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October
1999
Epidural Labor Analgesia and the Incidence of Cesarean
Delivery for Dystocia.
Fogel ST, Shyken JM, Leighton BL, Mormol JS, Smeltzer JS.
Anesth Analg. 1998;87:119-123.
Commentary by Dr.
Dwane
Return to the Current Literature
Review Front Page
[ see abstract below ]
JA Thorpe, in
an article in 1993, highlighted the association between labor epidurals
and the incidence of cesarean section for dystocia. However, he erroneously
went further and stated that epidurals were the cause of increased of
cesarean section rate, even thought the study design could not support
this conclusion. His article is responsible for a mass of research that
has begun to show the same association without the cause and effect relationship.
In addition, other studies will go on to explore the reasons behind this
association between epidurals and dystocia for cesarean section.
In Fogel et al's study there was no change in obstetric
practice, patient demographics, and oxytocin use, and indications for
cesarean section were protocol driven. Fogel and coworkers demonstrated
no change in the total cesarean section rate, the rate of cesarean section
for dystocia, or the nulliparous cesarean section rate between the before
and after groups, even though the labor epidural rate had increased from
1.2% to 29.4%. They also showed that although there was no change in cesarean
section rate for dystocia (3.0-3.1%), with the introduction with the introduction
of epidurals, there was an eight-fold increase in cesarean section for
dystocia in those women who chose to have epidurals. See tables.
| |
Epidural Rate (%)
|
Total C/S Rate
(% Dystocia)
|
C/S Rate (%)
|
Nulliparous
Dystocia C/S Rate (%)
|
|
Before
|
1.2
|
9.1
|
3.0
|
5.7
|
|
After
|
29.4
|
9.7
|
3.1
|
6.4
|
| |
Epidural Rate (%)
|
Nulliparous
Dystocia C/S Rate (%)
|
|
After with Epidural
|
100
|
8.0
|
|
After without Epidural
|
0
|
1.0
|
Although not as
powerful in design as a randomized clinical trial, this "impact study"
which is retrospective and uses historical controls (where an abrupt change
occurs, without other changes in practice) avoids difficulty of recruiting
patients randomly to the non-epidural group. It also allows for much larger
numbers of patients to be studied and this design is thought to be an
acceptable study model for examining the epidural-cesarean section dystocia-cesarean
section for dystocia relationship.
This is the first significant paper which makes the
point that perhaps it's the dysfunctional labor causing increased pain,
which is responsible for the patient's selecting epidural analgesia. And
the cesarean section is pre ordained by the dysfunctional labor, and not
the epidural.
Return to the Current
Literature Review Front Page
ABSTRACT
Epidural labor analgesia
and the incidence of cesarean delivery for dystocia.
AUTHORS: Fogel ST; Shyken JM; Leighton BL; Mormol JS; Smeltzer JS.
SOURCE: Anesth Analg
1998 Jul;87(1):119-23.
We performed this retrospective
study to examine the changes in cesarean delivery rates associated with
the establishment of a labor epidural service. In April 1993, St. Louis
Regional Medical Center established an on-demand labor epidural service.
We obtained demographic data for all patients and reviewed the operative
records of all patients undergoing cesarean section who delivered 12 mo
before and 16 mo after the start of the labor epidural service. We compared
labor epidural rates and total and nulliparous dystocia cesarean delivery
rates before and after the epidural service started and among patients who
did and did not receive labor epidural analgesia when it was available.
Included were 3195 patients who delivered before and 3733 patients who delivered
after epidural analgesia became available.
Labor epidural rates
were 1.2% vs 29.4% for the Before group versus the After group (P <
0.001). Total (9.1% vs 9.7%) and nulliparous dystocia (5.7% vs 6.4%) cesarean
delivery rates did not significantly change with the availability of epidural
analgesia. However, the total (11.6% vs 8.8%; P = 0.009) and dystocia
(8.0% vs 1.0%; P = 0.001) cesarean delivery rates were higher among patients
who received epidural analgesia when it was available. We conclude that
epidural labor analgesia is associated with, but does not cause, cesarean
delivery for dystocia. Implications: Increased epidural analgesia use
did not change the overall dystocia cesarean delivery rate, although dystocia
was more common among women who chose an epidural analgesia. Consequently,
limiting epidural availability will not affect cesarean delivery rates.
The evidence does not support advising patients that epidural labor analgesia
increases the risk of cesarean delivery.
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