the spinal needle to ensure the stylet slides in and out easily.
Recheck your landmarks and make sure the patient's position has
not shifted. Warn the patient that a feeling of pressure or an odd
sensation in the back may occur.
using the standard cutting needle, insert the needle at the identified
site with the bevel facing upward (if the patient is in the left
or right lateral position). The bevel is thus directed in the horizontal
plane (parallel to the axis of the spine) ensuring that the bevel
is parallel to the dural fibres.
Direct the needle at an angle of approximately 10 degrees cephalad.
the line of site from your eye to the point of
needle insertion will probably be tilted downwards
(i.e. your head is above the midline), there will
be a tendency to insert the needle in a downward
angle. Resist this temptation.
the needle approximately 1.5 inches or until a slight "pop" is
felt as the dura is penetrated. At this point, remove the stylet
and wait 2 seconds for CSF drainage. If there is no CSF return,
advance the needle 1-2 mm. at a time, checking for CSF return
each advance and thus avoiding going through the ventral epidural
space and the venous plexus there. If the needle tip encounters
solid obstruction (bone), withdraw the needle tip to just below
the skin, check your landmarks and patient positioning and advance
the needle again.
to obtain a CSF return may be related to improper positioning
of the patient (not perpendicular to the bed or curled
enough), or the insertion point may be off the midline
or because the needle may be directed too far caudally.
frank blood drips from the needle after the stylet is withdrawn
then discard this needle and try again, perhaps at another space.
ligamentum flavum in a young and fit individual
is firm - the sensation is similar to that of pushing
a needle through an eraser – whereas bone
is very hard and will not give and the patient
may complain of pain if the needle touches bone.