(RxWiki News) We expect surgery to help heal a painful condition, but sometimes the procedure can lead to a new type of pain. Researchers behind a new study explored post-op pain after heart surgery.
The researchers followed patients for two years after having heart surgery and measured their postoperative pain, analyzing the rate and risk factors for pain.
The researchers found that just under 10 percent of patients still experienced persistent pain two years after their heart surgery.
"Tell your doctor if you have persistent pain after surgery."
According to the authors of this study, led by Manon Choinière, PhD, of the Department of Anesthesiology at the University of Montreal in Canada, lingering pain after an operation can be an underrecognized complication of surgery.
The researchers aimed to examine rates of persistent pain and risk factors for pain following cardiac surgery. To do so, Dr. Choinière and team looked at patients who were scheduled to receive a coronary artery bypass grafting or a valve replacement procedure, or both, during February 8, 2005 through September 1, 2009 at four different Canadian university surgical centers.
These procedures are both common surgeries to regulate issues with blood flow for patients with heart problems like heart disease.
For the purposes of this study, pain was considered "persistent postoperative pain" if it developed after surgery, it was not related to pain felt before surgery or to another cause like an infection and lingered for at least three months.
The final analysis included 975 patients with an average age of 61.9 years, and 79 percent of these patients were men.
The researchers measured the patients' pain levels using The Pain Catastrophizing Scale prior to their operation, in the first week after the procedure and three, six, 12 and 24 months later. Measures of mental health were also taken using the Hospital Anxiety and Depression Scale.
Dr. Choinière and team found that persistent postoperative pain was common, but seemed to decrease as time went on. Three months after surgery, 40.1 percent of participants had persistent pain, a number which dropped to 22.1 percent at six months, 16.5 percent at 12 months and 9.5 percent at 24 months after surgery.
A similar trend was seen in patients who classified their persistent pain as "moderate to severe." Three months after surgery, 14.1 percent of patients experienced moderate to severe pain, which fell to 7 percent at six months, 6.6 percent at 12 months and 3.6 percent at 24 months.
The researchers found that levels of pain in the initial healing period seemed to predict levels of pain down the road.
"The more intense the pain during the first week after surgery and the more it interfered with functioning, the more likely the patients were to report persistent postoperative pain," wrote Dr. Choinière and team.
Additionally, the researchers saw a connection between pre-existing pain, preoperative anxiety and later, persistent post-op pain.
It is important to note that pain was self-reported by patients and is a topic that can be interpreted differently from person to person.
"Future research is needed to determine whether interventions to modify certain risk factors, such as preoperative anxiety and the severity of pain before and immediately after surgery, may help to minimize or prevent persistent postoperative pain," suggested Dr. Choinière and team.
This study was published online February 24 in CMAJ, the journal of the Canadian Medical Association. No conflicts of interest were reported.