Clinical trial NCT06819579: Exploring the Optimal Concentration of Lidocaine Test Dose for Labor Analgesia
Official title: Exploring the Optimal Concentration of Lidocaine Test Dose for Labor Analgesia
Study type: INTERVENTIONAL
Overall status: ACTIVE_NOT_RECRUITING
Phase: NA
Conditions: Labor Pain
Lead sponsor: The Second Affiliated Hospital of Chongqing Medical University
Sponsor class: OTHER
First posted: 2025-02-11
Enrollment: 99
Sex: FEMALE
Minimum age (years): 20
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: This study aims to compare the analgesia effects and side effects of different concentrations of test dose lidocaine (1.5% lidocaine 3 ml, 1.0% lidocaine 5 ml, 0.5% lidocaine 10 ml) in labor analgesia, so as to provide a scientific basis for the clinic al practice of labor analgesia.

Detailed description: Epidural analgesia is the most effective and widely used analgesic method for relieving labor pain in clinical practice. However, inadvertent insertion of an epidural catheter into a blood vessel or subarachnoid space may result in local anesthesia or total spinal anesthesia, which can be life-threatening. Therefore, a low-concentration, low-volume dose of local anesthetic is usually injected as a test dose before injecting a large dose of local anesthetic through the epidural catheter to ensure that the catheter is within the epidural space. At present, the guidelines recommend 3 ml of 1.5% lidocaine as the test dose, but in clinical practice and the study of Chen et al., it was found that the test dose of 1.5% lidocaine 3ml still has a high incidence of lower limb motor block of 57.1%, which affects maternal activity and labor progression. In addition, Liu Henry et al. found that the incidence of 0.5% lidocaine 10 ml test dose-induced motor block was 0%, and the analgesic effect could be quickly achieved. Therefore, it is uncertain which concentration of lidocaine has the fastest onset of analgesia and the fewest side effects in labor analgesia. Therefore, this study aims to compare the effects of different concentrations of lidocaine (1.5% lidocaine 3 ml, 1.0% lidocaine 5 ml, 0.5% lidocaine 10 ml) in labor analgesia, so as to provide a scientific basis for the clinical practice of labor analgesia.

Eligibility criteria: Inclusion Criteria:

1. Singleton primipara
2. Aged 20-40 years
3. Pre-assessed as eligible for vaginal delivery
4. Height between 155-170 cm, BMI between 18.5-35 kg/m²
5. Cervical dilation between 2-6 cm
6. No significant history of cardiopulmonary disease
7. No history of surgical trauma
8. American Society of Anesthesiologists (ASA) Grades I-III
9. Patients are willing to participate and be able to understand and sign an informed consent form

Exclusion Criteria:

1. Contraindications for spinal anesthesia, such as coagulopathy or ongoing anticoagulant therapy, infection at the puncture site, bacteremia, epidural abscess, increased intracranial pressure, severe hypovolemia
2. Physical or mental disabilities, such as scoliosis and depression, alcohol or drug abuse
3. Major organ diseases, such as hyperthyroidism, cardiopulmonary diseases, diabetes treated with insulin, and neuromuscular diseases
4. Numerical Pain Rating Scale (NPRS) \< 5
5. Refusal to participate in the study

Primary outcomes:
measure: The incidence of motor block
timeFrame: 3,5,7,9,11,13,15,20,25,30 minutes after lidocaine administration
Secondary outcomes:
measure: Pain scores
timeFrame: 3,5,7,9,11,13,15,20,25,30 minutes after lidocaine administration
measure: Time of analgesia onset
timeFrame: 3,5,7,9,11,13,15,20,25,30 minutes after lidocaine administration
measure: Sensory block level
timeFrame: 3,5,7,9,11,13,15,20,25,30 minutes after lidocaine administration
measure: Incidence of complications related to labor analgesia
timeFrame: 30 minutes after lidocaine administration
measure: frequency and intensity of uterine contractions
timeFrame: 30 minutes after lidocaine administration
measure: Maternal blood pressure
timeFrame: 5,10,15,20,25,30 minutes after lidocaine administration
measure: Maternal heart rate
timeFrame: 5,10,15,20,25,30 minutes after lidocaine administration
measure: Pulse oximetry （SPO2）
timeFrame: 5,10,15,20,25,30 minutes after lidocaine administration
measure: fetal heart rate
timeFrame: 5,10,15,20,25,30 minutes after lidocaine administration
measure: Patient satisfaction score
timeFrame: 30 minutes after lidocaine administration
measure: First stage of labor
timeFrame: From enrollment to 1 minute after the baby comes out.
measure: Second stage of labor
timeFrame: From enrollment to 1 minute after the baby comes out.
measure: neonatal Apgar score
timeFrame: 1, 5, and 10 minutes after baby comes out.
Other outcomes:
Locations:
city: Chongqing
country: China
facility: The Second Affiliated Hospital of Chongqing Medical University
state: Chongqing
Study officials:
affiliation: The Second Affiliated Hospital of Chongqing Medical University
name: Bing Chen
role: PRINCIPAL_INVESTIGATOR
References: