Epidurals in the obese

Speaking from my vast experience (40 epidurals about 10 of them in the obese).

If you look at an obese patients back, there is usually a crease in th skin around the L3-4 level. I don't know why it is there, but it seems to be there on the patients I have seen. In this region, I place 5cc of 1% lido generously in the skin and deep tissues. While doing this I use the needle as a finder by walking it up a process until I find a space between the vertebrea. Using the middle fingers of my left hand, I pin the skin down and reach for the touhy. Now I advance the touhy through the original puncture from the local. I advance the touhy roughly 1 to 1.5 cm thus anchoring it in the interspinous ligamnet. From there, its just like every other placement until you reach the hub and have to switch needles to the 15 cm instead of the 10 cm.

the most difficult part of an obese patient in my opinion is that it is very difficult to assess for spinal curvature which will affect your placement approach.

I placed an epidural two nights ago that required me to bury the touhy to the hub. I was actually afraid that the dimple it made in the skin, would spring it out of the epidural space if I didn't have my hand on it. Fortunately this did not happen and the placement was successful. This patient was 5'2" and 300 pounds.

Craig

palpating the pelvis to identify L4 can be done most of the time, if not they will have a nice fat roll that gives an approx location of L4. ususally you can't feel any interspaces so basically I end up using the needle i inject local as a finder needle. if you go in and hit bone right away you know you have to move up or down about 1/2 - 3/4 inch to get into ligament. you need to make sure you also have a long enough needle because the tuohy needle is 9cm to the hub so if more is needed you either need to get a longer needle or be able to push the hub into patient's back a couple of cm.