Page 36 - Radiology Book

myelogram / lumbar Puncture Protocol continued
with uoro to con rm both the appropriate spinal level and that the needle is midline. Advance the needle initially about a millimeter
at a time with serial uoro spots to readjust the needle as desired. Remember, if using midline approach, that you want your hub directly superimposing the needle. If you are able to see your needle tip, your needle is now angulated.
6. As you get deeper, use both hands to move the needle. One had
at the hub and the other ngers pinching the needle a millimeter
or less above the skin surface. This creates more control of depth. You may or may not feel the actual “pop” as you puncture the dura. For this reason, you need to empirically and frequently pull the stylet out of the needle and check for CSF, EACH TIME you move the needle when you are close to the canal. Rule: You will hit fewer nerve roots and hurt the patient less often if you keep the needle tip as close to MIDDLE of the spinal canal as possible.
PARASPINOUS APPROACH
1. Roll the patient 10-15 degrees to the left or right so that under uoroscopy, you can see the “white” space between the lamina, over or just below the desired disk space. Place a wedge cushion under the patient’s side to achieve prone RAO or LAO positioning
2. Clean and prep the puncture site. Lay sterile towels.
3. The needle position is different than the midline approach. Place
the skin puncture site directly over the “white” space. This will
usually be 2-5 cm lateral to the midline of the skin.
4. Anesthetize the skin. Then place the spinal needle vertically.
5. Just as with the midline approach, the closer you are to the middle
of the spinal canal when the needle punctures the dura, the fewer painful complications. Steer the needle to the midline, midway between the pedicles. Check frequently, both the needle position under uoro and for CSF return after each needle advance as stated above.
6. As above.
IV. Con rm needle tip is in the subarachnoid space
If you feel the “pop” or if CSF return is minimal, gently push the needle 1-2 mm deeper with the stylet in. This will often reduce the chance of a mixed subdural/subarachnoid injection.
Rule: If you want to con rm CSF return or if you need to collect CSF and want to aspirate on the syringe to speed the process, DO NOT DO THIS WITHOUT DIRECT SUPERVISION OF AN ATTENDING. Ensure that the needle tip is either in the cranial or caudal direction. If it is sideways the cauda equina roots can suck up against the needle tip preventing uid return and giving the patient a rude shock down the leg.
Southfield16
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