Intrathecal / Spinal / Epidural

[worrywart]

I'm getting confused on the three types of pain management for labor and was wondering if anybody could clear up the differences. Is an intrathecal a type of spinal block and do you use a catheter for it? Does the intrathecal get inserted below the spinal block? Also do you get the spinal headaches from both spinal blocks and epidurals or just spinal blocks? I've heard different things about each of them and was getting them confused. I understand the placements of spinal and epidural but the intrathecal was throwing me off. Also, at the hospital that I do my clinicals at my teacher told me they do mostly spinal blocks, but when the pain wears off do you just keep injecting them? She said not many doctors are precise on doing epidurals, but I would hate to get poked everytime my pain came back. Why would they not train their doctors to do this more often? Any answers on these questions would be greatly appreciated. Thanks

[Daytonite, BSN, RN]

this website describes the different anesthesias for ob: http://www.med.umich.edu/anes/sections/ob/ob2006_patient%20care.htm a "block" refers to the anesthetic, or numbing agent. epidural and spinal refer to anatomical locations. a spinal needle is what is initially inserted into the lumbar area of the spine to access the epidural or spinal spaces. the drawing on the website shows the anatomical difference between the epidural and spinal fluid spaces.

does the intrathecal get inserted below the spinal block?

the intrathecal catheter would be inserted through a spinal needle and enter the canal containing the cerebrospinal fluid. this catheter can be advanced upward within the spinal space to an elevation that the physician wants it. anesthetic and/or analgesic agents can be injected into the catheter. what you are calling a

spinal

block

would be an anesthetic injected through this catheter. pain medication would also be given through this same catheter for pain relief.

when the pain wears off do you just keep injecting them?

if they have inserted and left the catheter in place, yes, they can keep injecting the patient with pain medication. if they have not, then they need to perform another epidural or spinal injection.

do you get the spinal headaches from both spinal blocks and epidurals or just spinal blocks?

anytime there is a sudden disruption in the volume of the cerebrospinal fluid the patient can get spinal headaches.

she said not many doctors are precise on doing epidurals, but i would hate to get poked everytime my pain came back.

this sounds like a judgment your instructor is making based on her own personal observations in delivery. you may observe something quite different. what were you taught in nursing school about other people's judgments?

[RedCell]

The words intrathecal and spinal mean the same thing.

The anatomy goes as follows:

skin

subcutaneous tissue

supraspinous ligament

Intraspinous ligament

ligamentum flavum

epidural space

dura mater

arachnoid mater

Yes you can thread a catheter into the intrathecal space to provide continuous anesthesia, though epidural catheters are far more common. Typically, a spinal is a one shot deal meaning you don't go back to make more jabs into the patient's spine once the anesthetic wears off. Many anesthesia providers will give duramorph (preservative free morphine) with the local anesthetic when administering the spinal to provide up to 12 hours of analgesia, far exceeding the duration of action of the local anesthetic.

You have the potential to develop a postdural puncture headache (PDPH) any time you breach the dura. A properly placed epidural will not cause a PDPH. Most spinals do not result in PDPH because spinal needles are small gauge needles. When an epidural gets shoved in too far (17gauge touhy a big ass needle) you can get a large CSF leak resulting in a PDPH.

Pregnant patients have about an 18% chance of getting a PDPH when the dura is punctured with a touhy needle. Your risk goes up with a younger age, being female, being pregnant vs not pregnant, multiple needle sticks and using larger gauge needles.

Your teacher is completely inaccurate with her statement regarding anesthesia providers and properly placed epidurals. The majority of anesthesia practitioners working on a labor deck could place an epidural in a laboring gravida 37 week tick if given the right supplies (and assuming ticks had a spinal cord). CRNAs, anesthesiologists and anesthesiologist assistants have plenty of training in neuraxial anesthesia. Practitioners working OB are usually even better as skills are built on repetition.