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Flashcards in Ultrasound Deck (23)
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1
Q

Field depth < 2.0 cm

A

Wrist, ankle block

2
Q

Field depth 2- 3 cm

A

Interscale ( LA anesthetic around the root or trunk of brachial plexus at the level of C6 in between the scalene muscle )
Axillary Brachial plexus block

3
Q

Field depth 3- 4 cm

A

Femoral
Supraclavicular
Tranversus abdominis plane block

4
Q

Field depth 4-7 cm

A

Infraclavicular ( cords and terminals )
Popliteal
Subgluteal sciatic nerve block

5
Q

Field depth 7.0 cm 10.0 cm

A

Pudendal block
Gluteal sciatic nerve ( subgluteal is 4-7cm )
Lumbar plexus block

6
Q

Field depth > 10.cm

A

Anterior approach to sciatic nerve

7
Q

Gain

A

Brightness

8
Q

Two function button of Gain

A

Gain and TGC ( Time-gain compensation )

9
Q

Excessive or Inadequate gain

A

The boundaries of the tissues get blurry

You lose information

10
Q

Optimal gain for peripheral nerve

A

The gain at which Best contrast that you get between the muscle and the adjacent connective tissue
You want a nice contrast between the muscle and the adjacent connective tissue !

11
Q

ASRA Recommendations

A

1- visualize : muscle, fascia , bones and blood vessels
2- ID the nerve or plexus on shot-Axis with depth set at 1 cm deep to target nerve
3- Confirm normal anatomy and recogonize variations ..we don’t all have the same body!!
4- Chose the safest most effective needle approach
5- Aseptic needle insertion technique
6- Follow the needle in real time live as you advance it toward the target
7- Secondary stimulation technique , ex: nerve stimulator
8- Needle tip in the correct position ? Inject Small volume of test solution
9- Adjust your needle as necessary for optimal perineural LA spread
10- Safety: Aspiration, monitoring , patient response, assessment, resistance to injection

12
Q

US machine set up on which side of patient

A

Opposite side

13
Q

Needle selection for Peripheral nerve block

A

Large bore 17G: easily visualized directed under US -deep blocks -i.e Infraclavicular when needle in steep (>45) angle .
Smaller bored 22 G: More diff to see , but still easily visualized in superficial blocks i.e. Axillary block when needle angle is shallow PLUS more comfortable for awake patient

14
Q

Insulated needle is what exactly ?

A

Electrical current is concentrated at the needle tip and a wire attached to the needle hub connects to a nerve stimulator .
Used for 1) accurately ID specific nerve = improve adequacy of block .

15
Q

What is Peripheral Nerve Stimulation via insulated needle ?

A

Method of using low intensity electric current ( 0-5mA current at a set 1-2 Hz interval) to elicit a response/muscle twitch .
When an insulated needle close to to a motor nerve = muscle contraction

16
Q

How is the circuit completed in Insulated needle PNS?

A

Ground electrode is attached to the patient to complete the circuit

17
Q

Needle technique for US . What is the position and what is visualized ?

A

Position -Inline and parallel to transducer

Both shaft and tip are seen

18
Q

Transducer prep

A

Sterile sheath
Gel inside sheath
Smooth sheath cover over transducer = no wrinkles that can impede full contact
Rubber band = transducer can’t move inside sheath
Lots of sterile gel to skin

19
Q

Peripheral nerve block technique

A

2 person: get an assistant !
Monitors : BP, EKG, Pulse ox
OXYGEN/SUCTION/EMERGENCY MEDS / CRASH CART/ INTRALIPID
Make sure your nerve stimulator and your connecting cables work before starting
Premedicate but DON’t OVERSEDATE = benzo/opioid for comfort but pt should always be able to respond to verbal cues
Proper patient position = favorable for clinician and comfy for patient

20
Q

Negative pole vs Positive Pole location

A

Negative pole connected to the needle N-N
Positive pole connected to the Pt Skin P- S
Negative - Needle
Positive - Skin

21
Q

You have started set for the block , start the procedure ..

A

1 Time -Out
2 Disinfect skin - sterile field
3 Connect the PNS needle to the nerve stimulator- only turn it on after in subQ tissue = before will cause pain then Deliver 2 mA!!
Apply gel to transducer
Position transducer on skin- always keep within sterile field
Introduce needle / start procedure !

22
Q

You introduced the PNS needle in SubQ now what ?

(Slide 23)

A

Once the muscle you are looking for is obtained reduce 1)current 2) intensity and 3)amplitude GRADUALLY and advance needle SLOWLY

23
Q

When is Optimal LA injection reached ?

A

When muscle contraction is maintained at a current between 0.2 - 0.5 mA
<0.2mA eliciting muscle contraction= increased risk of intraneural injection = neural damage!