Comparing Spinal, Epidural, and Dural Puncture Epidural Anesthesia for Cesarean Delivery: Hemodynamics and Block Quality

Background: Spinal anesthesia is the most commonly used technique for cesarean delivery and provides a rapid, dense block; however, the sudden sympathetic blockade leads to maternal hypotension in up to 70-80% of cases, which may reduce uteroplacental blood flow and compromise the fetus. Conventional epidural anesthesia offers greater hemodynamic stability but has a slower onset and may result in patchy or inadequate block. The dural puncture epidural (DPE) technique, in which the dura is punctured with a spinal needle without intrathecal drug injection before epidural catheter placement, may facilitate translocation of epidural drugs into the intrathecal space, potentially combining a faster onset with hemodynamic stability. Existing studies show considerable methodological heterogeneity, and few trials have compared all three techniques simultaneously under a standardized protocol.

Design: This is a single-center, prospective, randomized controlled trial with three parallel arms. After written informed consent, 120 parturients scheduled for elective cesarean delivery will be randomized in a 1:1:1 ratio using a computer-generated sequence and sequentially numbered sealed envelopes on the morning of surgery to one of the following groups:

• Group S (Spinal): Intrathecal 10 mg 0.5% hyperbaric bupivacaine + 10 mcg fentanyl.
• Group E (Epidural): Epidural catheter placement followed by a test dose and 15-20 mL of local anesthetic solution (10 mL 0.5% isobaric bupivacaine + 50 mcg fentanyl + 5 mL 2% lidocaine + 4 mL normal saline).
• Group DPE (Dural Puncture Epidural): Dural puncture with a 27G atraumatic spinal needle without intrathecal drug administration, followed by epidural catheter placement, test dose, and the same epidural solution as Group E.

In Groups E and DPE, if bilateral T6 sensory block is not achieved within 10 minutes, 5 mL of 0.25% bupivacaine will be administered every 5 minutes up to a cumulative maximum of 30 mL. Patients who fail to achieve adequate block or require conversion to general anesthesia will be excluded from the study.

All blocks will be performed by an experienced anesthesiologist not involved in data collection. All patients will receive standardized intravenous hydration.

Measurements: Baseline values will be recorded before the neuraxial block. Non-invasive blood pressure, heart rate (ECG), and SpO2 will be recorded every 3 minutes for the first 20 minutes after completion of the block and every 5 minutes thereafter until the end of surgery. Shock index (heart rate / systolic blood pressure) and diastolic shock index (heart rate / diastolic blood pressure) will be calculated. Hypotension is defined as a decrease in mean arterial pressure of more than 20% from baseline or systolic blood pressure below 90 mmHg and will be treated with intravenous ephedrine boluses; bradycardia is defined as heart rate below 50 beats/min and will be treated with atropine. Sensory block will be assessed bilaterally with pin-prick and cold tests, and motor block with the modified Bromage scale. Neonatal outcomes will be assessed with 1- and 5-minute Apgar scores and umbilical cord blood gas analysis. Maternal satisfaction, side effects, and post-dural puncture headache will be evaluated at the postoperative 24-hour visit. Patients will also be contacted by telephone on postoperative day 3 to assess post-dural puncture headache.

Sample size: Based on an expected hypotension incidence of 65% after spinal anesthesia and 30% after epidural and DPE techniques, a sample size of 34 patients per group was calculated (effect size w = 0.33, α = 0.05, power = 80%, G*Power 3.1.9.7). Allowing for a 15% dropout rate, 40 patients per group (120 in total) will be enrolled.

Statistical analysis: Data will be analyzed using SPSS v26.0. Normality will be assessed with the Shapiro-Wilk test. Normally distributed data will be presented as mean ± standard deviation, and non-normally distributed or ordinal data as median (minimum-maximum). One-way ANOVA or Kruskal-Wallis tests will be used to compare the three groups, followed by Tukey or Dunn post-hoc tests, respectively. Chi-square or Fisher's exact tests will be used for categorical variables, and repeated measures ANOVA for time-dependent hemodynamic changes. A p value < 0.05 will be considered statistically significant.