An evidence based systematic review of remifentanil associated opioid-induced hyperalgesia

Introduction: Therapeutic opioid use continues to grow, with greater than a fivefold increase in usage of fentanyl-based products over a 10-year period. Opioids are known for their side-effect profile, including bradycardia and respiratory depression; questions remain, however, regarding lesser known side effects such as opioid-induced hyperalgesia (OIH). Areas covered: A systematic review of published literature addressing remifentanil OIH in the surgical setting was completed. A search was conducted of PubMed, Embase and Ovid from 1946 until June 2013. Inclusion criteria consisted of age 18 years, humans, full-text articles and English language. A total of 35 unique articles were included. Sixteen articles reported outcomes that supported remifentanil OIH and 6 that refuted and 22 were focused on prevention. Expert opinion: There is conflicting evidence regarding the existence of remifentanil OIH. Outcomes evaluating measures of hyperalgesia frequently conclude that remifentanil OIH exists, while those evaluating opioid consumption do not. Therefore, remifentanil does induce a degree of hyperalgesia, but we do not believe that it reaches a level of clinical significance that requires prevention. If a significant concern for the development of remifentanil OIH is suspected, we suggest using the least possible effective dose of remifentanil as the primary prevention strategy.