Immunology

New combinations of postoperative pain treatment decreased both pain and the use of narcotic pain relievers according to two studies presented this week at the 2013 Clinical Congress of the American College of Surgeons. One pain treatment utilized the simple but nonstandard application of ice packs after major abdominal operations in patients, and the other treatment was a prolonged drug delivery method using nanotechnology in animals.

Past research has shown that postoperative pain is often undertreated. The standard pain treatment after most major operations is narcotics, also called opioids, such as morphine. However, these medicines have many possible side effects, including sleepiness, constipation, and-when used long term-the risk of drug dependence.

"A growing body of scientific evidence shows that narcotics may not be the best way to control pain," said the principal investigator of the ice pack study, Viraj A. Master, MD, PhD, FACS, associate professor of urology at Emory University School of Medicine, Atlanta. "We now know that it is more effective to use combination treatments that reduce the amount of narcotics needed."

New use for ice following open abdominal procedures

Multiple studies have found that cryotherapy-application of ice to the surgical wound-is safe and effective at reducing pain after some types of operations, such as orthopedic procedures. However, researchers have not studied the use of cryotherapy in patients undergoing major, "open" (large-incision) abdominal operations, Dr. Master explained.

For the Emory study, Dr. Master and his colleagues compared the effect on postoperative pain of applying soft ice packs to the incision area after open abdominal operations (27 patients), versus no ice application (28 patients).

Patients in the cryotherapy group applied ice packs to the wound at desired intervals for at least 24 hours. They also had the option of taking prescribed opioids, whereas the other group received only opioids for pain relief. Twice a day the patients rated their pain intensity on a line indicating a range from no pain (zero) to severe pain (100).

The results showed that patients who used ice packs reported significantly less pain than those who did not ice their surgical wounds. On average, the cryotherapy group had about 50 percent less pain on the first and third days after the operation compared with the no-ice control group, according to the investigators. In addition, on the first postoperative day, the cryotherapy group used 22.5 percent less opioid pain medication than controls, while some patients who iced reportedly used no narcotics.

According to Dr. Master, surgeons should recommend that their patients who have open abdominal operations intermittently apply ice packs to the surgical wound, removing the ice when it becomes too cold. "An ice pack," he said, "is safe and inexpensive, gives the patient a sense of empowerment because it is self-care, and doesn't require high-tech devices."

Prolonged delivery of lidocaine effective in animals

The pain treatment utilized in the second study used a high-tech device-nanoparticles-to create a controlled-release delivery system for the nonopioid numbing medication lidocaine. Although the effects of lidocaine injections usually are short-lived, nanotechnology allowed researchers at Houston Methodist Research Institute to extend the drug's delivery time so that pain relief lasted all seven days of the study.