Psychological factors predict an unfavorable pain trajectory after hysterectomy: a prospective cohort study on chronic postsurgical pain

A Prospective Cohort Study of Acute Pain and In-Hospital Opioid Consumption After Cardiac Surgery: Associations With Psychological and Medical Factors and Chronic Postsurgical Pain

BACKGROUND

Understanding the association of acute pain intensity and opioid consumption after cardiac surgery with chronic postsurgical pain (CPSP) can facilitate implementation of personalized prevention measures to improve outcomes. The objectives were to (1) examine acute pain intensity and daily mg morphine equivalent dose (MME/day) trajectories after cardiac surgery, (2) identify factors associated with pain intensity and opioid consumption trajectories, and (3) assess whether pain intensity and opioid consumption trajectories are risk factors for CPSP.

METHODS

Prospective observational cohort study design conducted between August 2012 and June 2020 with 1-year follow-up. A total of 1115 adults undergoing cardiac surgery were recruited from the preoperative clinic. Of the 959 participants included in the analyses, 573 completed the 1-year follow-up. Main outcomes were pain intensity scores and MME/day consumption over the first 6 postoperative days (PODs) analyzed using latent growth mixture modeling (GMM). Secondary outcome was 12-month CPSP status.

RESULTS

Participants were mostly male (76%), with a mean age of 61 ± 13 years. Three distinct linear acute postoperative pain intensity trajectories were identified: "initially moderate pain intensity remaining moderate" (n = 62), "initially mild pain intensity remaining mild" (n = 221), and "initially moderate pain intensity decreasing to mild" (n = 251). Age, sex, emotional distress in response to bodily sensations, and sensitivity to pain traumatization were significantly associated with pain intensity trajectories. Three distinct opioid consumption trajectories were identified on the log MME/day: "initially high level of MME/day gradually decreasing" (n = 89), "initially low level of MME/day remaining low" (n = 108), and "initially moderate level of MME/day decreasing to low" (n = 329). Age and emotional distress in response to bodily sensations were associated with trajectory membership. Individuals in the "initially mild pain intensity remaining mild" trajectory were less likely than those in the "initially moderate pain intensity remaining moderate" trajectory to report CPSP (odds ratio [95% confidence interval, CI], 0.23 [0.06-0.88]). No significant associations were observed between opioid consumption trajectory membership and CPSP status (odds ratio [95% CI], 0.84 [0.28-2.54] and 0.95 [0.22-4.13]).

CONCLUSIONS

Those with moderate pain intensity right after surgery are more likely to develop CPSP suggesting that those patients should be flagged early on in their postoperative recovery to attempt to alter their trajectory and prevent CPSP. Emotional distress in response to bodily sensations is the only consistent modifiable factor associated with both pain and opioid trajectories.

The mechanisms and management of persistent postsurgical pain

An estimated 10%-50% of patients undergoing a surgical intervention will develop persistent postsurgical pain (PPP) lasting more than 3 months despite adequate acute pain management and the availability of minimally invasive procedures. The link between early and late pain outcomes for surgical procedures remains unclear-some patients improve while others develop persistent pain. The elective nature of a surgical procedure offers a unique opportunity for prophylactic or early intervention to prevent the development of PPP and improve our understanding of its associated risk factors, such as pre-operative anxiety and the duration of severe acute postoperative pain. Current perioperative pain management strategies often include opioids, but long-term consumption can lead to tolerance, addiction, opioid-induced hyperalgesia, and death. Pre-clinical models provide the opportunity to dissect mechanisms underpinning the transition from acute to chronic, or persistent, postsurgical pain. This review highlights putative mechanisms of PPP, including sensitisation of peripheral sensory neurons, neuroplasticity in the central nervous system and nociceptive signalling along the neuro-immune axis.

A cross-sectional study of fear of surgery in female breast cancer patients: Prevalence, severity, and sources, as well as relevant differences among patients experiencing high, moderate, and low fear of surgery

BACKGROUND

Fear of surgery has been associated with more postoperative pain, disability, and a lower quality of life among patients undergoing various surgical procedures. While qualitative studies indicate breast cancer patients to be afraid of surgery, detailed quantitative analyses are lacking. The present research aimed at investigating the prevalence, severity, and sources of fear of surgery in this patient group and to compare patients reporting different degrees of such fear.

METHODS

This cross-sectional study included 204 breast cancer patients, 18-70 years old, and scheduled for surgery at Oslo University Hospital, Norway. Following their preoperative visit participants completed validated psychological questionnaires online. Among these, the primary outcome measure, the Surgical Fear Questionnaire (SFQ; scores: 0-10 per item, 0-80 overall). Patients were grouped based on SFQ-percentiles (<25th = little, 25th-75th = moderate and >75th percentile = high fear) and compared on psychological (anxiety, depression, experienced injustice, optimism and expected postsurgical pain), sociodemographic, and medical outcomes.

RESULTS

195 patients completed the SFQ. On average fear of surgery was low (M = 26.41, SD = 16.0, median = 26, min-max = 0-80), but omnipresent. Only 1.5% (n = 3) indicated no fear at all. Overall, patients feared surgery itself the most (M = 3.64, SD = 2.8). Groups differed significantly (p < .001) in their experience of anxiety, depression, and injustice, as well as their disposition to be optimistic, and expectance of postsurgical pain. Differences between groups concerning demographic and medical information were largely insignificant.

DISCUSSION

This study was the first to demonstrate fear of surgery to be prevalent and relevant among female breast cancer patients. The higher a patients' fear group, the poorer their preoperative psychological constitution. This, largely irrespective of their current diagnoses or treatments, medical history, and demographics. Fear of surgery might thus cater as a prognostic marker and treatment target in this patient group. However, given the cross-sectional character of the present data, prognostic studies are needed to evaluate such claims.

The role of catastrophizing and basic psychological needs satisfaction on health-related quality of life and pain in patients with lumbar disc herniation

Introduction

Lumbar disc herniation (LDH) is one of the most common conditions associated with functional disability, affecting patients' quality of life (QOL). Disability can be affected by cognitive factors, such as pain catastrophizing. Similarly, unfulfilled basic psychological needs (i.e., autonomy, competence, relatedness) are associated with biases in pain perception and QOL. Using the fear-avoidance model and the self-determination theory, this study investigates: (1) the separate contribution of pain-related variables and basic psychological needs satisfaction in predicting QOL in patients proposed for LDH surgery; (2) pre- and post-surgical differences in pain catastrophizing and basic psychological needs satisfaction.

Methods

First, we used hierarchical regression on 193 patients (M_age = 46.10, SD_age = 11.40) to identify predictors of QOL. Second, we performed paired t-tests on 55 patients to investigate pre- and post-surgical differences in pain catastrophizing and basic psychological needs satisfaction.

Results

Hierarchical regression showed that the model predicts 27% of the variance in QOL; medium pain level, age, pain catastrophizing, and basic psychological needs satisfaction were significant predictors. Also, pain catastrophizing significantly decreased after surgery [t (54) = 6.07, p < 0.001, Cohen's d = 0.81], but basic psychological needs satisfaction did not modify significantly.

Discussion

This research confirms the importance of pain perception and pain catastrophizing for LDH patients' QOL and broadens the applicability of the self-determination theory for spinal patients.

A prospective study of chronic postsurgical pain in elderly patients: incidence, characteristics and risk factors

BACKGROUND

Due to the continued growth of surgical procedures in older adults and the significant impact of chronic postsurgical pain (CPSP), it is crucial to improve our understanding of the occurrence of CPSP as well as the appropriate prevention and treatment. We therefore conducted this study to determine the incidence, characteristics and risk factors of CPSP in elderly patients at both 3 and 6 months after surgery.

METHODS

Elderly patients (aged ≥ 60 years) undergoing elective surgery in our institution between April 2018 and March 2020 were prospectively enrolled in this study. Data on demographics, preoperative psychological well-being, intraoperative surgical and anesthesia management, and acute postoperative pain intensity were collected. At 3 and 6 months after surgery, patients received telephone interview and completed the questionnaires regarding chronic pain characteristics, analgesic consumption, and interference of the pain with activities of daily living (ADL).

RESULTS

A total of 1065 elderly patients were followed up for 6 postoperative months and included in final analysis. At 3 and 6 months after operation, the incidence of CPSP was 35.6% [95% confidence interval (95% CI) 32.7 - 38.8%] and 21.5% (95% CI 19.0% - 23.9%), respectively. CPSP cause negative impacts on patient's ADL and most particularly on mood. Neuropathic features were found in 45.1% of the patients with CPSP at 3 months. At 6 months, 31.0% of those with CPSP reported that the pain had neuropathic features. Preoperative anxiety [3 months: Odds ratio (OR) 2.244, 95% CI 1.693 to 2.973; 6 months: OR 2.397, 95% CI 1.745 to 3.294], preoperative depression (3 months: OR 1.709, 95% CI 1.292 to 2.261; 6 months: OR 1.565, 95% CI 1.136-2.156), orthopedic surgery (3 months: OR 1.927, 95% CI 1.112 to 3.341; 6 months: OR 2.484, 95% CI 1.220 to 5.061), higher pain severity on movement within postoperative 24 h (3 months: OR 1.317, 95% CI 1.191 to 1.457; 6 months: OR 1.317, 95% CI 1.177 to 1.475) were associated with a higher risk for CPSP independently at both 3 and 6 months after surgery.

CONCLUSIONS

CPSP is a common postoperative complication in elderly surgical patients. Preoperative anxiety and depression, orthopedic surgery, and greater intensity of acute postoperative pain on movement are associated with an increased risk for CPSP. It should be kept in mind that developing psychological interventions to reduce anxiety and depression and optimizing the management of acute postoperative pain will be effective in reducing the development of CPSP in this population.

Randomized controlled trial of intrathecal oxytocin on speed of recovery after hip arthroplasty

ABSTRACT

Recovery from surgery is quicker in the postpartum period, and this may reflect oxytocin action in the spinal cord. We hypothesized that intrathecal injection of oxytocin would speed recovery from pain and disability after major surgery. Ninety-eight individuals undergoing elective total hip arthroplasty were randomized to receive either intrathecal oxytocin (100 μg) or saline. Participants completed diaries assessing pain and opioid use daily and disability weekly, and they wore an accelerometer beginning 2 weeks before surgery until 8 weeks after. Groups were compared using modelled, adjusted trajectories of these measures. The study was stopped early due to the lack of funding. Ninety patients received intrathecal oxytocin (n = 44) or saline (n = 46) and were included in the analysis. There were no study drug-related adverse effects. Modelled pain trajectory, the primary analysis, did not differ between the groups, either in pain on day of hospital discharge (intercept: -0.1 [95% CI: -0.8 to 0.6], P = 0.746) or in reductions over time (slope: 0.1 pain units per log of time [95% CI: 0-0.2], P = 0.057). In planned secondary analyses, postoperative opioid use ended earlier in the oxytocin group and oxytocin-treated patients walked nearly 1000 more steps daily at 8 weeks ( P < 0.001) and exhibited a clinically meaningful reduction in disability for the first 21 postoperative days ( P = 0.007) compared with saline placebo. Intrathecal oxytocin before hip replacement surgery does not speed recovery from worst daily pain. Secondary analyses suggest that further study of intrathecal oxytocin to speed functional recovery without worsening pain after surgery is warranted.

Can perioperative psychological interventions decrease the risk of postsurgical pain and disability? A systematic review and meta-analysis of randomized controlled trials

ABSTRACT

Many patients experience pain after surgery. Psychological factors such as emotion and cognition are shown to be associated with the development of acute and chronic postsurgical pain (CPSP). Therefore, the question arises whether targeting these psychological factors can reduce negative postsurgical outcomes. The aim of the current review was to investigate the efficacy of perioperative psychological interventions in reducing (sub)acute postsurgical pain and CPSP and disability in adults. Randomized controlled trials were identified through 4 databases (Web of Science, PsychINFO, PubMed, and Cumulative Index to Nursing and Allied Health Literature [CINAHL]). The outcomes of interest were (sub)acute (ie, within 3 months after surgery) and chronic (>3 months after surgery) pain and disability. After screening, 21 studies were included in the final analyses. It was found that psychological interventions significantly reduced (sub)acute pain (d = -0.26, 95% confidence interval [CI] [-0.48 to -0.04]) and disability (d = -0.43, 95% CI [-0.84 to -0.03]) as well as CPSP (d = -0.33, 95% CI [-0.61 to -0.06]) and disability (d = -0.43, 95% CI [-0.68 to -0.18]). In addition, interventions delivered after surgery and interventions delivered by a psychologist tended to be more effective than interventions delivered before surgery and interventions delivered by another healthcare provider. Furthermore, the current review points to the need for more research to determine which specific type of intervention may be most beneficial for surgical patients. Finally, the current review identified that research in this domain has concerns regarding bias in missing outcome data due to withdrawal and drop out.

Pain Management of Acute and Chronic Postoperative Pain

Inadequate management of acute postoperative pain is associated with effects related to both physiological and psychological function. Postoperative pain increases the risk of perioperative complications, so postoperative pain should be prevented. Postoperative pain management by sufficient analgesia is important while considering the use of various kinds of analgesics. Insufficient management of postoperative pain may lead to chronic postsurgical pain (CPSP). It is suggested that CPSP is dependent not only upon biological factors but also upon psychological factors, including the type of surgery, age, physical health, mental health, and preoperative pain. As CPSP is a severe complication that may prolong hospitalization and interferes with activities of daily living (ADL) and quality of life (QoL), its prevention of development is paramount. Therefore, in order to prevent the onset of CPSP, it is necessary to craft analgesic management to prevent CPSP during the perioperative period.

Predictive value of quantitative sensory testing for acute and chronic postsurgical pain after total joint arthroplasty: a systematic review

ABSTRACT

Quantitative sensory testing (QST) can be useful to identify high-risk patients for the development of chronic postsurgical pain. This systematic review aims to assess if presurgical sensory sensitivity measured using QST is associated with acute and chronic postsurgical pain after total joint arthroplasty. A systematic search was performed in September 2020 in PubMed, EMBASE, Web of Science, and Scopus, using terms related to total joint arthroplasty and QST. Prospective studies were included if they reported an association between presurgical QST and postsurgical pain in adults with osteoarthritis undergoing primary unilateral total joint arthroplasty. From 2994 identified studies, 18 met the inclusion criteria (1869 patients). Total knee arthroplasty was the most common surgery (16 studies), and pressure pain threshold was the most common test (11 studies), followed by dynamic measures (9 studies). Postsurgical pain was assessed at acute (5 studies), subacute (2 studies), and chronic (13 studies) time points. Risk of bias was assessed using the Quality in Prognosis Studies tool and evaluated as low to moderate in most domains. Fourteen studies reported at least one statistically significant association between QST and pain (acute: 4 studies, subacute: 1 study, and chronic: 9 studies). Pressure pain threshold was associated with postsurgical pain in 6 studies (of 11, 55%), heat pain threshold in 2 studies (of 6, 33%), conditioned pain modulation in 1 study (of 6, 17%), and temporal summation of pain in 5 studies (of 8, 63%). The predictive role of presurgical QST for postarthroplasty pain remains unclear, mainly because of heterogeneous methodologies and inconsistent results.

Predictors of Persistent Postsurgical Pain After Hysterectomy-A Prospective Cohort Study

STUDY OBJECTIVE

To determine sociodemographic, surgical, and psychologic risk factors, including pain sensitivity, for persistent postsurgical pain (PPSP) after hysterectomy.

DESIGN

A prospective cohort study.

SETTING

Canadian academic medical center.

PATIENTS

Patients (N = 200) who underwent hysterectomy (vaginal, laparoscopic, robotic, or open) between 2013 and 2014.

INTERVENTIONS

Participants completed preoperative questionnaires assessing baseline pain scores and psychologic factors, including the Pain Sensitivity Questionnaire, Brief Pain Inventory Interference Items, the Beck Depression Inventory, the Numeric Rating Scale (NRS), and the Pain Catastrophizing Scale. Pain was recorded 1 and 24 hours postoperatively using the NRS. Patients were reassessed at 6 weeks postoperatively and completed the Brief Pain Inventory Interference Items, Patient Global Impression of Change, and the NRS. Patients who reported pain at 6 weeks were reassessed at 12 weeks using the above-mentioned questionnaires.

MEASUREMENTS AND MAIN RESULTS

Of 200 study participants, 58 (32%) met the definition for PPSP (NRS ≥ 1 at 12 weeks), and 11 (6.1%) met the definition for moderate to severe postsurgical pain (NRS ≥ 4 at 12 weeks). Risk factors for PPSP included baseline pain scores, depression, pain catastrophizing, uterine mass, open surgical approach, acute postoperative pain, history of chronic pain, and having a hysterectomy due to pain. Multivariate regression analysis revealed that depression, pain catastrophizing, open surgical approach, and acute postoperative pain at 1 hour represent independent predictors of PPSP. Pain sensitivity was not associated with PPSP but was associated with acute and severe acute (NRS≥4) pain at 24 hours.

CONCLUSION

Patients at risk for PPSP after hysterectomy can be identified preoperatively using validated questionnaires. This information can be used to guide targeted perioperative interventions to mitigate their risk.

The predictive value of quantitative sensory testing: a systematic review on chronic postoperative pain and the analgesic effect of pharmacological therapies in patients with chronic pain

Studies have suggested that quantitative sensory testing (QST) might hold a predictive value for the development of chronic postoperative pain and the response to pharmacological interventions. This review systematically summarizes the current evidence on the predictive value of QST for chronic postoperative pain and the effect of pharmacological interventions. The main outcome measures were posttreatment pain intensity, pain relief, presence of moderate-to-severe postoperative pain, responders of 30% and 50% pain relief, or validated questionnaires on pain and disability. A systematic search of MEDLINE and EMBASE yielded 25 studies on surgical interventions and 11 on pharmacological interventions. Seventeen surgical and 11 pharmacological studies reported an association between preoperative or pretreatment QST and chronic postoperative pain or analgesic effect. The most commonly assessed QST modalities were pressure stimuli (17 studies), temporal summation of pain (TSP, 14 studies), and conditioned pain modulation (CPM, 16 studies). Of those, the dynamic QST parameters TSP (50%) and CPM (44%) were most frequently associated with chronic postoperative pain and analgesic effects. A large heterogeneity in methods for assessing TSP (n = 4) and CPM (n = 7) was found. Overall, most studies demonstrated low-to-moderate levels of risk of bias in study design, attrition, prognostic factors, outcome, and statistical analyses. This systematic review demonstrates that TSP and CPM show the most consistent predictive values for chronic postoperative pain and analgesic effect, but the heterogeneous methodologies reduce the generalizability and hence call for methodological guidelines.

Does Pain Acceptance Buffer the Negative Effects of Catastrophizing on Function in Individuals With Chronic Pain?

OBJECTIVES

Pain catastrophizing and pain acceptance are psychological factors that have been shown to be associated with pain-related outcomes and predict multidisciplinary pain treatment outcomes. However, they are rarely examined in the same study. This study aimed to: (1) assess the independent roles of pain catastrophizingand pain acceptance as predictors of pain intensity, pain interference, and depression; and (2) evaluate the potential moderating role of pain acceptance on the association between pain catastrophizing and both pain and function.

MATERIALS AND METHODS

A sample of 467 adults with chronic pain completed an online survey including measures of pain intensity, pain interference, depression, pain catastrophizing, and pain acceptance.

RESULTS

Pain catastrophizing and pain acceptance were independent predictors of pain interference. Only pain catastrophizing and the activity engagement domain of pain acceptance were independent predictors of pain intensity and depression. Activity engagement moderated the association between pain catastrophizing and depression, indicating a buffering effect on the negative effects of catastrophizing on depression. Pain willingness moderated the association between pain catastrophizing and pain interference, such that endorsing low pain willingness may override any negative effects of pain catastrophizing.

DISCUSSION

The findings suggest that pain catastrophizing and pain acceptance are independently important to adjustment to chronic pain. Research is needed to determine if treatments that target both for change are more effective than treatments that target only one.

Conditioned pain modulation predicts persistent pain after knee replacement surgery

Introduction

Persistent pain after total knee replacement is an underestimated outcome leading to significant health burden. Sensory testing has been explored to help surgeons in decision making and better patient selection. Patients with different chronic pain syndromes exhibit a poor descending pain inhibition that can be quantified through experimental paradigms (conditioned pain modulation). A poor preoperative descending pain inhibition response predicted persistence of pain after surgery in previous studies.

Methods

This study investigated the correlation between a preoperative inefficient endogenous analgesia and a bad postoperative pain outcome (painful prosthesis). One hundred forty-six patients were studied preoperatively by quantitative sensory testing. Conditioned pain modulation was calculated as the relative decrease in pain intensity (thermal stimulus) during heterotopic painful stimulation.

Results

Approximately 21.2% of patients had a bad pain outcome (painful prosthesis), 6 months after surgery. Preoperatively, 47.9% of patients exhibited an insufficient endogenous analgesia. The probability to develop persistent pain after surgery in that group was higher than that in patients with a sufficient endogenous analgesia (31.4% [20.9-43.6, 95% CI] vs 11.8% [5.5-21.3, 95% CI], respectively; P < 0.004). Correlation between conditioned pain modulation values and postoperative intensity of pain was also established. Besides, a preoperative lower quality of life (mental component) predicted a worse pain outcome, too.

Conclusions

This cohort study shows that preoperative sensory testing predicts a bad pain outcome after total knee replacement. This tool could help clinicians in a better indication of patients with advanced knee osteoarthritis for replacement surgery.

Registration Details

ClinicalTrials.gov: NCT01811888 (prospective).

Quantitative Sensory Testing to Predict Postoperative Pain

Purpose of Review

We review the relevance of quantitative sensory testing (QST) in light of acute and chronic postoperative pain and associated challenges.

Recent Findings

Predicting the occurrence of acute and chronic postoperative pain with QST can help identify patients at risk and allows proactive preventive management. Generally, central QST testing, such as temporal summation of pain (TSP) and conditioned pain modulation (CPM), appear to be the most promising modalities for reliable prediction of postoperative pain by QST. Overall, QST testing has the best predictive value in patients undergoing orthopedic procedures.

Summary

Current evidence underlines the potential of preoperative QST to predict postoperative pain in patients undergoing elective surgery. Implementing QST in routine preoperative screening can help advancing traditional pain therapy toward personalized perioperative pain medicine.

Characterisation of pragmatic postoperative PAin Trajectories over seven days and their association with CHronicity after 3 months: a prospective, pilot cohort study (PATCH study)

BACKGROUND

Reliable outcome measurement providing information both on early and late postoperative pain outcomes are still lacking. The purpose of this study was: 1) to characterise postoperative pain trajectories according to an innovative pragmatic concept: ideal pain trajectory (rapid and sustained pain relief) vs non-ideal pain trajectories (late, transient, or no pain relief); and 2) to assess the incidence of persistent post-surgical pain (PPSP) and the potential association between non-ideal pain trajectories and PPSP.

METHODS

This prospective observational pilot cohort study was performed from March until June 2016. A total of 344 patients undergoing major general surgery were invited to complete a self-assessment of pain intensity using numerical rating scale (NRS; 0 = no pain to 10 = worst pain) from day 1 until day 7 after surgery, in order to establish their pain trajectory. Three months after surgery, patients were screened for PPSP.

RESULTS

Rest pain score was analysed in 308 participants. Among them, 210 (68% - 95% CI: 63-73) had an "ideal" pain trajectory, while 98 (32% - 95% CI: 27-37) had "non-ideal" pain trajectories. Three months after surgery, 31% (95% CI: 26-37) reported PPSP. Multivariable analysis showed that "non-ideal" pain trajectories [OR 2.25; (95% CI: 1.26-4.01) P =  0.006] were significantly associated with PPSP.

CONCLUSIONS

The present study proposes an innovative pragmatic concept of postoperative pain trajectories: ideal vs non-ideal pain trajectories, providing information both on acute postoperative pain resolution and early identification patients at risk for developing PPSP.

TRIAL REGISTRATION

NCT02599233; November, 6, 2015, with clinicaltrials.gov.

Trajectories in severe persistent pain after groin hernia repair: a retrospective analysis

Objectives

Severe persistent post-surgical pain (PPSP) remains a significant healthcare problem. In the third most common surgical procedure in the U.K., groin hernia repair, including 85,000 surgeries, estimated 1,500–3,000 patients will annually develop severe PPSP. While the trajectory of PPSP is generally considered a continuation of the acute post-surgery pain, recent data suggest the condition may develop with a delayed onset. This study evaluated pain-trajectories in a consecutive cohort referred from groin hernia repair-surgeons to a tertiary PPSP-center. Potential explanatory variables based on individual psychometric, sensory, and surgical profiles were analyzed.

Methods

Patients completed graphs on pain trajectories and questionnaires on neuropathic pain, pain-related functional assessments, and psychometrics. Surgical records and quantitative sensory testing profiles were obtained. Pain trajectories were normalized, and pre- and post-surgical segments were analyzed by a normalized area-under-the-curve (AUC) technique. Principal component analysis (PCA) was applied to the explanatory variables. Significant PCA-components were further examined using multiple logistic regression models.

Results

In 95 patients, the AUC identified groups of post-surgical pain trajectories (p<0.0001): group I (n=48), acute high-intensity pain progressing to PPSP; group II (n=28), delayed onset of PPSP; group III (n=7), repeat-surgery gradually inducing PPSP. Data from groups IV (n=3) and V (n=9) were not included in the statistical analysis due to small sample size and data heterogeneity, respectively. The PCA/logistic analyses indicated that neuropathic pain scores, composite pain scores, and pain-related functional assessments were explanatory variables for groups I and II.

Conclusions

Pain trajectories in PPSP after groin hernia repair are heterogeneous but can be classified into meaningful groups. Examination of pain trajectories, mirroring the transition from acute to severe persistent post-surgical pain, has the potential of uncovering clinically relevant pathophysiological mechanisms.

The Association Between Preoperative Pain Catastrophizing and Chronic Pain After Hysterectomy - Secondary Analysis of a Prospective Cohort Study

Purpose

Hysterectomy is associated with a high incidence of chronic post-hysterectomy pain (CPHP). Pain catastrophizing, a negative cognitive-affective response to pain, is associated with various pain disorders but its role in CPHP is unclear. We aimed to determine the association of high preoperative pain catastrophizing with CPHP development and functional impairment 4 months after surgery.

Patients and Methods

Secondary analysis of a prospective cohort study of women undergoing abdominal/laparoscopic hysterectomy to investigate the association between high pain catastrophizing (pain catastrophizing scale, PCS≥20) with CPHP and associated functional impairment (defined as impairment with standing for ≥30 minutes, sitting for ≥30 minutes, or walking up or down stairs). CPHP and functional impairment were assessed via 4- and 6-month phone surveys.

Results

Of 216 patients, 72 (33.3%) had high PCS, with mean (SD) of 30.0 (7.9). In contrast, 144 (66.7%) patients had low PCS, with mean (SD) of 9.0 (4.7). At 4 months, 26/63 (41.3%) patients in the high PCS group developed CPHP, compared to 24/109 (22.0%) in the low PCS group. At 6 months, 14/53 (26.4%) high PCS patients developed CPHP, compared to 10/97 (10.3%) patients with low PCS. High PCS was independently associated with CPHP at 4 months (OR 2.49 [95% CI 1.27 to 4.89], p=0.0082) and 6 months (OR 3.12 [95% CI 1.28 to 7.64], p=0.0126) but was not associated with functional impairment. High PCS≥20, presence of evoked mechanical temporal summation (MTS), and history of abdominal/pelvic surgery predict CPHP at 4 months with area under the curve (AUC) of 0.69. Similarly, PCS≥20 and increasing MTS magnitude predicted CPHP at 6 months with AUC of 0.76.

Conclusion

High PCS was independently associated with CPHP. Future studies should identify other CPHP associated factors to formulate a risk-prediction model and investigate the effectiveness of early intervention for pain catastrophizers in improving pain-related outcomes.

Chronic postsurgical pain: From risk factor identification to multidisciplinary management at the Toronto General Hospital Transitional Pain Service

Background: Chronic postsurgical pain is a highly prevalent public health problem associated with substantial emotional, social, and economic costs. Aims: (1) To review the major risk factors for chronic postsurgical pain (CPSP); (2) to describe the implementation of the Transitional Pain Service (TPS) at the Toronto General Hospital, a multiprofessional, multimodal preventive approach to CPSP involving intensive, perioperative psychological, physical, and pharmacological management aimed at preventing and treating the factors that increase the risk of CPSP and related disability; and (3) to present recent empirical evidence for the efficacy of the TPS. Methods: The Toronto General Hospital TPS was specifically developed to target patients at high risk of developing CPSP. The major known risk factors for CPSP are perioperative pain, opioid use, and negative affect, including depression, anxiety, pain catastrophizing, and posttraumatic stress disorder-like symptoms. At-risk patients are identified early and provided comprehensive care by a multidisciplinary team consisting of pain physicians, advanced practice nurses, psychologists, and physical therapists. Results: Preliminary results from two nonrandomized, clinical practice-based trials indicate that TPS treatment is associated with improvements in pain, pain interference, pain catastrophizing, symptoms of anxiety and depression, and opioid use. Almost half of opioid-naïve patients and one in four opioid-experienced patients were opioid free by the 6-month point. Conclusions: These promising results suggest that the TPS benefits patients at risk of CPSP. A multicenter randomized controlled trial of the TPS in several Ontario hospitals is currently underway.

A new measure to assess pain in people with haemophilia: The Multidimensional Haemophilia Pain Questionnaire (MHPQ)

People with haemophilia (PWH) experience acute pain during joint bleeds and might develop chronic pain due to joint degeneration. However, there is a lack of standardized measures to comprehensively assess pain in PWH. This study aimed to develop a multidimensional questionnaire for haemophilia-related pain, the Multidimensional Haemophilia Pain Questionnaire (MHPQ), and to present initial validation data among adults.The questionnaire distinguishes between acute/chronic pain and queries about pain locations, duration, frequency, triggering factors, intensity, interference, strategies, specialists for pain management and satisfaction with treatment. An initial version was tested with 16 patients to ensure item comprehensibility and face validity. The final version was answered by 104 adults, with 82 (78.8%) reporting haemophilia-related pain in the previous year (mean age = 43.17; SD = 13.00). The non-response analysis revealed good item acceptability. Exploratory and confirmatory factor analysis (EFA/CFA), reliability (internal consistency, test-retest, inter-item and item-total correlations) and convergent validity were analysed for the intensity and interference dimensions of the questionnaire. A combined EFA with these two constructs supported a 2-factor structure distinguishing intensity (α = 0.88) from interference items (α = 0.91). CFA was tested for the interference dimension, demonstrating suitability for this sample. Item-total correlations were >0.30 on both dimensions and most inter-item correlations were <0.70. Test-retest reliability (n = 42) was good for intensity (r = 0.88) and interference (r = 0.73), and convergent validity was confirmed for most hypotheses (r>0.30).This questionnaire is a comprehensible tool, achieving a thorough assessment of relevant pain dimensions. The MHPQ can help guide treatment recommendations by highlighting relevant topics and contributing to more effective, integrated treatments.