Test 2 Flashcards
What is the toxic dose limit of cocaine?
3-4mg/kg; trivia off of Pabalate slide
Who was responsible for the introduction of spinal anesthesia in 1898?
Bier
T/F? Regional anesthesia is performed to provide profound muscle relaxation?
True; from Pabalate slides
SAB, Neuraxial, conduction, and intrathecal are all types of ________ blocks.
spinal block
What are some absolute contraindications to spinal anesthesia?
patient refusal, sepsis or infection at injection site, coagulopathy or anticoagulapathy, elevated ICP or cerebral edema (FROM SLIDES)
What are some relative contraindications to spinal anesthesia?
patient appropriateness, local infection near injection site, hypovolemia, CNS disease, Chronic back pain or prior laminectomy, prior SAB with difficulty
T/F? precaution should be taken when doing spinal anesthesia on patients with Mobitz Type I, Mobitz Type II, 3rd Degree HB w/o pacemaker, Fixed volume cardiac states (IHSS, severe aortic stenosis).
TRUE (SLIDES)
T/F? Studies have shown NO difference in morbidity or mortality between GA and Regional in healthy patients.
TRUE (SLIDES)
Is there data to support one anesthesia technique (Spinal vs Epidural vs General) over the other?
NO (SLIDES); It is only speculation that spinal anesthesia is much less stressful to a patient’s physiology than a GA.
T/F? It is ok to assume that a patient that is too sick for GA will better tolerate spinal anesthesia as a viable alternative.
FALSE
Name some types or characteristics of patients that may benefit from spinal anesthesia.
patients with coexisting asthma or COPD (long history of pulmonary disease or heavy smoker), patient fearful of GA, OB patient for a C-section, patient with history of thrombophlebitis or at an increased risk of developing thrombophlebitis, any patient with an obvious difficult airway and who is undergoing a procedure that can be done with a spinal
Name some advantages to performing a spinal over an epidural.
quicker to perform, less painful to patient, fast onset
Name some disadvantages to performing a spinal over an epidural.
fixed duration, PDPH
Name some advantages to an epidural over a spinal.
continuous infusion, post-op pain management
Name some disadvantages to an epidural over a spinal.
more painful, longer to perform, slower onset
The ____________ __________ of the parietal lobe is primarily responsible for receiving painful stimuli.
“postcentral gyrus”
The _____________ ____________ of the parietal lobe is responsible for motor function and movement away from painful stimuli.
“precentral gyrus”
What type of blocks are segmental?
Epidural (blocks the ROOTS)
What level of sensory coverage do you need for C-section?
Go in at L1 or L2, so you can reach T6 at least, T8-10 is best
Does clonidine work pre or post synaptic? What receptor?
Alpha 2 agonist, works on pre-synapse to block the reuptake of norepinephrine…. thus reducing its release.
Epidural anesthesia is __________ dependent, so relatively (LARGE/SMALL?) volumes of LA are needed to achieve a block to span several dermatomes.
Diffusion dependent; LARGE (volume is primary factor to influence the level of block)
What is the number one factor for where you will get coverage (level) in spinals?
LOCATION (where you insert the needle)
What are some factors that can influence the height of the spinal block?
DOSE IS THE DEFINITE ANSWER, but this winds up meaning Volume (typically the higher the dose, the more volume you give) Patient positioning, speed of injection (these can all increase the height of the spinal block)
What is rostral spread?
rostral spread is the the distribution of an opioid within the cerebrospinal fluid during epidural or spinal administration; it is determined by fat and water solubility properties of the narcotic. Fentanyl is more lipid soluble than morphine, so it has LESS rostral spread.
What is Duramorph and what problem can occur when administered?
it is preservative free morphine (used during spinal anesthesia); rostral spread can occur; rarely occurs during epidurals because epidural is NOT directly getting into the CSF
We know that the MAIN factor that affects the level of an epidural block is VOLUME (vs. a spinal that is LOCATION). What are other factors that can influence the level of an epidural block?
injection site, dose, volume, concentration, position, age, height and weight
Unlike spinal anesthesia, epidural anesthesia produces a _________ block that spreads both _______ and _________ (direction).
segmental block that spreads both caudally and cranially.
Where should the injection site be for an epidural when considering the surgery and dermatomes?
In the MIDDLE of the range of dermatomes that needs to be anesthesized and closest to the main nerve roots involved.
Is positioning more important for spinals…. or epidurals?
SPINALS; but still a factor for epidural
How does the volume administered need to be altered in relation to the higher the insertion point chosen for epidural anesthesia?
You will typically DECREASE volume given.
________ and ________ are important variables in determining both spread and quality of an epidural block.
DOSE AND VOLUME
Why is less volume needed as you go higher with your epidural insertion site?
d\t the narrowing of the spinal canal as it progresses cranially.
Lumbar level doses are typically ____cc to ____cc per segment with an initial volume of 15-20cc.
1.25 to 1.5cc
Cervical/Thoracic doses are _____cc to ____cc per segment with an initial volume of 10cc (but less initial volume per Mr. Shores)
0.7 to 1.0cc
What common LA’s have an SLOW onset?
Ropivacaine and Bupivacaine
What common LA’s have an INTERMEDIATE onset?
Lidocaine and Mepivacaine
What common LA (s) have a FAST onset?
Chloroprocaine
What is the advantage of chloroprocaine over lidocaine?
fast onset and less toxicity (if it gets rapidly absorbed, lidocaine will cause more toxic effects); tachyphylaxis is a concern with chloroprocaine (pt can develop a quick tolerance)
What patient positing is most beneficial for the spread of LA with epidural insertion, LATERAL or SITTING?
Studies show small to NO differences in spread of block when comparing the two. It is provider preference.
All solutions should be injected in increments of ___cc to ____cc every 3 minutes and titrated to desired level. You should always _____ prior to every injection to show that no _____ is present.
3-5cc every 3 minutes; aspirate; check for CSF or Blood (catheter could have migrated or really be in vascular system)
Why is a blunted tip catheter typically used for an epidural? What gauges are used?
16, 17, or 18 gauge with blunted tip designed to facilitate passage of the catheter into the epidural space; the blunted tip is also designed specifically to avoid puncture of the dura (and if it comes into contact with the Dura, the lack of sharp point will hopefully just inwardly push the dura without puncturing it)
A skin wheal of lidocaine is normally made with ___cc to ____cc of local with a ____gauge skin needle.
1-2cc; 25g
The epidural is placed bevel (UP or DOWN?) and introduced into the skin.
UP
What ligament can you assume that you are “in” with a epidural needle if it stays supported when you let go (doesn’t drop down)?
interspinous ligament
If loss of resistance occurs at a needle depth of 6cm, where should you place your epidural catheter?
At least 6cm…. but normally no more than 5cm past the depth of the needle at “loss of resistance”…. so if at 6cm…. safe would be 10-11cm depth for epidural catheter.
What is the standard solution and amount administered for a “TEST” dose during epidural insertion?
LA with epinephrine of 3cc (lido 1.5% with epi is normal)
What is a CLEAR sign that you have administered the TEST dose intravascularly?
Increased HR within 30 seconds (this is caused by the epinephrine…. NOT the LA); other signs are ringing/buzzing in ears, metallic taste, or circum-oral numbness, or pounding in the chest
The syringe/needle combo should only be moved ___cm to ____cm at a time and then tested for resistance or LOR.
0.5cm to 1cm
If you advance a catheter past a needle tip and realize you are not in the correct location…. what should be your next action?
NEVER PULL CATHETER BACK BECAUSE IT CAN SHEAR OFF INTO THE SPACE; if anything you should pull out the needle first.
If you perform an accidental wet tap, PDPH occurs in up to ____% of patients who have a dural puncture with a touhy needle.
75%
Name some of the common treatments for a “wet-tap”.
conservative treatment includes IV fluids, analgesics, and IV/PO caffeine; lying flat in a dark room can temporarily soothe symptoms; invasive treatment involves an epidural blood patch (although it is more invasive, it can be effective up to 90% of the time)
What is a good type of anesthesia (epidural) for anorectal surgery in adults?
Caudal epidural
Caudal anesthesia involves needle or catheter penetration of the _______________ ligament covering the _________ __________.
sacrococcygeal ligament covering the sacral hiatus
The lateral femoral cutaneous nerve innervates:
The lateral anterior portion of the thigh
The femoral nerve innervates:
the anterior portion of the thigh
The saphenous nerve innervates:
the medial portion of the calf
What nerves are blocked with a 4-poster leg block?
lateral femoral cutaneous, femoral, obturator, and sciatic
The order of the vasculature and nerves of the femoral area from medial to lateral are:
femoral vein, femoral artery, femoral nerve: VAN
The femoral nerves arises from the dorsal branches of ____ to ____ (spinal column), and passes inferiorly, initially through the ______ muscle and then between the ______ and ______. It exits the abdomen via the retroinguinal space, lateral to the femoral vessels (VAN). In the femoral triangle, it divides into the ________ and ________ division.
The femoral nerve arises from the dorsal branches of L2 - L4. It passes inferiorly, initially through the psoas muscle and then between the iliacus and psoas. It exits the abdomen via the retroinguinal space, lateral to the femoral vessels. In the femoral triangle, it divides into anterior and posterior division. The anterior division gives off muscular branch to sartorious as well as the medial and intermediate cutaneous nerves of the thigh, supplying the skin of the medial and anterior thigh to the knee. The posterior division supplies the quadriceps and gives rise to the saphenous nerve. This long nerve accompanies the femoral artery to the adductor canal, before passing inferomedially to the long saphenous vein. It supplies the skin of the medial knee, lower keg and foot to the distal joint of the 1st metatarsal.
The _________ division of the femoral nerve gives off muscular brach to sartorious as well as the medial and intermediate cutaneous nerves of the thigh, supplying the skin of the medial and anterior thigh to the knee.
The anterior division gives off muscular branch to sartorious as well as the medial and intermediate cutaneous nerves of the thigh, supplying the skin of the medial and anterior thigh to the knee.
The ______ division of the femoral nerve supplies the quadriceps and gives rise to the saphenous nerve. This long nerve accompanies the femoral artery to the adductor canal, before passing inferomedially to the long saphenous vein. It supplies the skin of the medial knee, lower keg and foot to the distal joint of the 1st metatarsal.
The posterior division supplies the quadriceps and gives rise to the saphenous nerve. This long nerve accompanies the femoral artery to the adductor canal, before passing inferomedially to the long saphenous vein. It supplies the skin of the medial knee, lower keg and foot to the distal joint of the 1st metatarsal.
What are two major indications (surgical) for use of a femoral nerve block?
anterior thigh and knee surgery
The femoral nerve arises from the _____, ______, and ______ lumbar nerves.
2nd, 3rd, and 4th
Describe the positioning of the femoral nerve from the spine until it splits into other nerves.
The femoral nerve is the largest branch of the lumbar plexus. It arises from the second, third, and fourth lumbar nerves. The nerve descends through the fibers of the psoas muscle, emerging from the psoas at the lower part of its border, and passes down between the psoas and the iliacus. Eventually, the femoral nerve passes underneath the inguinal ligament into the thigh, where it assumes a more flattened shape. As the femoral nerve passes underneath the inguinal ligament, it is positioned immediately lateral and slightly deeper than the femoral artery.
What are the anterior and posterior divisions of the femoral nerve?
Anterior division: Middle cutaneous Medial cutaneous Muscular (sartorius) Posterior division: Saphenous nerve (most medial) Muscular (individual heads of the quadriceps muscle) Articular branches (hip and knee)
The lumbar plexus is derived from the ventral rami of L1-4, with occasional contribution from T12. However, The lumbar plexus is primarily from _____ to _____ (vertebrae), forms three major nerves that innervate the lower extremity….. what are they?
L2 to L4; the lateral femoral cutaneous, femoral, and obturator nerves (these nerves primarily supply motor and sensory innervation to the anterior portion of the LE and the cutaneous sensory portion of the medial lower leg (saphenous nerve)
The lumbosacral plexus is derived from the nerve roots _____ to ______ (lumbar) and _____ to ______ (sacral) and primarily forms the sciatic nerve, which courses posteriorly and supplies both motor and sensory innervation to the posterior aspect of the lower extremity and foot.
L4-5; S1-3
What nerve courses with the sciatic nerve as it emerges around the piriformis muscle and subsequently it too is blocked when a proximal sciatic nerve block is performed?
posterior cutaneous nerve
What is the easiest and most commonly used lower extremity block?
ankle block; typically used for foot surgery
What are the four main nerves that innervate the lower extremity, and from what vertebrae are they derived?
femoral (L2-4), obturator (L2-4), lateral femoral (L1-3), sciatic (L4-S3); the first 3 nerves are in the lumbar plexus and lie within the substance of the psoas muscle and emerge within a common fascial sheath that extends into the proximal thigh. The common pernieal and tibial nerves are continuations of the sciatic nerve
If a line is drawn connecting the top of the iliac crests, which vertebrae are you most likely at?
L4
