Upper extremity blocks (exam 2) Flashcards
Absolute contraindications of any nerve block?
Patient refusal
Uncorrected coagulation deficiencies
Infection at the site of the block
Systemic anticoagulation
When would you use a Cervical Plexus Block?
neck and shoulders
thyroid operations
carotid endarterectomies in which awake neurologic assessment is desired.
***Cervical plexus is formed from what rami?
Formed from the anterior rami of C1-C4
***The cervical plexus supplies sensation to what areas of the body?
jaw, neck, occiput, and areas of the chest and shoulder.
True or false, you want to inject LA into the sheath of the nerve?
False, you want to inject outside of the sheath. You want to be around the nerve but NOT in the sheath.
With the nerve stimulator, if you are still getting twitches below 0.2mAmps whats the problem?
you are probably in the sheath, and you DO NOT want to inject here.
Needle gauge for Retrobulbar block?
25-27g
How much LA are you injecting (ml) with a Retrobulbar block?
2-4ml
Complications of a Retrobulbar block?
Intra-arterial injection: local anesthetic toxicity (most common complication)
Oculocardiac reflex
Retrobulbar hemorrhage
Trauma to optic nerve
Retrobulbar injection
Injection into optic nerve sheath
Before you do a nerve block you need to know if they have an uncorrected coagulation deficiency, what is the platelet number you want it at or higher?
100,000 or higher (unless they are chronically below this number then exceptions can be made)
What are some relative contraindication of any nerve block?
Arbitrary values for platelet counts of less than 100,000
Prothrombin time (PT), activated partial thromboplastin time (aPTT), and bleeding times that are elevated
Severe bleeding with or without symptomatic hypovolemia or the potential for severe bleeding
Patient age
Uncooperative and/or Confused patients
Chronic neurological disorders
Local anesthetic allergy
Caution with patients that have history of Mobitz I, II, or third degree heart block
Peripheral neuropathy
If someone is allergic to a certain LA, then what could you give them?
The other class of LA, because there should not be cross-sensitivity between the two classes of LA. (amides and esters)
What generally precedes akinesia (loss or impairment of the power of voluntary movement) of the eye muscles?
Analgesia of the globe
When can effectiveness of the ocular block be evaluated?
2 minutes after block placement
True or False: with an ocular block, partial movement of one or more of the ocular muscles may occur?
True
Most common complication of Retrobulbar block?
Intra-arterial injection: local anesthetic toxicity
What nerve supplies the airway mucosa from the level of the epiglottis to the distal airways?
The Vagus nerve
Which block do you WANT to aspirate air with?
Translaryngeal (trans-tracheal) block!
**Block indicated for shoulder and proximal humerus surgery?
Interscalene
**Blocks for surgeries distal to the mid-humerus? (3)
supraclavicular, infraclavicular & axillary
When a block is used during surgery and you have the patient under GA, you may be able to do what with your inhaled anesthetic?
decrease the amount of inhaled anesthetic you are using bc they do not need as much bc there is no pain stimulation.
**How many cervical nerves do you have compared to cervical vertebrae?
8 cervical nerves
7 cervical vertebrae
How many: thoracic nerves lumbar nerves sacral nerves coccygeal nerves
thoracic nerves=12
lumbar nerves=5
sacral nerves=5
coccygeal nerve=1
Total PAIRS of spinal nerves?
31
Do spinal nerves emerge from the spinal cord in pairs or as a single strand?
in pairs
How many vertebrae does a normal human have?
33 vertebrae
*** Each spinal nerve has a BLANK and BLANK root?
anterior and posterior root.
***posterior roots form WHAT?
ganglia
*** Anterior nerve roots join to form WHAT?
Plexuses
List the four common plexus (the ones we focus on)
cervical
brachial
lumbar
sacral
What forms the cervical plexus?
formed by anterior divisions of the upper 4 cervical nerves.
C1-C4
***What forms the Brachial plexus?
formed by the anterior divisions of C5,6,7,C8, and T1 nerves.
What forms the Lumbar plexus
formed by the anterior division of L1-4
What forms the Sacral plexus?
formed by the roots of lumbar 4 - 5 and sacral 1-3 nerves
Brachial Plexus break down? (Robert Taylor Drinks Cold Beer)
5 Roots 3 Trunks 6 Divisions 3 Cords Terminal branches (nerves)
The Brachial Plexus roots are?
Arise from C5,6,7,8, & T1 nerves (between the scalenes)
The brachial plexus has 3 distinct trunks, what are they?
superior (C5-6), Middle (C7) , and inferior (C8-T1)
***Trunks pass over the lateral border of the WHAT and under the WHAT dividing into anterior and posterior divisions
Trunks pass over the lateral border of the FIRST RIB and under the CLAVICLE dividing into anterior and posterior divisions
How many divisions are there of the Brachial plexus?
6 divisions:
3 anterior and 3 posterior
The 3 cords of the brachial plexus are named based on what?
named after their relationship to the axillary artery
What are the 3 names of the cords of the brachial plexus?
Lateral cord
Posterior cord
Medial cord
***Each cord “gives off” a branch and terminates at a specific nerve. Tell me the details of this for each cord.
**Lateral cord gives off lateral branch of the median nerve and terminates as musculocutaneous(shallow nerve)
**Medial cord gives off medial branch of the median nerve and terminates as the ulnar nerve
**Posterior cord gives off the axillary nerve and terminates as the radial nerve
Terminal Branches of the Brachial Plexus, tell me the major neves of the branches?
Musculocutaneous Radial Ulnar Median (Axillary)
True or False:
The entire Brachial Plexus is a continuous fascial sheath and All techniques for blocking the brachial plexus involve the location of the nerves and injection of the LA within the fascial sheath.
True
Indication for an Interscalene block approach?
approach-optimal for procedures on the shoulder, proximal (upper) arm
Indication for a supraclavicular block approach?
procedures of the entire arm including hand
typically need a separate ulnar block, mid humerous down
Indication for a Infraclavicular block approach?
When would you not use this approach?
procedures of the hand, forearm, and elbow.
NOT good for upper arm.
Axillary block approach used for?
procedures up to the elbow.
For procedures that need to block the upper arm, what blocks would you NOT use?
infraclavicular or axillary
Can you use an axillary block to block the elbow?
axillary is for procedures UP TO the elbow, but I would not assume it includes the elbow.
Tell me 3 advantages of an Interscalene block?
Most appropriate for shoulder surgery
***Reduced risk (small risk) of pneumothorax
Clear landmarks (even in obese patients)
A disadvantage to an Interscalene block would be that a supplementary block may be required, which supplementary block would this be?
Ulnar block
Interscalene block is NOT recommended for what types of surgery?
hand surgery or any surgery below the level of the elbow.
What nerve is frequently NOT blocked by use of an interscalene block?
Ulnar nerve (that is why ulnar block is what may need to be supplemented with an interscalene block)
Why is an interscalene block not appropriate for surgeries distal to the elbow?
bc the ulnar nerve is frequently not blocked. (C8,T1)
Which block if performed properly almost invariable blocks the ipsilateral phrenic nerve?
Interscalene block
Which patients must be given careful consideration before the use of an interscalene block?
patients with severe pulmonary disease or preexisting contralateral phrenic nerve palsy
**Landmarks for Interscalene block?
Clavicle
Clavicular head of the Sternocleidomastoid muscle
Interscalene groove
Cricoid cartilage
External jugular vein
(Twitch response to deltoid)
What medication might you want to give a patient whom you are doing an interscalene block on?
Versed (want them to be relaxed)
What motor response are you looking for when using a simulator and trying to do an interscalene block?
Deltoid or bicips muscle is elicited.
What do you DO EVERY single time before you inject LA for a block?
ASPIRATE
How much LA solution will you inject for an interscalene block?
20-30 ml
Name four side effects of the interscalene block?
Horner’s syndrome
Block of the phrenic nerve
RLN block
Compression of the lumen of the carotid artery (hematoma)
An interscalene block may cause Horner’s syndrome , tell me what are the s/s of Horner’s syndrome?
myosis (variant of miosis),
ptosis,
anhidrosis (inability to sweat
An interscalene block may cause block of the phrenic nerve, tell me what that would look like?
ipsilateral phrenic nerve paralysis COMMON
Can lead to respiratory failure in pts. with inadequate pulmonary reserve. (C3-C5 is the phrenic nerve))
What would RLN block look like? (occurs with interscalene block)
Hoarseness
In a pt with contralateral vocal cord paralysis, respiratory distress could occur.
Interscalene Complications, name four?
Intravascular injection into a vessel in the neck, particularly the vertebral artery, and diffusion of the local anesthetic solution through the wall of the vertebral artery (CNS intoxication)
Subarachnoid injection (total spinal)
Epidural injection (high epidural)
pneumothorax
**Where does the Supraclaviular block occur at? (roots, trunks, divisions, cords, branches)
ppt states the 3 trunks, but per Barash it can be trunks or divisions depending on where exactly your needle is.
(MM indicates divisions)
4 advantages of using a supraclavicular block?
Low volume of solution is required
Quick onset
Arm can be in any position
***No danger of missing peripheral or proximal nerve branches because of failure of LA spread
4 disadvantages of the supraclavicular block?
Reliable quick-onset block is achieved only if paresthesias are elicited
Difficult to perform and/or teach
Considerable experience is required
***Risk of pneumothorax
Supraclavicular side effects can be similar to that of interscalne block, what are they?
Horner’s syndrome:
Myosis ,ptosis, anhidrosis
Phrenic nerve paralysis (unilateral diaphragmatic paralysis)
Recurrent laryngeal nerve paralysis (hoarseness)
Complications of Supraclavicular block are similar to that of Interscalene block, what are some?
Pneumothorax - 0.5 - 5% (US improves safety)
Plexus injury
Hematoma formation
High spinal or epidural anesthesia
Subclavian artery puncture
What nerves does the supraclavicular block NOT block and thus what is it used for?
Used for procedures at or distal to the elbow (hand, forearm, arm).
Not ideal for shoulder surgery and does not block the Ulnar nerve.
What lower extremity nerve does the Supraclavicular block NOT block?
Ulnar nerve
How is the arm positioned for a supraclavicular block?
Arm is pulled slightly caudad, parallel to the long axis of the body.
Where is the brachial plexus for a SCL block in relation to the Subclavian artery?
multiple hypoechoic disks just superficial and lateral to the SCL artery.
If using PNS for a SCL block what will you elicit?
response from the arm, forearm, or hand (the area you are trying to block)
Infraclavicular block occurs at the level of?
cords
Infraclavicular blocks provide excellant anesthesia for procedures WHERE?
elbow down (captures the MC and axillary nerves)
Is the upper arm and shoulder anesthetized with an infraclavicular block?
NO
Is the Musculocutaneous nerve blocked with an infraclavicular block?
Yes
What two patients should you avoid Infraclavicular blocks on?
Avoid in patients with vascular catheters in the SCL region
Avoid in patients with ipsilateral pacemaker
What motor response is wanted and elicited with PNS for an infraclavicular block?
finger flexion or extension
What PNS stimulation do you NOT want when performing an infraclavicular block?
elbow flexion/extension
When US is used with an infraclavicular block where do you position the transducer?
2 cm medial and 2 cm caudad to the coracoid process
Axillary block advantages (3)
Less risk of major complications
Suitable for ER and outpatient use
***Not imperative to seek paresthesias
Axillary Block disadvantages? (3)
Arm must be abducted in order to perform the block
***Extent of anesthesia is insufficient for shoulder or upper arm surgery without using large volumes of solution
***the axillary, musculocutaneous, & medial cutaneous nerves are usually missed because they exited the sheath proximal to the point of injection (outside the neurovascular sheath)
Which block is it NOT needed to seek parethesia?
Axillary block
What 3 nerves are typically missed with an axillary block technique?
axillary, MC, and medial cutaneous nerves.
Relationship of Nerves to Axillary Artery (at the Axillary Level)
Median nerve - anterior to the axillary artery
Ulnar nerve - posterior to the axillary artery
Radial nerve - posterior and somewhat lateral
What do you palpate and mark at the start of an axillary block of the brachial plexus?
palpate axillary artery and mark location.
PNS with axillary block will elicit a response from?
the hand
You inject LA around each nerve (median, ulnar, radial) in an axillary block, what nerve must you additionally block for an adequate block?
*** You must additionally block mucsculocutaneous in addition for adequate block.
What is interesting about a trans-arterial approach to an axillary block? Who is it not recommended for?
Axillary artery is intentionally punctured
Needle is advanced until negative aspiration
LA solution is injected behind the artery
Risk of hematoma - Not recommended if patient is to be heparinized.
How long must you hold pressure for a trans-arterial approach of an axillary block?
hold pressure for five min.
Musculocutaneous Block is commonly included while performing what block?
axillary block
How/When is a MC nerve blocked with the axillary block?
During an axillary block (after the other 3 nerves within the sheath are anesthetized), the needle is redirected superior and proximal to the artery (piercing the coracobrachialis muscle)
(5-10ml LA injected)
Do you use epi with peripheral nerve blocks?
may or may not be used. epi 1:200,000
When larger volumes of LA are used to perform a PN Block what else is adjusted?
larger volumes = lower concentrations.
Do digital nerve blocks contain epi?
Solutions for digital blocks should NEVER contain epinephrine
For a digital nerve block how much LA is used. What do you do if you hit a bone?
2-3 mL of local anesthetic without epi is injected on each side (if hit bone, come back 1-2 mm and inject)
size needle used for digital nerve block?
23-25G
How do you position the hand for a digital nerve block?
Position hand pronated and rested on a flat surface
Complications of Digital nerve block?
Vascular insufficiency and gangrene.
This results from digital artery occlusion together with failure of adequate collateral circulation
What causes the complications seen with digital nerve blocks?
epi-containing soluitons.
mechanical pressure of injecting solution into a confined space (do not exceed a max volume of 2ml on each side)
tourniquets- should avoid using RUBBER BAND type tourniquets at the base of the digit.
PVD
direct vascular damage by the needle.
Digital nerve block maximum amount of LA on each side should not exceed
2ml
Rules for using a tourniquet with digital nerve blocks (if used for surgical procedure)?
DO NOT use if a patient has Raynaud’s or PVD
15 min. limit
use actual tourniquet for arm, AVOID rubber bands etc…
IV regional analgesia is best used for brief minor surgery of an extremity, what is the time limit and typical surgery type for this?
up to 1 hour and an example would be carpal tunnel release.
When using a Bier Block what is the typical mmHG for upper and lower extremities?
usually 250mmHG upper and 350-400mmHG for lower.
With a Beir block you want to make sure you do not occlude what artery?
axillary artery (check both cuffs)
with a bier block, what strength LA will you use, what mL will you inject depending on the location and over what time period?
0.5% lidocaine
25ml = forearm 50ml = arm 100ml = thigh
injected over 2-3 min.
(popular dose is 40ml (assuming this is for arm))
Tell me what you do for a Bier block up to elevating the arm and wrapping with Esmarch elastic bandage?
check your tourniquet device (both cuffs)
supine position and apply all standard monitors.
small IV (22g) placed in hand of the arm you will be using (as well as an IV in the other arm (18g). Cath. should be firmly taped down.
Arm is then elevated to passively promote venous drainage while the extremity is wrapped in Esmarch elastic bandage from distal to proximal.
After wrapping the arm in bandage from distal to proximal for a Bier block what happens next up to taking the Esmarch bandage off?
The distal cuff is inflated first to squeeze blood further from the arm (check for occlusion of the radial artery pulse.)
Then the proximal cuff is also inflated to maintain a cuff pressure at 150mmHg above systolic blood pressure.
functionality should be checked for occlusion of the radial artery pulse (check both cuffs)
At this point if both cuffs work well, the distal tourniquet is deflated.
Esmarch bandage is removed, the patient’s arm is returned to the horizontal position.
When do you inject the LA into the IV cath. for a bier block?
after all blood has been pushed from the extremity, the distal cuff is deflated and the Esmarch bandage is removed then you inject the LA (the proximal cuff IS STILL inflated)
How long is the proximal cuff left inflated? How do you know when to deflate it?
The proximal Tourniquet is left inflated until the patient complains of tourniquet pain (may develop after 20-30 minutes)
At this point the distal tourniquet can be inflated and the proximal deflated. The distal cuff should be over an anesthetized area. (thus pain should go away)
When do you “test” the tourniquets for the bier block?
test tourniquet at all times in between cuff changes
this is in addition to your initial check before procedure
What type of anesthesia can be considered if the tourniquet pain is “too much”?
sedation/MAC
If the length of a surgery is 20 min. or less then what does that mean for the proximal cuff?
it should stay inflated for at least 20 min. before you start to release.
(if surgery was 15min. then proximal cuff will stay inflated for at least 5 more min.)
What is the single most common complication of a bier block?
systemic toxicity!
Systemic toxicity with a bier block is due to LA injected into the central circulation, how does this happen? (2)
a leak under the tourniquet or premature release.
EVERY patient receiving a major conduction nerve block should have what two things?
IV infusion line!
Be monitored to allow for timely detection of systemic toxicity of LA and immediate vascular access for its treatment.
How long do you monitor larger doses of LA (used for major conduction or plexus blocks) in order to monitor for anesthetic toxicity?
Why is this?
30 min. after block placement.
peak serum levels of LA typically occur 20 min. following injection. (even though toxic reactions occur during or immediately upon injection typically)
What basic monitoring will you do with any LA block?
Baseline level of consciousness
Pulse oximetry
Blood pressure
Heart rate
What kind of things will you document with every regional anesthesia?
Nerve block procedure Approach used Premedication Skin preparation Equipment used (needle/nerve stimulator) Number of attempts Type of response obtained on nerve stimulation (what elicited) Current (mA) accepted Local anesthetic (type, concentration, volume)
Intercostal block, the nerves run from what to what?
T1-T11
Result in the highest blood levels of LA per volume injected of any block in the body?
INTERCOSTAL BLOCK
Has one of the highest complication rates of any peripheral nerve block, which block and why?
INTERCOSTAL BLOCK
(due to close proximity of intercostal artery and vein– risk of intravascular LA injection, as well as underlying pleura– risk of pneumothorax)
is the duration of an intercostal block short or long?
SHORT due to high vascular flow
What kind of procedures or issues would you use an intercostal block for?
pain relief for thoracic and upper abd surgery, rib fractures, herpes zoster, cancer.
position of patient for intercostal block?
position pt in PRONE (on the belly) or lateral position.
Where do you insert your needle for an intercostal block and then how do you proceed?
it is inserted at the inferior edge of each selected ribs, bone is contacted, and the needle is then “walked off” inferiorly (important to NOT allow needle to enter a depth greater than the depth that palpating fingers can define a rib)- (2-4 mm)
What nerves are targeted with a TAP block?
The subcostal (T12), ilioinguinal (L1), and iliohypogastric (L1) nerves are targeted in the TAP Block
Where is the US placed for a TAP block?
between the lower costal margin and the iliac crest
For a TAP block 3 planes are identified, what are they?
external oblique, internal oblique, transversus abdominis (LA injection site)
For a TAP block where do you want to inject the LA? (when looking on US?)
Right above (superior border) the transverse abdominis on the fascia line.
Size needle for a TAP block?
long, 10cm and 21 G needle.
