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DISCUSSION
The main ﬁndings of this study are that EA did not inﬂuence the MCPC rate, hospital LOS, and 30-day mortality after
open colorectal surgery. The strength of this study includes use
of current data (i.e., 2014 and 2015); therefore, the information
reﬂects modern perioperative practice. Furthermore, the sample
size in this study was large compared with previous studies.
Also, we used propensity matching, which allows better control
for confounders and bias and provides an ability to elucidate
the diﬀerences. In addition, we were able to match the EA and
non-EA groups at a 1:3 ratio for socioeconomic, medical, and
surgical factors without signiﬁcant reduction in the sample size.
Our ﬁndings contradict the recommendations from the
ERAS Society (www.erassociety.org) that emphasize the use of
EA for open colorectal surgical procedures (2). Interestingly,
previous analysis of the data, collected between 2008 and 2013,
from an international, multicenter ERAS registry maintained by
the ERAS Society found that use of EA was associated with longer hospital LOS (14). In contrast to our ﬁndings, a Cochrane
systematic review of RCTs in patients undergoing abdominal
surgery found that EA was associated with reduced hospital LOS
after open abdominal surgery (8). However, the RCTs included
in these metaanalyses were performed before the introduction
of ERAS programs.
The use of EA in our study population in 2014 and 2015
was about 15%, which is higher than that reported previously
by Halabi et al (6), who observed an EA rate of 4.4% between
2002 and 2010. The higher EA rate observed in our study may
be related to recommendations by the ERAS Society. Another
possible reason for the low rate reported previously could be
undercoding of EA in the administrative data utilized (i.e.,
the Nationwide Inpatient Sample) (15). In contrast, the EA
rate reported by Cummings et al (16) in patients undergoing
colorectal cancer surgery between 1996 and 2005 was 22.9%,
slightly higher than that observed in our study. The higher
rate is most likely because the patient population included in
the Cummings study was older (>66 years) and may have had
several comorbid conditions. On the other hand, our EA rate
may be underestimated because of the strict exclusion criteria
for our study. For example, our study excluded all cases with EA
combined with other types of analgesic techniques.
In recent years, there have been several reports of association between EA and survival after cancer surgery, possibly
due to reduced perioperative complications (17). A large (n =
42,151) propensity-matched retrospective cohort study in patients with nonmetastatic cancer undergoing colorectal surgery
found that EA was associated with improved survival (16). In
contrast, secondary analysis of data from large multicenter
RCTs assessing eﬀects of EA on outcomes after major surgery
found no diﬀerence in mortality in the subset of patients undergoing surgery for abdominal malignancies (18). A recent
analysis of the claims database of a large nationwide commercial health insurer found that EA did not inﬂuence persistent
opioid use (19). Overall, it is unclear if EA or several other
confounding factors such as type of cancer, blood transfusion,
need for postoperative chemotherapy and radiation therapy,
July 2017

and reduced opioid use were the reasons for improved outcome
after cancer surgery.
Based on our ﬁndings, it appears that the role of EA in the
modern perioperative care of patients undergoing open colorectal surgery is limited. One of the major limitations of EA is
that it may delay ambulation, which is a major contributor
to enhanced recovery. The reasons for delayed ambulation associated with EA include the presence of catheter and pumps,
the presence of muscular weakness, and postural hypotension.
Given these limitations of EA, there is an increased interest in
alternate methods of analgesia, including ﬁeld blocks such as
transversus abdominis block (20) and surgical site local anesthetic inﬁltration with or without continuous local anesthetic
infusion in the surgical wound (3, 21). These methods have
been shown to be eﬀective analgesics when combined with
nonopioid analgesics such as acetaminophen and nonsteroidal
anti-inﬂammatory drugs as well as analgesic adjuncts such as
steroids (e.g., dexamethasone) (3).
This study has several limitations, particularly those related
to its retrospective nature. In addition, the limitations are related to use of databases, including the possibility that EA may
be under- or overcoded. In addition, the database has limited
information about details of the other nonopioid analgesic
techniques used and postoperative outcomes. Furthermore, it
is not possible to determine from the database which patients
were part of an ERAS program. However, we assessed the practices in the past 2 years because perioperative care is rapidly
changing and implementation of ERAS programs is increasingly becoming popular. Furthermore, the data were collected
only from ACS-NSQIP participating hospitals (many of which
are academic institutions), which may lead to sampling bias.
Details of the ACS-NSQIP database limitations are described
in its Participant Use Data File user guide (10). We assessed the
composite of MCPC because of a smaller number of patients
with individual cardiac and pulmonary complications, which
may not provide clinically useful information. Also, we assessed
the complications in the immediate postoperative period (i.e.,
within 7 days of surgery) because EA is typically used for 3 days
after surgery and any directly related complication would be
recognized within 7 days. Finally, the ﬁndings of this study can
only interpret associations and do not prove causation.
In summary, this study revealed that there was no association between EA and improved postoperative complications
and hospital LOS. Our data provide support for the notion
that EA should not be considered the "gold standard" for pain
management after open colorectal surgery. Future studies are
necessary to compare the outcomes with EA compared with
other multimodal analgesia modalities when implemented in
an ERAS protocol for open colorectal surgery.
1.

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Effects of epidural analgesia on recovery after open colorectal surgery

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http://www.erassociety.org

Table of Contents for the Digital Edition of Baylor University Medical Center Proceedings July 2017