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Exploring the Optimal Concentration of Lidocaine Test Dose for Labor Analgesia

Exploring the Optimal Concentration of Lidocaine Test Dose for Labor Analgesia

Status
Active, not recruiting
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06819579
Enrollment
99
Registered
2025-02-11
Start date
2025-03-10
Completion date
2026-12-30
Last updated
2025-06-02

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Labor Pain

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.

Interventions

After successful epidural puncture, 3ml of 1.5% lidocaine was injected as a test dose

DRUG1.0% Lidocaine

After successful epidural puncture, 5ml of 1% lidocaine was injected as a test dose

After successful epidural puncture, 10ml of 0.5% lidocaine was injected as a test dose

Sponsors

The Second Affiliated Hospital of Chongqing Medical University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)

Eligibility

Sex/Gender
FEMALE
Age
20 Years to 40 Years
Healthy volunteers
No

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

Design outcomes

Primary

MeasureTime frameDescription
The incidence of motor block3,5,7,9,11,13,15,20,25,30 minutes after lidocaine administrationBromage Scores were used to grade movement block: I free movement of legs and feet, II free movement of feet with only bent knees, III free movement of feet without bending knees, IV no movement of legs and feet, with scores of II, III and IV considered as movement block.

Secondary

MeasureTime frameDescription
Time of analgesia onset3,5,7,9,11,13,15,20,25,30 minutes after lidocaine administrationPain scores is assessed by the Numerical Pain Rating Scale (NPRS, where 0 means no pain and 10 means no pain tolerance). Analgesia is considered effective when NPRS is ≤3 or NPRS is reduced by ≥ 50% of the baseline value.
Sensory block level3,5,7,9,11,13,15,20,25,30 minutes after lidocaine administrationMidabdominal line acupuncture was used to assess the sensory block level
Incidence of complications related to labor analgesia30 minutes after lidocaine administrationAsk the patient if they have discomfort such as leg warmth, leg numbness, trembling, itching, headache, tinnitus, etc.
frequency and intensity of uterine contractions30 minutes after lidocaine administrationA contraction monitor is used to monitor the intensity and frequency of contractions
Maternal blood pressure5,10,15,20,25,30 minutes after lidocaine administrationAutomated monitoring with an ECG monitor
Maternal heart rate5,10,15,20,25,30 minutes after lidocaine administrationAutomated monitoring with an ECG monitor
Pain scores3,5,7,9,11,13,15,20,25,30 minutes after lidocaine administrationPain scores is assessed by the Numerical Pain Rating Scale (NPRS, where 0 means no pain and 10 means no pain tolerance)
fetal heart rate5,10,15,20,25,30 minutes after lidocaine administrationAutomatically monitored using a fetal heart rate monitor
Patient satisfaction score30 minutes after lidocaine administrationNumerical rating scale was used to score (0, completely dissatisfied; 1. Neutral; 2, satisfaction; 3, completely satisfied)
First stage of laborFrom enrollment to 1 minute after the baby comes out.The first stage of labor begins when labor starts and ends with full cervical dilation to 10 centimeters.
Second stage of laborFrom enrollment to 1 minute after the baby comes out.The time from the cervix dilated to 10 centimeters to the baby comes out.
neonatal Apgar score1, 5, and 10 minutes after baby comes out.The Apgar score is to evaluate the presence or absence of neonatal asphyxia and the severity of asphyxia from five aspects: Appearance, Pulse, Grimace, Activity and Respiration after birth, with each item being 0\ 2 points and a full score of 10 points.
Pulse oximetry (SPO2)5,10,15,20,25,30 minutes after lidocaine administrationAutomated monitoring with an ECG monitor

Countries

China

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026