Preoperative Psychosocial and Psychophysical Phenotypes as Predictors of Acute Pain Outcomes After Breast Surgery

Abstract

The severity and impact of acute pain after breast surgery varies markedly among individuals, underlining the importance of comprehensively identifying specific risk factors, including psychosocial and psychophysical traits. In this prospective observational study, women (n = 234) undergoing breast-conserving surgery, mastectomy, or mastectomy with reconstruction completed a brief bedside quantitative sensory testing battery, along with measures of psychosocial characteristics. Postoperative pain severity, impact, and opioid use at 2 weeks were assessed using Brief Pain Inventory and procedure-specific breast cancer pain questionnaires. Moderate-severe average pain (>3/10) was reported by 29% of patients at 2 weeks. Regression analysis of pain outcomes revealed that pain severity was independently predicted by axillary dissection, pre-surgical pain, temporal summation of pain (TSP), (-)positive affect, and behavioral coping style. Pain impact was predicted by age, education, axillary dissection, reconstruction, but also by negative affect and depression scores. Lastly, opioid use was predicted by age, education, axillary dissection, reconstruction, TSP, and reinterpreting coping style. Our findings suggest that, individuals with certain phenotypic characteristics, including high TSP and negative affect, may be at greater risk of significant pain and continued opioid use at 2 weeks after surgery, independent of known surgical risk factors. PERSPECTIVE: We measured differences in the psychosocial and psychophysical processing of pain amongst patients before breast surgery using simple validated questionnaires and brief quantitative sensory testing. Independent of younger age and procedural extent (axillary surgery and reconstruction), affect and greater temporal summation of pain predicted acute postoperative pain and opioid use.

Trial registration: ClinicalTrials.gov NCT02329574.

Keywords: Temporal summation of pain; depression; mastectomy; opioid analgesia; postsurgical pain.

Conflict of interest statement

Disclosures: There were no conflicts of interest for any of the authors pertaining to this work. This work was supported by the National Institutes of Health (NIH K23 GM110540 to KLS), and was registered at Clinicaltrials.gov: NCT02329574.

Copyright © 2018 the American Pain Society. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1:. Recruitment, enrollment and inclusion of participants.

N given refers to numbers completing different questionnaires at each timepoint.

Figure 2:. Characterization of Pain 2 weeks after surgery.

Patients reported severity (A) of pain in surgical area using the Brief Pain Inventory (BPI), which rating increased from baseline to 2 weeks postoperatively (paired t test =−9.8 (208), (CI: −1.5, −1.0), p<0.001). Patients also rated the location (B) of pain using the Breast Cancer Pain Questionnaire (BCPQ), which was most common in breast and axilla. On the BCPQ, patients rated the severity and frequency of pain at each site, allowing calculation of (C)the Pain Burden Index (PBI)= Σ [Pain score at each site × frequency], which was increased from baseline at 2 weeks (paired t test =−11.6 (233) (CI: −23.5, −16.7)). Box indicates group means and whiskers standard deviation, and dots indicate individual scores of participants.

Figure 3:. Pain at rest and with movement in different surgical subgroups over time.

Patients rated current pain at rest (A) and with movement (B) using the numerical rating scale (NRS) (0–10) at baseline and various times after surgery: on post operative day (POD) 0 (day of surgery, 2 hours after surgical end), POD 1 (24 hours after surgical end), and 2 weeks after surgery (POD14). Pain varied by surgical type (F=10.6 (df=2), p<0.001, with movement (F=151 (df=1), p<0.001), and there was a significant three-way interaction (time × surgical type × movement, F=3.5 (df=6), p=0.002), suggesting that more extensive surgeries are associated with longer acute pain and produced more pain with movement during the first 2 weeks after surgery. Y axis indicates % of each surgical group, and numbers on columns indicate actual number of patients.

Figure 4:. Correlation of pain Severity with sensory disturbance and pain impact.

Using the Breast Cancer Pain Questionnaire, patients answered questions regarding pain severity in the surgical area, but also different type of sensory disturbances in the surgical area (Table 2) and impact on aspects of their life (Appendix A). Pain severity was moderately correlated with the sensory disturbance score (A) (Spearman Rho 0.499, p<0.001) and the pain impact score (B) (Spearman Rho 0.552, p<0.001).

Figure 5:. Incidence of analgesic use at 2 weeks after surgery.

Using the Breast Cancer Pain Questionnaire, patients provided information about their use of any analgesic, as well as specifically about opioid analgesics, 2 weeks after surgery. More extensive surgery (A) including reconstruction (p=0.002) and (B) axillary dissection (p<0.001) was associated with higher likelihood of opioid use (right side of each graph) (see also Table 7 for further statistical testing).