Buffered Lidocaine in Paracervical Blocks

Phase 4

Completed

Conditions: Pain

Interventions: Drug: Lidocaine-Sodium Bicarbonate
Drug: Lidocaine

Registration Number: NCT03107754

Lead Sponsor: University of Hawaii

Brief Summary: For pain relief during a first trimester surgical aspiration, most providers use the paracervical block, either alone or in combination with other pain control techniques. Some providers use buffered lidocaine due to a belief that it decreases pain. Others use plain lidocaine. At our clinics, the standard pain management protocol is using 20 cc of 1% plain lidocaine in a two site injection. Few studies have compared buffered versus unbuffered lidocaine for paracervical blocks during first trimester uterine aspirations. This study seeks to determine if buffered lidocaine decreases injection pain versus plain lidocaine for paracervical blocks.

Detailed Description: Potential participants will be identified at their office visits to the University Women's Health Specialists. If a patient desires uterine aspiration of a first trimester pregnancy or management of a failed pregnancy in the first trimester, they will first receive standard counseling. Only after providing written informed consent for the procedure will the patient's be screened for eligibility for our study. If the patient is eligible, she will be asked by a member of the research team if she is interested in participating. If she is, the study will be explained to her and written consent will be obtained after she is given the opportunity to have all of her questions answered. The patient will then complete a written questionnaire to collect demographic data.

This prospective randomized control trial will consist of two study arms. Participants will be randomly assigned to Arm 1, where a paracervical block will be administered with 20 cc of 1% lidocaine, which is our standard office protocol, or to Arm 2, where a paracervical block will be administered with 20 cc of 1% lidocaine buffered with 8.4% sodium bicarbonate. Prior to the start of the study, study assignments will be generated in a 1:1 ratio.

All patients who consent to the study will receive standard counseling prior to their procedure. The procedure will start with a bimanual exam by the provider. Next, the provider will place a speculum, cleanse the cervix with betadine solution, and place a single-tooth tenaculum on the anterior lip of the cervix. At this point, participants assigned to Arm 1 will receive a paracervical block loaded with 20 cc of 1% lidocaine and injected at 2, 4, 8 and 10 o'clock positions of the cervicovaginal junction. Participants assigned to Arm 2 will receive a paracervical block loaded with 18 cc of 1% lidocaine and 2 cc of 8.4% sodium bicarbonate and inject the block in the same fashion. The research assistant will ask the patient to verbally report their level of pain based on the 100 mm visual analog scale (VAS) at the following points of the procedure:

1. Prior to the start of the procedure (baseline anxiety)

2. After speculum placement

3. After paracervical block

4. After cervical dilation

5. After suction curettage

6. At end of procedure

Recruitment & Eligibility

Status: COMPLETED

Sex: Female

Target Recruitment: 98

Inclusion Criteria

Pregnant women 14 years and older
Desiring uterine aspiration for pregnancy or surgical management of a miscarriage
Gestational age up to 13 weeks and 6 days to be established by best dating (i.e. last menstrual period or earliest ultrasound)
Treatment plan involves outpatient uterine aspiration
Participant able to provide informed consent in English and willing to participate in the study

Exclusion Criteria

Unable to read, speak, or understand English
Unable to provide informed consent
Currently incarcerated
Under the age of 14 years
Contraindications to receiving lidocaine or buffered lidocaine

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Buffered lidocaine paracervical block	Lidocaine-Sodium Bicarbonate	A paracervical block will be administered with 20 cc of 1% lidocaine buffered with 8.4% sodium bicarbonate
Standard paracervical block	Lidocaine	A paracervical block will be administered with 20 cc of 1% lidocaine, which is our standard office protocol

Primary Outcome Measures

Name	Time	Method
Injection Pain	Immediately after injection of the paracervical block	For the primary outcome, pain immediately after paracervical block injection was measured by a scale. The scale used was the 100-mm visual analog scale. The minimum score was 0 and the maximum score was 100. Higher numbers indicate worse pain.

Secondary Outcome Measures

Name	Time	Method
Pain After Speculum Placement, Cervical Dilation, and Aspiration	Immediately after speculum placement, cervical dilation, uterine aspiration	Pain scores were measured at multiple points throughout the procedure. Pain scores were measured using a 100 mm visual analog scale with 0 being no pain and 100 being the worst pain ever.