lumbar puncture ?

So if a pt goes in for a lumbar puncture (prone position) but the MD is not able to pull ANY spinal fluid, WHY would that be? (several attempts, and pt was not dehydrated) Low spinal pressure?
Prone position? The doc might not have been in the right spot. I know when I had my last LP, I was curled up like a question mark over the bedside table.

Quote from Leelee2So if a pt goes in for a lumbar puncture (prone position) but the MD is not able to pull ANY spinal fluid, WHY would that be? (several attempts, and pt was not dehydrated) Low spinal pressure?

As chloecatrn states, the prone position seems a little different to every LP I have ever assisted an MD to perform. The pt is usually curled up in a fetal position, but laying on one side... I wonder that CSF could ever be aspirated in a prone position, not because of low pressure, but because it seems almost impossible to insert a needle into the correct space if the pt is laying face down.

In Prone position, but on a tilt table. So fluid is able to flow downward, but patient is on stomach. Three attempts, in 3 different spots. No fluid.

MD is inexperienced?

It's usually not so much an issue of the fluid being able to flow downward. You want the spaces between the vertebrae to stick out so they are palpable, which is why you usually see it done with the patient sidelying and the back curved. In pediatric patients, sometimes you can accomplish the same curled position with the child sitting and leaned forward.

I have not seen an LP performed with a patient in that position. I have only seen patients in a side lying position curled up in the fetal position or sitting up leaning forward. I worked with an MD once who had spend a lot of time working in a third world country where meningitis was rampant. He could do an LP on anyone in the blink of an eye. He said they used to perform 10 or more per day when he was in Africa. I never saw him miss.

I had three ED docs try on me and they could not get any fluid. It was finally done under flouro and the radiologist said I just had a very deep spinal canal. He got it on the first try, prone.

I have never, never, never seen a pt placed prone for an LP, and it seems to me that in that position it would be difficult to get between the vertebrae.