Summer 2010 - The British Pain Society

CHANGING PRACTICE
Monitoring and
intravenous access for
epidural injections in
chronic pain management:
survey of practice
Table 1. Caudal approach
Caudal During procedure After Procedure
NO ECG 19 / 47 (40%) 6 / 47 (13%)
NO NIBP 26 / 47 (55%) 6 / 47 (13%)
NO SpO2 12 / 47 (25%) 8 / 47 (17%)
No intravenous access 17 / 47 (36%)
Table 2. Lumbar approach
Lumbar During procedure After procedure
NO ECG 18 / 45 (40%) 9 /45 (20%)
NO NIBP 23 / 45 (51%) 7 / 45 (15%)
NO SpO2 12 / 45 (27%) 10 / 45 (22%)
No intravenous access 12 / 45 (27%)
Dr Iordan Mihaylov
Dr Shyam Balasubramanian
University Hospitals Coventry and
Warwickshire
Epidural injections are performed
for pain secondary to nerve root
irritation. The three common
approaches for the epidural
injections are lumbar, caudal and
transforaminal routes. Although
pain clinicians perform these
procedures frequently, there
is paucity of robust guidelines.
We require evidence based
information on the medications
used, need for intravenous access
and the minimum monitoring
standards during and after the
procedure. The Royal College
of Anaesthetists and British
Pain Society have published
recommendations in 2002
regarding the minimum standards
of monitoring required for the
performance of epidurals via
the lumbar and caudal routes if
local anaesthetics are injected.
This includes blood pressure and
pulse oximetry during and blood
pressure and heart rate after the
procedure (1).
We conducted a prospective
survey of practice of members
attending the Interventional
Pain Medicine Special Interest
Group meeting in Manchester,
9th October 2009. Fifty two out
of fifty eight clinicians completed
the survey questionnaire, making
it a 90% response rate; 46 were
consultants, one was an associate
specialist and five were trainees.
Results
There was a wide variation
with the amount and volume
of medication injected. In the
caudal and lumbar approach,
the local anaesthetic injected
ranged between three and twenty
mls of 0.25% bupivacaine (or
levobupivacaine). The volume was
between one and four mls in the
transforaminal approach. Two of
the participants preferred lidocaine
0.5% over bupivacaine for the
lumbar and caudal approach.
The status of intravenous access
for these procedures and the
monitoring used are presented in
the tables 1-3.
The results highlight that about
one third of the epidural injections
are done without intravenous
access. It is debatable whether
intravenous access is necessary if a
small amount of local anaesthetic
is injected into the epidural
space (although the potential risk
of intrathecal spread is always
present). We noticed that many
of the clinicians inject significant
Table 3. Transforaminal approach
Transforaminal During procedure After procedure
NO ECG 14 / 37 (38%) 6 / 37 (16%)
NO NIBP 22 / 37 (59%) 5 / 37 (13%)
NO SpO2 9 / 37 (24%) 6 / 37 (16%)
No intravenous access 11 / 37 (30%)
amount of bupivacaine 0.25% (5 –
20 ml) without intravenous access.
The results also suggest that the
level of monitoring was often
better after the procedure rather
than during the procedure. Whilst
the post-procedure monitoring
is more important to rule out
any haemodynamic changes,
monitoring during the procedure
may equally be necessary
to identify episodes such as
vasovagal syncope. The purpose of
the audit is to survey the practice
rather than analyse the outcome
of these procedures.
Conclusion
The practice guidelines from
International Spine Intervention
Society (2) recommends
physiologic monitoring and
intravenous access for all
procedures in which needles are
placed near the dural sac.
Although epidural techniques for
pain management have been in
existence for several decades,
practitioners learn the techniques
and the practice in different
ways. The performance is based
on personal experience rather
than on robust evidence. One
of the widely raised concerns
and the discussion following the
publication of the recent NICE
low back pain guidelines was the
heterogeneity of the interventional
pain practice. Many of us agree
that interventional treatment
procedures form an important
facet in pain management. Whilst
there are several hurdles in
bringing uniformity to the practice
due to the multiple variables in
the nature of the patients we deal
with and the available resources,
still efforts must be taken to
standardise our practice as much
as we can. To survive in a world
of evidence based medicine,
focus should be on establishing a
guideline development group to
bring consistency to our practice.
Reference
1. http://www.britishpainsociety.
org/epi_inj.pdf
2. Spinal Diagnostic & Treatment
Procedures 2004, International
Spine Intervention Society
(ISBN 0-9744402-0-5)
5 8
PAI N N E W S S U M M E R 2010