Upper Extremity Blocks Flashcards
What are the upper extremity nerve blocks?
Interscalene
SupraClavicular
Infraclavicular
Axillary
Distal Forearm
Distal Wrist and Digits
Bier Block
The Interscalene Block targets what part of the brachial plexus?
The C5-C7 roots of the brachial plexus
Interscalene brachial plexus blocks (ISBPs) are commonly performed for surgical procedures involving the?
Shoulder and proximal upper arm. Distal Clavicle.
Surgery of the clavicle (combined with cervical plexus block)
Benefits of regional nerve blocks
Decreased incidence of N&V
Decrease postop pain
Decrease need for postop analgesics
Better communication with patient
Reduction in hospital stay
Increase patient satisfaction
What are “must have’s” for all patients receiving regional anesthesia
Patient consent
IV: access on all patients
Block cart: supplies, airway, equipment, drugs
Lipid emulsion: must be readily available
Monitoring: pulse ox + etCO2, EKG, and BP monitor
Light sedation: must be able to communicate with provider
What are three modes for monitoring for nerve injury?
Ultrasound, injection pressure, nerve stimulation
Advantages of ultrasound, guided regional anesthesia
-Direct visualization
-Observing local spread in real-time
-Detecting variations in anatomy
-Faster onset times
-Lower incidence of supplemental anesthesia
-Improves block quality
-Use of lower, more precise doses of local
-Possible increase in safety
-Less painful admin, compared with nerve stimulator
-Improved patient satisfaction
What are some peripheral nerve block safety tips?
-US guidance to avoid injury to structures
-aspirate every five ML to avoid intravascular injection
-ropivacaine is the least cardiotoxic
-used 20–22 gauge needle to avoid nerve injury
-use an injection pressure gauge
When should you aspirate your needle?
Any time you move the needle
and
Every 5mL
What pressure should your needle pressure manometer stay under?
Under 15psi
A pressure greater than 15psi on the needle manometer may indicate?
Intraneural needle placement
Can lead to severe fascicular injury and persistent neurologic deficits
What risks should be mentioned to the patient (if they want to know) regarding a peripheral nerve block?
All risks are rare.
Bleeding, Infection, hematoma, LAST, nerve damage (extremely rare).
More than what percent of cases of nerve injury are transient with full recovery over time after a PNB
over 95%
PNBs that block above the clavicle
Interscalene: root level
Supraclavicular: trunk level
PNBs that block below the clavicle
Infraclavicular: cord level
Axillary: branch level
Exparel is only recommended for which blocks?
Interscalene,
Adductor Canal,
Sciatic nerve in the popliteal fossa
Field Blocks: TAP/Rectus Sheath, PECS, Erector Spinae (ESP)
Why is an interscalene block not ideal for procedures below the elbow?
The inferior trunk of the brachial plexus (C8-T1) is spared ~30% of the time.
Where should local anesthetic be placed when performing an interscalene block?
Local anesthetic injection around the superior and middle trunks of the brachial plexus in the space (interscalene) between the anterior and middle scalene muscles.
What local anesthetic volume is usually used when performing an interscalene block
7-15mL
the brachial plexus is ______ to the carotid artery and internal jugular vein
lateral
the brachial plexus is _____ to the prevertebral fascia, superficial cervical plexus, and sternocleidomastoid muscle
Deep
If you can visualize it, placing your transducer right in front (anterior) of the ________ vein gets you in the right area for an interscalene block about 90% of the time.
External Jugular
Often over lies interscalene groove at the level of C6
The C6 level vertebra is determined by extending a line laterally from the _______
Cricoid Cartilage
The “snowman” or “stoplight” can be visualized when performing which upper extremity PNBs
Interscalene
What position should your transducer be in when performing an interscalene block??
Transverse on the neck, 3-4 cm superior to the clavicle over the external jugular vein
If using the landmark technique for an interscalene block, what three landmarks are you observing?
Cricoid cartilage
Clavicle
Lateral border of the clavicular head of the sternomastoid muscle
How should you position the patient before performing an interscalene block?
Position the patient supine or lateral with their head slightly elevated, facing the non-operative side.
Torabi PP - “HOB @ 45 degrees”
For a continuous interscalene block: where do you position the catheter, how far do you insert the catheter, and what should your local anesthetic run at?
-Position the catheter near the trunks of the brachial plexus between the scalene muscles
-Insert the catheter 3 to 5 cm beyond the tip of the block needle
-After the initial bolus, infuse the local anesthetic at 5mL/hour
When using a nerve stimulator for an interscalene block, where should you observe twitches? Red item for Dr. Torabi
Deltoid, Biceps, Triceps, or Pectoralis
When using a nerve stimulator for an interscalene block, once twitches are observed at 1mA, the stimulation intensity is reduced to _____? Twitch should remain at ____ mA but stop at lower stimulus. Red item for Dr. Torabi
0.5mA, and should maintain at 0.5mA
When using a nerve stimulator for an interscalene block, if twitches occur at _____ mA, stop. This is intraneural. Red item for Dr. Torabi
0.2mA
When using a nerve stimulator for an interscalene block, if paresthesia or pain occurs, what should you do?
Stop injection. Evaluate needle position.
What upper extremity PNB block these dermatomes, myotomes, and osteomes?
interscalene block
What kind of transducer should be used when performing an interscalene block?
High frequency linear array transducer
Whenever possible, avoid medial-to-lateral needle insertion for an interscalene block. Why?
To decrease risk of phrenic nerve injury. Phrenic nerve usually located medially (anteriorly) to the anterior scalene muscle.
What two upper extremity blocks have a high incidence of phrenic nerve blockade - diaphragm hemiparesis?
Interscalene and Supraclavicular
Blockade of the phrenic nerve can cause a ______% reduction in forced vital capacity (FVC) that may not be tolerated in patients with severe or symptomatic COPD. Particularly if the large _____ lung is affected.
25%
Right lung
What is Horner syndrome?
When the stellate ganglion (cervicothoracic ganglion), located at C7, is blocked during an interscalene block, resulting in ptosis, miosis, and anhydrosis.
As little as __ mL of local anesthetic into the vertebral artery can cause a seizure
1mL!
What two nerves often pass through the middle scalene muscle and have case reports of injury during an interscalene block?
Dorsal Scapular and Long Thoracic
(This is when a nerve stimulator is helpful)
Injection of large volumes of local anesthetic during an interscalene block has resulted in?
recurrent laryngeal paralysis, which presents as hoarseness.
What are the two causes of respiratory distress in a patient who received an interscalene block? How do you determine which is the cause?
Phrenic Nerve Blockade
Pneumothorax
Chest xray
What is the proposed mechanism of the Hypotensive Bradycardic Episode (HBE) following an interscalene block? L
Bezold-Jarisch reflex.
Pts typically in sitting or semi-upright position.
Venous pooling in the lower extremity, decreased ventricular preload
List 3 conditions that set the stage for a hypotensive bradycardic episode during upper extremity PNB
- interscalene block
- sitting position
- epinephrine used in the block
Indications for a supraclavicular peripheral nerve block
Surgical procedures of the upper arm, elbow, wrist, and hand
Why is a supraclavicular nerve block not indicated for shoulder surgery?
Because the suprascapular nerve arising from the upper trunk (C5-C6) may be missed
What parts of the brachial plexus does the supraclavicular nerve block target?
trunks/divisions
What upper extremity nerve block is demonstrated here?
Supraclavicular Block
What areas on the upper extremity are anesthetized with a supraclavicular block?
upper arm, elbow, forearm, wrist, lower part of shoulder
What are two landmarks to look for when performing a supraclavicular block?
Clavicle, subclavian artery, (could add 1st rib)
What are some complications that can occur when performing a supraclavicular block? Torabi Red Item
pneumothorax*most serious 6% risk, subclavian artery puncture, horners syndrome
Once all anatomic structures are identified when performing a supraclavicular block, how should you tilt your transducer and why?
Tilt transducer slightly caudal so the first rib is aligned beneath the brachial plexus and over the plural, creating a protective barrier against pneumothorax
How many mLs of local anesthetic is usually appropriate for a supraclavicular block
20-25mL
What is the acceptable nerve stimulator response for a supraclavicular block?
Finger twitch flexion, or extension
What nerve block are you performing if this is your view?
supraclavicular nerve block
Where are you aiming to inject your local anesthetic when performing a supraclavicular nerve block?
Around the trunk/divisions of the brachial plexus. Posterior and superficial to the subclavian artery.
Describe the orientation of the transducer when placing a supraclavicular block with ultrasound
Transverse in the supraclavicular fossa in a slightly caudal direction
Which artery is most likely to be injected with local anesthetic during supraclavicular block placement
Subclavian artery
Which artery is most likely to be injected with local anesthetic during interscalene block placement
vertebral artery
Which artery is most likely to be injected with local anesthetic during infraclavicular block placement
subclavian or axillary artery, depends on block level
Which artery is most likely to be injected with local anesthetic during axillary block placement
axillary artery
If you don’t see lung sliding on ultrasound, what does that likely mean about the patient’s lung?
The patient might have a pneumothorax if you do not see lung sliding. CXR to confirm.
True or False: phrenic nerve paralysis or Horner syndrome are two possible complications from a supraclavicular nerve block
true, but both are less common compared to an interscalene block
The infraclavicular block targets what part of the brachial plexus
The cords
An infraclavicular block is a good alternative for which patients?
Patient with a respiratory insufficiency (lower risk of phrenic nerve block)
and
Patient with limited upper extremity mobility
What dermatome area/area of skin in the upper arm is not reliably anesthetized by any brachial plexus block techniques?
Medial skin of the upper arm
T1-T2
What upper extrem nerve block correlates to the image
Infraclavicular nerve block
Unlike the interscalene and supraclavicular blocks, the nerves at the infraclavicular level on ultrasound appear _______ rather than ______
hyperechoic (bright) rather than hypoechoic (dark)
What volume of anesthetic will you likely inject when performing an infraclavicular block?
20-30mL
Indications for an infraclavicular block?
Surgeries of the arm below the shoulder, elbow, forearm, wrist, and hand
How should you position the pts arm when performing an infraclavicular nerve block?
abducted 90 degrees to stretch muscle and fascia
What is a possible complication with left-sided infraclavicular blocks?
Chylothorax due to the thoracic duct. if damaged lymph fluid can accumulate in the pleural cavity.
Which brachial plexus block is usually the most painful for the pt? why?
Infraclavicular
needles pieces pectoralis major and minor
What position should your transducer be in when performing an infraclavicular block?
parasagittal to the chest just medial to the coracoid process (below the clavicle)
When using a nerve stimulator when performing an infraclavicular block, stimulation of the lateral, medial, and posterior cord will elicit what kind of response?
Lateral (median): flexion of first 3 digits
Posterior (radial): extension of wrist and digits
Medial (median and ulnar): flexion of first three didigts (median), flexion of 4th and 5th digit (ulnar)
Where are you injecting your local anesthetic in an infraclavicular nerve block?
around the cords of the BP below the clavicle. LA will also spread around the axillary artery.
Which region is most likely to be inadequately anesthetized following an axillary block with a trans arterial technique?
lateral forearm
The axillary block targets, which four of the five terminal branches of the brachial plexus
Median, radial, ulnar, and musculocutaneous
Indications for an axillary nerve block
Surgical procedures of the forearm and hand
The axillary block does not cover which two skin areas?
Skin of the medial upper arm (intercostobrachial n)
Skin over the deltoid (axillary nerve)
How many mL around each nerve do you inject for an axillary block?
3-5mL per nerve
Which nerve needs to be blocked separately because it is usually outside of the neurovascular bundle when performing an axillary block? Torabi Red Content
Musculocutaneous nerve. inject into the coracobrachialis muscle.
Where are you trying deposit your local anesthetic when performing an axillary block
around 4 of the terminal branches of the brachial plexus
Describe the orientation of the terminal branches relative to the axillary artery in the anatomic position
median = anterior + medial
ulnar = posterior + medial
radial = posterior lateral
Msc = anterior + lateral
Which nerve is anesthetized by injecting local anesthetic in the antecubital fossa medial to the brachial artery
median nerve
IV Regional Anesthesia is also known as?
The Bier Block
What anesthetic, at what percent and volume, is used for a bier block
0.5% Lidocaine 50mL
(do not use ropivacaine or bupivacine)
Should you add epi to your lidocaine when doing a bier block?
NO, but ketorolac can be added
most serious risk of bier block?
LAST d/t cuff failure
Never deflate the bier block tourniquet less than _____ min after injection
20min!
When trying to block the radial nerve at the level of the forearm, where and how many mL do you aim to inject your local anesthetic?
Between the biceps tendon and brachioradialis
3-5mL
When trying to block the ulnar nerve at the level of the elbow, where and how many mL do you aim to inject your local anesthetic?
The elbow is flexed 90° and local anesthetic is injected between the olecranon and medial epicondyle of the humerus
3-5mL
What are two anatomic landmarks used to block the median nerve at the wrist? How many mL do you administer
Flexor carpi radialis tendon
Flexor Palmaris longus tendon
5mL between the two tendons
When blocking the radial nerve at the level of the wrist, what anatomic landmark are you using, and where do you inject?
Radial styloid
Subq injection (field block) of 10mL proximal to the radial styloid
When blocking the ulnar nerve at the level of the wrist, what anatomic landmark are you using, and where do you inject?
Ulnar styloid, ulnar pulse (artery), flexor carpi ulnaris
inject 3-5mL medial to and below the flexor capri ulnaris tendon
confirm negative aspiration d/t close proximity of ulnar artery
Where and how much do you inject your local anesthetic when performing a digital nerve block?
inject 2-3mL at the base of both sides of the finger. Do not use epi (at least for when answering questions for the NCE)
A bier block is best suited for procedures that?
produce minimal postop pain (carpal tunnel release, dupuytren’s contracture surgery)
What are the steps to applying the Esmarch and double tourniquet for a bier block?
Wrap the esmarch bandage around the extremity to further exsanguinated begin at the distal, limb, and move proximally until you reach the distal tourniquet cuff.
Inflate distal cuff
Inflate proximal cuff
Deflate distal cuff
Remove bandage
Bier block tourniquet inflation pressure should be?
~250mmHG or at least 100mmHg over SBP
What is the most common reason a patient would be unable to tolerate a Bier block
Tourniquet pain, despite the double tourniquet alternating pressure inflation to decrease pain
identify the section of the brachial plexus
Medial cord
3 o’clock position = medial cord
6 o’clock position = posterior cord
9 o’clock position = lateral cord
