Upper Extremity Nerve Blocks

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Upper Extremity Nerve Blocks
2014-02-13 16:04:22
Principles II Exam Two

Anesthesia II Exam II
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  1. If the needle is positioned correctly with a upper extremity block, when 1ml of LA is injected, this amount of solution should  rapidly....???
    abolish the muscle contraction or the sensation of pulses current.
  2. The branches of the lateral and medial nerves are all ______ nerves to the upper extremity.
  3. The posterior cord provides all ____ innervation to the upper extremity.
  4. The radial nerve supplies all the ____ musculature in the upper extremity below the shoulder.
  5. The _____ nerve innervates more heavily in the forearm, whereas the ____ nerve innervates more heavily in the hand.

  6. Interscalene blocks are especially effective for surgery of the _____ and _____.
    shoulder and upper arm
  7. Interscalene blocks are ideal for reduction of a dislocated shoulder and often can be achieved with as little as _____ of LA.
  8. What position must the arm be in for an interscalene block???
    can be in almost any position
  9. What kinds of patients are interscalene blocks good for??
    virtually all patients, even obese ones because everyone usually has an identifiable scalene and vertebral body anatomy
  10. What patients should you avoid the use of an interscalene block with? and why???
    patients with significantly impaired pulmonary function. 

    because the phrenic nerve is almost always effected causing hemidiaphragmatic paralysis (dyspnea, hypercapnia, hypoxia)
  11. Is an interscalene block considered a large volume block??

    need 25 - 30 cc normally
  12. Lidocaine and mepivacaine provide surgical anesthesia for ____ without epinephrine and for _____ when epinephrine is added in interscalene blocks.

  13. Why is epi used with LA in interscalene blocks??
    epi decreases the vascular uptake of a drug so it allows the LA to work longer
  14. For more extensive procedures with an interscalene block what drugs are used??
    Ropivacaine and bupivacaine

    these drugs last longer

    and may provide increased muscle relaxation
  15. Plain bupivacaine produces surgical anesthesia lasting from _____ ; the addition of epinephrine may prolong this to ____ in interscalene blocks.
    4-6 hours

    8-12 hours

    Ropivacaine's effects are slightly shorter in duration.
  16. Many sites use Ropivacaine 0.5% for interscalene blocks...
    if the percent increases what does this mean??
    it means it is more concentrated so you will get an increased motor block
  17. What problems can arise from interscalene blocks??
    • subarachnoid injection
    • epidural block
    • intravascular injection
    • pneumothorax
    • phrenic block
  18. List the drug concentrations that should be used with an interscalene block to obtain muscle relaxation or motor block during the procedure in the drugs below...
    • mepivacaine 1.5%
    • lidocaine 1.5%
    • bupivacaine 0.5%
    • ropivacaine 0.75%
  19. How long does it take for an interscalene block to take effect??
    20-35 mins

    the block needs time to set in

    this most is most often carried out through a single injection site and the operator relies on the spread of the local anesthetic solution, thus one should allow for adequate soak time after injection.

    so do this block before the patient gets in the OR
  20. Most of the injection difficulties that result in complications of interscalene blocks can be avoided if one remembers that this is a very superficial block..therefore no more than _____ of the needle should be necessary to reach the plexus.

    if the needle is inserted deeply..that's when you worry about other complications --- subarachnoid, epidural and intravascular injection.
  21. Which nerve is difficult to block with the interscalene approach??  Which nerve is this nerve derived from??
    ulnar nerve

    dervived from 8th cervical nerve

    with an interscalene block, the ulnar nerve and it's more peripheral distribution in the hand are spared so you'll need an additional block to block the hand if this space is required to be blocked during the procedure as well