Opioid Induced Loss of Local Anesthetic Potency in Patients Undergoing Total Knee Arthroplasty

Stopped early

Conditions studied: Opioid Tolerance, Opioid Naive, Opioid Exposure

In brief

Peripheral nerve blocks with local anesthetics (LAs) have become an integral part of postoperative pain management particularly for patients undergoing major limb procedures such as such as Total Knee Arthroplasty (TKA). And while postoperative pain management in patients with a history of chronic opioid use may be difficult with systemic opioids because of opioid tolerance, there is anecdotal evidence suggesting that these patients may also be less responsive to LAs. Preliminary data from pre-clinical animal study show that there is a decreased LA potency in blocking sciatic nerve in opioid tolerant rats. And the decrease in LA potency is reversed by the knock-down of the beta4 subunits of Voltage-gated sodium channels along the sciatic nerves, suggesting the opioid induced intrinsic changes in the peripheral nerve as an underlying mechanism for opioid induced loss of LA potency. Study Goals: To determine the extent to which the changes in beta4 subunits of voltage-gated sodium channels are reflected in surgical patients. Experimental Design / methodology: This is a prospective, double-blind, active treatment controlled study. TKA Patients who receive nerve blocks will be grouped according to their history of pre-operative opioid use, and then tested for local anesthetic use for nerve block. Synovial tissues will also be collected for the analysis of beta4 subunits. Subject population: Patients who are scheduled for TKA procedure, and agree to receive peripheral nerve block for postoperative pain control, will be recruited for the study. Patients will participate in one of the three study groups: opioid naive, opioid history and opioid tolerant. 30 patients for each group with a total of 90 patients will be recruited. This study will not only determine the extent to which the preclinical findings are reflected in clinical patients, but also identify the underlying mechanisms that may suggest strategies for more effective post-operative pain management in the growing population of opioid tolerant patients

Key facts

Study ID

NCT03294174

Run by

University of Pittsburgh

People needed

48

Expected to finish

2017-06-01

Last updated by the study team

2018-11-09

Who can join

Age: 18 and older, up to 80. Sex: any. Healthy volunteers: not accepted.

You may qualify if…

• American Society of Anesthesiologists Classification 1,2 and 3;
• Age between 18-80;
• Both males and females of all races
• Receive total knee arthroplasty (TKA)
• Agree to receive peripheral nerve blocks for postoperative pain control
• Participants of the study will belong to one of the three groups: opioid naive, opioid history (those with a history of opioid use, but who are not currently on opioids) and opioid tolerant (those using opioids at the time of surgery)

You may not qualify if…

• Intolerance and/or known allergy to opioids and/or LAs;
• TKA due to trauma;
• Use of general anesthesia for the operation

Where it is running

• University of Pittsburgh — Pittsburgh, Pennsylvania, United States

Full record on ClinicalTrials.gov

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