The Effect of Ultrasound Real-time Guidance Technique on the Effectiveness and Safety of Labor Analgesia

Ultrasound real-time guidance technology has great advantages over traditional blind exploration technology in terms of accuracy, success rate, and reduction of puncture damage in intervertebral space positioning through operational visualization, greatly improving the effectiveness and safety of spinal block. At present, Doppler ultrasound is rarely used for spinal block, especially for real-time ultrasound guidance technology, which has not been widely applied in clinical practice due to its high equipment requirements, lack of mature puncture plans, complex operation, and high learning curve. If a comprehensive diagnosis and treatment plan can be developed, it will greatly improve the delivery experience of mothers.

Study Overview

• Status: Completed
• Conditions: Labor Analgesia
• Intervention / Treatment: Device: Ultrasound Real-time Guidance combined with Dural Puncture Epidural Labor Analgesia; Device: Dural Puncture Epidural Labor Analgesia

Detailed Description

Traditional blind exploration of spinal canal puncture has many limitations, often forcing changes in anesthesia methods due to multiple puncture failures. However, the application of real-time ultrasound guidance technology in spinal canal puncture can completely solve this clinical difficulty. The ultrasound-guided real-time paramedian approach epidural puncture for labor analgesia is a new type of labor analgesia technology, and its specific operating standards and diagnostic and treatment routines have not yet been established, including the selection of puncture path, puncture needle model, distance between puncture hole and epidural injection point, drug type, dosage, solubility, volume and other parameters, all of which have great research space.

• Study Type: Interventional
• Enrollment (Actual): 212
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Fujian
    • Fuzhou, Fujian, China, 350001
      • Fujian Provincial Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. American Society of Anesthesiologists (ASA) Class I or II;
2. Single healthy pregnancy;
3. Head showing first;
4. 37 to 41 weeks;
5. The labor process is active, and the cervix dilates<5cm;
6. Require epidural labor analgesia;
7. Volunteer to participate in this study and sign an informed consent form.

Exclusion Criteria:

1. Presence of pregnancy diseases, such as pregnancy hypertension, pre eclampsia, pregnancy diabetes;
2. Contraindications to intraspinal analgesia: 1) Central nervous system diseases. 2) Infection or septicemia at the puncture site. 3) Coagulation dysfunction;
3. Known cases of fetal malformation or increased risk of cesarean section, such as a history of uterine rupture;
4. Persons with a history of mental illness, hysteria, epilepsy, etc. who cannot cooperate.
5. Patients with long-term use of opioids, steroids, and chronic pain.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Ultrasound Real-time Guidance combined with Dural Puncture Epidural Group; Ultrasound real-time guidance combined with dural puncture epidural Can improve the clinical effect of labor analgesia.	Device: Ultrasound Real-time Guidance combined with Dural Puncture Epidural Labor Analgesia; Ultrasound real-time guidance technology has great advantages over traditional blind exploration technology in terms of accuracy, success rate, and reduction of puncture damage in intervertebral space positioning through operational visualization, greatly improving the effectiveness and safety of spinal block.
Active Comparator: Dural Puncture Epidural Group; Dural Puncture Epidural is a clinical improvement of Combined Spinal-Epidural and is widely used in Maternal. The implementation step is to complete the epidural puncture, temporarily do not place a tube, puncture the dura mater with a subarachnoid anesthesia needle, but do not directly inject drugs into the subarachnoid space, and then leave an epidural catheter for administration according to epidural block.	Device: Dural Puncture Epidural Labor Analgesia; Dural Puncture Epidural is a clinical improvement of Combined Spinal-Epidural and is widely used in Maternal. The implementation step is to complete the epidural puncture, temporarily do not place a tube, puncture the dura mater with a subarachnoid anesthesia needle, but do not directly inject drugs into the subarachnoid space, and then leave an epidural catheter for administration according to epidural block.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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).	From initiation of labor analgesia to delivery (assessed up to 24 hours).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	Within 30 minutes after initial drug administration.
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.	From initiation of labor analgesia to delivery (assessed up to 24 hours).
Number of patient-controlled analgesia (PCA) demands	Number of PCA bolus demands during labor analgesia.	From initiation of labor analgesia to delivery (assessed up to 24 hours).
Local anesthetic consumption	Per-minute local anesthetic consumption during labor analgesia.	From initiation of labor analgesia to delivery (assessed up to 24 hours).
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.	During the labor analgesia period (assessed up to 24 hours).
Incidence of asymmetric block	Defined as a ≥ 2-dermatome difference in sensory blockade level between the left and right sides.	During the labor analgesia period (assessed up to 24 hours).
Sensory blockade at the second sacral dermatome (S2)	S2 sensory blockade categorized as bilateral, unilateral, or none.	During the labor analgesia period (assessed up to 24 hours).
Number of Participants with Physician Interventions	Physician interventions including analgesic regimen adjustments, epidural catheter repositioning, and re-puncture.	From initiation of labor analgesia to delivery (assessed up to 24 hours).
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.	During the labor analgesia period (assessed up to 24 hours).
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.	From analgesia initiation until delivery and postpartum (assessed up to 72 hours).
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).	At delivery.
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	From initiation of labor analgesia to delivery (assessed up to 24 hours).
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.	From initiation of labor analgesia to delivery (assessed up to 24 hours).
Incidence of uterine hypertonia	Defined as a single contraction lasting > 2 min.	From initiation of labor analgesia to delivery (assessed up to 24 hours).
Incidence of uterine tachysystole	Defined as > 5 contractions per 10 min.	From initiation of labor analgesia to delivery (assessed up to 24 hours).
Duration of each stage of labor	Duration of the first, second, third, and total stages of labor.	From labor onset to delivery of the placenta (assessed up to 24 hours).
Maternal body temperature	Maternal body temperature before analgesia and at delivery.	Pre-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.	From the baseline assessment (pre-analgesia) through delivery (assessed up to 24 hours).
NICHD category progression rate	Proportion of parturients whose NICHD category worsened from baseline during labor analgesia.	From baseline (pre-analgesia) through delivery (assessed up to 24 hours).
Fetal heart rate	Time-weighted mean fetal heart rate from analgesia to delivery, derived from area under the curve (AUC) calculation.	From initiation of labor analgesia to delivery (assessed up to 24 hours).
Fetal heart rate decelerations	Types of fetal heart rate decelerations (early, late, variable).	From the baseline assessment (pre-analgesia) through delivery (assessed up to 24 hours).
Fetal heart rate variability	Fetal heart rate variability categorized as absent, minimal, moderate, or marked.	From the baseline assessment (pre-analgesia) through delivery (assessed up to 24 hours).
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.	At 1, 5, and 10 minutes after birth.
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.	Pre-delivery (baseline, within 1 week before delivery) and 30 minutes after delivery.
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.	Pre-delivery (baseline, within 1 week before delivery) and 30 minutes after delivery.
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.	Pre-delivery (baseline, within 1 week before delivery) and 30 minutes after delivery.

Collaborators and Investigators

• Sponsor: Zongxun Lin
• Investigators: Principal Investigator: Zongxun Lin, Master, Fujian Provincial Hospital

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2024
• Primary Completion (Actual): December 31, 2025
• Study Completion (Actual): December 31, 2025

Study Registration Dates

• First Submitted: March 1, 2024
• First Submitted That Met QC Criteria: March 7, 2024
• First Posted (Actual): March 8, 2024

Study Record Updates

• Last Update Posted (Actual): July 30, 2026
• Last Update Submitted That Met QC Criteria: July 28, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Safety; Effectiveness; neonate; labor analgesia; delivery woman; Ultrasound Real-time Guidance
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Neurobehavioral Manifestations; Perceptual Disorders; Agnosia
• Other Study ID Numbers: Ultrasound Real-time Guidance

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No