Addition of Clonidine to Ropivacaine in Adductor Canal Block

Postoperative Pain Clinical Trial

Official title:

Addition of Clonidine to Ropivacaine in Adductor Canal Block for Postoperative Pain Relief in Total Knee Arthroplasty: A Prospective Randomized Double Blind Placebo Controlled Trial

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT03057015
• Other study ID #: CHRMS 17-0107
• Status: Recruiting
• Phase: Phase 4
• Start date: May 22, 2017
• Est. completion date: February 28, 2019

Study information

• Verified date: May 2018
• Source: University of Vermont
• Contact: Borzoo Farhang, DO
• Phone: 8028819927
• Email: borzoo.farhang[@]uvmhealth.org
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Total knee arthroplasty (knee replacement) is a common orthopedic procedure for osteoarthritis. This procedure is performed either under general anesthesia or spinal anesthesia; after the procedure in the recovery room, these patients undergo adductor canal block, which is a nerve block to provide 8-14 hours of postoperative pain control. For this nerve block, 15-20 ml of local anesthetic is combined with adjuvant medications to improve the quality of pain control as well as the duration of pain relief. The primary local anesthetic used for adductor canal block is ropivacaine, and the commonly used adjuvants are epinephrine and dexamethasone.

There is conflicting data available in the literature regarding efficacy of addition of clonidine to the local anesthetic injection in peripheral nerve blocks, and there is no data assessing the efficacy of this medication in adductor canal blocks.

Once the consent process is completed, patients are enrolled in two arms. Upon conclusion of surgery, a sealed and coded envelope with either clonidine or the placebo syringe will be given to the acute pain service staff performing the nerve block. This will be mixed with local anesthetic solution and injected in the adductor canal under ultrasound guidance.

The primary outcome measure will be the duration of analgesia, which will be assessed as the time interval between placement of adductor canal block to the first request of opioid analgesic by patients (which will be obtained from hospital electronic medical records). Secondary outcomes will include:

1. Duration of sensory block, which will be assessed as the time interval between injection of local anesthetic and report of postoperative pain of 3 or more on an 11 point scale (0=no pain; 10= worst pain imaginable) by the patient (this will be assessed every 4 hours).

2. Duration of motor block, which will be assessed as the time interval between the onset of motor block to complete recovery of motor block by assessing straight leg raise strength (this will be assessed every 4 hours).

3. Cumulative 24 and 48 hour opioid analgesic use.

4. Post-block pain scores, evaluated by an 11 point pain score (0-10), which will be done every 15 minutes for the first hour after surgery and every 4 hours thereafter for 24 hours.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 80
• Est. completion date: February 28, 2019
• Est. primary completion date: February 28, 2019
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Men and women ages 18 and older

• ASA physical status classification system I, II and III (healthy patient or patient with mild to moderate systemic disease)

• Patient coming in for elective total knee arthroplasty under general or neuraxial anesthesia and postoperative adductor canal block

• Patients staying for at least 24 hrs post operatively

• Patients who provide informed consent

• Patients presenting for surgery >1 hour in length and <6 hours.

Exclusion Criteria:

• History of recent common colds, upper respiratory infections or immune deficiencies

• Patients allergic to clonidine

• Pregnant women (all women of childbearing age undergo pregnancy testing prior to anesthesia as per UVMMC peri-operative protocol)

• Patients who are already on chronic clonidine therapy for management of blood pressure

• Patients on chronic opioid therapy defined as more than 10 mg of oxycodone per day (or equivalent doses of other opioid analgesics)

Related Conditions & MeSH terms

• Pain, Postoperative
• Postoperative Pain

Intervention

Drug:
• Clonidine
50 mcg Clonidine added to the solution of 0.5% ropivacaine, 2 mg dexamethasone and 5 mcg/ml epinephrine for adductor canal block-present in the treatment group.
• Placebo
Normal saline added to the solution of 0.5% ropivacaine, 2 mg dexamethasone and 5 mcg/ml epinephrine for adductor canal block-present in the placebo group.
• Ropivacaine
Clonidine or Placebo added to the solution of 0.5% ropivacaine, 2 mg dexamethasone and 5 mcg/ml epinephrine for adductor canal block-present in both treatment and placebo groups.
• Dexamethasone
Clonidine or Placebo added to the solution of 0.5% ropivacaine, 2 mg dexamethasone and 5 mcg/ml epinephrine for adductor canal block-present in both treatment and placebo groups.
• Epinephrine
Clonidine or Placebo added to the solution of 0.5% ropivacaine, 2 mg dexamethasone and 5 mcg/ml epinephrine for adductor canal block-present in both treatment and placebo groups.

Locations

Country	Name	City	State
United States	University of Vermont Medical Center	Burlington	Vermont

Sponsors (1)

Lead Sponsor	Collaborator
University of Vermont

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Duration of Analgesia	the time interval between placement of adductor canal block to the first request of opioid analgesic by patients	24 hours for primary outcome