Week 3 Regional - Epidural Everything Flashcards
Central neuraxial blockade (CNB)-
spinal and epidural blocks (involve placement of LA onto or adjacent to the spinal cord
Central neuraxial blockades are used for a variety of reasons. Name some:
-surgical procedures, -treatment of acute and chronic pain syndromes, -labor analgesia-safe transition if C/S required -May be used in combination with other types of anesthesia (MAC, GA etc..for surgery) -Post-op pain relief
CNB’s are a Surgeon preference due to:
- procedure (urologic procedures, can monitor neuro status etc..)
Incidence rate of persistent paresthesia and sensory or motor dysfunction is
< 1%
Discussion with patient alleviates most:
fear/concern
Additional discussion with patients include talking about topics such as:
risks, inadequate anesthesia, additional medications, paresthesia, hypotension, dyspnea, high or total spinal, N/V, and allergic reaction …
CNB Postoperative complications:
backache, postdural puncture headache (PDPH), hearing loss, transient neurologic symptoms (TNS), infection, abscess, or hematoma formation
Absolute vs relative contraindications- somewhat controversial
-Increased intracranial pressure (ICP) -Skin infection at site of injection -Bacteremia/sepsis/shock -Hypovolemia -Spinal cord disease -Progressive neurological diseases (MS, etc) -hypertrophic cardiomyopathy or -severe aortic stenosis) -Coagulopathy. -“anticipated” length of surgery
what are transient neruologic symptoms (TNS) *from his notes
TNS is a painful condition of the buttocks and thighs with possible radiation to the lower extermities, beginning as soon as a few hours after spinal anesthesia and lasting as long as ten days. Pain can be mild to severe. However, unlike in cauda equina syndrome, TNS is exclusively a pain syndrome - there is no bowel or bladder dysfunction, and neurologic, MRI , and electrophysiologic examinations are normal.
what is Cauda equina syndrome (CES)? ffrom his notes
Cauda equina syndrome (CES) is a serious neurologic condition in which damage to the cauda equina causes acute loss of function of the lumbar plexus, (nerve roots) of the spinal canal below the termination (conus medullaris) of the spinal cord. CES is a lower motor neuron lesion
why is ICP contraindication for spinal/epidural?
Increased ICP- spinal/epidural increases risk of brain herniation if dura is punctures… also, addition of large volume of fluid into epidural or SA space could increase already elevated ICP
What are some anatomical concerns that may have you NOT place an epidural or a spinal?
Severe kyphoscoliosis arthritis ( -kyphosis and scoliosis), -osteoporosis-vertebral deformities and -fractures with narrowing of the spinal canal, -lumbar fusion (may make placement difficult)
Coagulation contraindications (2:
Controversial range.. 1. Plt < 100,000 2. PT, PTT and bleeding times greater than 2 times the normal values Assess herbal medications that may affect hemostasis (garlic, ginkgo, ginseng)
what herbal medications should we Assess for and why?
- that may affect hemostasis -garlic, -ginkgo, -ginseng “anything with a “G”’
Regional thrombophrophylaxis: Contraindication or not? When to stop/Restart before/after block. ASA or NSAIDs
no contraindication
d/c ticlid prior to block
14 days
d/c plavix prior to block
7 days
GP 11b/111a inhibitors (Aggrastat, Integrilin) d/c prior to block
8 hours
ReoPro d/c
24-48 hours
Heparin- Subcutaneous is it contraindicated in regional techniques?
No contraindication in BID dosing of < 10,000 units
Regional thrombophrophylaxis: Heparin-IV Contraindication or not? When to stop/Restart before/after block.
…Heparinize 1 hour after block, -remove catheter 2-4 hours after last dose
LMWH (lovenox) plan for regional
-delay procedure at least 12-24 hours after last dose… -remove catheter 2 hours before first dose
Warfarin- usually requires d/c
for 4-5 days before Because:block requires normal INR.. Remove catheter when INR is 1.5 or less)
block requires
normal INR..
Thrombolytics (Retavase etc..)-
Absolute contraindication
Thrombin inhibitors-Angiomax
Avoid block insufficient info..
ASRA Guidelines
will add
Mini Dose heparin SQ prophylaxis is
not a contraindication to neuraxial anesthesia or epidural catheter removal
If a patient is to receive heparin intraoperatively, blocks may be performed
1 hour or more before heparin administration
IV Heparin stop _____ (hours) prior to catheter removal.
2-4 hours
IV Heparin – Wait _____ after neuraxial block or catheter removal before administration of drug
1 hour
Pradaxa- d/c
7 days prior to regional block;
Pradaxa first post-op dose (after needle placement and after catheter removal)
-24 hours after needle placement and -6 hours post catheter removal (whichever is later)
Herbal meds-
no evidence for d/c.. Be aware of drug interactions etc..
Infection (regional related) can cause persistent
neurologic deficit… -loss of bowel and bladder control, -chronic pain, -lower extremity paraplegia
Sources of Infectious complications:
-Abscess (epidural, spinal, or subdural; paravertebral, paraspinous) -Meningitis -Encephalitis -Sepsis -Bacteremia, fungemia, or viremia -Osteomyelitis -discitis
Ways we can limit infection in regional techniques:
-WBC -Use sterile technique -Use of sterile occlusive dressing at catheter insertion site -Use of bacterial filter during continuous infusion -Limit disconnection and reconnection of delivery system -Limit duration of catheterization
most common cause of epidural abscess
Staphylococcus aureus –
is there a set limit on WBC’s for when we won’t perform regional techniques?
No
When assessing WBCs what do you want to look at specifically?
neutrophils - associated with early infection/reaction
Advantages of Spinal anesthesia include:
-Reduced stress response to surgery -Less blood loss (hip surgery) -Less incidence of DVT -Pulmonary complications appear to be less -Possible less cardiac complications -Better in obstetrics —> less medications are administered to mother and fetus
What equipment do you want for spinal anesthesia?
**Always have your emergency equipment ready** -as well as equipment for block (kit, needles, syringes, solutions, meds, drapes, 4x4s, gloves, etc *FLUIDS
goal of needle design is to
minimally rend, tear, or cut dural tissues
2 main types of needles:
- Quincke-Babcock (or Pitkin ) 2. Whitacre, Sprotte, (Pencan)
describe Quincke-Babcock or Pitkin needles–
have cutting bevel tip with matching stylets that minimize tissue coring, and the tips cutting angle is blunter than that of standard needle
describe Whitacre, Sprotte, Pencan-
newer noncutting tip that are pencil point shaped with lateral opening (other new noncutting needles may have rounded bevel tip and an opening at the needles end)
gauges for spinal needles:
22-29 g
lengths for spinal needles:
3.5 and 5 inches
Most blocks are performed using a
25-27 gauge, 3.5 in needle
What needle is preferred? why?
Noncutting (pencil point/Whitacre/Sprotte) -less of incidence of complications such as: - infection, -PDPH -also have a clear, perceptible “click” or “pop” when pierce the dura
what needles has a clear, perceptible “click” or “pop” when pierce the dura
non-cutting - whitacre/sprotte/ pencil point
Newer, thin walled noncutting needles have improved
CSF flow rates
Pencil point needles are associated with what % of PDPH? % of failure rate?
<1% rate of PDPH and failure rate of approx. 5%
spinal structures entered (in order):
Skin Subcutaneous structures Supraspinous ligament Interspinous ligament Ligamentum flavum Dura Mater Arachnoid membrane “some say sister ida loves doing acid”
spinal anesthesia is what kind of blockade? this results in:
blockade of sympathetic nervous system (nerve transmission of sensory adn motor fibers) –> hypotension and bradycardia
If block is too high (T1-T4), what happens? why?
cardiac accelerator fibers -severe bradycardia -overall loss of normal CV homeostatic reflexes and ability to compensate for minor CV stresses
what is very important that we do DIRECTLY before block?
fluid bolus - tx hypotension with hydration, O2, meds
spinal cardiac arrest odds vs those of GA
spinal: 7:10,000 GA: 3:10,000
Depression of the cervical spinal cord and brain stem fxn, dysphonia, dyspnea, UE weakness, LOC, mydriasis, hypotension, bradycardia, and cardiac arrest are signs of
Total Spinal
Nausea and vomiting in spinal anesthesia results from:
- unopposed/dominant parasympathetic activity-GI hyperperistalsis… 2. hypotension
increased tone of urethral spinchter results in
urinary retention
paraplegia occurs how frequently?
< 1 per 10,000
PDPH causes - two theories:
- decrease in CSF available in SA space through leak created by dural puncture… medulla and mainstem lose support, drop into foramen magnum, stretch meninges and pull on tentorium… further irritated by movement and upright position 2. cerebrovasodilation as result of low CSF… beneficial effects of vasoconstrictor drugs such as caffeine and theophylline