A systematic review of adjuncts for intravenous regional anesthesia for surgical procedures

To review the use of adjuncts to intravenous regional anesthesia (IVRA) for surgical procedures in terms of their intraoperative effects (efficacy of block and tourniquet pain) and postoperative analgesia.A systematic search (Medline, Embase, reference lists) for randomized, controlled and double-blinded studies using adjuncts to IVRA for surgical procedures was conducted. Data were collected on intraoperative effects (onset/offset and quality of block and tourniquet pain), postoperative effects (pain intensity and analgesic consumption) and side effects recorded. Statistical significance as indicated in the original report and likely clinical relevance were taken into account to arrive at a judgment of overall benefit.Twenty-nine studies met all inclusion criteria. Data on 1,217 study subjects are included. Adjuncts used were opioids (fentanyl, meperidine, morphine, sufentanil), tramadol, non-steroidal anti-inflammatory drugs (NSAIDs; ketorolac, tenoxicam, acetyl-salicylate), clonidine, muscle relaxants (atracurium, pancuronium, mivacurium), alkalinization with sodium bicarbonate, potassium and temperature. There is good evidence to recommend NSAIDs in general and ketorolac in particular, for improving postoperative analgesia. Clonidine 1 microg/kg also appears to improve postoperative analgesia and prolong tourniquet tolerance. Opioids are poor by this route; only meperidine 30 mg or more has substantial postoperative benefit but at the expense of postdeflation nausea, vomiting and dizziness. Muscle relaxants improve intraoperative motor block and aid fracture reduction.Using NSAIDs or clonidine as adjuncts to IVRA improves postoperative analgesia and muscle relaxant improves motor block.