Authors: Chau, Anthony MD, MMSc, FRCPC et al
Anesthesia & Analgesia: February 2017 – Volume 124 – Issue 2 – p 560–569
Obstetric Anesthesiology: Original Clinical Research Report
BACKGROUND: The dural puncture epidural (DPE) technique is a modification of the combined spinal epidural (CSE) technique, where a dural perforation is created from a spinal needle but intrathecal medication administration is withheld. The DPE technique has been shown to improve caudal spread of analgesia compared with epidural (EPL) technique without the side effects observed with the CSE technique. We hypothesized that the onset of labor analgesia would follow this order: CSE > DPE > EPL techniques.
METHODS: A total of 120 parturients in early labor were randomly assigned to EPL, DPE, or CSE groups. Initial dosing for EPL and DPE consisted of epidural 20 mL of 0.125% bupivacaine plus fentanyl 2 μg/mL over 5 minutes, and for CSE, intrathecal 0.25% bupivacaine 1.7 mg and fentanyl 17 μg. Upon block completion, a blinded coinvestigator assessed the outcomes. Two blinded obstetricians retrospectively interpreted uterine contractions and fetal heart rate tracings 1 hour before and after the neuraxial technique. The primary outcome was time to numeric pain rating scale (NPRS) ≤ 1 analyzed by using Kaplan-Meier curves and Cox proportional hazard model. Secondary outcomes included block quality, maternal adverse effects, uterine contraction patterns, and fetal outcomes analyzed by using the χ2 test with Yates continuity correction.
RESULTS: There was no significant difference in the time to NPRS ≤ 1 between DPE and EPL (hazard ratio 1.4; 95% confidence interval [CI] 0.83–2.4, P = .21). DPE achieved NPRS ≤ 1 significantly slower than CSE (hazard ratio 0.36; 95% CI 0.22–0.59, P = .0001). The median times (interquartile range) to NPRS ≤ 1 were 2 (0.5–6) minutes for CSE, 11 (4–120) minutes for DPE, and 18 (10–120) minutes for EPL. Compared with EPL, DPE had significantly greater incidence of bilateral S2 blockade at 10 minutes (risk ratio [RR] 2.13; 95% CI 1.39–3.28; P < .001), 20 minutes (RR 1.60; 95% CI 1.26–2.03; P < .001), and 30 minutes (RR 1.18; 95% CI 1.01–1.30; P < .034), a lower incidence of asymmetric block after 30 minutes (RR 0.19; 95% CI 0.07–0.51; P < .001) and physician top-up intervention (RR 0.45; 95% CI 0.23–0.86; P = .011). Compared with CSE, DPE had a significantly lower incidence of pruritus (RR 0.15; 95% CI 0.06–0.38; P < .001), hypotension (RR 0.38; 95% CI 0.15–0.98; P = .032), combined uterine tachysystole and hypertonus (RR 0.22; 95% CI 0.08–0.60; P < .001), and physician top-up intervention (RR 0.45; 95% CI 0.23–0.86; p = .011).
CONCLUSIONS: Analgesia onset was most rapid with CSE with no difference between DPE and EPL techniques. The DPE technique has improved block quality over the EPL technique with fewer maternal and fetal side effects than the CSE technique for parturients requesting early labor analgesia.