ORLANDO, Florida—Perioperative pregabalin (Lyrica^®) may stave off chronic pain and allow knee surgery patients to be mobile earlier. Data on the efficacy of pregabalin for expediting mobility among patients with total knee replacement were presented at the 2008 annual meeting of the American Society of Anesthesiologists in Orlando, Florida.¹

“Chronic pain after total knee replacement is an underdiagnosed problem, and some doctors may not believe patients who complain of chronic knee pain after surgery and disregard them,” said lead study author Asokumar Buvanendran, MD, an associate professor of anesthesiology and director of orthopaedic anesthesia at Rush Medical College in Chicago. “Orthopaedic surgeons need to recognize that it is possible to have chronic pain after knee surgery and that preventing it would be beneficial for the patients and their doctors.”

Prevent pain from becoming chronic

Chronic pain affects between 1% and 10% of total knee arthroplasty patients, Dr. Buvanendran told MSKreport.com. Prevention is key. “Once you develop chronic pain, treatment is tough, patient comfort and quality of life decreases, and there is an increase in healthcare dollars.”

In the new trial of 240 patients having knee replacement surgery, half received 300 mg pregabalin 2 hours before surgery and repeat doses at 150 mg twice a day for 14 days following surgery; the other half of patients received a placebo at the same time intervals. All postsurgery patients received epidural infusion of fentanyl/bupivacaine using continuous basal infusion with superimposed patient-controlled bolus.

Better results even 6 months after pregabalin treatment

“Giving pregabalin perioperatively for 14 days after surgery still [had] an impact 6 months down the road,” he said. At 6 months post-knee replacement, 0.9% of treated patients had neuropathic pain compared with 9.4% in the placebo arm. Also at 6 months, the incidence of allodynia in the operated leg was lower for the treatment group than the placebo group (6.4% vs 19.5%, respectively) and the incidence of hyperalgesia also was lower (6.4% vs 21.1%, respectively).

Patients who received pregabalin also had better range of knee motion following surgery. They were able to perform simple tasks when returning home such as climbing stairs with a range of mobility of 85º compared with a range of mobility of 79º for placebo patients.

“Now that we know it works, we are trying to understand where or how it works in spine and brain by measuring various biochemicals,” Dr. Buvanendran said. While the treatment was safe, “the dose we picked was a bit too high, so we did see sedation postoperatively. Now we are using a smaller dose and getting the same efficacy.”

Reference

1. Buvanedran A, Reuben SS, Kroin JS, et al. Perioperative pregabalin reduces neuropathic pain at 6 months after total knee arthroplasty. Presented at: 2008 annual meeting of the American Society of Anesthesiologists; October 18-22, 2008; Orlando, Fla. Presentation A595.