Addition of Buprenorphine to Paracervical Block for Pain Control During Osmotic Dilator Insertion

Procedural Pain Clinical Trial

— ABCD&E  

Official title:

Addition of Buprenorphine to Paracervical Block Prior to Osmotic Dilator Insertion for Dilation and Evacuation: A Randomized Controlled Trial

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04254081
• Other study ID #: 192033
• Status: Completed
• Phase: Phase 4
• Start date: May 28, 2020
• Est. completion date: May 4, 2021

Study information

• Verified date: July 2023
• Source: University of California, San Diego
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Cervical preparation with osmotic dilators is commonly used prior to dilation and evacuation (D&E) procedures to decrease the risk of complications. Women have described the pain of osmotic dilator insertion as moderate to severe yet there have been few studies aimed at addressing pain during and after osmotic dilator insertion. In addition to the discomfort during insertion, pain after osmotic dilator insertion peaks at 2 hours post-insertion with use of a lidocaine paracervical block. One randomized trial found that use of a paracervical block with 1% buffered lidocaine decreased pain with osmotic dilator insertion compared to a sham block. There are adjunct treatments to optimize analgesia with local anesthetics at a variety of anatomic locations. Buprenorphine, a partial mu-opioid receptor agonist, has been found to increase the quality of the anesthetic at the time of administration and increase the duration of nerve block analgesia at several anatomic sites, though has never been studied as an adjunct in a paracervical block. This has been used extensively in orthopedic surgery with significant prolongation of the local anesthetic effect by almost threefold in some studies.

Primary Aim: To compare the mean pain score at the time of osmotic dilator insertion among women randomized to a 1% lidocaine and buprenorphine paracervical block compared to a 1% lidocaine paracervical block alone.

Secondary Aim: To compare the mean pain score 2 hours after osmotic dilator insertion among women randomized to a lidocaine and buprenorphine paracervical block compared to a lidocaine paracervical block alone.

The investigators hypothesize that in patients undergoing osmotic dilator insertion in preparation for dilation and evacuation, the addition of buprenorphine 0.15mg to a 1% lidocaine paracervical block will be associated with lower mean pain scores at time of osmotic dilator insertion compared to women who receive a 1% lidocaine paracervical block alone.

Description:

Dilation and evacuation (D&E) is the most common method of second trimester abortion in the United States. Cervical preparation prior to the procedure is essential in order to allow passage of operative instruments and pregnancy tissue safely through the cervix and to decrease the risk of complications. In the second trimester, cervical preparation is typically achieved with placement of osmotic dilators prior to the procedure. Women have described the pain of osmotic dilator insertion as moderate to severe yet there have been few studies aimed at addressing pain during osmotic dilator insertion. A lidocaine paracervical block is commonly used for pain control during other gynecologic procedures including procedures involving cervical dilation like dilation and curettage. One randomized controlled trial found that use of a paracervical block with 1% lidocaine decreased pain with osmotic dilator insertion compared to a sham block. Because the dilators slowly expand after insertion, there is continued discomfort for several hours after placement. Research has shown that pain after osmotic dilator insertion peaks at 2 hours post-insertion with use of a lidocaine paracervical block and a local anesthetic is not sufficient to provide lasting pain relief. Systemic medications, such as gabapentin and narcotic analgesics have been studied to treat post-insertional dilator pain, however these treatments have not been shown to be effective.

There are many adjunct treatments to optimize the duration of local analgesia from a peripheral nerve block. Buprenorphine, a partial mu-opioid receptor agonist, is a high potency, lipophilic opioid and has a high binding capacity for the mu-opioid receptor. Because of the high binding capacity, buprenorphine has the longest duration of action of all opioids. When administered perineurally in combination with a local anesthetic, buprenorphine has been found to drastically increase the duration of analgesia at several anatomic sites, including axillary and subclavian brachial plexus blocks and infragluteal sciatic nerve blocks. With the addition of buprenorphine at doses of 0.15 - 0.3mg, there is significant prolongation of the anesthetic sensory blockade up to three times the duration of the local anesthetic alone. The use of perineural buprenorphine is well established for postoperative analgesia. Buprenorphine itself also has local anesthetic properties. Buprenorphine blocks voltage gated sodium channels and inhibits C-fiber action potentials, thereby contributing to an analgesic effect. Buprenorphine not only prolongs the duration of local anesthetic effect but also improves the analgesic properties when administered in a perineural block.

The addition of buprenorphine to a perineural local anesthetic has not been studied in a paracervical block. This study will be the first trial to assess the efficacy of buprenorphine to provide analgesia for a gynecologic procedure. This medication has the additional benefit of providing long lasting pain relief for procedures that cause continued discomfort after the end of the procedure. The investigators hypothesize that the addition of 0.15mg of buprenorphine to a lidocaine paracervical block will improve pain during osmotic dilator insertion and provide continued pain relief several hours after osmotic dilator insertion. If this intervention proves to provide better pain control than a lidocaine paracervical block alone, it would be an intervention for women during a painful clinic procedure.

A total of 114 women undergoing D&E who require cervical preparation with osmotic dilators will be randomized to one of two study groups: (1) paracervical block with 20mL of 1% buffered lidocaine or (2) paracervical block with 20mL of 1% buffered lidocaine plus 0.15mg of buprenorphine. Participants, clinicians performing the procedure, and study personnel administering questionnaires will be blinded to study assignment. Participants will rate their level of pain on an 11-point numeric rating scale (NRS) during the insertion of osmotic dilators and at several time points after insertion. The primary outcome is to compare the median pain score at the time of osmotic dilator insertion in women randomized to a 1% lidocaine and buprenorphine paracervical block compared to a 1% lidocaine paracervical block alone. Secondary outcomes are to compare the median pain score 2 hours after osmotic dilator insertion; to assess overall narcotic and ibuprofen use after osmotic dilator placement and before dilation and evacuation procedure; to assess opioid related side effects; and to determine patient satisfaction with pain control during and after osmotic dilator insertion.

Primary Hypothesis: The addition of buprenorphine 0.15mg to a paracervical block using 1% lidocaine will be associated with a lower median pain score on the NRS at time of osmotic dilator insertion compared to women who receive a lidocaine paracervical block alone.

Secondary Hypothesis: The addition of buprenorphine 0.15mg to a paracervical block using 1% lidocaine will be associated with a lower median pain score on the NRS 2 hours after osmotic dilator insertion compared to women who receive a lidocaine paracervical block alone.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 57
• Est. completion date: May 4, 2021
• Est. primary completion date: May 4, 2021
• Accepts healthy volunteers: No
• Gender: Female
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Gestational age 14 0/7 weeks to 23 6/7 weeks at time of osmotic dilator insertion

• Require cervical preparation with placement of osmotic dilators

• At least 18 years of age

• Fluent in English or Spanish

Exclusion Criteria:

• Same day dilation and evacuation procedure

• Request for sedation during osmotic dilator insertion

• Liver disease

• Allergy to buprenorphine, lidocaine, or ibuprofen

• Narcotic or opioid medication use in the preceding 24 hours

• Use of recreational/illicit medications in the preceding 24 hours

• Currently incarcerated

Related Conditions & MeSH terms

• Adjuvants, Anesthesia
• Analgesics
• Buprenorphine
• Dilation and Evacuation
• Pain, Procedural
• Procedural Pain

Intervention

Drug:
• Buprenorphine 0.15 MG
Buprenorphine 0.15mg solution will be added to a 20mL 1% buffered lidocaine solution (paracervical block) which will be administered in the paracervical space prior to osmotic dilator insertion.
• Lidocaine 1% Injectable Solution
20mL of 1% buffered lidocaine solution (paracervical block) will be administered in the paracervical space prior to osmotic dilator insertion.

Locations

Country	Name	City	State
United States	University of California San Diego Health	San Diego	California

Sponsors (2)

Lead Sponsor	Collaborator
University of California, San Diego	Society of Family Planning

Country where clinical trial is conducted

United States, 

References & Publications (7)

Bailard NS, Ortiz J, Flores RA. Additives to local anesthetics for peripheral nerve blocks: Evidence, limitations, and recommendations. Am J Health Syst Pharm. 2014 Mar 1;71(5):373-85. doi: 10.2146/ajhp130336. — View Citation

Creinin MD, Schimmoeller NR, Matulich MC, Hou MY, Melo J, Chen MJ. Gabapentin for pain management after osmotic dilator insertion and prior to dilation and evacuation: A randomized controlled trial. Contraception. 2020 Mar;101(3):167-173. doi: 10.1016/j.contraception.2019.12.001. Epub 2020 Jan 10. — View Citation

Kosel J, Bobik P, Tomczyk M. Buprenorphine--the unique opioid adjuvant in regional anesthesia. Expert Rev Clin Pharmacol. 2016;9(3):375-83. doi: 10.1586/17512433.2016.1141047. Epub 2016 Jan 28. — View Citation

Mercier RJ, Liberty A. Intrauterine lidocaine for pain control during laminaria insertion: a randomized controlled trial. Contraception. 2014 Dec;90(6):594-600. doi: 10.1016/j.contraception.2014.07.008. Epub 2014 Jul 23. — View Citation

Schivone GB, Lerma K, Montgomery C, Wright P, Conti JA, Blumenthal PD, Shaw KA. Self-administered lidocaine gel for local anesthesia prior to osmotic dilator placement: a randomized trial. Contraception. 2019 Mar;99(3):148-151. doi: 10.1016/j.contraception.2018.11.013. Epub 2018 Nov 27. — View Citation

Soon R, Tschann M, Salcedo J, Stevens K, Ahn HJ, Kaneshiro B. Paracervical Block for Laminaria Insertion Before Second-Trimester Abortion: A Randomized Controlled Trial. Obstet Gynecol. 2017 Aug;130(2):387-392. doi: 10.1097/AOG.0000000000002149. — View Citation

Swain A, Nag DS, Sahu S, Samaddar DP. Adjuvants to local anesthetics: Current understanding and future trends. World J Clin Cases. 2017 Aug 16;5(8):307-323. doi: 10.12998/wjcc.v5.i8.307. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Pain Score at the Time of Osmotic Dilator Insertion	Median pain score on a 0 (no pain) to 10 (worst pain) numeric rating scale at the time of osmotic dilator insertion	Assessed immediately after last dilator inserted
Secondary	Pain Score 2 Hours After Osmotic Dilator Insertion	Median pain score on a 0 (no pain) to 10 (worst pain) numeric rating scale 2 hours after osmotic dilator insertion assessed via text message	2 hours after osmotic dilator insertion
Secondary	Pain Score 1 Hour After Osmotic Dilator Insertion	Median pain score on a 0 (no pain) to 10 (worst pain) numeric rating scale 1 hour after osmotic dilator insertion assessed via text message	1 hour after osmotic dilator insertion
Secondary	Pain Score 6 Hours After Osmotic Dilator Insertion	Median pain score on a 0 (no pain) to 10 (worst pain) numeric rating scale 6 hours after osmotic dilator insertion assessed via text message	6 hours after osmotic dilator insertion
Secondary	Overall Satisfaction Scores	To determine patient satisfaction with pain control during and after osmotic dilator insertion. This was assessed on the morning of D&E procedure. Participants following question and rated responses on a Likert scale: What was your overall satisfaction with the amount of pain control that you had during the procedure?	Morning of D&E procedure: after check-in, before D&E