ENDOblock: Bilateral Superficial Cervical Blocks With Local Wound Infiltration in Thyroid Surgery

May 8, 2026 updated by: University of California, Davis

ENDOblock: Do Bilateral Superficial Cervical Blocks With Local Wound Infiltration Decrease Postoperative Pain After Thyroid Surgery

This is a single center, prospective, double-blinded randomized controlled trial comparing the efficacy of bilateral superficial cervical plexus blocks (BSCPB) with local wound infiltration vs placebo with local wound infiltration in reducing thyroid surgery postoperative pain. Primary outcomes assessed are post operative pain, quality of life/recovery, post operative nausea/vomiting and opioid use.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

The study consists of enrollment period until 74 participants acquired (37 will be in each arm), a treatment period (day of surgery), and a 2 week follow up period.

A web-based randomizer (https://randomizer.org/) will be used to randomly assign participants into Group A (bilateral superficial cervical plexus blocks + local wound infiltration) and Group B (placebo + local wound infiltration). Numbered envelopes with respective assignments and medications sealed within will be prepared by a research assistant separate from the surgical team and brought to the operating theater together with subjects. Participants and surgeons will both be blinded to the intervention.

Induction of anesthesia will occur prior to performing a block. All participants will be closely monitored by anesthesia, including BP, HR, SpO2, tidal volumes, peak pressures, CO2.

Participants who are randomized to the bilateral superficial cervical plexus blocks + local wound infiltration (Group A) will have 10mL of 0.25% Bupivacaine injected bilaterally (total 20mL) at Erb's point, which is located at the mid-point between the mastoid process and the posterior border of the clavicular head of the sternocleidomastoid muscle (SCM). The injection is just below the lateral border of the SCM, which produces surface level anesthesia of the neck, targeting superficial nerves of the cervical plexus (1). Injections will be aimed at just below the dermis. Then 10mL of 0.25% Bupivacaine will be injected at the planned neck incision (local wound infiltration). The participants randomized to the placebo+local wound infiltration group will have 10mL of 0.25% Bupivacaine injected at the planned neck incision, with 10mL of normal saline injected at bilateral Erb's point (total 20mL). All injections will be performed by the same team of two surgeons and with 22 gauge needles to standardize the technique. Surgery will be performed according to standard clinical care, also by the same group of surgeons, standardizing the surgical technique.

As is our standard practice following thyroid surgery, participants will be observed for at least 4 hours in the post anesthesia care unit for postoperative complications, adequate pain control, neck hematoma, and possible complications from the BSCPB. These rare complications can include CNS toxicity, partial brachial plexus palsy, Horner's syndrome, or recurrent laryngeal nerve block. All participants will be assessed at 3-5 hours after surgery to ensure their post operative pain is acceptable on oral medications and they do not have any of the above complications. They will either stay overnight or be discharged home with standardized discharge instructions and pain medication regimen, which will include taking Tylenol every 6 hours, alternated with ibuprofen. This pain regimen will be used for participants unless changed for clinical contraindications as determined by the attending surgeon. If participants request additional medication, they will be prescribed with a few pills of 5mg oxycodone, which they can take up to every 4 hours.

A primary outcome will be postoperative pain. Neck pain intensity will be quantified using the numeric rating scale (visual analog score 0-10, VAS) at 3-5 hours (in post anesthesia care unit), post operative day 2, via telephone call, and 2 weeks +/- 3 days postoperatively (at their follow up video visit). In addition, comparisons between groups will be made for 48-hour opioid usage by participants self-reporting at the post operative day 2 follow up phone call.

Another primary outcome is the 15-item quality of recovery questionnaire score at post operative day 2 and two weeks postoperative.

Incidence of nausea, vomiting, dysphagia or hoarseness in the first 2 days after surgery will also be measured (roughly the first 48 hours after surgery).

The planned data analysis for quality of recovery scores will be done using independent t test, with 95% confidence interval and two-tailed p values reported. Significance levels will be set at p=0.05. The investigators plan to analyze pain scores across the 3 periods with linear regression, with output the difference between the groups across all periods (95% CI and p=0.05) and the difference between the groups in each period (95% CI and p=0.05). The 48-hour opioid usage will be likely analyzed by using independent t test with 95% confidence intervals and two-tailed p values reported (p=0.05). Nausea, vomiting, hoarseness, dysphagia will be recorded as categorical variables and the investigators plan to analyze them using the Pearson chi-squared test.

Study Type

Interventional

Enrollment (Estimated)

74

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • Sacramento, California, United States, 95817
        • UC Davis Medical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 99 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • undergoing thyroid surgery, either hemi- or total thyroidectomy
  • over 18 years-old and
  • able to consent for themselves

Exclusion Criteria:

  • have had previous neck surgery
  • have coagulation disorders
  • on anticoagulants
  • are pregnant
  • allergic to bupivacaine
  • anyone with chronic pain conditions
  • has received steroid injections or used opioids/pain medications in the two weeks leading up to surgery
  • have a substernal goiters
  • undergoing lateral neck lymph node dissection
  • unable to take NSAIDs
  • kidney dysfunction (defined as GFR <60) within 90 days of surgery, prohibiting the use of NSAIDs

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Supportive Care
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Bilateral superficial cervical plexus blocks + local wound infiltration
the bilateral superficial cervical plexus block will be performed with 10mL of 0.25% Bupivacaine injected bilaterally (total 20mL) at Erb's point in the lateral neck, which is located at the mid-point between the mastoid process and the posterior border of the clavicular head of the sternocleidomastoid muscle. The injection is just below the lateral border of the sternocleidomastoid muscle, which produces surface level anesthesia of the neck, targeting superficial nerves of the cervical plexus. Then 10mL of 0.25% Bupivacaine will be injected at the planned neck incision (local wound infiltration) on the anterior neck. These will be done intra-operative and only once
Procedure: bilateral superficial cervical plexus blocks and local wound infiltration
10mL bupivacaine at Erb's point bilaterally and 10mL 0.25% Bupicacaine at incision
Placebo Comparator: placebo + local wound infiltration
10mL of 0.25% bupivacaine injected at the planned neck incision (local wound infiltration), with 10mL of normal saline injected at bilateral Erb's point (total 20mL) (placebo at site of BSCPB). These will be done intra-operative and only once.
Procedure: placebo injection and local wound infiltration
10mL normal saline at Erb's point bilaterally and 10mL 0.25% Bupicacaine at incision

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
does the addition of bilateral superficial cervical plexus blocks with local wound infiltration decrease postoperative pain after thyroid surgery
Time Frame: assessed at 3-5 hours (in post anesthesia care unit [PACU])
Neck pain intensity will be quantified using the numeric rating scale (visual analog score 0-10, VAS). Higher scores mean more pain. Lower scores are a better outcome
assessed at 3-5 hours (in post anesthesia care unit [PACU])
does the addition of bilateral superficial cervical plexus blocks with local wound infiltration decrease postoperative pain after thyroid surgery
Time Frame: post operative day 2, via telephone call
Neck pain intensity will be quantified using the numeric rating scale (visual analog score 0-10, VAS). Higher scores mean more pain. Lower scores are a better outcome
post operative day 2, via telephone call
does the addition of bilateral superficial cervical plexus blocks with local wound infiltration decrease postoperative pain after thyroid surgery
Time Frame: 2 weeks +/- 3 days postoperatively (at their follow up video visit)
Neck pain intensity will be quantified using the numeric rating scale (visual analog score 0-10, VAS). Higher scores mean more pain. Lower scores are a better outcome
2 weeks +/- 3 days postoperatively (at their follow up video visit)
does the addition of bilateral superficial cervical plexus blocks with local wound infiltration increase patient quality of life/recovery after thyroid surgery
Time Frame: post operative day 2, via telephone call
15-item Quality of recovery (QoR) after anesthesia is a validated self reported measure of the early postoperative health status of patients. highest score possible 150, lowest 0. higher score means better quality of life and recovery
post operative day 2, via telephone call
does the addition of bilateral superficial cervical plexus blocks with local wound infiltration increase patient quality of life/recovery after thyroid surgery
Time Frame: 2 weeks +/- 3 days postoperatively (at their follow up video visit)
15-item Quality of recovery (QoR) after anesthesia is a validated self reported measure of the early postoperative health status of patients. highest score possible 150, lowest 0. higher score means better quality of life and recovery
2 weeks +/- 3 days postoperatively (at their follow up video visit)
Incidence of nausea and/or vomiting post operatively
Time Frame: assessed at 3-5 hours (in post anesthesia care unit [PACU])
patients are given a questionnaire assessing level of nausea on scale 0-10, higher score is more nauseated and worse outcome. yes/no question if they have vomited since surgery and how many times. more episodes of vomiting is worse outcome.
assessed at 3-5 hours (in post anesthesia care unit [PACU])
Incidence of nausea and/or vomiting post operatively
Time Frame: post operative day 2 via telephone
patients are given a questionnaire assessing level of nausea on scale 0-10, higher score is more nauseated and worse outcome. yes/no question if they have vomited since surgery and how many times. more episodes of vomiting is worse outcome.
post operative day 2 via telephone
Incidence of nausea and/or vomiting post operatively
Time Frame: 2 weeks +/- 3 days postoperatively (at their follow up video visit)
patients are given a questionnaire assessing level of nausea on scale 0-10, higher score is more nauseated and worse outcome. yes/no question if they have vomited since surgery and how many times. more episodes of vomiting is worse outcome.
2 weeks +/- 3 days postoperatively (at their follow up video visit)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
hoarseness
Time Frame: assessed at 3-5 hours (in post anesthesia care unit [PACU])
yes/no question on survey- yes answer is worse outcome
assessed at 3-5 hours (in post anesthesia care unit [PACU])
hoarseness
Time Frame: post operative day 2, via telephone call
yes/no question on survey- yes answer is worse outcome
post operative day 2, via telephone call
dysphagia (difficulty swallowing)
Time Frame: assessed at 3-5 hours (in post anesthesia care unit [PACU])
yes/no question on survey- yes answer is worse outcome
assessed at 3-5 hours (in post anesthesia care unit [PACU])
dysphagia (difficulty swallowing)
Time Frame: post operative day 2, via telephone call
yes/no question on survey- yes answer is worse outcome
post operative day 2, via telephone call

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of California, Davis

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 17, 2023

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

December 31, 2026

Study Registration Dates

First Submitted

March 14, 2023

First Submitted That Met QC Criteria

April 5, 2023

First Posted (Actual)

April 10, 2023

Study Record Updates

Last Update Posted (Actual)

May 12, 2026

Last Update Submitted That Met QC Criteria

May 8, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 1958184

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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