Epidural Anesthesia (pt 2)

Question 1

T/F: you can give Duramorph in a spinal.

Answer 1

False: too much volume

Question 2

Describe the dose, onset, and DOA for a morphine bolus in an Epidural (Duramorph)?

Answer 2

-Duramorph = 5mg/10 mL
-Give 3-5 mg
-Onset: 30 min
-DOA: 12-24 hours

Question 3

Describe the dose, onset, and DOA for a fentanyl bolus in an Epidural?

Answer 3

-50 - 100 mcg
-Onset: 5-10 min
-DOA: 2-6 hours

Question 4

What is Depodur?

Answer 4

15 mg ER Morphine (?)
-Meant to be used alone, WITHOUT LOCAL
-Do test dose, then flush with NS before using Depodur

Question 5

Why are epidural opioid doses much higher than intrathecal opioids?

Answer 5

-More systemic absorption due to presence of vascular plexus (similar to IV dose)
-Epidural fat causes lipophilic drugs to be sequestered here (may need higher doses to achieve analgesia)

Question 6

The goal is to have opioids get into the _____ via the dural cuff, and onto the spinal cord to the ______ _______.

Answer 6

The goal is to have opioids get into the CSF via the dural cuff, and onto the spinal cord to the Substantia Gelatinosa.

Question 7

What is the Combination Epidural/Spinal Anesthesia technique?

Answer 7

-Using the epidural technique, stop at the Epidural space.
-Take a spinal needle and put it through to the subarachnoid space, until you feel the pop and have the flow of CSF
-Inject a small amount of drug into the CSF. (15-25 mcg Fentanyl + 1 mL Marcaine 0.25%)
-Patient can get relief quickly while you dose your epidural.
-Use a combined spinal/epidural kit. Newer kits eliminated problems associated with metallic particles, aseptic meningitis.

Question 8

What are the 2 CSE techniques?

Answer 8

Two techniques:
1) 2 separate insertion sites: Place epidural including the test dose & catheter, then move 1-2 interspaces lower (according to Nagelhout) and use a spinal needle to create a puncture, give medications, then remove the spinal needle.
2) Needle through Needle technique: use a small pencil point spinal needle, put it through epidural needle until in intrathecal space, inject small amount of opioid and 1 mL of bupivicaine 0.25%, then remove needle and place catheter for epidural.

Question 9

How do you do a continuous spinal technique?

Answer 9

-Use a Tuohy needle, position it so you are splitting and not cutting the dura
-Get return of CSF
-Do slight advancement so catheter doesn’t hit Dura
-Thread catheter 2-3 cm in Subarachnoid space
-Dose catheter (catheter itself holds 0.25 mL of fluid)
-Flush with NS after dose
-LABEL CATHETER
-Use very small doses

Accidental wet tap can turn into a continuous spinal.

Question 10

What was causing Cauda Equina Syndrome?

Answer 10

-Thought to be r/t microcatheters and hyperbaric lidocaine
-Thought that the lido stayed in one area and pooled rather than diluting and moving.
-Caused high doses of LA to sit on these nerves, causing microtoxicity.
-Microcatheters have been removed from market
-Use Bupivicaine or dilute Lidocaine

Question 11

Why is Post-Dural Puncture Headache (PDPH) less with continuous spinal in place?

Answer 11

Appears to be r/t inflammatory reaction around the catheter, which plugs the hole in the dura, preventing the leakage of CSF.

Question 12

What should you do if the Epidural catheter is not threading?

Answer 12

-May not be midline, evaluate location
-Try flushing with NS to potentially open up the space.

Question 13

What should you do if you have a one-sided block?

Answer 13

-Pull back catheter 1 cm
-Put unaffected side down
-Re-dose
-Chart new position of catheter
-If this doesn’t work, start over

Question 14

What should you do if you are not able to flush the Epidural catheter?

Answer 14

-May be a clot, or may be against tissue/bone
-Can pull back and retry
-Use a tiny syringe (increased pressure)

Question 15

What should you do if you encounter fluid coming into the syringe?

Answer 15

-Could be NS if you used that to open up the space
-Could be CSF - use urine strip and test for BS, proteins

Question 16

What should you do if there is placement paresthesia?

Answer 16

Catheter may not be midline, may be in a root
-Check to make sure you are midline
-If consistent paresthesia, pull out and start again!
NEVER INJECT ON A PARESTHESIA

Question 17

What should you do if you are unable to remove the catheter?

Answer 17

-Do not pull it - risk of breaking
-Modest pressure only
-Ask patient to flex back
-Radiopaque - may need consult/imaging

Question 18

What causes a Post-Dural Puncture Headache (PDPH)?

Answer 18

-Leak of CSF due to trauma or puncture to the dura.
-Intracranial vessels dilate to compensate for lost CSF, making symptoms worse.
-Leak causes a downward shift/sag of brain and traction on the meninges.

Question 19

What are the S/Sx of PDPH?

Answer 19

-Headache (worse when sitting up)
-Feeling miserable
-N/V
-Unable to cope
-Diplopia
-Photosensitivity
Present within 1-2 days of puncture (can be up to 5 days)

Question 20

What is the tx for PDPH?

Answer 20

-Rule out other causes of HA
-Usually resolves within 5-7 days without treatment
-Bedrest, prone position, abdominal binder
-IV fluids: 3L /day
-Caffeine Sodium Benzoate IV: vasoconstriction may help with the dilated vessels and improve symptoms.
-Epidural Blood Patch if Caffeine and conservative measures fail

Question 21

What is the official definition of PDPH?

Answer 21

Onset within 15 minutes of moving to the sitting position (?) with at least 1 of the following: HA, Neck stiffness, tinnitus, photophobia, or nausea

Question 22

What is the differential diagnosis for headache (HAVE to rule out other causes before deciding PDPH)?

Answer 22

-Migraine
-HTN
-Subarachnoid hemorrhage
-Meningitis
-Lactation HA
-Pneumocephalus (air in the space, mimics PDPH. When you sit up, it gets worse)
-Brain tumor
-Sinusitis

Question 23

How do you perform an Epidural Blood Patch?

Answer 23

-Same setup as epidural
-Have someone drawing blood aseptically and hand it to you to inject into the epidural space
-Do Patch 1 level lower then original puncture
-Blood can travel up as high as 9 segments
-Inject 10-20 mL of blood (optimal is 15 mL)

Common complaints: pressure, back ache, and hip fullness
Can cause bradycardia
Corrects PDPH 85-90% of the time on 1st try
Can repeat in 24 hours

Question 24

Compare SAB to Epidural.

Answer 24

Spinal:
-Less time to perform
-Quick set up of block
-Sensory and motor block is more dense
-Can’t extend the length of time
-More severe and quick drop in BP
-Venous pooling > arterial dilation

Epidural:
-Less hypotension (still venous pooling)
-Takes time for set up, more challenging
-Can prolong block with catheter
-Catheter can be used for postop pain management
-Less PDPH

Question 25

How do you assess your level of block?

Answer 25

-Same for SAB vs Epidural (Epidural takes longer though) -Alcohol swab (temperature) -Sharp tongue depressor -Both cold and sharp occur before painful. -Motor test: lift leg or push on the gas

Question 26

What do you need to assess pre-op before NA?

Answer 26

-What level of blockade do we need -Duration of surgery - check with surgeon if NA is appropriate (will operation outlast SAB? Large blood loss expected?) -Cardiac disease, uncontrolled BP or ICP -Coagulation issues -Patient cooperation -Skill of practitioner (anesthesia and surgeon) -Have plan to secure airway if block fails

Question 27

What should you do if patient is receiving subcut Heparin <5,000 BID or TID?

Answer 27

-Place > 4 hours after last dose -Check plts if drug given > 4 days -Dose 1 hr after placement -Daily neuro monitoring -Hold Heparin until >1 hour after removal

Question 28

What should you do if patient is receiving subcut Heparin >5,000 units /dose?

Answer 28

-aPTT < 40 -Place 4 hours after last dose -Check plts if drug given >4 days -Usually C/I for indwelling epidural catheter -Hold Heparin until 1 hr after removal

Question 29

What should you do if patient is receiving a continuous IV Heparin infusion?

Answer 29

-Stop Heparin 2-4 hours before placement -aPTT < 40 -Indwelling catheter usually C/I and requires documentation of mutual team agreement if placed -Neuro exam daily -Hold heparin until >1 hr after removal -Neuro eval q 2 hours for first 12 hrs after removal.

Question 30

What are absolute contraindications to NA Anesthesia?

Answer 30

-Patient refusal/uncooperative -Infection, derm issues, psoriasis -Septic or hypovolemic shock -High, rapid blood loss case -Severe hypotension, hypovolemia -Increased ICP (herniation) -Gross abnormality of clotting mechanisms or taking anti-thrombotic meds -Severe Aortic Stenosis/Mitral Stenosis (don't want big ANS response) -Diseases that can't tolerate a drop in BP

Question 31

What are relative contraindications to NA Anesthesia?

Answer 31

-Spinal pathology (depends on degree of pathology, neuro diseases, deformities, and preexisting symptoms) -Chronic HAs/Backaches (document) -Document existing paresthesias -Stop attempting after failed 3xs

Question 32

What is the Dural Puncture Epidural technique?

Answer 32

Typically performed using the needle-through-needle approach, but instead of administering any medication through the subarachnoid needle, the needle is withdrawn following dural puncture, and the epidural catheter is threaded into the epidural space. Following placement of the epidural catheter, the epidural needle is removed, and conventional epidural anesthesia/analgesia is done using the epidural catheter