A pain that never ends?

A pain that never ends?

Researchers to study patient pain post surgery

By Marilee Griffin
Dr. Patrick Tighe

Dr. Patrick Tighe

Most patients undergoing surgery expect some pain and discomfort after the procedure. For a surprising number of people, however, the pain never really goes away.

With the help of a federal grant, researchers are studying how postoperative pain can change days and months after surgery — and how certain factors affect the way patients experience this pain. Their study also will examine how this data may predict the development of chronic postoperative pain, which is generally defined as pain persisting for more than three months.

Chronic postoperative pain is a recognized complication of many common procedures, and contributes substantially to chronic pain’s annual price tag of $600 billion, said Patrick Tighe, M.D. M.S., an assistant professor of anesthesiology in the College of Medicine and principal investigator of the grant.

“Up to 50 percent of patients can develop lifelong pain after certain types of surgery,” he said. “That’s an important risk for certain patient populations, since most of us generally enter into surgery with the hope of eventually feeling better.”

The five-year, $2.5 million grant from the National Institute of General Medical Sciences will allow Tighe’s team to assess 500 surgical patients immediately after surgery and six months into recovery.

In recent years, the pain research community has been looking closely at how different patients experience different sensations as painful, Tighe said. While it’s often expected that a patient’s pain will gradually decrease during the first week after surgery, recent research suggests that this is not always the case, with up to one-third of patients experiencing the same amount or more pain during the first postoperative week.

“Some people will have a surgery and after five to seven days, most of the pain from that surgery goes away,” Tighe said. “Other patients have increasing pain for seven days and may stabilize to have chronic pain that stays for the rest of their lives.”

To track the participants’ pain for the first week after surgery, the researchers will measure pain three different ways: first, every few minutes via a computerized pump called the patient-controlled analgesia device, which allows patients to control their pain using IV pain medication; second, every few hours with an evaluation by a medical professional; and third, every day through two well-known questionnaires that will allow patients to rate their pain.

Patients will again be queried six months after surgery to determine the presence and extent of any postoperative pain. Those findings, combined with previously collected data — including sociodemographic information, clinical data on patient activity and survey results evaluating how patients think about pain — will be used to give the results context.

Tighe and his team have three specific goals in collecting the data.

The first is to look at variations in patients’ pain measurements throughout the day during the first week after surgery to see if patterns can be identified. Next, the team will review clinical, biological, psychological and social variables that may contribute to these patterns. Finally, the researchers will use this information to determine whether there’s an association between these patterns and patients’ risk of developing chronic postsurgical pain.

“If we can stop pain from developing into a chronic condition, we can help ameliorate a significant public health issue that impacts many facets of society,” Tighe said.

Participant enrollment for the study is anticipated to begin in late summer.

“We are very fortunate to have such a great opportunity to study this issue,” Tighe said. “We have a simply awesome team from a wide range of disciplines, allowing us to examine this problem from several new and exciting perspectives.”

Tighe’s cross-disciplinary team includes Roger Fillingim, Ph.D., a professor in the College of Dentistry and director of the UF Pain Research and Intervention Center of Excellence; Parisa Rashidi, Ph.D., an assistant professor of biomedical engineering in the College of Engineering; Margaret Wallace, Ph.D., a professor of molecular genetics and microbiology in the College of Medicine; and Baiming Zou, Ph.D., an assistant professor of biostatistics in the colleges of Medicine and Public Health and Health Professions.