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T or F, nerve blocks are more immunosuppressive than GA
F, less immunosuppressive than GA
For what procedures is a cervical plexus nerve block used for?
Procedures of the anterior or lateral neck (CEA)
From what nerve roots does the cervical plexus arise from?
What 4 approaches can be used to block the brachial plexus?
interscalene, supraclavicular, infraclavicular, and axillary
What type of brachial plexus block is most commonly done?
For what procedures is an ISB best for?
Shoulder, arm, and forearm procedures
In what dermatomes is the ISB most intense? Least intense- what is the impact of this?
- Most intense- C5-C7
- Least intense- C8-T1- ulnar border of the forearm may be missed
For what procedures is an axillary brachial plexus block best for? At what nerve roots is it most intense?
- Procedures involving the area from the elbow to the hand.
- Most intense at C7-T1
What nerve roots does the brachial plexus consist of?
What trunks does the brachial plexus consist of?
superior, inferior, and middle
What nerve roots supply the ulnar nerve?
C8 - T1
What are the 4 terminal nerve branches of the brachial plexus?
Axillary nerve, radial nerve, medial nerve, and ulnar nerve
At what level is an ISB performed at (where is needle inserted and what landmarks are used)?
Level of the cricoid cartilage
Lateral SCM muscle is found, then proceed laterally to find the groove between the anterior and middle scalene muscles- insert needle here
What motor response confirms ISB proper needle location?
Motor response of the deltoid arm or hand
When inserting an ISB, if trapezius muscle movement is noted- what does this mean?
The needle is too posterior
When inserting an ISB, if phrenic muscle movement is noted- what does this mean?
Needle is too anterior
How is a nerve stimulator used to confirm needle placement?
- Start with mA of 15 and have desired muscle movement
- Decrease to 0.5 mA (or less) and still maintain muscle twitches in the desired location
What nerve block can affect the phrenic nerve? What complications may result?
Is what pts must particular caution be payed?
- Resp failure
- Pts with COPD or severe resp compromise
Potential complications from ISB
- pneumothorax (cough or CP)
- injection into intervertebral foramina (get total spinal)
- CNS toxicity due to injection into the intervertebral artery
ISB can produce Horner's syndrome- what are the s/sx?
- ptosis (drooping eyelid)
- miosis (pupil constriction)
- anhydrosis (lack of ability to sweat)
- due to spread of LA to sympathetic chain on the anterior vertebral body
When performing an ISB, what structure should be seen under US?
The 3 hypo echoic circles which represent with brachial plexus nerve roots
For what surgeries is a supra or infraclavicular block indicated for?
Surgeries of the humorous, elbow, hand
What is the risk of pneumothorax with a supraclavicular block?
T or F, risk of Horners syndrome and phrenic nerve involvement is possible with a supraclavicular block?
Why is there a risk of chylothorax with a left infraclavicular block?
The thoracic duct is on the left, and if damaged, lymph fluid can accumulate in the pleural cavity
For what surgeries is an axillary block ideal for?
- Humorous, elbow, and hand
- Ideal for surgeries distal to the elbow
Will an axillary block provide analgesia for tourniquet pain?
No, an ax block affects C8-T1. It misses the musculocutaneous nerve (it's already left the nerve sheath). This nerve needs to be blocked separately.
What LA and how much are typically used for ISB?
- bupiv or ropiv 0.25% or 0.375%
- 20-30 ml
Where is a radial nerve block performed?
AC or the wrist
The radial nerve is the terminal branch of the ____ cord of the brachial plexus
Where is an ulnar nerve block performed at?
Elbow or wrist
To provide adequate local anesthesia for hand surgery- what nerves must be blocked?
Radial, medial, and ulnar; each with 5-7 ml of LA
The medial nerve is derived from the ____ and _____ nerves (cords) of the brachial plexus
Lateral and medial
The ulnar nerve is derived from the ____ nerve (cord) of the brachial plexus
The radial nerve is derived from the ____ nerve (cord) of the brachial plexus
For what type of surgery would a digit block be used for?
Minor finger surgery
How is a digital block performed?
Inject 1-3 ml of LA at base of each side of finger (digital nerves run in tissue on both sides of phalanges)
For what types of blocks is LA with epi contraindicated?
Digits, nose, toes, penis
Steps in the treatment of LA toxicity
- 1) secure airway, hyperventilate, 100% O2
- 2) anti-sz meds to abolish convulsions
- 3) intralipids (1.5 ml /kg over 1 min), then con't infusion 0.25 ml / kg / min
- 4) CPR / ACLS