Epidural blood patch (EBP) is a modality useful in the management of persisting "post dural puncture head ache" (PDPH) caused by leaking of the cebrospinal fluid (CSF) from a dural puncture site.
A typical PDPH may be caused by anesthesia-related dural puncture, myelography, certain surgical procedures, or trauma in the vicinity of the spinal dura.
In this technique, autologous blood (10-20 ml) form the patient is usually drawn via an existing intravenous(IV) access and injected into the spinal epidural space in order to seal the leak of CSF.
The access to the epidural space may be
- via the lumbar route, or
- through the caudal root.
During this procedure, some of the patients are known to experience some degree of pain in the lower limbs(usually not too severe) and are generally warned about this and are instructed to indicate if they feel pain, so that, in case there is pain, the injection may be slowed down.
Arterial blood is not needed for this procedure.
There have been reports of inadvertent nerve injuries due to arterial punctures or cannulations. Using the conventional radial artery technique for drawing arterial blood sampling, complications are unusual. They include local pain, limited hematomas and vasovagal episode, occurring in less than 0.58% of the procedures. Reflex sympathetic dystrophy and expanding aneurysm of the radial artery have been reported even more rarely (that too, after frequent punctures). Medial nerve injuries are more frequently reported following brachial artery cannulations/puncture, rather than in relation to radial artery (perhaps related to anatomic reasons).
You were perhaps one of the very unfortunate few who develop
such severe distress during the procedure. The persisting pain in your lower limbs may have a contribution from your original back problem as well.To identify any nerve involvement, a clinical examination is mandatory. Your surgeon will be better placed to asses you and advise regarding this.
MB BS, MS, FRCS(Edinburgh)