Persistent Post-Mastectomy Pain: The Impact of Regional Anesthesia Among Patients with High vs Low Baseline Catastrophizing.

BACKGROUND: Persistent post-mastectomy pain (PPMP) varies both in its severity and impact, with psychosocial factors such as catastrophizing conferring greater risk. Preoperative regional anesthesia (RA) is an important nonopioid therapy, but with variable success at preventing PPMP in previous reports. We previously reported that RA was associated with lower acute post-mastectomy pain and opioid use, but more prominently among patients with higher baseline catastrophizing. The current longitudinal investigation at 3, 6, and 12 months postop aimed to detect differential long-term impact of RA on PPMP among patients with high vs low catastrophizing. METHODS: In this prospective observational study, patients (n = 123) completed preoperative psychosocial assessment and underwent mastectomy either with (n = 56) or without (n = 67) preoperative RA. Generalized estimating equation (GEE) regression analysis assessed impact of baseline catastrophizing, RA, and their interaction, on the primary outcome of pain severity index, as well as secondary outcomes including cognitive and emotional impact of pain, and persistent opioid use. RESULTS: We observed a significant interaction between the effect of catastrophizing and RA on PPMP. Specifically, RA was associated with reduced pain severity and pain impact 3, 6, and 12 months postoperatively, but only among those with high baseline catastrophizing scores. In addition, both RA and lower catastrophizing scores were associated with lower incidence of persistent opioid use. CONCLUSIONS: The efficacy of therapies to prevent PPMP may be importantly influenced by pain-modulatory psychosocial characteristics. These findings underscore the importance of considering individual patient factors when applying preventive treatments, and of including their assessment in future trials.

Conditioned open-label placebo for opioid reduction after spine surgery: a randomized controlled trial.

ABSTRACT: Placebo effects have traditionally involved concealment or deception. However, recent evidence suggests that placebo effects can also be elicited when prescribed transparently as "open-label placebos" (OLPs), and that the pairing of an unconditioned stimulus (eg, opioid analgesic) with a conditioned stimulus (eg, placebo pill) can lead to the conditioned stimulus alone reducing pain. In this randomized control trial, we investigated whether combining conditioning with an OLP (COLP) in the immediate postoperative period could reduce daily opioid use and postsurgical pain among patients recovering from spine surgery. Patients were randomized to COLP or treatment as usual, with both groups receiving unrestricted access to a typical opioid-based postoperative analgesic regimen. The generalized estimating equations method was used to assess the treatment effect of COLP on daily opioid consumption and pain during postoperative period from postoperative day (POD) 1 to POD 17. Patients in the COLP group consumed approximately 30% less daily morphine milligram equivalents compared with patients in the treatment as usual group during POD 1 to 17 (-14.5 daily morphine milligram equivalents; 95% CI: [-26.8, -2.2]). Daily worst pain scores were also lower in the COLP group (-1.0 point on the 10-point scale; 95% CI: [-2.0, -0.1]), although a significant difference was not detected in average daily pain between the groups (-0.8 point; 95% CI: [-1.7, 0.2]). These findings suggest that COLP may serve as a potential adjuvant analgesic therapy to decrease opioid consumption in the early postoperative period, without increasing pain.

Prediction of Persistent Pain Severity and Impact 12 Months After Breast Surgery Using Comprehensive Preoperative Assessment of Biopsychosocial Pain Modulators.

BACKGROUND: Persistent post-mastectomy pain (PPMP) is a significant negative outcome occurring after breast surgery, and understanding which individual women are most at risk is essential to targeting of preventive efforts. The biopsychosocial model of pain suggests that factors from many domains may importantly modulate pain processing and predict the progression to pain persistence. METHODS: This prospective longitudinal observational cohort study used detailed and comprehensive psychosocial and psychophysical assessment to characterize individual pain-processing phenotypes in 259 women preoperatively. Pain severity and functional impact then were longitudinally assessed using both validated surgery-specific and general pain questionnaires to survey patients who underwent lumpectomy, mastectomy, or mastectomy with reconstruction in the first postsurgical year. An agnostic, multivariable modeling strategy identified consistent predictors of several pain outcomes at 12 months. RESULTS: The preoperative characteristics most consistently associated with PPMP outcomes were preexisting surgical area pain, less education, increased somatization, and baseline sleep disturbance, with axillary dissection emerging as the only consistent surgical variable to predict worse pain. Greater pain catastrophizing, negative affect, younger age, higher body mass index (BMI), and chemotherapy also were independently predictive of pain impact, but not severity. Sensory disturbance in the surgical area was predicted by a slightly different subset of factors, including higher preoperative temporal summation of pain. CONCLUSIONS: This comprehensive approach assessing consistent predictors of pain severity, functional impact, and sensory disturbance may inform personalized prevention of PPMP and also may allow stratification and enrichment in future preventive studies of women at higher risk of this outcome, including pharmacologic and behavioral interventions and regional anesthesia.

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

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.

Chronic Pain After Breast Surgery: A Prospective, Observational Study.

BACKGROUND: Chronic pain is an important complication of breast surgery, estimated to affect 20-30% of patients. We prospectively examined surgical, demographic, and psychosocial factors associated with chronic pain 6 months after breast surgery. METHODS: Patients undergoing breast surgery for benign and malignant disease preoperatively completed validated questionnaires to assess baseline pain and psychosocial characteristics. Pain at 6 months was quantified as the Pain Burden Index (PBI), which encompasses pain locations, severity, and frequency. Surgical type was categorized as breast-conserving surgery (BCS), mastectomy, and mastectomy with reconstruction; axillary procedure was categorized as no axillary surgery, sentinel lymph node biopsy (SLNB), and axillary dissection. PBI was compared between groups using one-way analysis of variance (ANOVA) or Kruskal-Wallis ANOVA, and the relationship between baseline demographic and psychosocial factors and PBI was assessed using Spearman's Rank Correlation. p < 0.05 was considered significant. RESULTS: PBI was variable amongst patients reporting this endpoint (n = 216) at 6 months, but no difference was found between primary breast surgical types (BCS, mastectomy, and mastectomy with reconstruction) or with surgical duration. However, axillary dissection was associated with higher PBI than SLNB and no axillary procedure (p < 0.001). Younger age (< 0.001) and higher BMI (p = 0.010), as well as higher preoperative anxiety (p = 0.017), depression (p < 0.001), and catastrophizing scores (p = 0.005) correlated with higher 6-month PBI. CONCLUSIONS: Amongst surgical variables, only axillary dissection was associated with greater pain at 6 months after surgery. Patient characteristics that were associated with higher PBI included lower age and higher BMI, as well as higher baseline anxiety, depression, and catastrophizing.