Common Anesthetic Prevents Chronic Pain After Breast Cancer Surgery
Many women suffer from chronic pain after mastectomy, but that may soon change. Doctors have found that women treated with a local anesthetic during surgery were less likely to experience pain after breast surgery.
Chronic pain after a breast cancer surgery (mastectomy) is a common problem—up to 68% of women experience pain following a mastectomy. However, doctors from the University of Virginia may have found a way to prevent it in the form of a common anesthetic.
At the recent ANESTHESOLOGY 2014 annual meeting of the American Society of Anesthesiologists, the research team reported evidence that lidocaine, a local anesthetic with noted anti-inflammatory properties,1 may have prevented chronic post-surgical pain (CPSP) in their mastectomy patients.
Women with CPSP typically experience significant inflammation and nerve damage, which causes neuropathic pain in the chest, armpit or upper arm that can affect their ability to perform simple tasks.2 This condition, also referred to as post-mastectomy pain syndrome (PMPS), can last for several years, even indefinitely,3 affecting quality of life and possibly leading to depression.4
Surgical Technique and Medical Therapy
While refining the mastectomy procedure with careful dissection and minimally invasive surgical techniques can help prevent the nerve damage that leads to CPSP,5 medical therapies may be a vital step to reducing adverse pain outcomes, as well.
Lead author of the study, Mohamed Tiouririne, MD, an associate professor of anesthesiology at the University of Virginia in Charlottesville, said he was curious to see if lidocaine's anti-inflammatory benefits could be useful in preventing CPSP.
"What got me interested [in lidocaine] is that it has all the anti-inflammatory action that might help during the surgery [manage] the stress response to surgery and the inflammatory response," Dr. Tiouririne said. Lidocaine "may mitigate that response and avoid the development of acute pain and chronic pain."
How the Study Was Conducted
Lidocaine is already a commonly used anesthetic for many procedures, Dr. Tiouririne said. Since it's been found to reduce opioid consumption and improve post-surgical response to abdominal surgeries, Dr. Tiouririne and colleagues decided to conduct a trial. In the study, 61 women were split into two groups. In the first group, 33 patients were given intravenous lidocaine during their mastectomy procedures and then up to two hours afterwards; while the remaining 28 women were given an IV with no pain medication (placebo). The physicians were blinded as to which group was given the lidocaine. All patients were evaluated at the time of surgery and then 6 months later.
Initially, lidocaine did not seem to show any noticeable acute improvements: opioid consumption, pain scores, fatigue, and postoperative nausea and vomiting weren't noticeably different between the two groups of patients.6
However, when Dr. Tiouririne reinterviewed the patients 6 months later they found that lidocaine was associated with 20-fold decrease in CPSP. Only 12 patients reported CPSP—4 (12%) in the lidocaine group compared with 8 (30%) in the placebo group.7
Other treatments for mastectomy patients in the acute (perioperative) and chronic settings are being explored. These include ropivacaine, gabapentinoids, eutectic mixture of local anesthetics and antidepressants.
According to Stephen Humble, PhD, from the Imperial College London, these methods have all shown efficacy in reducing the acute neuropathic pain that results from mastectomy procedures, though application of these drugs varies.
"These medications are already being used around the world in this setting – but in a disjointed fashion." He had his own doubts about lidocaine intravenous infusion as a sole means to chronic pain relief. >"I feel that lidocaine may [have] little impact on inflammation. However, I think that intravenous lidocaine could reduce the incidence of chronic pain in mastectomy patients as part of a multimodal approach," Dr. Humble said. There's a lack of "hard evidence" into the optimal dosages for this patient group, however.
Indeed, Dr. Tiouririne said he hopes to organize a new study to increase lidocaine dosage past the two-hour post-operative period and see if patient outcomes further improve. As for using lidocaine in a multimodal approach, "I cannot say more is merrier," Dr. Tiouririne said, but he noted "it may be helpful."
The University of Virginia analysis also found that women who had breast implants or had undergone radiotherapy associated with 16-fold and 29-fold increases in CPSP, respectively. According to Dr. Tiouririne, this could give practitioners a better understanding of chronic pain incidence in certain mastectomy patients.
"I think that for patients that do have breast implants or do have radiation, they may have more tissue damage than the ones who did not, and… that's why they may have more chronic pain than the other population that did not have any of those. This is a good thing to know, so maybe we need to target our treatments a little bit differently for this patient population."
Dr. Tiouririne's analysis of lidocaine intravenous infusion for mastectomy patients can be found in Regional Anesthesia and Pain Medicine. The secondary analysis is pending publication.
The authors declared no conflict of interest.