The effect on maternal temperature of delaying initiation of the epidural component of combined spinal-epidural analgesia for labor: a pilot study.

BACKGROUND

Labor epidural analgesia is associated with maternal hyperthermia. This pilot study compared the effects on maternal temperature during labor of different timing of initiation of the epidural component of combined spinal-epidural analgesia.

METHODS

After induction of analgesia with intrathecal bupivacaine 2 mg and fentanyl 20 μg, healthy term nulliparas in spontaneous labor were randomized to receive immediate epidural analgesia (n=26) or delayed epidural analgesia after the return of pain (n=28), by patient-controlled epidural analgesia with 0.125% bupivacaine and fentanyl 1 μg/mL. Maternal tympanic temperature, visual analog scale pain score and dermatome block level were measured hourly during labor.

RESULTS

The duration of labor for most parturients (83.3%) was <5 h. Mean maternal temperature gradually increased over time but did not significantly differ from either from baseline or between the two groups. There was no significant difference in the incidence of maternal fever (≥38°C) between the two groups. At 2 h post spinal analgesia the visual analog scale score was higher (P=0.03) and the dermatome block level was lower (P=0.005) in the delayed epidural analgesia group compared to the immediate epidural analgesia group.

CONCLUSIONS

Delaying the epidural component of combined spinal-epidural analgesia did not significantly affect maternal temperature in the study population of whom 83.3% had a labor of <5 h. However, this study was underpowered to detect a difference in the incidence of fever and a larger prospective study is required.