超声实时引导技术对分娩镇痛有效性和安全性的影响

实验性的：超声实时引导联合硬脑膜穿刺硬膜外组

超声实时引导联合硬脑膜穿刺硬膜外麻醉可提高分娩镇痛的临床效果。

设备：超声实时引导联合硬脑膜穿刺硬膜外分娩镇痛

超声实时引导技术在通过操作可视化进行椎间隙定位的准确性、成功率、减少穿刺损伤等方面较传统盲目探查技术具有很大优势，大大提高了脊柱阻滞的有效性和安全性。

有源比较器：硬脑膜穿刺硬膜外组

硬脑膜穿刺硬膜外麻醉是脊髓硬膜外联合麻醉的临床改进，广泛应用于产妇。 实施步骤是完成硬膜外穿刺，暂时不置管，用蛛网膜下腔麻醉针刺破硬膜，但不要直接将药物注入蛛网膜下腔，然后按照硬膜外阻滞留下硬膜外导管给药。

设备：硬脑膜穿刺硬膜外分娩镇痛

硬脑膜穿刺硬膜外麻醉是脊髓硬膜外联合麻醉的临床改进，广泛应用于产妇。 实施步骤是完成硬膜外穿刺，暂时不置管，用蛛网膜下腔麻醉针刺破硬膜，但不要直接将药物注入蛛网膜下腔，然后按照硬膜外阻滞留下硬膜外导管给药。

Composite endpoint of labor analgesia outcome

The primary outcome is a binary composite endpoint: "satisfactory" (Grades I-II) versus "unsatisfactory" (Grades III-IV). Grading followed a hierarchical rule (IV > III > II > I): if more than one grade applied, the highest (worst) was assigned.

Grade I (best): vaginal delivery (spontaneous or instrumental) with analgesic onset ≤ 20 min, mean VAS ≤ 40 mm, no catheter or protocol adjustment, and modified Bromage score < 2.

Grade II (good): vaginal delivery not meeting Grade I criteria but with onset ≤ 30 min, mean VAS ≤ 60 mm, and no Grade IV-listed complications.

Grade III (poor): cesarean delivery, or onset > 30 min, or mean VAS > 60 mm.

Grade IV (worst): serious analgesia-related complications (unintended dural puncture with the epidural needle, Bromage score ≥ 2, persistent neurological injury, local anesthetic toxicity, or severe hypotension requiring intervention).

Time to analgesia onset

Time from initial drug administration to the first documented Visual Analogue Scale (VAS) score ≤ 30 mm. VAS scale: 0 = no pain, 100 mm = worst possible pain.

Visual Analogue Scale (VAS) score

Time-weighted mean pain VAS score from analgesia start to delivery, derived from area under the curve (AUC) calculation. VAS scale: 0 = no pain, 100 mm = worst possible pain.

Number of patient-controlled analgesia (PCA) demands

Number of PCA bolus demands during labor analgesia.

Local anesthetic consumption

Per-minute local anesthetic consumption during labor analgesia.

Sensory blockade level

Sensory blockade level assessed by loss of cold sensation using an alcohol swab, recorded at 30 min after the loading dose and at the highest level.

Incidence of asymmetric block

Defined as a ≥ 2-dermatome difference in sensory blockade level between the left and right sides.

Sensory blockade at the second sacral dermatome (S2)

S2 sensory blockade categorized as bilateral, unilateral, or none.

Number of Participants with Physician Interventions

Physician interventions including analgesic regimen adjustments, epidural catheter repositioning, and re-puncture.

Modified Bromage score

Motor blockade assessed by the modified Bromage score: 0 = full flexion of knees and ankles, 1 = partial flexion of knees with full flexion of ankles, 2 = inability to flex knees with partial flexion of ankles, 3 = inability to flex knees and ankles.

Side effects of labor analgesia

Incidence of lower limb numbness (defined as loss of cold sensation by alcohol swab test), urinary retention (defined as inability to void spontaneously within 8 h postpartum requiring catheterization), nausea and vomiting, and postpartum headache.

Cesarean delivery rate and indications

Rate of cesarean delivery and indications for cesarean delivery (non-reassuring fetal heart rate, arrest of descent, maternal indications, other).

Mean uterine contraction frequency

Time-weighted mean uterine contraction frequency, derived from area under the curve (AUC) calculation from analgesia to delivery. Unit of measure: contractions per 10 minutes

Mean single uterine contraction duration

Time-weighted mean single uterine contraction duration, derived from area under the curve (AUC) calculation from analgesia to delivery. Unit of measure: seconds.

Incidence of uterine hypertonia

Defined as a single contraction lasting > 2 min.

Incidence of uterine tachysystole

Defined as > 5 contractions per 10 min.

Duration of each stage of labor

Duration of the first, second, third, and total stages of labor.

Maternal body temperature

Maternal body temperature before analgesia and at delivery.

NICHD fetal heart rate tracing classification

NICHD (National Institute of Child Health and Human Development) Fetal Heart Tracing Classification: Category I (normal), Category II (indeterminate), Category III (abnormal). A higher category indicates a less reassuring fetal status.

NICHD category progression rate

Proportion of parturients whose NICHD category worsened from baseline during labor analgesia.

Fetal heart rate

Time-weighted mean fetal heart rate from analgesia to delivery, derived from area under the curve (AUC) calculation.

Fetal heart rate decelerations

Types of fetal heart rate decelerations (early, late, variable).

Fetal heart rate variability

Fetal heart rate variability categorized as absent, minimal, moderate, or marked.

Neonatal Apgar scores

Apgar scores assessed at 1, 5, and 10 minutes after birth. The Apgar score ranges from 0 to 10, with higher scores indicating better condition. The proportion of neonates with Apgar < 7 at 1 minute is also reported.

Post-delivery hs-CRP level

Post-delivery hs-CRP level in venous blood, adjusted for pre-delivery baseline value using analysis of covariance (ANCOVA). Unit of measure: mg/L.

Post-delivery IL-6 level

Post-delivery IL-6 level in venous blood, adjusted for pre-delivery baseline value using analysis of covariance (ANCOVA). Unit of measure: pg/mL.

Post-delivery cortisol level

Post-delivery cortisol level in venous blood, adjusted for pre-delivery baseline value using analysis of covariance (ANCOVA). Unit of measure: nmol/L.