Who should be treated?
A mother has received a 'wet tap' epidural or subarachnoid injection, and who has a headache which:
1. is sufficiently incapacitating as to interfere with her ability to care for her baby,
2. has the characteristics of a PDPH, and
3. has not been relieved by 2-3 days of conservative management
(bed rest in the supine position, hydration, caffeine or caffeine-containing drinks, oral simple analgesics, non-steroidal anti-inflammatory agents),
and who also has:
4. no neurological symptoms* arising from the index lumbar puncture
5. no active neurological disease (13) (Chapter 96),
6. no infection Iocalised to the lumbar area or septicaemia,
7. no coagulopathy (13).
* (This requirement may be waived if the headache or nuchal pain is very severe and associated with protracted vomiting or if there is evidence of auditory nerve (hearing loss) or abducens nerve (diplopia preceded by headache) stretching (14) .)
Why use the technique?
EBP has an extremely high success rate of close to 100% when placed in the epidural space at the same level as the initial needle puncture (1, 7, 8). The blood patch works as a gelatinous glue which prevents CSF leakage and allows the dural hole to heal (2). Blood may also be forced through the dural puncture forming a plug (9). The immediate relief from PDPH may be due to an increase in CSF pressure.
When should EBP be used?
Preferably, 48-72hrs after the puncture which caused the PDPH (when success rate is 91-100%) (1, 7, 8, 13). If performed at the time of inadvertent dural puncture, or through an epidural catheter placed at this time, the success rate is dismal and is no different to doing nothing at all (3). If EBP is attempted at <24hr the success rate is reported to be as low as 29% but it may reduce the occurrence rate of PDPH (4, 10).
How should EBP be performed?
Prepare the patient by:
1. Explaining the technique, hazards and anticipated success rate.
2. Obtaining consent for the procedure (Chapter 55).
3. Pre-medicating if necessary.
4. Starting an intravenous infusion of crystalloid.
5. Positioning in the left lateral, fully-flexed position.
The EBP is, preferably, a two-operator technique.
Both operators should scrub, gown and glove as is standard in the particular institution.
Operator 1.
1. Cleans and drapes the patient's back using a standard epidural kit and technique,
2. Identifies the site of original puncture and locates the epidural space using a standard technique (Figure E.3).
Operator 2.
1. At the same time as operator 1 is prepping the back, the second operator cleans and drapes the antecubital area of (usually) the left (downside) arm. A second epidural/spinal kit and drapes containing a 20cc glass syringe with 22G sterile straight or butterfly needle is ideal for the task.
2. Once the epidural space is located by operator 1, the second operator, using a rigidly aseptic technique, performs a venepuncture, withdraws 22ml of blood, removes the needle from the syringe, hands the syringe to the first operator (without breaching the integrity of the sterile fields) and applies pressure and a sterile dressing to the venepuncture site.
How should the blood should be injected?
1. Inject the blood slowly until either, the patient complains of tightness in the buttocks, lower back or thighs (usually when 12 to 15ml are injected) (11) or, until 20 ml is injected.
2. Withdraw the needle, apply a sterile dressing and turn the patient to the supine position.
3. Inject the residual blood through a fresh, sterile needle into a blood culture bottle and send to bacteriology for culture and antibiotic sensitivity.
How should the patient be managed subsequently?
1. Place a pillow under the mother's knees.
2. Nurse her supine for four hours.
What advice should be given to the patient?
Advise her;
1. not to carry anything heavier than the baby for 2-3 weeks,
2. to squat rather than bend when picking items in a low position,
3. to avoid excessive straining,
- all of which can cause 'patch blow-out' with return of the PDPH.
4. To report pyrexia, back or radicular pain, return of PDPH or other untoward symptoms immediately.
The patient can, in the majority of cases, expect almost instantaneous relief from the PDPH. In some, the relief comes on gradually over a 24hr period. Following the EBP some will experience mild backache for a few days (5). Less than 2% will also have mild, transient paraesthesiae, neck pain or radicular pain (6, 12). The EBP should not cause obliteration of the epidural space, infection, cauda equina syndrome or adhesive arachnoiditis.
References:
1. Ostheimer GW: Headache in the Postpartum Period in Clinical Management of Mother and Newborn (Eds. Marx GF), Springer-Verlag, New York, p.27-41, 1979.
2. DiGiovanni A J, Galbert MW, Wahle WM: Epidural Injection of Autologous Blood for Postlumbar-puncture Headache. Anesth Analg 51:226-232, 1972.
3. Palahnuik R J, Cumming M: Prophylactic Blood Patch Does Not Prevent Postlumbar Puncture Headache. Can Anaesth Soc J 26:132-133, 1979.
4. Looser EA, Hill GE, Bennett GM, et al: Time Versus Success Rate for Epidural Blood Patch. Anesthesiol 49:147-148, 1978.
6. Ostheimer GW, Palahnuik RJ, Shnider SM. Epidural Blood Patch for Post-Lumbar Puncture Headache. Anesthesiol 41:307-308, 1974.
7. Glass PM, Kennedy WF: Headache following Subarachnoid Puncture: Treatment with Epidural Blood Patch. JAMA 219:203-204, 1972.
8. Crawford JS: Experience with Epidural Blood Patch. Anaes 35:513, 1980.
10. Colonna-Romano P, Shapiro BE: Unintentional Dural Puncture and Prophylactic Epidural Blood Patch in Obstetrics. Anesth Analg 69:522, 1989.
11. Szeinfeld M, Ihmeidan IH, Moser MM, et al: Epidural Blood Patch: Evaluation of the Volume and Spread of Blood Injected into the Epidural Space. Anesthesiol 64:820, 1986.
12. Carrie LES: Postdural Puncture Headache and Extradural Blood Patch. Anaes 71:179, 1993.
13. Ostheimer GW: Prophylactic Epidural Blood Patch. Reg Anes Oct-Dec, 17-19, 1979.
14. Hayman IR, Wood PM: Abducens Nerve Paralysis following Spinal Anaesthesia. Ann Surg 115:864, 1942.