BY PAM MCGRATH

“Chronic pain is pain that lasts longer than expected, usually in the timeframe of three months or more,” says Lara Crock, MD, PhD, WashU Medicine anesthesiologist at Barnes-Jewish Hospital. “For instance, it’s normal to have pain after spraining an ankle or breaking a bone, but it resolves as the tendons or bones heal. Chronic pain can be constant or come and go, but it continues over months or years.”

Chronic pain can be caused by a number of conditions, including nerve damage, muscle pain, injuries that don’t heal properly, arthritis, cancer and sickle cell disease. In some instances, Crock says, “identifying the source of someone’s pain can be a trial-and-error process. Even if two people have the same source of pain, they may experience different pain symptoms. Pain’s subjective nature makes it complicated to diagnose.”

In some instances, chronic pain can be relieved through an intravenous (IV) infusion of lidocaine. The Pain Management Center at Barnes-Jewish Hospital is the only clinic in the St. Louis region to offer lidocaine infusion to treat chronic pain. For some people, the treatment can provide weeks or months of relief from debilitating nerve pain and improve their quality of life.

Lidocaine is a familiar over-the-counter drug, often an ingredient in pain-relief medications applied to the skin. Lidocaine is also classified as an antiarrhythmic medication and as such has been used in clinical settings for years as an IV infusion to treat people with ventricular arrhythmias. In recent years, lidocaine infusions have been used to manage acute pain—sudden pain with a specific cause—during surgery or after, and to control chronic pain.

“The Pain Management Center began offering lidocaine infusions to patients several years ago. Our experience using this treatment has shown that it is most effective for people with neuropathic, or nerve, pain rather than for those with other conditions, including herniated discs, sciatica or arthritis,” says Crock. To date, the center has treated more than 400 people with lidocaine infusion, with nearly half of those receiving ongoing treatment with positive results.

According to Crock, research suggests that chronic pain may be caused by the spontaneous “firing” of injured nerves. Lidocaine infusion works by inhibiting those spontaneous discharges.

As is true with many treatments, patients’ responses to lidocaine infusion vary. In some, the chronic pain is lessened for weeks or months; in others, relief may be experienced only during the infusion process or not at all.

“If effective, lidocaine infusion is safe to use regularly and indefinitely,” says Crock. “Lidocaine is generally well tolerated, with few people experiencing side effects. We evaluate patients on a regular basis to ensure they are continuing to benefit from the treatment and that they are not experiencing a secondary pain generator—a herniated disc or sciatica, for instance—that should also be addressed.”

Patients who are not good candidates for lidocaine infusion are those with pain not caused by nerve damage, those with an allergy to the medication, those with poor kidney or liver function or those who have a history of heart arrhythmias or uncontrolled seizures.

Crock notes that most people who derive benefit from lidocaine infusion also receive other treatments for their pain. “Our goal at the Pain Management Center is to provide holistic care for each patient,” she says.

People treated at the center receive an individualized treatment plan developed by a team of interventional pain-management physicians, clinical pain pharmacologists, pain psychologists, and physical and occupational therapists. Crock notes: “After assessment, we determine the most beneficial approach to managing a patient’s pain, whether with medication, injection, physical and occupational therapy, pain psychology and, sometimes, interventions such as spinal cord stimulation. As much as possible, we develop treatment plans that keep opioids at a low dosage, or we succeed in avoiding their use completely.”