Page 234 Acute Pain Management
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Drugs used in postoperative patient-controlled epidural analgesia
The
drugs
used
for
PCEA
are
the
same
as
those
used
for
continuous
epidural
infusions
(see

also
Section
5).
Generalisations
about
the
efficacy
of
different
drugs
and
drug
combinations

administered
via
PCEA
are
difficult
because
of
the
wide
variety
of
analgesic
agents
and

concentrations
used
in
the
various
studies.



7.2.4 Adverse effects
Neurological injury
Permanent
neurological
damage
is
the
most
feared
complication
of
epidural
analgesia.


A
retrospective
survey
from
Sweden
put
the
risk
of
a
severe
neurological
complication
after

obstetric
epidural
analgesia
at
1:25
000
and
for
all
other
patients
at
1:3600;
67%
of
events

resulted
in
permanent
neurological
deficit
(Moen
et
al,
2004
Level
IV).
It
also
identified

osteoporosis
as
a
previously
neglected
risk
factor.
A
review
of
data
from
publications
reporting

adverse
events
after
obstetric
epidural
analgesia
reported
a
risk
estimate
of
1:
240
000
for

persistent
neurological
injury
and
1:6700
for
transient
(resolved
within
one
year)
neurological

symptoms
(Ruppen
et
al,
2006a
Level
IV).

A
review
of
data
from
published
studies
of
the
risk
of
neurological
injury
associated
with

epidural
and
other
regional
anaesthesia
and
analgesia
differentiated
between
the
risk
of

permanent
(neurological
deficit
lasting
more
than
12
months)
neurological
injury
and
transient

neuropathy
(Brull
et
al,
2007
Level
IV).
This
review
focussed
on
adverse
neurological
sequelae

associated
with
the
technique
and
did
not
address
the
overall
risk
of
epidural
haematoma
or

abscess,
nor
did
it
differentiate
between
obstetric
and
non‐obstetric
neuraxial
block

outcomes.
The
incidence
of
transient
neuropathy
(radiculopathy)
after
epidural
anaesthesia

was
estimated
to
be
2.19:10
000.
The
risk
of
permanent
neurological
injury
was
less
and
the

CHAPTER
7
 rates
of
paraplegia
and
cauda
equina
syndrome
associated
with
epidural
anaesthesia
were

incidences
reported
in
the
studies
included
in
this
review
ranged
from
0
to
7.6:10
000.
The

estimated
to
be
0.09:10
000
and
0.23:10
000
respectively
(Brull
et
al,
2007
Level
IV).


A
project
in
the
United
Kingdom
assessed
the
incidence
of
neurological
complications
in
an

estimated
97
925
adult
patients
with
perioperative
epidural
catheters
(Cook
et
al,
2009
Level
IV).

Depending
on
the
inclusion
or
exclusion
of
cases
with
unlikely
causation,
pessimistic
and

optimistic
data
were
published.
The
incidence
of
permanent
injury
was
pessimistically

assessed
as
17.4
per
100,000
(95%
CI
7.2
to
27.8;
1
in
5800)
and
optimistically
as
8.2
per

100,000
(95%
CI
3.5
to
16.1;
1
in
12
200).
Laminectomy
was
performed
with
an
incidence

of
12.3
per
100
000
cases
(95%
CI
6.3
to
21.4,
1
in
8100).
Paraplegia
was
caused
in
6.1
per

100
000
(95%
CI
2.2
to
13.3;
1
in
16,400)
in
the
pessimistic
and
in
1.0
per
100,000
(95%
CI
1.0

to
5.7;
1
in
100,000)
in
the
optimistic
model.

The
worst‐case
estimate
for
persistent
neurological
injury
after
epidural
anaesthesia
for

vascular
and
cardiothoracic
surgery
is
1
in
4600
based
on
a
meta‐analysis
of
case
series
with

an
event
rate
of
zero
in
14
105
patients;
the
risk
of
transient
neurological
injury
was
1
in
1
700

(Ruppen
et
al,
2006b
Level
IV).


Audit
data
from
a
single
(non‐obstetric)
tertiary
institution
showed
that
8210
epidural

catheters
were
inserted
over
a
16‐year
period
for
postoperative
pain
relief
and
that
two
spinal

haematomas
and
six
epidural
abscesses
were
diagnosed
during
this
time;
only
one
patient

(with
an
epidural
abscess)
required
surgical
decompression
and
no
patient
suffered
any
long‐
term
neurological
loss
(Cameron
et
al,
2007
Level
IV).





186
 Acute
Pain
Management:
Scientific
Evidence

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