Pharmacological interventions for improving the postoperative pain
intensity in adults after opioid-based anesthesia: a systematic review
and network meta-analysis
Abstract
Background: Opioid-induced hyperalgesia (OIH) is an adverse event after
exposure to opioids which would increase pain intensity. The optimal
drug to prevent these adverse effects is still unclear. We aimed to
perform a network meta-analysis to compare different pharmacological
interventions in preventing the increase in postoperative pain caused by
OIH. Methods: Several databases were searched independently for
randomized-controlled trials (RCTs) comparing different pharmacological
interventions in preventing OIH. The primary outcomes were postoperative
pain intensity at rest at 24h and the incidence of postoperative nausea
and vomiting (PONV). Secondary outcomes included pain thresholds at 24h
after surgery, cumulative morphine consumption over 24h, time to first
postoperative analgesic requirement, and the incidence of shivering.
Results: In all, 33 RCTs comprising 1711 patients were identified. In
terms of postoperative pain intensity, amantadine, magnesium sulphate,
pregabalin, dexmedetomidine, ibuprofen, flurbiprofen plus
dexmedetomidine, parecoxib, parecoxib plus dexmedetomidine, and S
(+)-ketamine plus methadone were associated with milder pain intensity
than placebo, with amantadine ranked the most effective (SUCRA values
=96.2). In terms of the incidence of PONV, intervene with
dexmedetomidine or flurbiprofen plus dexmedetomidine means a lower
incidence placebo and dexmedetomidine showed the best result (SUCRA
values =90.3). Conclusions: Amantadine was identified as the best in
postoperative pain intensity as well as non-inferior to placebo in the
incidence of PONV. Dexmedetomidine was the only intervention that is
superior to placebo in all indicators.