Abstract: Objective To evaluate the safety and efficacy of intravenous dexmedetomidine(Dex) infusion for epidural-related maternal fever during labor analgesia. 
Methods A total of 192 term laboring nulliparous women, with a singleton fetus in vertex presentation, were randomly allocated into two groups. 97 cases of primiparas were received an intravenous Dex infusion of 0.4 μg·kg-1·h-1 following epidural analgesia initiation, discontinued at full cervical dilatation as the experimental group(Group D), and 95 cases of primiparas were received an intravenous normal saline infusion of equivalent volume following epidural analgesia initiation, discontinued at full cervical dilatation as the control group(Group C). Maternal tympanic temperature, febrile rate, visual analogue scale(VAS) and Ramsay sedation scale were evaluated at the initiation of analgesia, 1, 2, 3, 4 h post analgesia and parturition. Blood samples were obtained before analgesia and at parturition to detect maternal serum interleukin-6(IL-6) and interleukin-1β(IL-1β) levels. The analgesic consumption, analgesic time, neonatal umbilical artery lactate levels, Apgar scores, labor duration, delivery mode, oxytocin dosage, postpartum hemorrhage and adverse effects were also recorded. 
Results Maternal tympanic temperature increased progressively in two groups as analgesic time increased(P＜0.05).  Primiparas in group D had a lower tympanic temperature at 4 hours post analgesia and at parturition compared with group C(P＜0.05). The febrile rate of parturient in group D was lower than that in the group C at parturition(P＜0.05). Maternal Ramsay sedation scale increased in two groups after labor analgesia(P＜0.05). Primiparas in group D had a higher Ramsay sedation scale at 4 hours post analgesia and at parturition compared with group C(P＜0.05). VAS decreased significantly in two groups after labor analgesia(P＜0.05). Serum IL-1β and IL-6 levels showed a highly significant rise in two groups, serum IL-6 levels decreased in group D at parturition compared with that in group C(P＜0.05). Primiparas in group D had less analgesic consumption and a low incidence of urinary retention than that in group C(P＜0.05). There were no difference between two groups in VAS at same time-points, analgesic time, labor duration, delivery mode, oxytocin dosage, postpartum hemorrhage, neonatal Apgar scores and umbilical artery lactate levels(P＞0.05). 
Conclusion Intravenous Dex infusion during labor analgesia is effective and safe in attenuating epidural-related maternal fever through alleviating IL-6 production and reducing anaesthetic requirments. 

Key words: dexmedetomidine, labor analgesia, fever