No difference in analgesic efficacy between uniport and multiport wire-reinforced flexible catheters for labor epidural analgesia (LEA) was seen in a randomized controlled trial published in Anesthesia & Analgesia.1
John Philip, MD, from the Department of Anesthesia at Baylor All Saints Medical Center, Fort Worth, Texas, and colleagues evaluated the efficacy of multiports for LEA, using wire-reinforced flexible catheters. Researchers randomly assigned 592 women undergoing spontaneous or induced labor to receive LEA, using an open-tip uniport flexible catheter or a closed-tip multiport flexible catheter.
LEA was administered as 15 mL 0.1% bupivacaine plus fentanyl 2 μg/mL over the course of a 5-minute period. Analgesia adequacy 30 minutes after LEA was the trial’s primary outcome and was assessed using the visual analog score (VAS) pain score on a 10-cm scale. Adequate analgesia was defined as “the satisfactory relief of pain during contractions, as reported by the patient, without the need for catheter manipulation and/or further epidural medication.” Study participants also received patient-controlled epidural analgesia for the maintenance of LEA.
Secondary outcomes consisted of the number of patients needing clinical interventions throughout LEA maintenance, anesthetic success, and maternal satisfaction regarding the quality of LEA.
VAS pain scores at LEA initiation were similar between the 2 groups (7.7 cm ± 2.0 for uniport vs 7.6 cm ± 2.0 for multiport; standardized difference, 0.020). Analgesic adequacy at LEA initiation was successful in 93.6% of patients in the uniport group and 89.5% of patients in the multiport group (4.1% difference; 95% Cl, −0.4% to 8.5%; P =.077).
Secondary outcome measurements were also similar in both groups. Clinician intervention during LEA maintenance was required in 14.2% of patients in the uniport group and 18.9% of patients in the multiport group (−4.7% difference; 95% Cl, −10.7% to 1.2%, P =.122). Eighty percent of the patients in the uniport group reached anesthetic success vs 81.5% of the patients in the multiport group (−1.5% difference; 95% Cl, −16.7% to 13.7%, P =.848).
Maternal satisfaction with LEA quality was higher in the uniport group (89.9%) than in the multiport group (83.4%); however, this analysis includes data that were unavailable for 32 patients. When excluding the unavailable data, maternal satisfaction remained similar in both groups (92.7% vs 90.5%, uniport vs multiport catheter groups, respectively).
“Our findings demonstrate the presence of multiports in flexible catheters may not provide additional analgesic benefit,” concluded Dr Philip. “[A]lthough multiport catheters are designed to facilitate multidirectional flow of epidural solution…multiport catheters may clinically behave like uniport catheters.”
- Although research personnel collecting data were blinded, clinicians inserting and removing the catheters could not be blinded to catheter type, which may have introduced a bias.
- The primary outcome was based on self-reported patient data, which may lack precise measurement and may affect reproducibility.
- A larger study population would help determine whether the observed difference using uniport vs multiport flexible catheters yields statistically significant differences in analgesic success.
- A potentially confounding variable may have been introduced as the study included women of “mixed parity in spontaneous and induced labor,” which differ in characteristics of labor and associated pain.
Philip J, Sharma SK, Sparks TJ, Reisch JS. Randomized controlled trial of the clinical efficacy of multiport versus uniport wire-reinforced flexible catheters for labor epidural analgesia. Anesth Analg. 2017. doi: 10.1213/ANE.0000000000002359. [Epub ahead of print]