Page 42 - Journal of World Association of Laparoscopic Surgeons

Pain Relief After LVHR
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statement where possible. Two authors (JR and VA) independently SD measures were attempted based on the methods described in
performed electronic searches of four databases (MEDLINE, EMBASE, the Cochrane Handbook of Systematic Reviews of Interventions,
Cochrane Central Register of Controlled Trials, and Google Scholar). where attempts to contact authors for clarification were
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With the assistance of a subject librarian, the first author (JR) collated unsuccessful (up to two emails).
a list of keywords and search terms to incorporate them into the
strategies adapted for each database. The search terms combined Risk of Bias Assessment
the concepts of LA, LVHR, post-operative pain, and morphine The Cochrane Collaboration tool for assessing risk of bias was
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consumption (Table 1). Results were limited to adults (>18 years) implemented and generated by RevMan 5.1. Two reviewers (JR
and randomized controlled trials (RCT). No other limitations were and LP) independently assessed the methodological quality of
applied. Search results were downloaded and managed with trials for sequence generation, allocation concealment, blinding
RefWorks citation management software (ProQuest LLC, USA). of participants and personnel, blinding of outcome assessment,
incomplete outcome data, selective reporting, lost to follow-up,
Study Selection intention-to-treat, and financial conflicts.
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Abstracts were screened and full-text papers obtained to identify
primary research studies reporting the effectiveness of the review results
addition of LA techniques in reducing pain scores and morphine The literature search identified 637 records in the initial database
consumption in the first 24 hours following LVHR. All published search. A PRISMA flow diagram for the systematic review is
studies comparing LA modalities for post-operative pain relief presented in Flowchart 1. Four RCT met the inclusion criteria
following LVHR by randomized trial were included. The primary and were included in the review. All four studies compared
29–32
outcomes of interest were pain scores at rest and total morphine bupivacaine with normal saline and only one of these studies used
consumption in the first 24 hours following LVHR. Exclusion bupivacaine with epinephrine (Table 2). All studies were classified as
criteria included nonrandomized studies, pediatric studies, and having a low risk of bias (Fig. 1). Variations in the timing of outcome
those articles for which full-text publications were not available measures, the duration and type of the intervention and the study
(e.g., conference abstracts). Three reviewers (JR, LP, and VA) cohorts limited meaningful synthesis of the data. The data are
independently performed the searches and examined titles and therefore presented as a narrative review.
abstracts to exclude irrelevant reports and produce a list of studies
for full-text review in an iterative process. Any disagreement Pain Scores
over inclusion or exclusion was discussed with the senior author There was variation in the types of post-operative pain-scoring
(AGH) and a consensus reached. Additional articles and abstracts questionnaires used in the included studies. Two studies utilized
were retrieved by manually examining reference lists of relevant visual analog scores (VAS), one study used a numerical rating
29,30
publications. The last search was performed on June 19, 2018. scale (NRS), and the remaining study used VAS and present pain
31
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intensity (PPI) scores. Only one trial, the largest of the included
Data Extraction studies, demonstrated a statistically significant difference in pain
Data extraction for morphine consumption and pain scores in the scores at 24 hours. This trial was assessed as having a low risk of
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first 24 hours was performed independently by two reviewers bias and bupivacaine was comparedwith saline using a laparoscopic
(JR and VA) and entered into predesigned electronic tables. Data transverse abdominis plane (TAP) block and only a very small
were reported as mean ± standard deviation (SD) where possible. difference (0.08 mg) was noted in pain scores, which is unlikely
Morphine consumption within the first 24 hours following to be clinically significant. However, a statistically and clinically
surgery was reported as morphine equivalents where possible significant difference in morphine consumption clearly favored
and as reported by individual trials. The median score was used the TAP block with bupivacaine (see below). Three trials showed a
as an estimate of the mean where the latter was not reported. significant reduction in the reported pain scores at the one-hour
mark, of which two reached statistical significance in favor of the
Table 1: Search strategy used in OVID Medline® in-process and other intervention group at one hour post-surgery.
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non-indexed citations (search strategy was modified as required for each
database used. exp. exploded MeSH term, mp key word, mt methods) Morphine Consumption
Search terms Three of the four included studies demonstrated decreased
(postoperat* or post-operat* or postoperative pain or postoperative morphine consumption in the intervention group at 24 hours, of
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pain or pain*).mp which only one reached statistical and clinical significance. The
and remaining study reported a statistically insignificant increase in
exp. analgesics, opioid/or placebo.mp or morphine.mp or opiate*. morphine use in the intervention group at 24 hours following LVHR
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mp or opioid*.mp or analg*.mp and did not provide a measure of variance.
and Complications and Adverse Effects
Anesthesia, local/mt or local anesth*.mp or local anesth* or There were no reports of adverse events following the application
ropivacaine.mp or bupivacaine.mp or lidocaine.mp or lignocaine. of LA interventions. None of the trials reported plasma levels of LA
mp or procaine.mp agents. Only one study reported a major complication: a single case
and of mesh infection with methicillin-resistant Staphylococcus aureus
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.
“laparoscopic ventral hernia repair”.mp or exp. hernia, ventral/
mt OR ventral hernia.mp. discussion
and This systematic review includes four trials comparing various
exp. laparoscopy/mt or laparoscop*.mp or endoscop*.mp bupivacaine interventions to usual/standard care or a saline control

34 World Journal of Laparoscopic Surgery, Volume 12 Issue 1 (January–April 2019)