Maverick Modules (7-9) ISB, Femoral, & Lateral Popliteal Sciatic Blocks Flashcards
What is the most proximal block of the Brachial Plexus?
Interscalene block
Which of the following are being targeted with an interscalene block?
- Roots
- Trunks
- Divisions
- Cords
- Branches
Roots and Trunks
What is the Winnie Approach for an interscalene block?
When should it be used?
- Palpate for fissure between anterior and middle scalene, insert needle perpendicularly to the brachial plexus.
- Never. This approach is now dangerous
What are the indications for an interscalene block?
- Any surgery of upper arm or shoulder (arthroplasties, shoulder mobilizations, etc.)
When should a continuous catheter placed for an interscalene block be removed?
60 hours or POD#3
What is a limitation of the interscalene block?
Interscalene blocks upper but not lower arm
What are contraindications to an interscalene block?
- Infection at site
- COPD/Emphysema (Home O₂ = no block for you)
- Contralateral pneumothorax/pneumonectomy
- Patient refusal
- Non-cooperative / mentally handicapped
- Acute respiratory compromise (ex. fluid overload)
- New neuro deficit associated with ISB path
What are your landmarks for an Interscalene Blocks (ISB) ?
Insert at posterior border of sternocleiodomastoid above and parallel to the cricoid cartilage
What has to be removed for an ISB?
Wraps/splints on the arm (necessary so that motor response can be assessed).
How deep, typically, is the brachial plexus?
1 - 3 cm
What initial current is utilized in locating the brachial plexus for an ISB?
1.0 mA
What initial current should be utilized in locating the brachial plexus for an ISB if the patient has a local fracture?
0.7 mA
What endpoint current is necessary for proper location of the brachial plexus using the nerve stimulator?
≤ 0.4 mA
What are the five acceptable motor responses associated with brachial plexus nerve stimulation?
- Musculocutaneous
- Radial
- Pectoral
- Axillary Nerve
- Hand/Fingers
What is the primary motor response you want for a should surgery requiring an ISB?
Axillary nerve response → Contraction of Deltoid muscle
What are unacceptable motor responses that might be seen with a brachial plexus stimulation for an ISB?
- Diapragmatic contraction (needle is too anterior)
- Trapezius contraction (needle is too posterior)
- Posterior compartment neck muscles (needle is too posterior)
What nerves are most likely going to be stimulated with a successful ISB?
- Axillary
- Median
- Radial
- Musculocutaneous
- Suprascapular
- Pectorals
- Lateral cutaneous of the arm
What nerves are most likely to be unaffected with a successful ISB?
- Medial cutaneous of the forearm
- Ulnar
What are side effects of an Brachial Plexus block?
- Phrenic Nerve Palsy & hemidiaphragmatic paralysis
- SNS blockade (Horner’s syndrome)
- Unilateral flushing
- Laryngeal nerve palsy (particularly with right sided blocks)
What complications can occur with brachial plexus block?
- Pneumothorax
- Intrathecal injections (Winnie Technique)
- CNS LA toxicity
- Phrenic nerve palsy → hemidiaphragmatic paralysis
What typical side effect of femoral nerve blocks leads to difficulties with ambulation?
Quadriceps weakness
What are indications for the femoral nerve block?
Anything in the blue area.
- ACL
- Total Knee Replacement
Anything necessitating a thigh tourniquet
What is the major limitation of a femoral nerve block?
Sciatic block is a necessary addition for many surgeries to gain total coverage of the leg.
What are absolute contraindications for femoral nerve block?
- Infection at site
- Patient/Surgeon refusal
What is the largest nerve branch of the lumbar plexus?
Femoral nerve
Label the following structures.
- Femoral Artery
- Femoral Nerve
- Femoral Vein
- Anterior/Superior Iliac Spine
- Inguinal Ligament
- Sartorius
What muscle response should be seen when using nerve stimulation to locate the femoral nerve?
Quadricep twitch (particularly noticeable right above the patella of the knee)
Does the femoral nerve innervate the entirety of the femur?
No; no posterior femur innervation
What are the pertinent landmarks for a femoral nerve block?
Needle insertion is 1.5cm lateral to femoral artery and 2cm distal from inguinal ligament
What is the angle of insertion for a femoral nerve block?
Motor responses from which muscles would indicate improper femoral block needle placement?
- Sartorius
- Gracilis
- Adductor Longus
What needle types are acceptable for femoral nerve block?
- 50 - 100 mm Insulated B-bevel needle
- 50 mm Lifetech Insulated needle
- 2 - 4 inch 22g Stimulplex needle
What is a Popliteal Sciatic Nerve Block (SNB) appropriate for?
Lower Extremity Surgeries
- Tib/Fib fractures
- Achilles Repair
- Ankle ORIF
What are SNB usually combined with?
Femoral or Saphenous blocks
What approach is ideal for the SNB?
Medial and slightly posterior 10° approach
What are the landmarks for an SNB?
- Groove between Vastus Lateralis (VL) and the Biceps Femoris (BF)
- 7-10 cm cephalad of lateral femoral condyle or superior aspect of patella
What areas of the photo are innervated by the Tibial nerve?
Blue
What areas of the photo below are innervated by the common peroneal nerve?
Saphenous nerve?
- Common Peroneal Nerve = Orange
- Saphenous Nerve = Green
What motor responses are acceptable as we approach the Sciatic nerve for an SNB?
- Inversion (CP & Tibial)
- Dorsiflexion (CP)
- Plantarflexion (Tibial)
If dorsiflexion is noted on nerve stimulator advancement in performing a SNB, what should be done?
CP nerve is being stimulated → advance needle to Tibial nerve
