Lower Extremity Peripheral Nerve Blocks

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Lower Extremity Peripheral Nerve Blocks
2013-12-01 13:05:55
BC Nurse Anesthesia CP1

LE nerve blocks
Show Answers:

  1. Another name for a lumbar plexus block
    psoas block, the lumbar plexus courses the fascia of the psoas muscle
  2. What nerves does a lumbar plexus block anesthetize?
    • Genitofemoral nerve (L1, 2)
    • Lateral femoral cutaneous nerve (L2, 3)
    • Femoral nerve (L2-4)
    • Obturator nerves (L2-4)
  3. For what surgeries would a lumbar plexus block be indicated for?
    Knee, anterior thigh, hip
  4. Describe how to locate the injection site for a lumbar plexus block
    • Find iliac crest, this is L4 level
    • Find PSIS, draw line cephalad
    • Intersection of the 2 lines is the injection site
    • Generally 4 cm from the midline
  5. What motor movement would confirm lumbar plexus block?
    Quadricep muscle twitch and patella snaps upwards
  6. What are possible complications of a lumbar plexus block?
    • vessel or organ puncture
    • done under CT, dangerous as inject deeper than a spinal
  7. Most common LE block
  8. What 3 nerves does a FNB supposedly block?
    • femoral nerve
    • obturator nerve
    • lateral femoral cutaneous nerve
  9. What areas does a FNB affect?  What type of surgeries would it be indicated for?
    • Anterior knee
    • Knee surgery
  10. Describe how to find the injection site for a FNB
    • -find inguinal ligament (draw line btw ant superior iliac spine and pubic tubercle)
    • -at midpoint of line, palpate for femoral pulse
    • -insertion site is 2 cm lateral and 2 cm distal (needle should point cephalad)

  11. what motor movement confirms proper position for FNB?
    Quad movement or patellar snap (patella moves cephalad)
  12. What does it mean if lateral leg movement is seen when attempting to place a FNB?
    -you’re too lateral, move medial
  13. What nerve supplies the posterior leg
    -sciatic nerve
  14. What motor activity does the sciatic nerve supply?
    hamstring and all muscles distal to the knee
  15. what nerve roots are blocked for a sciatic nerve block?
    L4,5 and S1-3
  16. What nerve does a pop fossa block block?
  17. For what type of surgery is a pop fossa block indicated?
    Lower leg or calf surgery; ankle and foot surgery
  18. What 2 nerves does the sciatic nerve divide into, and where?
    • Tibial and common peroneal 
    • High in the popliteal fossa
  19. How is the injection site for a pop fossa block
    Triangle formed by popliteal crease, medial tendons, and lateral biceps femurs muscle

    Inject 1 cm lateral and 1 cm from the apex of the triangle

    Needle should point cephalad
  20. What does the saphenous nerve innervate?
    Medial aspect of lower leg
  21. What 2 blocks would provide total anesthesia distal to the knee?
    Pop fossa and saphenous 
  22. The saphenous nerve is the terminal extension of the _______ nerve.
  23. Where is the injection site for a saphenous nerve block located?
    Start at tibial tuberosity and direct medially
  24. What 5 nerves supply sensation to the foot?
    • 1) saphenous (terminal branch of the femoral nerve)
    • All others branch off the sciatic nerve
    • 2) deep peroneal (toes, medial foot btw 1st and 2nd digits) 
    • 3) superficial peroneal (dorsum of foot, all toes)
    • 4) posterior tibial (heel, sole, lateral foot)
    • 5) sural nerve (lateral foot)
  25. What 3 nerves supplying the ankle can be blocked via 1 injection site?
    Deep peroneal, supericial peroneal, and saphenous