Intra‐operative analgesia with remifentanil vs. dexmedetomidine: a systematic review and meta‐analysis with trial sequential analysis

Abstract

Intra-operative remifentanil is associated with increased postoperative analgesic requirements and opioid consumption. Dexmedetomidine has characteristics suggesting it may substitute for intra-operative remifentanil during general anaesthesia, but existing literature has reported conflicting results. We undertook this meta-analysis to investigate whether general anaesthesia including dexmedetomidine would result in less postoperative pain than general anaesthesia including remifentanil. The MEDLINE and PubMed electronic databases were searched up to October 2018. Only randomised trials including patients receiving general anaesthesia and comparing dexmedetomidine with remifentanil administration were included. Meta-analyses were performed mostly employing a random effects model. The primary outcome was pain score at rest (visual analogue scale, 0-10) at two postoperative hours. The secondary outcomes included: pain score at rest at 24 postoperative hours; opioid consumption at 2 and 24 postoperative hours; and rates of hypotension, bradycardia, shivering and postoperative nausea and vomiting. Twenty-one randomised trials, including 1309 patients, were identified. Pain scores at rest at two postoperative hours were lower in the dexmedetomidine group, with a mean difference (95%CI) of À0.7 (À1.2 to À0.2), I 2 = 85%, p = 0.004, and a moderate quality of evidence. Secondary pain outcomes were also significantly better in the dexmedetomidine group. Rates of hypotension, shivering and postoperative nausea and vomiting were at least twice as frequent in patients who received remifentanil. Time to analgesia request was longer, and use of postoperative morphine and rescue analgesia were less, with dexmedetomidine, whereas episodes of bradycardia were similar between groups. There is moderate evidence that intra-operative dexmedetomidine during general anaesthesia improves pain outcomes during the first 24 postoperative hours, when compared with remifentanil, with fewer side effects.

A randomised controlled trial of the pectoral nerves‐2 (PECS‐2) block for radical mastectomy

“…dexamethasone [12]. A possible mechanism might be secondary hyperalgesia [17,18], but this needs further research to confirm this hypothesis.…”

Acute postoperative pain management

“…The α‐2 receptor agonists clonidine and dexmedetomidine can be administered orally (clonidine only), intravenously, intrathecally, perineurally or via a transdermal patch, and have been used both during and after operation. Although they are associated with reduced opiate use and duration of nerve blocks, their benefit is offset by sedation and hypotension. In view of the haemodynamic effects, postoperative α‐2 agonist infusion would necessitate admission to a high‐dependency area in most UK centres.…”

Effect of Dexmedetomidine and Remifentanil on Renal Function in Patients Undergoing Bariatric Surgery

“…In addition, intraoperative remifentanil is associated with increased postoperative analgesic needs and consumption of opioids [1]. Dexmedetomidine has characteristics suggesting that it can replace intraoperative remifentanil during general anesthesia, but the existing literature has reported conflicting results.…”

“…The time to request analgesia was longer, and the use of postoperative morphine and rescue analgesia was shorter, with dexmedetomidine, while episodes of bradycardia were similar between groups. There is moderate evidence that intraoperative dexmedetomidine during general anesthesia improves pain results during the first 24 hours after surgery when compared to remifentanil, with fewer side effects [1].…”

“…In obese patients, the distribution of anesthetics occurs in the fatty peripheral compartment, which is increased, delaying recovery from anesthesia [1]. Based on this information, the choice of substances with faster recovery, less production of active metabolites and predictable elimination are recommended for anesthesia in bariatric surgeries [2].…”