To the Editor:—

We read with interest the recent article by Tsen et al. , 1who showed a more rapid cervical dilation in nulliparous women in labor who received combined spinal–epidural (CSE) sufentanil and bupivacaine (compared with those who received epidural 0.25% bupivacaine). It is interesting to note that, in our previous study, of 70 patients, 2no difference was seen in cervical dilation when comparing a “walking epidural” (40 μg epidural sufentanil after a lidocaine–epinephrine test dose) to a CSE technique (10 μg intrathecal sufentanil). In our study, there was no significant difference in cervical dilation at time of subsequent dose (5.6 ± 1.6 in the epidural group vs.  5.5 ± 1.8 in the CSE group), nor was there a difference in the time from analgesic administration to full cervical dilation (295 ± 160 min in the epidural group vs.  297 ± 155 min in the CSE group). This was specifically for patients who received epidural analgesia in the latent phase of labor.

Perhaps it is not the CSE technique that is associated with a more rapid cervical dilation; rather, it may be that administering high (0.25%) concentrations of local anesthetic (0.25% bupivacaine) to nulliparous patients is associated with slower cervical dilation.

For the past 10 yr, we have rarely administered any labor epidural with 0.25% bupivacaine; our most common “local anesthetic” epidural is 0.1% bupivacaine with 3 μg/ml fentanyl. Perhaps the results of Tsen et al.  1would have been different if they had used a lower concentration of epidural bupivacaine or if their epidural technique had consisted of opioid without bupivacaine.

Tsen LC, Thue B, Datta S, Segal S: Is combined spinal-epidural analgesia associated with more rapid cervical dilation in nulliparous patients when compared with conventional epidural analgesia? A nesthesiology 1999; 91:920–5.
Dunn SM, Connelly NR, Steinberg RB, Lewis TJ, Bazzell M, Klatt JL, Parker RK: Intrathecal sufentanil versus epidural lidocaine with epinephrine and sufentanil for early labor analgesia. Anesth Analg 1998; 87:331–5.