Preventive Effect Of Subcutaneous Naloxone For Neuraxial Morphine-induced Pruritus

Objective:To investigate the effects of subcutaneous naloxone for the treatment of neuraxial morphine-induced pruritus.Methods:Sixty patients (20-40yr, American Society of Anesthesiologists physical status I or II) undergoing elective ceaserean section received spinal anesthesia with 0.5% bupivacaine l0mg and morphine 0.2mg. At the end of operation they were randomly assigned to receive either naloxone 0.8mg subcutaneous injection (group A) or the equal volume saline subcutaneous injection (group B). Pain scores, comfort scores and pruritus scores were assessed 6h and 24h respectively after surgery by a blinded investigator.Results:VAS and BCS at 6h and 24 h after surgery showed no significant differences between the two groups. No differences in pain or sedation scores were found. Pruritus score at 6h after surgery was lower in group A than group B(P<0.05). Pruritus score at 24h after surgery was similar between the two groups.Conclusions:This study suggests that subcutaneous naloxone 0.8mg can effectively prevent the neuraxial morphine-induced pruritus. Moreover, no deterioration in postoperative analgesia could be found.