Epidural Anesthesia Flashcards
Epidural needle
17 or 18 gauge needle which permits passage of 19 or 20 gauge catheter.
9 cm in markings
Distance of epidural space
Generally 4-6 cm but is affected by body weight and angulation of needle (depth greater with cephalic angle).
Additionally depth greater if slightly off midline
(Example CSE with Malik- good LOR, but hit bone with spinal needle insertion. Remove spinal needle and rotate tuohy 90 degrees and try to reinsert spinal needle). If off midline, slightly, our LOR would be at a greater depth due to route through LF.
Loss of Resistance Technique
If needle is properly seated in ligamentum flavum, it will be difficult to inject the saline or air bubble and plunger will “spring back” to original position.
After proper positioning in ligamentum flavum, needle is advanced while continuous pressure is exerted on plunger of syringe. An abrupt LOR to injection signals passage through ligamentum flavum and into epidural space and at which point contents of syringe delivered.
Epidural test dose
3mL of 1.5% lidocaine with 1:200,000 (5mcg/mL)epinephrine
After 3 minutes failure of test dose to produce motor and sensory block rules out SA injection.
Epinephrine signals intravascular injection with incr. HR
Continuous epidural anesthesia (catheter insertion)
Catheter is advanced 3-5 cm beyond the tip of the needle positioned in epidural space.
Example- loss at 7cm- catheter inserted to 12 cm. Can thread all the way to 20cm and then pull back to 12.
On the epidural catheter 4 bold lines is 20cm. 3 lines is 15cm.
Push the lip of the yellow catheter lock till you hear two clicks.
Sodium bicarbonate
Adding NaHCO3 to LA favors non ionized form of LA for more rapid onset of epidural anesthesia.
Commonly, 1ml of 8.4% NAHCO3 to every 10ml of lidocaine or chloroprocaine.
Once bicarbonate added to LA- stabilization is reduced to 30-45 minutes because of the change in pka and ionization.
Labor Epidural bolus doses
*0.125% (0.25% Bupivacaine diluted to 0.125% (5ml saline with 5ml 0.25 Bupivacaine)
: 10 ml in 5ml increments
*Ropivacaine 0.2% : 10ml in 5ml increments
*Lidocaine 1%: 10 ml in 5ml increments - sometimes for denser block before pushing OR to check if epidural is working.
Break through pain when level is adequate. May also need to increase the rate and concentration.
Sacral sparing : 10-15 ml 0.125% bupi or lidocaine 1%
Non invasive PDPH treatment
PDPH occurrence
Acetaminophen, NSAIDs,
*caffeine ( dose 100mg. 200mg tab on formulary- can be cut in half). Not to exceed 200mg per day in postpartum women (altered clearance).
Fiorcet
PDPH occurrence is 1:100
Rate of second PDP is 10% if try new space versus threading catheter. If you’ve worked very hard/challenging to get to space (ex: obese patient, difficult anatomy) high consideration to thread intrathecal catheter
Labor CSE
0.5 cc 0.25% Bupivacaine + 15mcg Fentanyl (total 0.8mL)
Pulling catheter
Generally*** fibrinogen > 400 can pull catheter. Make sure patient no longer bleeding for high EBL deliveries!
