need to pay attention to for ultrasound orientation?
A
- patient orientation
- axial plane
- sagittal plane
- probe orientation
S11/12
22
Q
Static vs Dynamic Approach for Ultrasound
A
Static:
* Identifying the target vessel, assessing the patency
* marking an appropriate insertion site
* cannulating blindly.
Dynamic:
* Performing the procedure in real-time
* viewing the needle puncturing the vessel wall.
S13
23
Q
Tips and Tricks for using Ultrasound.
A
- Hold the Transducer probe like a pencil
- Focus using gain and depth buttons
- Proper Ergonomics
- Use Conductive gel
Hacks For Performing Ultrasound
S14,15,16,,17
24
Q
- What is gain?
- How do you adjust gain?
A
- Gain is the brightness signal quality usually
- adjusted with a knob.
- Twist the knob back and forth until fluid is black and soft tissue is mid-grey
S18
25
* how many buttons are there for depth?
* where can you see depth measurment?
* how do you adjust depth?
* often 2 buttons [up and down]
* depth measures are shown in cm on side of screen
* start at high depth then work to bring object of interest into middle of screen
| S20
26
What does In-plane vs. Out-of-plane refers to?
* the relationship of **needle** to the ultrasound plane.
| S22
27
in-plane vs out of plane is also called?
why is this name innaccurate?
* also called short vs long axis.
* axis refers to vessel
* should always be in the long axis for procedures
| S22
28
In in-plane vs out-of-plane, what is the orientation of the needle for each?
* In plane: needle parallel to transducer
* Out of plane: needle cross sectional to the transducer
| S22 lecture
29
* What is the advantage of in-plane ultrasound?
* Disadvantage?
* Advantage: See the whole needle
* Disadvantage: Easy to be off plane. *Needle could be in front or back of the vessel and not IN the vessel*.
| S23
30
* What is the advantage of out-of-plane ultrasound?
* Disadvantage?
* Advantage: The needle is positioned directly under the plane of an ultrasound
* Disadvantage: Unclear where tip of the needle is
| S25
31
What do you look for to determine that your guidewire is in the vessel's lumen?
* **Vanishing Sign**
* as you scan from high to low on the vessel, the needle will get closer.
- get artifact
- see better needle/wire then it goes away. The needle/metallic part moves.
- its looking at the wire/tip of the needle. As you get deeper its gets better.
- its a way to prove the needle is in the vessel.
| S26
32
Common anesthesia use for ultrasound.
* Guided IV Access
* Central Venous Access
* Focused Assessment with Sonography for Trauma
* Ultrasound-guided Nerve Blocks
* Gastric Ultrasound
| S28, S30, S31, S37, S38
33
* What are the indications for using USG IV Access?
* What probe do you use?
* **Indictions**:
* History of difficult cannulation
* Multiple failed attempts
* Best to use a linear probe bc high frequency, if the patient is obese, use the curve probe
| S28
34
What are the contraindications for using USG IV Access?
* Does not substitute for IO access in life-threatening situations
| S28
35
* Indications to use a FAST.
* contraindications?
* **Indication**: To rule out free fluid in the abdomen and pericardium
* **CI**: none :)
| S31
36
What probe is used for a FAST?
* Curvilinear probe
| S21
37
What are the assessment points for FAST?
* (1) RUQ- Morison’s pouch (Liver, Right Kidney)
* (2) LUQ- Peri-splenic view (Spleen, Left Kidney)
* (3) Pelvic view- Suprapubic (Bladder rupture)
* (4) Cardiac view (Pericardial sac)
*Look at 4 quadrants + pericardium*
| S32
38
* what does free fluid around the kidney look like?
* what view would you use?
* RUQ- morisons pouch [pic on left bc liver]
* LUQ- peri-splenic view [pic on right bc spleen]
| S33/34
39
* what does bladder rupture look like?
* what view would you use?
Pelvic view- Suprapubic (Bladder rupture)
| S35
40
* what does pericardial effusion look like?
* what view do you use?
Cardiac view (Pericardial sac)
| S36
41
Steps to perform USG peripheral nerve blocks
* pre-block scan to plan route
* use "heeling" to help maintain parallel alignment
* line the probe with nerve bundle not the skin .
* await fascial pop
* verify nerve doesnt move with needle
| S37
42
What are the indications for the gastric US?
* Lack of adherence to fasting instructions
* Unclear fasting history
* Potential delay in gastric emptying
| S38
43
Grade the Antrum
* Grade 0 Antrum: Empty Stomach [NPO]
* Bull's Eye
| S39/40
44
Grade the Antrum
* Grade 1 Antrum: < 1.5 ml/kg
* Clear liquids
* rounder more disteneded
* starry night
* peristalsis starts
* Milk, thick fluids:
* thinner walls
* increased echogenicity
* low aspiration risk
| S39/40
45
Grade the Antrum
* Grade 2 Antrum: > 1.5 ml/kg
* Solid Food
* hyperechoic
* High Risk of Aspiration
| S39/40
46
chart on estimating gastric volume
| S40
