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Why should do we use blocks?
- Less Post op pain
- Less used of narcotics(side effects)
- Less cognitive impairments (elderly)
- Less Imunosuppresive
In what instance would a cervical plexus block be used?
Procedures of the lateral or anterior neck e.g. carotid endarterectomy
From what roots does the cervical plexus arise?
C2-C4 nerve roots
What are some types of airway block?
- Aerosolized lidocaine
- Superior laryngeal nerve block
Describe the procedure of Superior laryngeal nerve block.
Needle is advance superiorly off the lateral wing of the thyroid cartilage. When it drops through the thyro-hyoid membrane 2.5 ml 1% lido bilaterally
Name the 4 approaches to blocking the brachial plexus.
Interscalene, supraclavicular, infraclavicular and axillary.
What branches of the brachial plexus are commonly missed by interscalene blocks?
C-8 and T-1
If C-8 and T-1 branches are missed during an interscalene block, what area of the arm is not covered?
The caudad, or ulnar border of the forearm.
What approach is best for proceedures of the shoulder, arm, or forearm?
What block is most intense in the C5-C7 Dermatomes?
What approach is best for procedures of the elbow or hand?
Which roots are most intensely blocked by the axillary approach to the brachial plexus?
Describe the landmarks for ISB?
- Lateral border sternocleidomastoid
- pt lift head, palpate groove btw anterior and middle scalene muscles
- level of the cricoid
What are the potential complication of ISB?
Pneumo, Spinal or epidural anesthesia, CNS toxicity, Horners syndrome (ptosis, miosis, anhydrosis), Hoarseness, and dyspnea (Phrenic nerve lies over the anterior scalene muscle).
What motor response is seen with stimulation during ISB?
Response of deltoid, arm or hand
How much of what is typically used in ISB?
25-30 ml .25% bupivicain
What does activity of phrenic nerve suggest while using stimulus to locate Brachial plexus for ISB?
Needle is too anterior
What does activity of the trapezieus muscle indicate when stimulating to locate BP for ISB?
Needle is too posterior
Describe the titration of voltage when using a nerve stimulator to perform ISB.
Start at 15 mA. The correct nerve should react with less than 5 mA. If you can get to 0.5 mA you are very close.
What causes horners syndrome?
Spread of LA to the sympathetic chain on anterior vertebral body
Why is caution advised in pts with pulmonary disease for ISB?
Paralysis of the phrenic nerve can occur causing acute respiratory distress.
For what procedures are infraclavicular and supraclavicular blocks indicated for?
Surgeries of humerus, Elbow, hand
Why are supra and infra-clavicular blocks used less often than ISB?
Higher risk pneumothrorax
What are some complications of supra-clavicular blocks?
- Higher risk of pneumothorax
- horners syndrome
- phrenic nerve block
What are some complications of infracalvicular blockade?
- chylothorax (Lt sided)
For what procedures is the axillary block indicated for?
- Humerus, Elbow and hand
- Mostly for surgeries distal to elbow
Which nerve roots are blocked greatest with the axillary block?
- What nerve is missed by the axillary block?
- musculocutaneous nerve
What could cause a patchy block to form when performing an axillary block?
The brachial plexus begins to form facial compartments
Where can radial nerve blocks be performed?
The wrist or the antecubital space
The radial nerve is the terminal branch of what cord?
Where are ulnar nerve blocks perfomrmed?
The wrist or the elbow
From what nerves does the median nerve arise from?
Lateral and medial
In what places can the median nerve be blocked?
Elbow or the wrist
From what nerve does the ulnar nerve spring from?
To achieve complete anesthesia of the hand what three nerves need to blocked?
Ulnar, radial, and median
How much local is sued to provide anesthesia for the nerves in a wrist block?
5-7 ml for each nerve
For what procedures is a digital blockade indicated?
Minor operations of the fingers
How much local would be appropriate for a digital blockade?
1-3 mls either side of the digit at the base.
How is local anesthetic systemic toxicity treated?
- 1. Airway, hyperventilation
- 2. Abolish convulsions (Diazepam, Midazolam)
- 3. Intralipid
- 4 CPR/ACLS - Consider CPB
What is the dosage of intralipid used for LAST?
1.5 ml/kg over 1 minute then infusion at 0.25 ml/kg/min
What is another name for lumbar plexus block?
What nerves are aneshtetised with a LPB (psoas block)?
- Gentitofemoral L1,L2
- Lateral femoral cutaneous L2, L3
- Femoral L2,L4
- Obturator nerves L2-L4
What nerve could be blocked for a skin graft from the anterior thigh?
Lateral femoral cutaneous
What block would be appropriate for procedures involving the knee, anterior thigh, or hips?
Lumbar plexus block
What Block would be appropriate for an anterior knee procedure?
Femoral nerve block
What is the origination of the sciatic nerve?
What nerve roots compose the sciatic nerve?
L4-5, and S1-3
What areas of the lower extremity does the Sciatic nerve supply?
the posterior hip and knee and distal to knee except for anteromedial aspect which is supplied by the saphenous nerve
Where does the Sciatic nerve supply motor activity to?
the hamstring and all muscles distal to knee
What is the typical dose of LA used in a sciatic block?
How do you position the pt for Sciatic block?
lateral decubitus position with operative extremity up (nondependent)
What two nerves does the sciatic nerve divide into in the popliteal fossa?
tibial and common peroneal nerves
What motor response is sought when performing an pop fossa block?
motor response is sought at the distal ankle, foot, or toes
What is the typical amount of LA used in a pop fossa block?
30-40 ml of local anesthetic is injected.
What types of surgeries are appropriate for a pop fossa block?
Foot and ankle surgeries
What two blocks can provide complete anesthesia for procedures involving the LE distal to the knee?
When the pop fossa block is combined with a separate saphenous nerve block one can achieve complete anesthesia distal to the knee.
What is the origin of the saphenous nerve?
What areas does the saphenous nerve supply sensation to?
provides sensory innervation to the medial aspect of the lower leg
Describe technique of a saphenous nerve block.
infiltrate 7-10 ml of local anesthetic staring from the tibial tuberosity and directed medially, completing the injection at the posterior knee
What five nerves supply the sensation to the foot?
- Saphenous-terminal end of the femoral nerve
- a. Deep peroneal nerve-Innervates toes, medial foot between 1st and 2nd digits
- b. Superficial peroneal nerve-Dorsum of foot and all 5 toes
- c. Posterior tibial nerve-Heel, sole,lateral foot
- d. Sural nerve-Lateral foot