Large studies examining the efficacy of intraoperative lidocaine infusions on breast cancer surgery-associated pain were found to be feasible, according to a pilot study published in the Journal of Pain.
A total of 100 women scheduled to undergo unilateral or bilateral mastectomy or lumpectomy at a Canadian hospital were enrolled in the trial (and randomly assigned to receive an intraoperative lidocaine infusion of 1.5 mg/kg bolus followed by lidocaine at 2 mg/kg/hour (n=51), placebo and 300 mg perioperative pregabalin (followed by pregabalin 75 mg twice daily for 9 days; n=50), or placebo (n=50).
The feasibility of performing a larger randomized trial was the primary aim of this study. Secondary outcomes were the efficacy of each intervention, persistent postoperative neuropathic pain at 3-month follow-up, acute postoperative pain assessed with a numeric rating scale (NRS) at rest and with movement, postoperative opioid consumption, length of hospital stay, and quality of life.
The recruitment target was reached after 42 weeks, which surpassed the feasibility outcome of a 52-week recruitment period, and the follow-up target was met at 100% at 3 months. A total of 53% of patients had persistent neuropathic pain at the 3-month follow-up, with 77.4% of these patients reporting mild pain (ie, a NRS score of 0-3) and 7.5% reporting severe pain (ie, a NRS score of 7-10). On abduction of the arm on the ipsilateral side of surgery, the percentage of patients who reported mild pain, moderate pain, and severe pain were 69.8%, 17.0%, and 13.2%, respectively, on the abduction of the arm to 90 degrees on the ipsilateral side of surgery.
Treatment with lidocaine vs pregabalin was associated with lower rates of persistent neuropathic pain (43.1% vs 63.3%, respectively; risk ratio [RR], 0.68; 95% CI, 0.47-1.0; P =.049). Lidocaine treatment was not found to be associated with a reduction in moderate to severe persistent neuropathic pain (ie, NRS ≥4; 7.8% vs 16.3%, respectively; RR, 0.48; 95% CI, 0.16-1.49; P =.205). Treatment with pregabalin was not associated with a decrease in persistent neuropathic pain (60% vs 46%, respectively; RR, 1.3; 95% CI, 0.90-1.90; P =.166) or moderate to severe persistent neuropathic pain (12% vs 12%; RR, 1.00; 95% CI, 0.35-2.89; P =1.00). Lidocaine/pregabalin combinations were not associated with reductions in persistent pain at follow-up (52% vs 58.3%, respectively; RR, 0.89; 95% CI, 0.54-1.48; P =.656).
Study limitations include a small sample size, the inclusion of patients from 2 hospitals in Canada, and the lack of standardization of perioperative pain treatment.
“Persistent pain after breast cancer surgery is a common problem and there are no established interventions known to reduce its development. Results of this pilot trial are encouraging and provide insights into developing a larger definitive trial,” concluded the study authors.
Khan JS, Hodgson N, Choi S, et al. Perioperative pregabalin and intraoperative lidocaine infusion to reduce persistent neuropathic pain after breast cancer surgery: A multicenter, factorial, randomized, controlled pilot trial [published online March 4, 2019]. J Pain. doi:10.1016/j.jpain.2019.02.010