Preoperative psychological factors influence analgesic consumption and self-reported pain intensity following breast cancer surgery.

BACKGROUND

Psychological factors such as anxiety and mood appear to influence acute postoperative pain; however, there is conflicting evidence on the relationship between preoperative psychological parameters and the severity of postoperative pain. In the context of the stressful setting of initial surgery for breast cancer, we conducted a prospective observational study of patients who were scheduled to undergo initial breast cancer surgery.

METHODS

The objectives were to examine the potential associations between predefined preoperative psychological parameters and (i) Self-reported pain scores at discharge from the postoperative acute care unit, (ii) Cumulative perioperative opioid consumption at four hours postoperatively and (iii) Self-reported pain as measured during the first seven days after surgery. Patients completed the following questionnaires during the three hours prior to surgery: the Spielberger State Trait Anxiety Inventory (STAI State and Trait), the Pain Catastrophizing Scale (PCS), the Cohen Stress Questionnaire (CSQ), the Hospital Anxiety and Depression Scale (HADS A and D), and the short-form McGill Pain Questionnaire. Postoperative pain experience was assessed using patient self-reports of pain (SF Magill Pain questionnaire on discharge from the postanaesthesia care unit and a pain diary for seven days postoperatively) and records of analgesic consumption.

RESULTS

Pre- to postoperative self-reported pain was significantly different with respect to the STAI State, Cohen score and PCS for both low and high values (p < 0.001), but only patients categorized as having low STAI Trait, HADS A, and HADS D values achieved significant differences (p < 0.001). A significant positive correlation was demonstrated between preoperative state anxiety (STAI) and the most severe pain reported during the first seven days postoperatively (r = 0.271, p = 0.013). Patients who were categorized preoperatively as having a "high value" for each of the psychological parameters studied (HADS A and D, STAI State and Trait and PCS) tended to have greater perioperative opioid consumption (up to four hours postoperatively); this trend was statistically significant for HADS D and HADS A only. Using a linear regression model, state anxiety was found to be a significant predictor of postoperative pain based on self-reports during the first seven postoperative days (standardized β = 0.271, t = 2.286, p = 0.025).

CONCLUSION

Preoperative state anxiety, in particular, is associated with the severity of postoperative pain experienced by women undergoing initial breast cancer surgery. Formal preoperative assessment of anxiety may be warranted in this setting with a view to optimize perioperative analgesia and wellbeing.