Elective Umbilical Hernia Repair: Outcomes of postoperative Pain in Adults after local Wound Infiltration or ultrasound-guided bilateral REctus Sheath block. (EUHROPA WIRES trial)

Elective umbilical hernia repair (EUHR) is a commonly performed procedure in
adults. A nationwide register-based study in Denmark [Burcharth, et al. 2015]
reported that, over the 5-year period from January 1st 2006 until December 31st
2010, from a total of 5,639,885 people, 10,107 patients underwent umbilical
hernia repair. Males aged 60-70 years were found to have the highest 5-year
prevalence 0.53% (95% CI 0.51-0.56%). [Burcharth, et al. 2015] At the Máxima
Medical Center (MMC) Veldhoven-Eindhoven, a total of 83 and 111 EUHR were
performed in respectively 2013 and 2014.
EUHR in adults is generally perceived as a minor procedure and mostly scheduled
as day care surgery, with exceptions made depending on the patients* individual
health status. A subset of day care patients, however, requires prolonged
hospital length of stay (LOS), with pain being reported as the main reason (27%
of cases), followed by major complications (19%) and seroma formation (9%).
[Helgstrand, et al. 2011] Gerbershagen and colleagues conducted a large
prospective cohort study including 70,765 adult patients, to investigate pain
intensities during the first postoperative day for a broad range of surgical
procedures. [Gerbershagen, et al. 2013] With respect to EUHR they report
estimated mean pain intensities of NRS 4.73 and 4.20, for respectively a
laparoscopic and open approach. [Gerbershagen, et al. 2013] As a reference,
according to the local recovery and hospital discharge criteria at the MMC,
patients need to have their postoperative pain levels controlled to a level of
*acceptable pain*, which is generally comparable to an NRS of *3 by
anesthesiologists. [NICE guideline: Ultrasound-guided regional nerve block.
2009.]
From an anesthesiologists* perspective, pain is therefore also the most
important factor to improve, to contribute to better patient and healthcare
outcomes with respect to EUHR.
At the MMC, current management of postoperative pain following EUHR as day care
surgery involves intravenous non-opioid and short-acting opioid analgetics
peroperatively, combined with LWI with long-acting local anaesthetic (LA) by
the surgeon at the end of the procedure. In the postoperative period the
intravenous non-opioid analgetics are continued via the oral route, while the
intravenous short-acting opioid analgetics are switched to oral opioid
analgetics, to allow same-day discharge. During the last decades, the combined
use of ultrasound guidance and neurostimulation, by means of echogenic needles
with neurostimulatory properties, has resulted in a subset of techniques that
allow delivery of LA to strategic locations with high precision. [NICE
guideline: Ultrasound-guided regional nerve block. 2009.] As a counterpart of
LWI, these techniques are nowadays referred to as LRA. Important advantages of
these techniques are (i) the ability to continuously visualize the needle
point, minimalizing the risk of nerve damage or LA injection into the
bloodstream; (ii) increased success rate with respect to analgetic effectivity;
(iii) the ability to lower total administered doses of LA without decreasing
analgesic effectivity, which decreases the risk of LA toxicity. [NICE
guideline: Ultrasound-guided regional nerve block. 2009.] Disadvantages of LRA
are the expensive ultrasound equipment needed, and the long training period to
master the skills to administer LRA. [Baldi, et al. 2007.] So far, literature
reports very low rates of morbidity and mortality associated with LRA,
underlining the safety of these techniques. [NICE guideline: Ultrasound-guided
regional nerve block. 2009.] With respect to EUHR and its associated
postoperative pain, interest has risen in the effectiveness of the USBRSB to
improve postoperative analgesia for this surgical procedure. The USBRSB is one
of the LRA. It specifically involves ultrasound-guided injection of LA
bilaterally into the tendon sheath of the rectus abdominis muscle.
So far, only a limited number of studies have compared the analgesic
effectiveness of the USBRSB with LWI in EUHR. All of these studies have been
performed in paediatric patients and results are contradictory. [Dingeman, et
al. 2013; Gurnaney, et al. 2011; Isaac, et al. 2006; Charlton, et al. 2010]
The current study protocol investigates USBRSB versus LWI with respect to
postoperative pain following EUHR repair in adults, with the aim of decreasing
both patient and healthcare burden in this patient population. We hypothesize
that USBRSB with a long-acting LA, through its highly specific delivery into
the rectus sheath compartment, is superior to LWI in terms of duration of low
pain intensity (NRS *3).

To determine the reduction in pain after elective umbilical hernia repair
(EUHR) in adult patients when using an ultrasound-guided bilateral rectus
sheath block (USBRSB) versus local wound infiltration (LWI).

Double-blinded, randomized controlled trial (RCT) in a single center
non-university hospital in The Netherlands.

In the intervention group, after induction of general anesthesia (GA) and
before surgical incision, patients receive an ultrasound-guided bilateral
rectus sheath block with 20 ml ropivacaine 0.75% by an experienced
anesthesiologist (in-training). In the control group, patients receive local
wound infiltration with 20 ml ropivacaine 0.75% by the surgeon (in-training) at
the end of surgery.

Rectus sheath block under ultrasound guidance allows to continuously visualise
the needle tip which, according to previous studies, translates into a safe
performance of locoregional anesthesia (LRA). Literature reports a very low
incidence of adverse events (AE) and serious adverse events SAE related to
USBRSB. Patients receive the rectus sheath block or LWI under GA. During the
postoperative period patients will be asked to fill out a short questionnaire
(max 5 min) at four time points (3, 6, 12 and 24 hours postoperatively) with
respect to their pain intensity, use of analgesics and possible PONV. The
expected benefit is a decrease in incidence of moderate-to-severe pain (NRS >3)
after EUHR.