Epidural volume extension in combined spinal epidural anaesthesia for elective caesarean section: a randomised controlled trial

We investigated the effect of epidural volume extension on spinal blockade in pregnant women undergoing elective caesarean section with a combined spinal‐epidural technique. We randomly allocated 90 healthy subjects to three groups to receive spinal hyperbaric bupivacaine 7.5 mg (group B7.5), spinal hyperbaric bupivacaine 7.5 mg immediately followed by epidural volume extension with saline 5 ml (group B7.5‐EVE) or spinal hyperbaric bupivacaine 10 mg without epidural volume extension (group B10). We evaluated the height of the block every 5 min for 15 min following the spinal injection. The overall sensory block level increased with time (p < 0.001), regardless of the group studied, and there were significantly fewer failures of block in the group B10 compared with both B7.5 and B7.5‐EVE groups (p = 0.001). In conclusion, we could not demonstrate a benefit in using epidural volume extension with 5 ml saline as part of a combined spinal epidural technique in term parturients undergoing elective caesarean section.