The effect of epidural fentanyl on the minimum local analgesic concentration of epidural chloroprocaine in labor

Efficacy and Safety of Epidural Chloroprocaine for Breakthrough Pain During Labor Analgesia: A Prospective, Double-Blind, Randomized Trial

INTRODUCTION

A significant number of women who undergo neuraxial labor analgesia experience breakthrough pain. Prompt mitigation of breakthrough pain is essential to improve maternal and fetal outcomes. We evaluated epidural chloroprocaine compared with ropivacaine in alleviating labor breakthrough pain.

METHODS

We performed a double-blind randomized controlled clinical trial between May and July 2023. Eligible parturients received epidural analgesia with ropivacaine and sufentanil. Those with breakthrough pain were randomized to receive either 0.125% epidural ropivacaine (group R) or chloroprocaine at concentrations of 0.5% (group C1), 1.0% (group C2), or 1.5% (group C3), all in a volume of 6 mL. The primary outcome was the treatment success rate, indicated by a decrease of at least 4 points on the numerical rating scale pain score 9 min after analgesic injection. Secondary outcomes and adverse effects were also recorded.

RESULTS

Out of 323 patients receiving epidural analgesia, 192 experienced breakthrough pain. After exclusion of three patients because of protocol deviation, there were 47, 48, 47, and 47 patients in group R, C1, C2, and C3, respectively. Group C3 demonstrated a higher treatment success rate (39/47, 83.0%) in managing breakthrough pain than group R (26/47, 55.3%), group C1 (12/48, 25.0%), and group C2 (30/47, 63.8%) (p < 0.001). Group C3 had lower numerical rating scale scores at 6 and 9 min after injection and required fewer patient-controlled epidural boluses than other groups. In addition, group C3 reported greater satisfaction than the other groups (p < 0.001). No significant differences were observed in obstetric or neonatal outcomes across these groups.

CONCLUSION

Parturients experiencing breakthrough pain could receive 1.5% epidural chloroprocaine, rather than lower chloroprocaine concentrations and ropivacaine, to achieve more rapid and better pain relief with higher patient satisfaction.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2300071069, http://www.chictr.org.cn/index.aspx .

Sparing effects of sufentanil on epidural ropivacaine in elderly patients undergoing transurethral resection of prostate surgery

PURPOSE

This study examined the sparing effect of sufentanil on the median effective concentration (EC₅₀) of epidural ropivacaine in elderly patients undergoing elective transurethral resection of prostate (TURP).

MATERIALS AND METHODS

This was a prospective randomized double-blind dose-response study. Fifty eight elderly patients with American Society of Anesthesiologists physical status I-II who were scheduled for TURP surgery under epidural anesthesia were randomly allocated to a group receiving 15 mL of ropivacaine (group R) or a group receiving ropivacaine plus 5 μg of sufentanil (group RS). The concentration of ropivacaine was determined by a Dixon's up-and-down sequential allocation. The first participant received 0.3% of ropivacaine in both groups and subsequent concentrations were determined by the response of the previous patient in the same group. The EC₅₀ of epidural ropivacaine was analyzed using the Dixon and Massey method.

RESULTS

The EC₅₀ of ropivacaine during TURP surgery was 0.186% (95% confidence interval, 0.173-0.200%) in group R, and 0.136% (95% confidence interval, 0.127-0.144%) in group RS (p<0.01). No differences in Bromage scale of motor block examination and the onset time of sensory block were observed.

CONCLUSION

Administration of 5 μg of epidural sufentanil caused a 37% reduction in the EC₅₀ of epidural ropivacaine in elderly patients who underwent TURP surgery. Thus, sufentanil addition during surgery of TURP can decrease the dose of ropivacaine anesthesia required.

Minimum local anaesthetic dose (MLAD) of intrathecal levobupivacaine and ropivacaine for Caesarean section*

We determined the minimum local anaesthetic dose (MLAD) of spinal levobupivacaine and ropivacaine for Caesarean section. Ninety women were randomly allocated to two groups and received 3 ml of study solution by a combined spinal/epidural technique. The initial dose was 12 mg for levobupivacaine and 17 mg for ropivacaine groups. To be considered effective, a test solution had to achieve a visual analogue pain score (VAPS) of 30 mm or less at skin incision, uterine incision, birth, peritoneal closure, and at the end of surgery. Effective or ineffective responses determined, respectively, a 0.3 mg decrease or increase of the same drug for the next patient in the same group, using up-down sequential allocation. The MLAD of levobupivacaine was 10.58 mg (CI 95%: 10.08-11.09) and the MLAD of ropivacaine 14.22 mg (CI 95%: 13.67-14.77), using the Dixon and Massey formula. The potency ratio between spinal levobupivacaine and spinal ropivacaine was 1.34.