Intrathecal labor analgesia using levobupivacaine 2.5 mg with fentanyl 25 microg--would half the dose suffice?

This randomized, double-blinded, controlled trial of 40 patients in early labor was conducted to determine whether a reduction in the total amount of intrathecal levobupivacaine and fentanyl would reduce the incidence of motor blockade and pruritus, respectively.

Combined spinal epidural (CSE) analgesia was instituted. Group A (n=20) received 2.5 mg levobupivacaine with 25 microg fentanyl intrathecally while group B (n=20) received half that dose.

The duration and quality of spinal analgesia were comparable in the 2 groups. There was a reduced incidence of motor blockade in patients from Group B (P<0.01). This was apparent 5 minutes after the spinal injection and persisted throughout the next 30 minutes. However, there were also 2 parturients from this group who required epidural supplementation as a result of partial analgesia. Other side effects were not different between the 2 groups.

A reduction in the intrathecal dose of 2.5 mg levobupivacaine with 25 microg fentanyl by half is an option for CSE in labor because it can reduce the incidence of motor impairment. Although the reduced dose does not differ significantly from the full dose with respect to onset, duration, and quality of analgesia for the majority of parturients, it must be highlighted that insufficient labor analgesia may occur in certain individuals. In this respect, further studies related to dosage of intrathecal levobupivacaine in obstetric labor analgesia will be beneficial in substantiating this point.