Lower Extremities- Kelly Flashcards
(157 cards)
1
Q
Name 5 contraindications to lower extremity anesthesia
A
- Infection at the injection site
- Anticoagulant therapy
- Persistent peripheral neuropathies and/or paresthesias.
- High risk of developing compartment syndrome post op
- Surgical intervention on lower extremity nerves.
1
Q
What are indications for lower extremity anesthesia?
A
-Surgery and/or tourniquet use of lower extremity-Post-operative analgesia-Diagnostic-Therapeutic-Arterial Occlusive Disease
2
Q
Ahhhhh compartment syndrome… Let’s read a lil bit on how that comes to be shall we…..
A
Acute compartment syndrome is a complication following fractures, soft tissue trauma, and reperfusion injury after acute arterial obstruction. It is caused by bleeding or edema in a closed, nonelastic muscle compartment surrounded by fascia and bone. The most common cause for a compartment syndrome is bleeding, which can develop after vascular injuries or from cancellous bone following fractures or osteotomies. Another cause is edema developing after an increased capillary permeability which also may be due to an oxygen deprivation caused by bleeding. The edema increases the perfusion barrier resulting in hypoxia and acidosis. Following a vicious circle, hypoxia and acidosis again increase capillary permeability and fluid extravasation. Furthermore, the nonelastic osteofascial planes limit volume expansion of the edema and therefore increase the intracompartmental pressure. This leads to a reduced transmural pressure gradient between microcirculation and interstitium, which induces ischemia within the affected compartment.
2
Q
Give an example of why the patient would have lower extremity anesthesia for a therapeutic indication.
A
Sympathetic outflow problems
3
Q
When you twitch the sciatic nerve what do you want to see?
A
plantar flexion of the foot, or dorsiflexion of the foot…
3
Q
For what diagnostics would the patient have lower extremity anesthesia?
A
Trying to diagnose different chronic pain syndromes or neuropathies
4
Q
bonus question: If you get a plantar flexion or a dorsiflexion of the foot- what nerves are responding?
A
the posterior tibial nerve and the common perineal nerve respectively.
4
Q
How or why is lower extremity anesthesia used to help arterial occlusive disease?
A
It’s used to compensate for arterial occlusive surgery - for example in peripheral vascular surgery (i.e., fem-tib or fem-pop bypass) - dilating those native blood vessels using the sympathectomy from the peripheral nerve block can sometimes make it easier for surgeons to do their anastomoses because the vessels are maximally dilated at the time that they’re operating on them
5
Q
When you are twitching for the femoral nerve what are you looking for?
A
Patellar snap, which is twitching of the quadriceps femoris
5
Q
When you are twitching the obturator nerve what are you looking for?
A
the adductor muscles of the medial side of the leg
5
Q
What areas would you be most concerned about with compartment syndrome?
A
Generally with smaller sheath areas (i.e., popliteal block)
6
Q
When you are twitching the lateral femoral cutaneous what are you looking for?
A
trick question……. no motor innervation.
6
Q
The lumbosacral plexus is composed of the nerve roots from?
A
L2 to S3
7
Q
Where is the sciatic nerve derived from?
A
L4-S3 nerve roots
7
Q
Is the sciatic one nerve or multiple?
A
Runs as one nerve however it has a medial (tibial nerve) and a lateral (peroneal) division.
7
Q
The femoral nerve is composed of which nerve roots?
A
L2-4
8
Q
Where does the sciatic nerve divide into the tibial and the peroneal nerve?
A
At the popliteal fossa
8
Q
The lateral femoral cutaneous is composed of which nerve roots?
A
L2-3
9
Q
Where does the tibial nerve run and how does it divide?
A
It runs down the posterior of the leg and forms the posterior tibial nerve and the sural nerve.
9
Q
The obturator nerve is composed of which nerve roots?
A
L2-4
10
Q
Where does the peroneal nerve run and how does it divide?
A
laterally around the head of the fibula and further divides to form the deep peroneal nerve.
10
Q
Which nerve(s) will we worry about for anterior type pain above the knee?
A
Femoral nerveLateral femoral cutaneousObturator
11
Q
Psoas Compartment block: What does the psoas sheath refer to?
A
it is the potential space between the psoas muscle and the posterior fascia.
11
Q
Which nerve(s) will we worry about for posterior type pain above the knee?
A
Sciatic
12
random.... what does PSIS mean?
posterior superior iliac spines
12
What nerve predominantly innervates below the knee?
Sciatic nerve - the lateral, medial until you get to the tibia, posterior gastrocnemius, and entire foot is all by branches of the sciatic.
13
What is the intercrystal line?
It is the line you draw from one PSIS to the other.
13
What portion below the knee is not innervated by the sciatic nerve? What nerve innervates this portion?
A thin band below the knee located anterior tibially all the way down to the medial malleolus, is the distal innervation path of the saphenous nerve (originates from femoral nerve).
14
PSOAS block
There is an upper and a lower approach to the psoas compartment. Here we see the landmarks for the lower approach. Note the midline, PSIS, the intercrystal line (body of L4 or the L3-L4 interspace. Here the injection point is just superior to the PSIS. When you do the upper approach to the compartment, you come @4-5 cm (where PSIS line and intercrystal line intersect) lat on intercrystal line and use this point as your injection point. This approach makes more sense to me because it is right in the middle of L2----L4.
14
Motor innervation: which main nerve is responsible for the plantar flexion and dorsiflexion of the foot?
Sciatic nerve
15
Explain the 7 steps for the Psoas block
1. Sterile prep
2. LA skin wheel (DEEEEEP)
3. Introduce needle perdindicular to all planes
4. Elicit femoral twitch (patellar snap)
5. Inject 1ml of LA
6. Inject 3ml test dose of LA
7. Inject 5ml aliquots to desired amount (roughly 35-40ml)
15
Motor innervation: which specific branch of the sciatic nerve is responsible for plantar flexion of the foot?
Posterior tibial nerve
16
Name 4 blocks at the level of the hip
1. Sciatic
2. Femoral
3. Lateral femoral cutaneous
4. Obturator
16
Motor innervation: which specific branch of the sciatic nerve is responsible for dorsiflexion of the foot?
Common perineal nerve
17
Sciatic blocks: Starting from the "12 o'clock" position in a clockwise fashion identify the 4 structures highlighed by pink dots.
starting at 12 o'clock:
1. midpoint of the greater trochanter
2. PSIS
3. Sacral hiatus
4. sciatic nerve
17
Motor innervation: which nerve is responsible for twitching of the quadriceps femoris (a.k.a. patellar snap)?
Femoral nerve
18
just another photo
18
Motor innervation: which nerve is responsible for twitching of the adductor muscles on the medial side of the leg?
Obturator nerve
19
Femoral Block
indicated for what?
surgical procedures of the anterior thigh, combined with lower extrem block for lower leg sx, femoral fx anesthesia. Continuous epidual may be used for knee surgery as well.
19
Motor innervation: which nerve provides no motor innervation?
Lateral femoral cutaneous
20
What is so AWESOME about the femoral block (pt selection wise)?
Because the patient is positioned supine virtually EVERY patient is a canidate for this block. And because paresthesia is not neccessary to perform this block it can be done on an anesthesitized patient!
20
The sciatic nerve runs as one nerve up until which point?
The popliteal fossa.
21
Explain the steps necessary for performing this block- begin with positioning.
1. Position the patient supine an stand at the patient's side allowing easy palpation of the patient's femoral artery.
2. Draw a line from the anterior superior iliac spine to the pubic tubercle.
3. Palpate the femoral artery along this line
4. Insert a 22G needle so that it abuts the femoral artery and inject in a fan like fashion away from the artery. Approx 20ml
21
At the popliteal fossa, the sciatic nerve divides into a medial and a lateral division. What are the names of these nerves, respectively?
Medial division = tibial nerveLateral division = peroneal nerve
22
If combining the sciatic and the femoral nerve blocks- which should be performed first and why?
The femoral because it needs a longer "soak" time.
22
Extra credit: They used to say that the sciatic nerve divided ~4 cm above the popliteal fossa but newer research indicates that it actually divides where in most people?
7-10 cm above the fossa! So people were doing blocks lower and were missing one branch or the other. Watching Boyd give this lecture....and that was one of his tidbits he added.
23
What you landmarks should look like for the femoral block
23
"I owned it!!!!!"
Ok, had to add a "newby" card. Unfortunately, those of you not in Tampa might not get the full joke, but let's just say I didn't die that day crossing the rode at a totally inappropriate time because Newby said, "GAME ON! GO LO"
24
Where does the lateral femoral cutaneous nerve pass? And what does it innervate?
Passes under the lateral end of the inguinal ligament. It may be superfical or deep to the sartorious muscle and it descends at first deep to the fascia lata.
Cutaneous innervation to the lateral portion of the buttock distal to the greater trochanter and to the proximal 2/3 of the lateral aspect of the thigh.
24
Why is it critically important to know the motor innervation of the lower extremity nerves?
Because it is how you will assess the adequacy of your block.
25
How do you approch a lateral femoral cutaneous nerve block?
1. Position the patient supine
2. stand at the patient's side as you would for a femoral block.
3. Locate and mark the anterior superior iliac spine.
4. Draw a line 2cm medial and then 2cm caudal to the ASIS
5. Insert a 22G 4cm needle and advance until a "pop" is felt as it passes though the fascia lata
6. LA is then inject in a fan like manner above and below the fascia lata from medial to lateral.
25
The "psoas sheath" refers to what?
The potential space between the psoas muscle and its posterior fascia
26
Why are low concentration of LA acceptable with the femoral lateral cutaneous nerve block?
Because it is a sensory nerve.
26
The psoas compartment block produces a block of what nerves and thus provides anesthesia/analgesia for what part of leg?
It produces block of all lumbar and some sacral nerves, thus providing anesthesia of the anterior, lateral, and medial thigh and medial aspect of the lower leg.
27
Let's review the anatomy of the abturator nerve... and what the nerve innervates
It emerges from the medial border of the psoas muscle at the pelvic brim and travels along the lateral aspect of the pelvis anterior to the obturator internus muscle and posterior to the iliac vessels and ureter. It enters the obturator canal cephaled and anterior to the obturator vessels. In the obturator canal the nerve divides anterior and posterior.
The anteroir branch supplies the anterior adductor muscles and sends an articular branch to the hip and cutaneous area on the medial aspect of the thigh.
The posterior branch innervates the DEEP adductor muscles and sends an srticular branch tot he knee joint.
27
If anesthesia/analgesia of the lateral lower leg, foot, ankle or posterior thigh is required, will the psoas compartment block be enough?
No. You will need to add a sciatic nerve block.
28
How do you go about the obturator nerve block?
1. Position the patient supine with the legs positioned slightly abducted while protecting the genitals.
2. The pubic tubercle should be located and an X marked 1.5 cm caudad and 1.5cm lateral to the tubercle. The needle is inserted at this point 1.5-4sm deep until the horizontal ramus of the pubis is reached.
3. The needle is then withdrawn and redirected laterally in a horizontal plane and inserted 2-3 cm deeper than the initial contact with bone. This is the obturator canal
4. 10-15ml of LA injected while the needle is advanced and withdrawn slightly to create a "wall" of LA in the canal.
28
When is the psoas compartment block used?
-Pain associated with hip arthroplasty-Surgery to the femur and acetabulum of the hip-Typically used when it is not practical or possible to place a femoral block
29
What 3 blocks are at the level of the knee?
Popliteal fossa
common perineal nerve
saphenous
29
Where is the local anesthetic injected for a psoas compartment block?
Near the lumbar plexus, which is situated in the psoas compartment, anterior tot he transverse process of the lumbar vertebral body.
30
Identify the following structures
1. Popliteal artery
2. Popliteal vein
3. Tibial nerve
4. Common Peroneal nerve
30
Name some of the positions in which the patient may be placed in order to administer a psoas compartment block.
-Lateral decubitus position with the thighs flexed-Sitting or prone position
31
More identification!!!!
1. Tibial nerve
2. Common peroneal nerve
3. Biceps femoris tendon
4. Cephalolatoral quadrant
5. Gastrocnemius muscle
6. Semitendinous tendon
7. Semimembranous muscle
31
What landmarks are used for the psoas compartment block?
After the patient is positioned, a line is drawn between the superior margins of the iliac crests (Tuffer's line or intercristal line).The vertebral spine palpable on this line in the midline is most often L4. Midline is marked.The intersection of the intercristal line with a line drawn parallel to the spine from the posterior superior iliac spine determines the initial needle insertion point (this is 5 cm lateral from the midline in most patients)
32
Popliteal fossa blocks are useful in which surgeries? And what is important about patient selection?
This block is useful for foot and ankle surgery.
When assessing patient's capacity for this block, the patient must be able to assume the prone position. Being able to elicite paresthesia and motor response is ideal and improves effectiveness.
32
When using a nerve stimulator for the psoas compartment block, which nerve are you trying to twitch?
A femoral twitch (patellar snap)
33
Popliteal fossa block- gimme the rundown.
1. Position the patient in a prone position and stand at the pt's side to allow palpation of the borders of the popliteal fossa.
2. Ask/ assit the patient in flexing leg at the knee to allow more accurate identification of the popliteal fossa.
3. Once idetified, divide the fossa into equal medial and lateral triangles.
4. Draw an X 5-7cm superior to the skin crease of the fossa. and 1cm lateral to the midline of the triangles.
5. Insert a 22G 4-6cm needle at a 45 to 60 degree angle to the skin and direct anterosuperiorly.
6. Paresthesia and/or motor response is sought- Once obstained 30-40ml of LA injected. (DON't BE STINGY WITH THE LA ON THIS BLOCK)
33
How much and in what sequence will you inject the local anesthetic for a psoas compartment block?
Inject 1 cc of local anestheticInject 3 cc test dose of local anestheticInject 5 cc aliquots to desired amount (35-40 cc)
34
What are the blocks at the level of the hip?
SciaticFemoralLateral Femoral CutaneousObturator
34
Can most lower extremity procedures be performed with sciatic block alone?
No, few can. Most often must be combined with femoral, lateral femoral cutaneous, or obturator nerve blocks.
35
Name some indications for a sciatic nerve block.
-Patients needing analgesia before transport for definitive orthopedic surgical repair of lower leg or ankle fractures.-Patients that you need to avoid sympathectomy (so can't get neuraxial) - combined with femoral nerve block to allow ankle/foot procedure-Patients undergoing distal amputations of lower extremity who have vascular compromise (i.e., DM or PVD)
36
For the classic approach, how is the patient positioned for a sciatic nerve block?
Laterally, with the side to be blocked nondependent. The nondependent leg is flexed and its heel placed against the knee of the dependent leg
37
What landmarks are used for a sciatic nerve block?
Draw a line between the greater trochanter to the posterior superior iliac spine.Draw a second linefrom the grater trochanter to the patient's sacral hiatus. Determine the pont of initial insertion by drawing a line perpendicular form the midpoint of the first line to its insertion with the second line
38
Below the knee, which nerve is the only nerve that is not from the sciatic?
The saphenous nerve
39
What distribution is saphenous?
Femoral - it's the only one below the knee that's femoral.
40
Is a sciatic or a popliteal block sufficient for a medial ankle surgery?
No; will not cover the medial ankle area. It's a femoral distribution - you will need a separate saphenous block
41
After performing a good femoral nerve block, you can assess the quality of your block by asking the patient to do what?
Bend the patient's leg and ask them to kick, as if they were kicking a football. They won't be able to do it because they're quardiceps are completely blocked so they have no movement there.
42
When you do an obturator block, what can you ask the patient to do in order to determine if you've achieved a good block?
Since the obturator nerve is the adductor nerve, swing the patient's leg out, place your hand on the medial aspect of the leg to put counterforce, and ask the patient to adduct their leg midline. They should not be able to do this.
43
Before doing a block, you give versed. What does versed do, besides sedating your patient? (Seizure threshold)
Benzos lower the resting membrane potential causing a greater gap between the stimulus and the attainment of threshold action potential thereby "raising" the seizure threshold as the term is commonly used. Basically, it makes it more difficult to reach the seizure threshold - so versed is your friend in regional anesthesia :)
44
The obturator nerve provides sensation to what parts of the leg?
Inner lower thigh and knee, and also the adductor muscles of the leg
45
Like the lateral femoral cutaneous nerve, which nerve that innervates below the knee provides sensory innervation only?
The saphenous vein
46
If you perform a popliteal block for ankle surgery which nerve(s) will you get and which nerve(s) will you miss?
You will get 4/5:
1. Posterior tibial nerve
2. Sural nerve
3. Deep peroneal nerve
4. Superficial peroneal nerve
You will miss: saphenous nerve
47
Describe where you tibial nerve is.
It runs with the tibial artery (remember checking patient's PT pulses) cuz nerves run with arteries.
So medial aspect behind the medial malleolus
48
Do you use a nerve stimulator for the nerves to block the ankle?
No. These are field blocks. You're just going into the general area of the nerve and dumping a bunch of local anesthetic there
49
What is the lumbar plexus made up of and where is it located?
The lumbar plexus is made up of the first 4 lumbar nerves and it is located deep within the psoas muscle & anterior to transverse processes of each lumbar vertebrae
50
The lumbar plexus divides into which component nerves?
iliohypogastric
ilioinguinal
genitofemoral
lateral femoral cutaneous
obturator
femoral
51
Blockade of the lumbar plexus can be used for anesthesia/analgesia in surgeries to what body part(s)?
lower extremities
52
What is a disadvantage to the fascia iliaca compartment block (lumbar plexus block)?
It often requires multiple injections to block nerves separately
53
For a fascia iliaca compartment block (lumbar plexus block), what are the major nerves needing blockade?
femoral nerve
obturator nerve
lateral femoral cutaneous nerve
54
Describe the technique for performing a fascia iliaca compartment block (lumbar plexus block).
* Position patient in supine position
* Palpate inguinal ligament and draw outline on skin
* Divide inguinal ligament drawing into 3 equal parts (lateral, middle, medial)
* Place a mark 1 cm caudal to where the middle & lateral marks meet → prep & drape → anesthetize area over mark
* Insert 18g Touhy needle at 75o angle to the skin using LOR technique (NS)
* 1st LOR is felt when needle tip crosses fascia lata and the needle advanced further until 2nd LOR is felt (when the fascia iliaca is pierced) → decrease angle of needle to 30o and advance needle approximately 1 cm in a cephalad direction → aspirate for heme and if negative inject 25-30 ml of local anesthetic solution (with frequent aspirations) over a 2 minute period while performing distal pressure below injection site → on needle removal massage area in a cephalad direction until no groin swelling is noted and hold firm pressure over injection site for at least 2 minutes
55
Is it common to see swelling once you have performed a fascia iliaca compartment block?
Yes. It is common to see SOME degree of swelling. It should be alleviated following massage and digital pressure.
56
What block has the fascia iliaca compartment block replaced?
the 3-in-1 block
57
Why is the fascia iliaca compartment block safer?
Because the insertion site is at a **safe distance from the nerve structures** (little chance of intraneural injection) **and blood vessels** thereby minimizing risk of complications
58
Which nerve is the largest branch of the lumbar plexus?
The femoral nerve
59
From which lumbar plexus branches is the femoral nerve formed from?
The posterior branches of the 2nd, 3rd and 4th lumbar nerves
60
The femoral nerve passes underneath ________ ligament and in the groove formed by the ___________ and ___________ muscles.
inguinal; psoas; iliacus
61
The femoral nerve block is useful for procedures in which part of the leg?
Procedures of the anterior thigh
62
Is the femoral block sufficient as the only block placed for such procedures?
No, it is most commonly combined with other nerve blocks.
63
1. Femoral artery
2. Inguinal ligament
3. Lateral femoral cuaneous n.
4. Femoral n.
5. Obturator n.
6. Saphenous n.
7. Pubic tubercle
8. Femoral artery
9. Anterior superior iliac spine
64
Describe the landmarks and lines you'd draw to delineate where the femoral nerve is.
* Draw line connecting the anterior superior iliac spine & pubic tubercle
* Palpate femoral artery and draw line denoting its course in groin
* Prep & drape in aseptic manner
* The point just lateral to the femoral artery (along the same plane as the line drawn from the iliac spine & pubic tubercle is chosen for needle insertion) (NAVI)
65
Describe the technique for performing a femoral nerve block.
* Mildly sedated the patient
* Ensure monitors in place
* Use ample skin wheal anesthesia
* Palpate femoral pulse just below inguinal ligament.
* Use a 22ga ‘B’ bevel (2cm) insulated/non-insulated needle.
* Gently aspirate.
* Begin with 2-3 mAmp/1sec impulse, locate quadriceps twitch, lower output \< 1 mAmp, inject 2 ml watch for a fade in twitch.
66
Give 4 reasons why one performs a femoral nerve block BEFORE general anesthesia and surgery.
1. Preemptive analgesia, blocks nociceptive response. (should be used for all PNBs)
2. Avoids intraneural injection.
3. Difficult after surgery: pain, dressings, splints.
4. May augment primary anesthetic.
67
Name 3 possible complications of peripheral nerve blocks
1. Intravascular injection
2. Hematoma
3. Slight chance of intraneural injection (test dose)
68
Which nerve of the ones we're studying in this lecture is considered on of the largest nerve *trunks* in the body?
Sciatic nerve
(Femoral nerve is the largest *branch of the lumbar plexus*)
69
From where does the sciatic nerve arise from?
Arises from sacral plexus & is formed from anterior divisions of L4-S1
(remember: femoral arises from the *posterior* branches of *L2-L4* of the *lumbar plexus*)
70
The sciatic nerve block is useful for surgical procedures of what part of the leg? Is it sufficient to cover this part?
Surgical procedures of the knee but often requires supplemental nerve blocks to provide surgical anesthesia/full postoperative analgesia (especially when surgery involves posterior knee)
71
Name 4 examples of surgeries where the sciatic nerve block is used
1. Total knee arthroscopy
2. ACL repair
3. Saphenous vein stripping
4. Ankle/foot surgery
72
For the total knee arthroscopy, besides a sciatic nerve block, what supplemental nerve block(s) will be necessary to provide surgical anesthesia/full postoperative analgesia?
femoral nerve block and obturator nerve block
73
For the an ACL repair, besides a sciatic nerve block, what supplemental nerve block(s) will be necessary to provide surgical anesthesia/full postoperative analgesia?
femoral nerve block
74
For saphenous vein stripping, besides a sciatic nerve block, what supplemental nerve block(s) will be necessary to provide surgical anesthesia/full postoperative analgesia?
posterior cutaneous nerve block
75
For ankle/foot surgeryf, besides a sciatic nerve block, what supplemental nerve block(s) will be necessary to provide surgical anesthesia/full postoperative analgesia?
femoral nerve block
76
Name two patient scenarios that a sciatic nerve block would be useful.
For patients requiring analgesia prior to OR transport
For patients in which you want to avoid sympathectomy
(Brown also stated, this block is useful for those undergoing distal amputations of lower extremity who have vascular compromise based on diabetes or PVD)
77
What does some current evidence state re:
sciatic nerve block with general anesthesia
VERSUS
systemic analgesia with general anesthesia?
Some investigations report that sciatic nerve block alone provides better analgesia than systemic analgesia when given in conjunction with general anesthesia
78
Sciatic nerve blocks can be performed using a variety of techniques. Which approach is reported to be easier to perform and have a higher success rate than when the anterior approach is used?
Peripheral (classic) approach
79
Describe the landmarks/lines (classic approach) used for performing a sciatic nerve block.
* Patient placed in **lateral Sims position** with **leg to be blocked uppermost, flexed at the knee, resting on dependant lower extremity**
* Line drawn from posterior superior iliac spine (**PSIS) to midpoint greater trochanter**. Perpendicular to the midpoint of this **line is extended caudomedially for 5 cm and marked** (this is the point of needle insertion)
* As a crosscheck some practitioners will draw line from sacral hiatus to greater trochanter (this line should intersect with previously drawn 5 cm mark)
80
Describe the technique Mr. Kelly described to perform a sciatic nerve block using a peripheral nerve stimulator.
* Prep & drape (aseptic technique)
* 22g 10-12cm spinal needle (connect negative lead of the PNS near hub of needle)
* Advance needle with initial settings of PNS at 2 mAmp until dorsiflexion and plantar flexion of foot is noted → ↓ to 1 mAmp & maximize response at 0.5 mAmps → 1-2 ml “test dose” of LA (to observe for intraneural injection) followed by 0.15 ml/kg (20-30 ml) of LA solution in 3-5 ml increments (with frequent aspirations)
* If no response is noted on entry redirect until desired response is elicited via PNS (while performing frequent aspirations to detect possible intravascular entry)
81
Name the 5 nerves that can be blocked at the level of the ankle
1. Posterior Tibial Nerve
2. Sural Nerve
3. Deep Peroneal Nerve
4. Superficial Peroneal Nerve
5. Saphenous
82
1. Superficial peroneal n.
2. Saphenous n.
3. Sural nerve
4. Tibial n.
5. Deep peroneal n.
83
1. Tibial artery
2. Tibial nerve
3. Sural nerve
84
Time for the: "What-nerve-am-I-blocking" GAME!!!!
Posterior Tibial nerve
85
What nerve am I blocking?
Sural nerve
86
What nerve am I blocking?
Deep peroneal nerve
87
What nerve am I blocking?
Superficial peroneal nerve
88
What nerve am I blocking?
Saphenous nerve
89
Name those nerves!!
1. Superficial peroneal nerve
2. Saphenous nerve
3. Deep peroneal nerve
90
What are some complications of lower extremity anesthesia (there's 9 total!)
1. Infection
2. Intrathecal and/or epidural injection of local anesthetic
3. Intraabdominal injury
4. Puncture or injury of the vagina (yikes!) or bladder
5. Intravascular injection of local anesthetic
6. Intraneural injection
7. Hematoma
8. Persistent paresthesias
9. Post-procedural pain
91
When describing the technique for injection with insulated needles and nerve stimulator, what are the first 3 steps one must ensure before even piercing the skin with the needle?
1. Prep and drape area of injection with betadine
2. Ensure that all equipment is present and in working order
3. Have all resuscitation equipment readily available
92
After the first 3 steps (and once the needle tip has pierced the skin), describe the next 3 steps in the technique for injection with insulated needles and nerve stimulator.
1. Once tip of needle has pierced the skin surface, turn nerve stimulator on and set to 1 mA.
2. With continuous intermittent aspiration, advance needle until desired twitch is elicited.
3. Decrease mA until twitch is lost
93
Describing the technique for injection with insulated needles and nerve stimulator:
You have advanced your needle, obtained a desired twitch and decreased your mA until twitch is lost.
What are the next steps?
1. If twitch is lost with mA between 0.2-0.4 mA, inject local anesthetic.
1. *FYI: During lecture, Mr. Kelly stated we now tend to stay at 0.5 mA to be safe. No need to go down to 0.2 mA anymore*
2. If twitch is lost before 0.4 mA, advance needle until twitch is elicited again. Then, decrease mA until twitch is lost. Repeat process until twitch is lost with mA between 0.2-0.4 mA. Inject drug.
3. If twitch is still present with 0.2 mA or less, withdraw needle and begin again. (Intraneural)
94
Describing the technique for injection with insulated needles and nerve stimulator:
Prior to injecting local anesthetic, what must you do?
Aspirate to ensure a negative aspirate
95
Describing the technique for injection with insulated needles and nerve stimulator:
Why do you inject a 1cc test dose of local anesthetic? What are you trying to rule out?
Intraneural injection
96
Describing the technique for injection with insulated needles and nerve stimulator:
## Footnote
Why do you inject a 3 cc test dose of local anesthetic? What are you trying to rule out?
intravascular injection
97
Describing the technique for injection with insulated needles and nerve stimulator:
## Footnote
After injecting your test doses, what is the best way to deliver your remaining local anesthetic dose?
Inject remaining local anesthetic in 5 cc aliquots
98
Name 3 different local anesthetic mixtures used
* 2% Lidocaine with/without epinephrine and sodium bicarbonate
* 0.5% Bupivacaine or Ropivacaine with/without epinephrine and sodium bicarbonate
* 2% Lidocaine with 0.5% Bupivacaine or Ropivacaine (equal volumes) with/without epinephrine and sodium bicarbonate
99
1. Medial epicondyle
2. Saphenous nerve
100
1. Deep peroneal nerve
2. Superficial peroneal nerve
3. Plantar nerve (PT)
4. Sural nerve
5. Saphenous nerve
6. Superficial peroneal nerve
7. Plantar nerve (PT)
8. Calcaneal nerve (PT)
9. Saphenous nerve
10. Sural nerve
11. Calcaneal nerve (PT)
12. Saphenous nerve
Repeats:
* #2 and 6 = superficial peroneal nerve
* #3 and 7 = plantar nerve
* #4 and 10 = sural nerve
* #5, 9 and 12 = saphenous nerve
* #8 and 11 = calcaneal nerve
101
Which color is the distribution of the femoral nerve?
Which color is the distribution of the sciatic nerve?
Which numbers are branches of the posterior tibial nerve?
Femoral nerve = green
Sciatic nerve = yellow
Branches of the posterior tibial nerve:
* Plantar nerve (#3, 7)
* Calcaneal nerve (#8, 11)
102
Brown: Sciatic nerve - True or False:
Uptake of local anesthteic from lower extremity sites is not as rapid as with epidural or intercostal block; thus, a larger mass of local anesthetic may be appropriate in this region.
True
103
Brown - Sciatic Nerve:
Which of the following will be feasible options to use if a motor blockade is desired:
* 1.5% mepivacaine
* 1.5% lidocaine
* 0.5% bupivacaine
* 0.5-0.75% ropivacaine
All of the above will be effective
104
Brown - Femoral nerve block
Is elicitation of paresthesia necessary to carry out a femoral block?
Nope. Because of this, even anesthetized patients are candidates!
105
Brown - Femoral nerve blocks
If a continuous catheter is placed for postoperative analgesia, what concentration, local anesthetic and rate may be used?
0.25% bupivacaine or 0.2% ropivacaine (and even lower concentrations of these drugs may be used after a trial).
A rate of 8-10 ml/hr usually suffices
106
Brown - Lateral femoral cutaneous nerve block. True or False:
Because the lateral femoral cutaneous nerve does not have motor components, a lower concentration of 10-15 mL of local anesthetic is effective.
True
107
Brown - Lateral femoral cutaneous nerve block
Because this is a sensory nerve, low concentrations of local anesthetic are useful. Give some examples of the concentrations used for this block.
10-15 ml of:
* 0.5-0.7% mepivacaine or lidocaine
* 0.25% bupivacaine
* 0.2% ropivacaine
Side note: *by keeping the concentration lower for this portion of a 3 to 4 nerve lower extremity block, adequate volumes and concentrations of local anestheteic can be maintained for the sciatic and femoral nerves*
108
Brown - Obturator nerve block
What are some indications for this block?
* If an operation on the knee is using peripheral blocks, the obturator block is often essential
* In patients who have hip pain
* Can be used diagnostically to help identify the cause of pain because obturator nerve block may provide considerable pain relief if the nerve's aticular branch to the hip is involved in pain transmission
* May be useful in the evaluation of lower extremity spasticity or chronic pain syndromes
109
Brown - Lateral femoral cutaneous nerve
What are some indications for using this block?
* allows lower leg procedures to be carried out with fewer complaints of tourniquet pain
* allows superficial procedures ont he lateral thigh (i.e., skin graft harvesting)
* allows the diagnosis of myalgia paresthetica (neuralgia involving the LFC nerve)
110
Brown - Obturator nerve block. True or False:
Unlike, femoral and lateral femoral cutaneous nerve blocks, elicitation of paresthesias IS essential for an obturator block.
False. As with femoral and LFC nerve blocks, elicitation of paresthesias is not essential for obturator block.
111
Brown - Popliteal block:
The sciatic nerve divides into the tibial nerve and common peroneal nerve at the upper limit of the popliteal fossa. Of the two divisions, which one is the larger. And into which to nerves does the common peroneal nerve divide into (hint: two of the nerves we are studying in the ankle block)
The tibial nerve is the larger of the two sciatic divisions.
As the common peroneal nerve leaves the popliteal fossa, it travels around the head of the fibula and divides into the:
superficial peroneal nerve & deep peroneal nerve
112
Brown - ankle block. True or False:
This block is principally an infiltrative block and does not require elicitation of paresthesia; therefore, patient cooperation is not mandatory.
113
Brown - Ankle block
Is motor blockade often needed for procedures carried out during ankle block?
No, thus lower concentrations of local anesthetics may be used.
examples:
* 1% lidocaine or mepivacaine
* 0.25-0.5% bupivacaine
* 0.2-0.5% ropivacaine
114
Brown - ankle block: True or False:
The only branch of the the femoral nerve below the knee is the superficial peroneal nerve.
False. Saphenous
115
Brown - ankle block:
The tibial divides into which two nerves?
Posterior tibial nerve & sural nerve
116
Brown - ankle block
While the medial and lateral malleoli approaches to ankle block appear similar, they are not. What is the main difference?
The sural nerve (lateral ankle) is found in a more superficial position relative to the malleolus than the tibial nerve (medial ankle). Keep this distinction in mind whiel performing the sural portion of the block.
117
Brown: ankle block. True or False:
The block should not be chosen if high tourniquet pressures are required to carry out the surgical procedure.
True
118
Brown: ankle block.
What kind of solutions shoould be avoided in circumferential injections of the ankle?
Epinephrine-containing solutions
119
Brown: psoas compartment block.
This block produces anesthesia or analgesia of what portions of the lower leg?
anterior, lateral, and medial thigh and the medial aspect of the lower leg
120
Brown: psoas compartment block
If performing a psoas compartment block and anesthesia of the lateral lower leg, foot, ankle or posterior thigh is required, which block must be added?
Sciatic nerve block
121
Brown - psoas compartment block
What are the usual indications for this block?
* Postoperative analgesia after lower limb surgery and trauma involving hip or thigh
* Most common use: pain associated with hip arthorplasty
* Can also use for surgery to femur and acetabulum of hip
* Typically used when it is not practical or possible to place a femoral nerve block
