Upper Ext Blocks Flashcards by Kelsey Fuller

Advantages of peripheral nerve block

Potent analgesia

Reduction in stress response

Reduction in systemic analgesia requirement

Reduction in opioid-related side effects

Reduction in general anesthesia requirement

Decrease the incidence/occurrence of chronic pain

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Regional anesthesia is often favored in pts with

multiple comorbidities for whom a general anesthetic carries a greater risk.

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T/F - Periph nerve blocks last longer than spinals

True

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Pt. cooperation and participation are key to the success and safety of every regional anesthetic/procedure. What pt populations would be at increased risk for complications?

Pts. who are unable to remain still may be exposed to increased risk - younger pts., developmentally delayed individuals, dementia, movement disorders.

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No regional block if platelets < _____ and pt/aptt >_____

100,000

2X normal

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Never inject through infected tissue, what will happen to your block of you do?

you can tract infection

there will be more unionized medication and it won’t work as well

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Pts with pre-existing nerve injuries may pose a risk or contraindication - what should you do before you place a block?

Make sure you document prior existing nerve injury BEFORE you place block incase you cause damage or so the patient cant say caused it

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T:F - Peripheral neuropathy or previous nerve injury may have a higher incidence of complications

True, could have prolonged sensory block

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What should you do if you get LAST

Call for help - code blue

CPR

Lipid emulsion administration to sequester the LA - intralipid 20% 1.5ml/kg/min bolus, max 8ml/kg

Preparation for cardiopulmonary bypass

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What happens when you mix epi with LA?

prolongs duration

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How long can bupivocaine and ropivicaine have effects for?

up to 12-18 hrs

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Lidocaine
2% = ___ mg/ml
0.5% = ____ mg/ml
0.25% = ____mg/ml

2% = 20mg/ml

5% = 5mg/ ml
25% = 2.5mg/ml

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How do you determine the concentration of epi if you are given:

EPI 1:200,000

divide 1 million by second number

1,000,000/200,000 = 5mcg/ml

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If I have 3cc Lido 1.5 % with 1:200,000 Epi, what are my concentrations?

Lido
1.5% = 15mg/ml X 3cc = 45 mg

Epi
1 mil/200,000 = 5 X3 cc = 15 mcg

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What standard hemodynamic monitors should be on for a block?

BP and pulse Ox

have O2 nearby

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Placing blocks is a ____ _____ technique

strick sterile

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What is a field block technique

A local anesthetic injection that targets terminal cutaneous nerves

Commonly used by surgeons to minimize incisional pain

Dentist

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Why can a field block be undesirable?

Undesirable when block may obscure the operative anatomy or where local tissue acidosis (ie. Infection) prevents effective local anesthetic function

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What is the paresthesia technique?

Practitioner uses known anatomic relationships and surface landmarks as a guide

Block needle is inserted in proximity of the target nerve or nerve plexus

When needle makes direct contact with a sensory nerve, a paresthesia is elicited and the LA is injected

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What is the nerve stimulation technique?

When the insulated needle is placed in proximity to a motor nerve, muscle contractions are induced.

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For nerve stimulation technique, It is common to redirect the block needle until muscle contractions occur at a current less than

0.5 mA

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For nerve stimulation technique, what does 0.5mA mean?

Lets me know I am close to the nerve
Usually start around 2
If I lose signal, going away from nerve

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Some thought that a muscle contraction elicited at less than 0.2 mA implies

intraneural needle placement

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What is the ultrasound technique?

Ultrasound for peripheral nerve location and subsequent block

high-frequency sound waves emitted from piezoelectric crystals that travel at different rates through tissues of different densities, returning a signal to the transducer.
1-20 MHz

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What is Echogenicity

the degree of efficiency with which sound passes through a substance Hypoechoic Hyperechoic Anechoic

What is Hypoechoic

structures and substances through which sound easily passes. Appear DARK or BLACK on the ultrasound screen. solid organs, deep structures

What is Hyperechoic

structures reflecting more sound waves appear BRIGHTER, “WHITE” on the ultrasound screen. diaphragm, gallstones, bone, pericardium

What is Anechoic

no reflection fluid and blood filled structures

What does muscle look like on an ultrasound?

striations

T/F: nerve bundles can bee hyper or hypoechoic?

TRUE

Linear probe - a high frequency transducer that offers a high resolution picture with

less tissue penetration.

What is a linear probe good for?

Good for superficial nerves Provide undistorted image First choice among practitioners

Curvilinear probe - a low frequency transducer that offers better tissue penetration with

lower resolution, or poorer image quality.

What is a curvilinear probe good for?

Good for deeper structures

The optimal transducer varies depending on the ____ of the target nerve and ___ _____ of the needle relative to the transducer.

depth approach angle

Nerves are best imaged in

cross section (short axis)

What is the characteristic appearance of nerves?

honeycomb | bundle of grapes

In-plane needle alignment (longitudinal, long-axis): In-plane needle alignment refers to aligning the needle with the long-axis of the transducer (along the ultrasound beam) so that the ______________________. One of the disadvantages of the in-plane needle view is that, it is easy to lose the image with a slight movement of the transducer as the ultrasound beam is thin. This technique requires excellent hand-eye coordination.

entire shaft and tip of the needle are visible

Out-of-plane alignment (transverse or short axis): This refers to when the transducer and the needle are perpendicular to each other. It is important to slide the transducer along the shaft of the needle to identify the needle tip. Both the needle tip and shaft in cross section appear as a ________ ______ ______ on the screen. Since only the needle tip is observed as a bright dot, it is sometimes difficult to accurately observe the needle during advancement.

hyperechoic white dot

Which plane alignment is easier for a peripheral nerve block

Out-of-plane

nerve(s) are identified and local anesthetic is infiltrated via a one time injection, to achieve desired effect

Single injection nerve block

involves placement of a percutaneous catheter adjacent to a peripheral nerve, followed by local anesthetic administration to prolong the effect

Continuous Peripheral Nerve Block

Advantages of peripheral nerve block

* Reduction in resting and dynamic pain * Reduction in supplemental analgesia requirements * Reduction in opioid related side effects * Reduction in sleep disturbance * Improved patient satisfaction * Improved patient ambulation * Accelerated resumption of passive joint range-of-motion * Reduced time to discharge

Complications of continuous peripheral nerve block

``` Systemic local anesthetic toxicity Catheter retention Nerve injury Infection Retroperitoneal hematoma Increased risk of falling (femoral nerve catheter) ```

T/F: Local anesthetics are the primary medication infused, as adjuvants do not add benefits to perineural infusions (unlike single-injection peripheral nerve blocks).

TRUE

Pain pumps - Long acting LA (eg. Ropivacaine) are more commonly used as they provide a favorable sensory to motor block ratio, optimizing analgesia while

minimizing motor block

Pain pumps: Recent studies suggest that it is the _______ and not the concentration that determines the majority of block effects.

total dose

What are the 4 brachial plexus blocks?

Interscalene block Supraclavicular block Infraclavicular block Axillary block

Interscalene blocks are indicated for surgical procedures involving the

shoulder and upper arm

What roots are commonly used for an interscalene block?

C5-C7

In an interscalene block, the _______ originating from C8-T1 may be spared

ulnar nerve

What is an interscalene block NOT appropriate for?

surgery at or distal to the elbow

For complete surgical anesthesia of the shoulder, the _____ cutaneous branches may need to be supplemented with a superficial cervical plexus block or local infiltration

C3-C4

Does an interscalene block cover the neck?

Not necessarily

A good interscalene block has 100% block of the

phrenic nerve

Never ever do a ____ interscalene block

Contraindications to interscalene block (4)

Local infection Severe coagulopathy Local anesthetic allergy Patient refusal

A properly performed interscalene block will invariably block the ipsilateral phrenic nerve. Careful consideration should be given to patients with

severe pulmonary disease or preexisting contralateral phrenic nerve palsy

The hemidiaphragmatic paresis may result in

dyspnea, hypercapnia, and hypoxemia

With an interscalene block, Horner’s syndrome may result from proximal tracking of local anesthetic and blockade of sympathetic fibers to the

cervicothoracic ganglion

What is Horner’s Syndrome

myosis(pupil constricts), ptosis (droopy eyelid), anhidrosis (no sweat, no tear), can also turn red on that side Superior cervical ganglia is blocked

In a patient that has pre-existing contralateral vocal cord paralysis, respiratory distress may ensue if there is _____ involvement

RLN

If there is RLN involvement, 1 VC = 2VC =

1 VC = hoarseness | 2VC = stridor

How do know if you have an accidental vertebral artery injection?

if immediate seizure activity is observed

In an interscalene, how will you know if you have accidental spinal or epidural injection

Massive hypotenon, bradycardia, pneumothorax

Why is a pneumothorax possible with an interscalne block

possible due to close proximity of pleura

In a good interscalene block, does the lung aerate?

no, because we blocked it

The interscalene triangle is formed by

Clavicaulr head, sternal head, mastoid head

Where does the nerve bundle come out in regards to the interscalene triangle..

inbetween the middle and anterior scalene muscles (scalene triangle)

____ & ____ are right next to the interscalene triangle

subclavian artery and IJ

A supraclavicular block is used for which surgical procedures

at or distal to the elbow. Does NOT reliably anesthetize the axillary

Historically, the supraclavicular block fell out of favor due to the high incidence of complications that occurred with paresthesia and nerve stimulator techniques. ______ guidance has improved its safety and increased its current use.

Ultrasound

Which brachial plexus block has the highest risk of pneumothorax

Supraclavicular block

For a supraclavicular block, we are down to the

divisions

Complications of supraclavicular block

Ipsilateral phrenic nerve palsy in ~50% of patients (Still caution in patients with COPD) Horner’s syndrome Recurrent laryngeal nerve palsy Pneumothorax Subclavian artery puncture

Where do you place a supraclavicular block?

just above clavicle

What surgical procedures is an Infraclavicular block used for?

at or distal to the elbow

Where do you place an infraclavicular block?

just below clavicle

The Infraclavicular block is a brachial plexus block now at the level of

cords

In an Infraclavicular block, the _______ nerve is spared (T2 dermatome)

intercostobrachial

with an Infraclavicular block, the chorioid process...

2 cm medial, 2 cm inferior -Put needle in

What is a pretty high contraindication for this block?

anticoagulants

The axially block is good for what surgical procedures?

entire arm distal to the elbow

Axillary block - Multiple injections of ___ each may be required to reliably produce anesthesia of the entire arm distal to the elbow.

10ml

At the lateral border of the ____ ____ _____, the cords of the brachial plexus form large terminal branches.

pectoralis minor muscle

The axillary block provided good block of what 3 nerves

ulnar, median, radial

Axillary block: What nerves branch proximal to local injection site and are usually spared?

axillary, musculocutaneous, and medial brachial cutaneous

T/F: Axilla is highly vascularized - there is a risk of LA uptake through small veins traumatized by needle placement.

TRUE

Contraindications for axillary block

Local infection NEUROPATHY Bleeding risk

A single _____ ____ is often anesthetizes for minor surgical procedures with a limited field or as a supplement to an incomplete brachial plexus block.

terminal nerve

Terminal nerves may be anesthetized anywhere along their course, but the ____ & _____ are the favored sites for injection.

elbow and the wrist

What is a bier block used for?

Surgical anesthesia for short duration procedures 45-60 minutes Carpal tunnel release

BIER BLOCK IV Catheter is inserted on the ____ of the surgical hand/foot A _____ pneumatic tourniquet is placed on the arm/thigh The extremity is elevated and exsanguinated by tightly wrapping an ____ elastic bandage from distal to proximal direction The _____ TQ is inflated, the Esmarch bandage removed, and 0.5% lidocaine is injected over ____ minutes through the IV catheter which is subsequently removed Anesthesia is usually established after ____ minutes. TQ pain usually develops after ____ minutes at which time the distal TQ is inflated and the proximal TQ is subsequently deflated. Pts. Usually tolerate the distal TQ for an additional 15-20 minutes because it is inflated over an ______

dorsum double Esmarch proximal 2-3 min 5-10 20-30 anesthetized area.

Why can you not let the TQ down for 20 minutes after lidocaine is injected?

huge blast of LA – systemic toxicity

What else can you do to provided a additional margin of safety when letting a TQ down?

Slow, incremental deflation of tourniquet

Upper Ext Blocks Flashcards

(95 cards)