The longer a patient is in severe pain during the first 24 hours following surgery, the more likely he or she will still be experiencing some form of chronic postsurgical pain one year later, according to a study presented at Euroanaesthesia 2015.
This prospective, observational study (abstract ESAPC1-2), designed to investigate the incidence, characteristics and risk factors for chronic postsurgical pain in Europe, assessed patients undergoing elective procedures in 21 hospitals in 11 countries. Pain was measured during the first 24 hours following surgery using a standardized questionnaire, and follow-up evaluations were performed at six and 12 months postoperatively, using the Brief Pain Inventory (BPI) and DN4 (Douleur Neuropathique en 4 questions).
In all, more than 3,000 patients were assessed on day 1 following surgery, and six- and 12-month follow-up was performed on 889 of these patients. The authors found that the incidence of at least moderate chronic postsurgical pain (defined as Numeric Rating Scale score ≥3) was 16% on day 1 and 11.8% at six and 12 months. Severe pain (defined as Numeric Rating Scale score ≥6) was reported by 2.9% and 2.2% of patients at six and 12 months, respectively. In addition, at 12 months, signs of neuropathic pain were recorded in 39.2% of the patients with moderate pain, and in 57.1% of the patients with severe chronic postsurgical pain. Not surprisingly, the functional effect of pain on activities increased with severity of chronic postsurgical pain (P<0.001).
Multivariate analysis identified orthopedic surgery, preoperative chronic pain and percentage of time in severe pain 24 hours after surgery as predictive factors for chronic postsurgical pain. Furthermore, a 10% increase in the percentage of time in severe pain on day 1 was associated with a 30% increase in chronic postsurgical pain incidence at one year following surgery.
“The last variable has not been [previously] described as a risk factor [for chronic postsurgical pain],” said Ulrike Stamer, MD, a professor in the Department of Anesthesiology and Pain Therapy at the University of Bern Hospital, Switzerland, and one of the co-authors of the Euroanaesthesia study. “In contrast to previous investigations, we could not confirm that high pain scores after surgery were associated with chronic postsurgical pain, however.”
Dr. Stamer and colleagues also noted the unique design of their study, which unlike previous studies of similar populations used Web-based patient questionnaires for the six- and 12-month follow-up assessments and documented perioperative data in the “Pain Out” registry.
Jonathan S. Gal, MD, assistant professor of anesthesiology at Icahn School of Medicine/The Mount Sinai Medical Center, in New York City, who was not involved in the study, believed it drew necessary attention to a previously understudied issue, while incorporating an innovative methodology to do so. “Chronic postsurgical pain is a serious complication of surgery that can significantly impair a patient’s quality of life, thereby making it a crucial issue,” he said. “Oftentimes, however, it is not constantly considered, but rather takes a backseat to more acute perioperative issues.”