Page 37 - Radiology Book

myelogram / lumbar Puncture Protocol continued
TIP: Placing the patient in REVERSE TRENDELENBERG (table head- up) will increase hydrostatic pressure if needed and allow CSF to ow faster from the needle. It is much safer than aspirating on the syringe. If you keep hitting bone after numerous attempts or go all the way to the needle hub without getting CSF, get a cross-table lateral lm to determine why your needle is out of position. Use this information to then adjust needle angulation and/or depth.
FOR LUMBAR PUNCTURE
1. Attach tubing and place distal/open end of tube below the level
of the patient’s spine to create pressure difference that may allow
CSF to ow out.
2. Obtain opening pressures with patient either in left lateral
decubitus (most accurate) or prone positioning, with the 3-way ow switch at the level of the thecal sac (usually estimated). Ensure the patient is at, and not in Reverse T-Berg.
3. Collect samples in tubes based on chronological labeling. Patient may be placed in REV TBERG to accommodate quicker out ow of CSF. Roughly 4 cc of CSF should be collected in each tube (15-16 cc total). Total samples up to 30 cc (~7cc/tube) may be obtained
if requested by Neurology or for pseudotumor cerebri to bring closing pressures <20 cm H20. TIP: Telling the pt to “lightly cough” may help ow surpass the end of the needle tip and through the tubing.
4. Obtain closing pressures (see #2).
V. Inject contrast under serial uoroscopic pulse images
Draw up contrast per protocol (below). Remove any bubbles from the syringe and connecting tubing. Attach the connecting tubing to the spinal needle hub CAREFULLY USING BOTH HANDS FOR NEEDLE SUPPORT. Inject slowly. NB: THE TUBING USUALLY HOLDS APPROX 3-4 cc OF FLUID.
CONTRAST per protocol:
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L SPINE: 12-15 cc of Omnipaque 300
C or T SPINE: 12-15 cc of Omnipaque 240
CTL SPINE: 12-15 cc of mix of Omnipaque 300 (75%)/240 (25%)
Infuse contrast via needle under uoro. If the contrast is in the subarachnoid space it will disperse then collect in a central pool.
An adequate injection will often collect off to one or both sides in a more irregular pattern, often with visualization of the intrathecal spinal nerves. If after 3-5 cc you are concerned, STOP!
1. Prone tipping method: Tip the prone patient head down until the contrast runs up out of the lumbar area into the low thoracic area around T12.
2. Supine log-roll method: The goal is to get the contrast out of the sacral area into the cervical/thoracic area. Tip the table top
LP ProtocoL