Epidural Flashcards
Difference between spread of epidural vs spinal
Baricity only applies to local in CSF which epidurals are not…
Parasympathetic innervation in spinal cord
Craniosacral
Placement difference between epidural and spinal
Epidural can be placed at lumbar, thoracic and cervical
Indication of correct epidural placement
Note the loss of resistance
-with saline syringe!!
Most commonly used epidural needle
Touhy
Blunt, curved
Main Advantage of epidural
Continuous or re-bolusing
Mechanism of cleaning with chlorhex vs betadine
Chlorhex-scrub
Betadine-drying
Trick with the chloraprep
Flip it upside down so it doesn’t drip on you
What did we miss about the tray set up with spinals»
Uncap your needles!!
How to not accidentally inject the test does
Either ALWAYS draw the whole thing up or don’t use it
Loss of resistance technique associated with higher pdph
Air
LOR fluid technique
Should be able to to compress bubble but not inject saline in ligamentum flavum
If air bubble can not be compressed w/o
injecting fluid, needle placement is most
likely in the interspinous ligament or off
midline in paraspinous muscle
What we use markings for on the epidural catheter
How much is in the space and if it migrated (what’s it taped at)
What is the thick line on the epidural catheter for?
Everything after this point is the length actually inserted into the epidural space
Common test dose for epidural and what it will do in different spaces
3ml of 1.5% lidocaine and 15mcg epi
-epi will act on intravascular space
-lidocaine will tell you if you have a spinal
Why is EA different from SAB in dosing?
We are not injecting into fluid!!!
Volume required per spinal segment for epidural band
1-2ml
If inserting L4 and you want a T6 block, what volume of local do you need?
At least 12cc t6-L4=12 spaces
Impact of age on epidurals
Greater spread in older patients
If you trend your patient with a continuous epidural what is going to happen?
Nothing
Position matters less with epidurals
Dose of epidural
Determines density of block
Volume of epidural determines:
Spread
Rate of epidural dosing
3-5cc of LA every 3 minutes until you hit your level
Why do we dose epidurals incrementally?
To avoid serious complications!
Thing you do before every SINGLE injection with epidural
Aspiration to prevent systemic toxicity
What increases speed of onset of motor and sensory block?
Dose increase
Short acting LA spread time vs long acting
15-20 minutes
20-25 min
Block duration determinants
Short-Chloroprocaine
Intermediate- lidocaine or Mepivacaine
Long-Bupivacaine, Ropivacaine
Where does the local disperse to from the epidural space?
The epidural veins
Density is determined by
Concentration of LA
Dermatomal spread of epidural is determined by:
Volume of Local
Treating hypotension from epidural
Fluid and ephedrine
High block impact on respiratory physiology
May not be able to forcibly exhale
Nausea is associated with blocks higher than:
T5
Sympathetic blockade T6-12 produces what?
Unopposed parasympathetic vagal activity
-secretions, relaxed sphincters, bowel constriction
What procedures can we use lumbar epidurals?
Any procedure below the diaphragm
Thoracic epidural considerations
Higher risk of spinal cord injury and technically difficult
Paramedian technique frequently used
Cervical block consideration
Not common, typically done in pain clinics
What do we not feel on paramedian approach?
Supra or intraspinous ligament
Layers passed during paramedian approach in thoracic epidurals
Paraspinous muscle until you hit bone or ligamentum flavum
Lower abdominal procedures
Colectomy
• Abdominal AAA
• Bowel resection
• Nephrectomy
Upper abdominal procedures
• Esophagectomy
• Splenectomy
• Hepatic resection
• Pancreatectomy
Thoracic epidural dosing
3-6 ml of LA followed by infusion (3-5cc/hr)
Usually dilute (0.125% Bupivacaine)
Classic opioid addition to thoracic epidural
2 mcg/ml of fentanyl
What would be indications of Subdural catheter?
THESE ARE NOT SAFE, TAKE OUT
May be unilateral
May have greater hemodynamic consequences at high doses
Disadvantages to CSE
Higher risk of sub arachnoid catheter
placement
Increased PDPH
Inability to test catheter at time of insertion
How much blood for a patch and what do you need to get it?
20 ccs
A second person
-inject through tuohy
