When the injection is complete, withdraw the spinal needle, introducer and syringe as one and apply a sticking plaster to the puncture site. The spinal needle feels as if it is in the right position but no CSF flows. Wait at least 30 seconds, then try rotating the needle 90 degrees and wait again. If there is still no CSF, attach an empty 2ml syringe and inject 0.5-1ml of air to ensure the needle is not blocked then use the syringe to aspirate whilst slowly withdrawing the spinal needle. Stop as soon as CSF appears in the syringe.
Blood flows from the spinal needle.
Wait a short time. If the blood becomes pinkish and finally clear, all is well. If blood only continues to drip, then it is likely that the needle tip is in an epidural vein and it should be advanced a little further or angled more medially to pierce the dura. The patient complains of sharp, stabbing leg pain. The needle has hit a nerve root because it has deviated laterally.