A comparison of the effects of two analgesic regimens on the development of persistent post-surgical pain (PPSP) after breast surgery

Background: Multimodal perioperative analgesic regimens may decrease the incidence of persistent post-surgical pain (PPSP) following surgery for breast cancer. We carried out a prospective, randomised, controlled, single-blind trial to test the hypothesis that multimodal analgesic regimen of pregabalin, paravertebral block and regular analgesics decreases the prevalence of PPSP compared to ‘standard’ analgesic regimen. Our secondary hypothesis was that associations exist between PPSP and genetic, neurophysiological, psychological and clinical parameters measured perioperatively. Methods: Fifty-one patients undergoing breast surgery were randomly allocated to either the control group, receiving ‘as required’ oral analgesics and intravenous morphine, or the intervention group, receiving a multimodal analgesic regimen consisting of perioperative pregabalin, paravertebral block and regular acetaminophen and diclofenac sodium. Clinical measurements included visual analogue scale for pain, area of hyperalgesia surrounding the surgical wound and pain catastrophising. Patients were interviewed three months postoperatively to determine the presence of persistent pain. Results: Twenty patients (20/51; 39.2%) developed PPSP. There was no difference in the incidence of PPSP between patients in the control and intervention groups (11/26; 42.3% vs 9/25; 36.0%, p = 0.39). Patients who developed PPSP and those who did not were similar in terms of perioperative clinical measurements. Conclusions: This study confirms the high prevalence (39%) of PPSP after surgery for breast cancer. The most important finding of this study is the failure to identify a benefit of a multimodal analgesic regimen consisting of perioperative pregabalin, paravertebral block and regular acetaminophen and diclofenac sodium in decreasing the incidence of PPSP three months after breast surgery compared to the ‘standard’ analgesic regimen described.