Predicting poor postoperative acute pain outcome in adults: an international, multicentre database analysis of risk factors in 50,005 patients

Preexisting chronic pain is not associated with moderate-to-severe acute pain after laparoscopic cholecystectomy: a prospective cohort study

Introduction

We aimed to evaluate the relationship between preexisting chronic pain and acute postoperative pain after laparoscopic cholecystectomy (LC) and to identify predictors of acute postsurgery pain.

Methods

In this prospective cohort study, patients undergoing LC with general anesthesia were enrolled. The primary outcome was the incidence of moderate-to-severe pain during movement in the first 24 hours after surgery. Logistic regression analysed the association of perioperative risk factors with acute postoperative pain. Model performance was assessed using receiver operating characteristic curves (ROC), calibration belt plots, and 10-fold cross-validation.

Results

Of the 193 patients analysed, 49.74% experienced moderate-severe acute pain. Univariable analysis indicated that preoperative chronic pain increased the likelihood of acute postoperative pain (odds ratio [OR], 2.53; 95% confidence interval [CI], 1.40-4.55). Risk factors identified in the multivariable analysis were higher preoperative pain intensity (OR, 1.28; 95% CI, 1-1.65), sleep disturbances (OR, 1.42; 95% CI, 1.24-1.61), intraoperative fentanyl supplementation (OR, 3.68; 95% CI, 1.48-9.12), incision extension for gallbladder retrieval (OR, 7.27; 95% CI, 1.58-33.39), and abdominal drain placement (OR, 6.09; 95% CI, 1.08-34.34). Dexamethasone use was associated with reduced pain (OR, 0.05; 95% CI, 0.004-0.74). The model demonstrated strong discrimination (ROC = 0.909) and good calibration (test statistic = 0.02; P = 0.89). Cross-validation showed slightly lower accuracy (ROC = 0.896).

Conclusions

Preexisting chronic pain was not associated with acute postoperative pain following laparoscopic cholecystectomy. Significant predictors for acute pain included higher preoperative pain intensity, sleep disturbances, intraoperative fentanyl, incision extension, and abdominal drain placement, while dexamethasone use was associated with reduced pain.

Prognostic clinical prediction models for acute post-surgical pain in adults: a systematic review

BACKGROUND

Acute post-surgical pain is managed inadequately in many patients undergoing surgery. Several prognostic risk prediction models have been developed to identify patients at high risk of developing moderate to severe acute post-surgical pain. The aim of this systematic review was to describe and evaluate the methodological conduct of these prediction models.

METHODS

We searched MEDLINE, EMBASE and CINAHL for studies of prognostic risk prediction models for acute post-surgical pain using predetermined criteria. Prediction model performance was evaluated according to discrimination and calibration. Adherence to TRIPOD guidelines was assessed. Risk of bias and applicability was independently assessed by two reviewers using the prediction model risk of bias assessment tool.

RESULTS

We included 14 studies reporting on 17 prediction models. The most common predictors identified in final prediction models included age; surgery type; sex or gender; anxiety or fear of surgery; pre-operative pain intensity; pre-operative analgesic use; pain catastrophising; and expected surgical incision size. Discrimination, measured by the area under receiver operating characteristic curves or c-statistic, ranged from 0.61 to 0.83. Calibration was only reported for seven models. The median (IQR [range]) overall adherence rate to TRIPOD items was 62 (53-66 [47-72])%. All prediction models were at high risk of bias.

CONCLUSIONS

Effective prediction models could support the prevention and treatment of acute post-surgical pain; however, existing models are at high risk of bias which may affect their reliability to inform practice. Consideration should be given to the goals, timing of intended use and desired outcomes of a prediction model before development.

Prospective Study of Preoperative Negative Affect and Postoperative Pain in Patients Undergoing Thoracic Surgery: The Moderating Role of Sex

Objective: Preoperative negative affect is a risk factor for worse postoperative pain, but research investigating this association among patients undergoing thoracic surgery is inconsistent. Additionally, female patients often report greater negative affect and postoperative pain than males. This prospective observational study investigated the association between preoperative negative affect and postoperative pain after thoracic surgery and whether this association differed by sex. Methods: Patients (n = 105) undergoing thoracic surgery completed preoperative assessments of pain and negative affect (PROMIS anxiety and depression short forms). Patients reported their daily worst pain over the first 7 postoperative days, and an index score of acute postoperative pain was created. Six months after surgery, a subsample of patients (n = 60) reported their worst pain. Results: Higher levels of preoperative anxiety (r = 0.25, p = 0.011) and depression (r = 0.20, p = 0.042) were associated with greater acute postoperative pain, but preoperative negative affect was not related to chronic postsurgical pain (anxiety: r = 0.19, p = 0.16; depression: r = -0.01, p = 0.94). Moderation analyses revealed that the associations between both preoperative anxiety (b = 0.12, 95% CI [0.04, 0.21], p = 0.004) and depression (b = 0.15, 95% CI [0.04, 0.26], p = 0.008) with acute postoperative pain were stronger among females than males. Similarly, the association between preoperative anxiety and chronic postsurgical pain was stronger among females (b = 0.11, 95% CI [0.02, 0.20], p = 0.022), but the association between preoperative depression and chronic pain did not differ based on sex (b = 0.13, 95% CI [-0.07, 0.34], p = 0.201]). Conclusions: Our findings suggest that negative affect may be especially important to the experience of pain following thoracic surgery among female patients, whose degree of preoperative anxiety may indicate vulnerability to progress to a chronic pain state. Preoperative interventions aimed at reducing negative affect and pain may be particularly useful among females with high negative affect before thoracic surgery.

Effect of age on postoperative 24-hour moderate-to-severe pain after radical resection of lung cancer-specific pain in the post-anaesthesia care unit: a single-centre retrospective cohort study

OBJECTIVES

To explore the relationship between age and postoperative 24-hour moderate-to-severe pain after radical resection of lung cancer and the specific effect of moderate-to-severe pain in the post-anaesthesia care unit (PACU) on this relationship.

DESIGN

Retrospective cohort study.

SETTING

Single medical centre.

PARTICIPANTS

Patients ≥18 years having radical resection of lung cancer between 2018 and 2020.

MEASUREMENTS

Postoperative 24-hour moderate-to-severe pain.

RESULTS

A total of 3764 patients were included in the analysis. The incidence of postoperative 24-hour moderate-to-severe pain was 28.3%. Age had a significant effect on the prediction model of postoperative 24-hour moderate-to-severe pain. Among the whole population and those without moderate-to-severe pain in the PACU, those who were younger than 58.5 years were prone to experience moderate-to-severe pain 24 hours after surgery, and in patients with moderate-to-severe pain in the PACU, the age threshold was 62.5 years.

CONCLUSION

For patients who underwent elective radical resection for lung cancer, age was related to postoperative 24-hour moderate-to-severe pain, and moderate-to-severe pain in the PACU had a specific effect on this relationship. Patients among the whole population and those patients without moderate-to-severe pain in the PACU were more likely to experience postoperative 24-hour moderate-to-severe pain when they were younger than 58.5 years old, and in patients with moderate-to-severe pain in the PACU, the age threshold was 62.5 years old.

Differences in the relationship between pain and anxiety in total knee and hip arthroplasty: a longitudinal cross-lagged analysis mediated by depression and pain catastrophizing

Acute postsurgical pain (APSP) is an important risk factor for pain chronification, with reports of being more intense after total knee arthroplasty (TKA) than after total hip arthroplasty (THA). Psychological variables have been associated with differences in postsurgical pain experience. This study aimed to analyse the longitudinal reciprocal association between pain and anxiety levels in patients undergoing TKA or THA, to investigate the moderator role of the type of surgery and to explore psychological mediators in the anxiety - pain association. Patients undergoing TKA (n = 120) or THA (n = 109) were evaluated before surgery and in the acute postsurgical period (48 h postsurgery). Presurgical assessment comprised sociodemographic, pain-related and psychological variables (anxiety, depression, pain catastrophizing, self-efficacy, optimism and satisfaction with life). Postsurgical assessment focused on pain frequency, pain intensity and anxiety. Longitudinal associations were explored using cross-lagged panel models that included the indirect effect paths through possible mediators (pain catastrophizing and depression). Multigroup analyses compared TKA and THA. In the global sample, higher APSP was predicted by higher presurgical pain and worse presurgical anxiety. Multigroup analyses revealed that worse APSP was predicted by higher presurgical anxiety in patients undergoing TKA and by higher presurgical pain in patients undergoing THA. Furthermore, there was a positive significant indirect effect of pain catastrophizing, but not depressive symptoms, in the relationship between presurgical anxiety and APSP in THA. Anxiety and APSP are differently interrelated in TKA and THA. Psychological characteristics could be managed before surgery to favour better APSP control and potentially prevent pain chronification after total joint arthroplasty.

One-year opioid consumption trajectories among individuals receiving multidisciplinary postsurgical care: a single-center observational study from the Toronto General Hospital Transitional Pain Service

INTRODUCTION

The Transitional Pain Service (TPS) is an innovative, personalized approach to postsurgical opioid consumption and pain management. The objectives of this study were to identify trajectories of opioid consumption and pain intensity within 12 months after initiating treatment through the TPS, identify biopsychosocial factors associated with trajectory membership, and examine the relationship between trajectory membership and other outcomes of interest over the same 12-month period.

METHODS

Consecutive patients referred to the TPS were included in the present study (n=466). After providing informed consent, they completed self-report questionnaires at the initial visit at the TPS (either pre surgery or post surgery) and at every TPS visit until 12 months. Growth mixture modeling was used to derive trajectories and identify associated factors.

RESULTS

Results showed three distinct opioid consumption trajectories for both presurgical opioid consumers and opioid-naïve patients. These trajectories all decreased over time and among those who were consuming opioids before surgery that returned to presurgical levels. Being man, having a substance use disorder, or reporting higher levels of pain interference were associated with higher daily opioid consumption for presurgical opioid consumers. For presurgical opioid-naïve individuals, higher opioid consumption trajectories were associated with higher levels of psychological distress. Five pain intensity trajectories were identified, and there were no significant association between opioid consumption and pain intensity trajectories.

CONCLUSIONS

Results suggest that opioid consumption and pain intensity trajectories mostly decrease after surgery in a high-risk population enrolled in a TPS. Results also show heterogeneity in postsurgical recovery and highlight the importance of using personalized interventions to optimize individual trajectories.

Postoperative Negative Pain Thoughts and Their Correlation With Patient-Reported Outcomes After Arthroscopic Rotator Cuff Repair: An Observational Cohort Study

BACKGROUND

Pain and pain perception are influenced by patients' thoughts. The short form Negative Pain Thoughts Questionnaire (NPTQ-SF) can be used to quantify unhelpful negative cognitive biases about pain, but the relationship between NPTQ-SF scores and orthopaedic surgery outcomes is not known.

PURPOSE/HYPOTHESIS

The purpose was to assess the relationship between negative pain thoughts, as measured by the NPTQ-SF, and patient-reported outcomes in patients undergoing arthroscopic rotator cuff repair, as well as to compare NPTQ-SF scores and outcomes between patients with and without a history of chronic pain and psychiatric history. It was hypothesized that patients with worse negative pain thoughts would have worse patient-reported outcomes.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

In total, 109 patients undergoing arthroscopic rotator cuff repair were administered the 4-item NPTQ-SF, 12-item Short Form Health Survey (SF-12), American Shoulder and Elbow Surgeons (ASES) Shoulder Evaluation Form, and visual analog scale pain survey preoperatively between July 2021 and August 2022. The same surveys were completed ≥6 months postoperatively by 74 patients confirmed to have undergone arthroscopic rotator cuff repair.

RESULTS

Preoperative NPTQ-SF scores did not show any correlation with the postoperative patient-reported outcomes measured in this study. Postoperative NPTQ-SF scores were statistically significantly negatively correlated with postoperative SF-12 Physical Health Score, SF-12 Mental Health Score, ASES, and satisfaction scores (P < .05). Postoperative NPTQ-SF scores were statistically significantly positively correlated with postoperative visual analog scale scores (P < .001). Moreover, postoperative NPTQ-SF scores were statistically significantly negatively correlated with achieving a Patient Acceptable Symptom State and the minimal clinically important difference on the postoperative ASES form (P < .001 and P = .009, respectively).

CONCLUSION

Postoperative patient thought patterns and their perception of pain are correlated with postoperative outcomes after rotator cuff repair. This correlation suggests a role for counseling and expectation management in the postoperative setting. Conversely, preoperative thought patterns regarding pain, as measured by the NPTQ-SF, do not correlate with postoperative patient-reported outcome measures. Therefore, the NPTQ-SF should not be used as a preoperative tool to aid the prediction of outcomes after rotator cuff repair.

Risk Factors for Acute Postsurgical Pain: A Narrative Review

Acute postsurgical pain (APSP) has received growing attention as a surgical outcome. When poorly controlled, APSP can affect short- and long-term outcomes in patients. Despite the steady increase in awareness about postoperative pain and standardization of pain prevention and treatment strategies, moderate-to-severe APSP is frequently reported in clinical practice. This is possibly because pain varies widely among individuals and is influenced by distinct factors, such as demographic, perioperative, psychological, and genetic factors. This review investigates the risk factors for APSP, including gender, age, obesity, smoking history, preoperative pain history, pain sensitivity, preoperative anxiety, depression, pain catastrophizing, expected postoperative pain, surgical fear, and genetic polymorphisms. By identifying patients having an increased risk of moderate-to-severe APSP at an early stage, clinicians can more effectively manage individualized analgesic treatment protocols with a combination of pharmacological and non-pharmacological interventions. This would alleviate the transition from APSP to chronic pain and reduce the severity of APSP-induced chronic physical disability and social psychological distress.

Regional anaesthesia for postoperative pain management following laparoscopic, visceral, non-oncological surgery a systematic review and meta-analysis

BACKGROUND

Postoperative pain management following laparoscopic, non-oncological visceral surgery in adults is challenging. Regional anaesthesia could be a promising component in multimodal pain management.

METHODS

We performed a systematic review and meta-analysis with GRADE assessment. Primary outcomes were postoperative acute pain intensity at rest/during movement after 24 h, the number of patients with block-related adverse events and the number of patients with postoperative paralytic ileus.

RESULTS

82 trials were included. Peripheral regional anaesthesia combined with general anaesthesia versus general anaesthesia may result in a slight reduction of pain intensity at rest at 24 h (mean difference (MD) - 0.72 points; 95% confidence interval (CI) - 0.91 to - 0.54; I2 = 97%; low-certainty evidence), which was not clinically relevant. The evidence is very uncertain regarding the effect on pain intensity during activity at 24 h (MD -0.8 points; 95%CI - 1.17 to - 0.42; I2 = 99%; very low-certainty evidence) and on the incidence of block-related adverse events. In contrast, neuraxial regional analgesia combined with general anaesthesia (versus general anaesthesia) may reduce postoperative pain intensity at rest in a clinical relevant matter (MD - 1.19 points; 95%CI - 1.99 to - 0.39; I2 = 97%; low-certainty evidence), but the effect is uncertain during activity (MD - 1.13 points; 95%CI - 2.31 to 0.06; I2 = 95%; very low-certainty evidence). There is uncertain evidence, that neuraxial regional analgesia combined with general anaesthesia (versus general anaesthesia) increases the risk for block-related adverse events (relative risk (RR) 5.11; 95%CI 1.13 to 23.03; I2 = 0%; very low-certainty evidence).

CONCLUSION

This meta-analysis confirms that regional anaesthesia might be an important part of multimodal postoperative analgesia in laparoscopic visceral surgery, e.g. in patients at risk for severe postoperative pain, and with large differences between surgical procedures and settings. Further research is required to evaluate the use of adjuvants and the additional benefit of regional anaesthesia in ERAS programmes.

PROTOCOL REGISTRATION

PROSPERO CRD42021258281.

Perioperative pain management models in four European countries: A narrative review of differences, similarities and future directions

There is general agreement that acute pain management is an important component of perioperative medicine. However, there is no consensus on the best model of care for perioperative pain management, mainly because evidence is missing in many aspects. Comparing the similarities and differences between countries might reveal some insights into different organisational models and how they work. Here, we performed a narrative review to describe and compare the structures, processes and outcomes of perioperative pain management in the healthcare systems of four European countries using Donabedian's framework as a guide. Our comparison revealed many similarities, differences and gaps. Different structures of acute pain services in the four countries with no common definition and standards of care were found. Protocols have been implemented in all countries and guidelines in some. If outcome is assessed, it is mainly pain intensity, and many patients experiencing more intense pain than others have common risk factors (e.g. preoperative pain, preoperative opioid intake, female sex and young age). Outcome assessment beyond pain intensity (such as pain-related physical function, which is important for early rehabilitation and recovery) is currently not well implemented. Developing common quality indicators, a European guideline for perioperative pain management (e.g. for patients at high risk for experiencing severe pain and other outcome parameters) and common criteria for acute pain services might pave the way forward for improving acute pain management in Europe. Finally, the education of general and specialist staff should be aligned in Europe, for example, by using the curricula of the European Pain Federation (EFIC).

Time-Dependent Prediction Models for Individual Prognosis of Chronic Postsurgical Pain following Knee Replacement Based on an Extensive Multivariable Data Set

(1) Background: Clinically useful prediction models for chronic postsurgical pain (CPSP) in knee replacement (TKA) are lacking. (2) Methods: In our prospective, multicenter study, a wide-ranging set of 91 variables was collected from 933 TKA patients at eight time points up to one year after surgery. Based on this extensive data pool, simple and complex prediction models were calculated for the preoperative time point and for 6 months after surgery, using least absolute shrinkage and selection operator (LASSO) 1se and LASSO min, respectively. (3) Results: Using preoperative data only, LASSO 1se selected age, the Revised Life Orientation Test on pessimism, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)-subscore pain and the Timed "Up and Go" Test for prediction, resulting in an area under the curve (AUC) of 0.617 and a Brier score of 0.201, expressing low predictive power only. Using data up to 6 months after surgery, LASSO 1se included preoperative Patient Health Questionnaire-4, Knee Injury and Osteoarthritis Outcome Score (KOOS)-subscore pain (pain) 3 months after surgery (month), WOMAC pain 3 and 6 months, KOOS subscore symptoms 6 months, KOOS subscore sport 6 months and KOOS subscore Quality of Life 6 months. This improved the predictive power to an intermediate one (AUC 0.755, Brier score 0.168). More complex models computed using LASSO min did little to further improve the strength of prediction. (4) Conclusions: Even using multiple variables and complex calculation methods, the possibility of individual prediction of CPSP after TKA remains limited.

Risk Factors of Acute Pain in Elderly Patients After Laparoscopic Radical Resection of Colorectal Cancer

OBJECTIVE

To investigate the risk factors of acute pain after laparoscopic radical resection of colorectal cancer (CRC) in elderly patients.

METHODS

Totally, 143 elderly patients (≥ 60 y old) who received laparoscopic radical resection of CRC in the People's Hospital of Xinjiang Uygur Autonomous Region from March 2021 to August 2022 were retrospectively analyzed. The patients were divided into 2 groups according to visual analog scale (VAS) scores 24 h after surgery: mild pain group (VAS score ≤ 3, n=108) and moderate to severe pain group (VAS score >3, n=35). The data of the patients, including sex, age, height, body mass, intraoperative blood loss, intraoperative urine volume, intraoperative opioid dosage, operation duration, preoperative Hospital Anxiety and Depression Scale (HADS) scores, preoperative Mini-Mental State Examination scores, VAS scores, postoperative nausea and vomiting scores were recorded. Multivariate logistic regression analysis was used to screen the risk factors of postoperative acute pain in elderly patients undergoing laparoscopic radical resection of CRC.

RESULTS

The preoperative HADS score of the moderate to severe pain group was significantly increased compared with that of the mild pain group (10.8±2.4 vs. 6.2±1.9), as well as the operation duration (226.4±18.3 vs. 186.1±12.7), the intraoperative dosage of remifentanil (3.7±0.2 vs. 3.2±0.4), the preoperative VAS score [4(2, 7) vs. 2 (0, 4)] and postoperative VAS score [5 (4, 6) vs. 3 (2, 3)] ( P <0.05). Multivariate logistic regression analysis showed that high preoperative HADS score, long operation duration, and high preoperative VAS score ( P <0.05) were independent risk factors for acute pain after laparoscopic radical resection of CRC in elderly patients.

CONCLUSION

Preoperative anxiety and depression, preoperative pain, and long operation duration are risk factors for acute pain in elderly patients after laparoscopic radical resection of CRC.

Prediction of early postoperative pain using sleep quality and heart rate variability

PURPOSE

Accurate predictions of postoperative pain intensity are necessary for customizing analgesia plans. Insomnia is a risk factor for severe postoperative pain. Moreover, heart rate variability (HRV) can provide information on the sympathetic-parasympathetic balance in response to noxious stimuli. We developed a prediction model that uses the insomnia severity index (ISI), HRV, and other demographic factors to predict the odds of higher postoperative pain.

METHODS

We recruited gynecological surgery patients classified as American Society of Anesthesiologists class 1-3. An ISI questionnaire was completed 1 day before surgery. HRV was calculated offline using intraoperative electrocardiogram data. Pain severity at the postanesthesia care unit (PACU) was assessed with the 0-10 numerical rating scale (NRS). The primary outcome was the model's predictive ability for moderate-to-severe postoperative pain. The secondary outcome was the relationship between individual risk factors and opioid consumption in the PACU.

RESULTS

Our study enrolled 169 women. Higher ISI scores (p = 0.001), higher parasympathetic activity (rMSSD, pNN50, HF; p < 0.001, p < 0.001, p < 0.001), loss of fractal dynamics (SD2, alpha 1; p = 0.012, p = 0.039) in HRV analysis before the end of surgery were associated with higher NRS scores, while laparoscopic surgery (p = 0.031) was associated with lower NRS scores. We constructed a multiple logistic model (area under the curve = 0.852) to predict higher NRS scores at PACU arrival. The five selected predictors were age (OR: 0.94; p = 0.020), ISI score (OR: 1.14; p = 0.002), surgery type (laparoscopic or open; OR: 0.12; p < 0.001), total power (OR: 2.02; p < 0.001), and alpha 1 (OR: 0.03; p < 0.001).

CONCLUSION

We employed a multiple logistic regression model to determine the likelihood of moderate-to-severe postoperative pain upon arrival at the PACU. Physicians could personalize analgesic regimens based on a deeper comprehension of the factors that contribute to postoperative pain.

Sex moderates the association between quantitative sensory testing and acute and chronic pain after total knee/hip arthroplasty

OBJECTIVES

Acute postsurgical pain (APSP) may persist over time and become chronic. Research on predictors for APSP and chronic postsurgical pain (CPSP) has produced inconsistent results. This observational study aimed to analyze psychological and psychophysical variables associated with APSP and CPSP after total knee or hip arthroplasty, and to explore the role of sex.

METHODS

Assessments were conducted before surgery, 48 h, and 3 months postsurgery, including questionnaires (sociodemographic, pain related, and psychological) and quantitative sensory testing (QST). Hierarchical linear regression models analyzed potential predictors of APSP and CPSP, and moderation analyses evaluated the role of sex.

RESULTS

The study included 63 participants undergoing total knee (34, 54%) or hip (29, 46%) arthroplasty. Thirty-one (49.2%) were female and 32 (50.8%) were male. APSP (48 h) was associated with impaired conditioned pain modulation (CPM) (β = 0.301, p = 0.019). CPSP (3 months) was associated with being female (β = 0.282, p = 0.029), longer presurgical pain duration (β = 0.353, p = 0.006), knee arthroplasty (β = -0.312, p = 0.015), higher APSP intensity (β = 373, p = 0.004), and impaired CPM (β = 0.126, p = 0.004). In multivariate analysis, these clinical variables were significant predictors of CPSP, unlike sex, and CPM (adj. R 2 = 0.349). Moderation analyses showed that wind-up ratio (WUR) was a significant predictor of APSP in men (WUR × sex: b = -1.373, p = 0.046) and CPM was a significant predictor of CPSP in women (CPM × sex: b = 1.625, p = 0.016).

CONCLUSIONS

Specific QST parameters could identify patients at risk for high-intensity APSP and CPSP, with sex as a moderator. This has important clinical implications for patient care, paving the way for developing tailored preventive pain management strategies.

Mechanisms inherent in acute-to-chronic pain after surgery - risk, diagnostic, predictive, and prognostic factors

PURPOSE OF REVIEW

Pain is an expected consequence of a surgery, but it is far from being well controlled. One major complication of acute pain is its risk of persistency beyond healing. This so-called chronic post-surgical pain (CPSP) is defined as new or increased pain due to surgery that lasts for at least 3 months after surgery. CPSP is frequent, underlies a complex bio-psycho-social process and constitutes an important socioeconomic challenge with significant impact on patients' quality of life. Its importance has been recognized by its inclusion in the eleventh version of the ICD (International Classification of Diseases).

RECENT FINDINGS

Evidence for most pharmacological and non-pharmacological interventions preventing CPSP is inconsistent. Identification of associated patient-related factors, such as psychosocial aspects, comorbidities, surgical factors, pain trajectories, or biomarkers may allow stratification and selection of treatment options based on underlying individual mechanisms. Consequently, the identification of patients at risk and implementation of individually tailored, preventive, multimodal treatment to reduce the risk of transition from acute to chronic pain is facilitated.

SUMMARY

This review will give an update on current knowledge on mechanism-based risk, prognostic and predictive factors for CPSP in adults, and preventive and therapeutic approaches, and how to use them for patient stratification in the future.

Validation of the Calgary Postoperative Pain after Spine Surgery Score for Poor Postoperative Pain Control after Spine Surgery

OBJECTIVE

The Calgary Postoperative Pain after Spine Surgery (CAPPS) score was developed to identify patients at risk of experiencing poorly controlled pain after spine surgery. The goal of this study was to independently validate the CAPPS score on a prospectively collected patient sample.

METHODS

Poor postoperative pain control was defined as a mean numeric rating scale (NRS) for pain >4 at rest in the first 24 hours after surgery. Baseline characteristics in this study (validation cohort) were compared to those of the development cohort used to create the CAPPS score. Predictive performance of the CAPPS score was assessed by the area under the curve (AUC) and percentage misclassification for discrimination. A graphical comparison between predicted probability vs. observed incidence of poorly controlled pain was performed for calibration.

RESULTS

Fifty-two percent of 201 patients experienced poorly controlled pain. The validation cohort exhibited lower depression scores and a higher proportion using daily opioid medications compared to the development cohort. The AUC was 0.74 [95%CI = 0.68-0.81] in the validation cohort compared to 0.73 [95%CI = 0.69-0.76] in the development cohort for the eight-tier CAPPS score. When stratified between the low- vs. extreme-risk and low- vs. high-risk groups, the percentage misclassification was 21.2% and 30.7% in the validation cohort, compared to 29.9% and 38.0% in the development cohort, respectively. The predicted probability closely mirrored the observed incidence of poor pain control across all scores.

CONCLUSIONS

The CAPPS score, based on seven easily obtained and reliable prognostic variables, was validated using a prospectively collected, independent sample of patients.

The evolution of Big Data in neuroscience and neurology

Neurological diseases are on the rise worldwide, leading to increased healthcare costs and diminished quality of life in patients. In recent years, Big Data has started to transform the fields of Neuroscience and Neurology. Scientists and clinicians are collaborating in global alliances, combining diverse datasets on a massive scale, and solving complex computational problems that demand the utilization of increasingly powerful computational resources. This Big Data revolution is opening new avenues for developing innovative treatments for neurological diseases. Our paper surveys Big Data's impact on neurological patient care, as exemplified through work done in a comprehensive selection of areas, including Connectomics, Alzheimer's Disease, Stroke, Depression, Parkinson's Disease, Pain, and Addiction (e.g., Opioid Use Disorder). We present an overview of research and the methodologies utilizing Big Data in each area, as well as their current limitations and technical challenges. Despite the potential benefits, the full potential of Big Data in these fields currently remains unrealized. We close with recommendations for future research aimed at optimizing the use of Big Data in Neuroscience and Neurology for improved patient outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40537-023-00751-2.

[Identifying patients with risk for severe pain after ophthalmological surgery]

Modern ophthalmology includes a wide range of surgical options and, accordingly, also requires appropriate pain management. There are established risk factors for severe postoperative pain that should be identified and considered in the perioperative management. The main risk factors and existing recommendations are presented in this article. Patients at risk should be identified before surgery. It is important that perioperative pain management is implemented in the treatment plan as part of an interdisciplinary cooperation to identify and address the risks as early as possible.

Predicting severe pain after major surgery: a secondary analysis of the Peri-operative Quality Improvement Programme (PQIP) dataset

Acute postoperative pain is common, distressing and associated with increased morbidity. Targeted interventions can prevent its development. We aimed to develop and internally validate a predictive tool to pre-emptively identify patients at risk of severe pain following major surgery. We analysed data from the UK Peri-operative Quality Improvement Programme to develop and validate a logistic regression model to predict severe pain on the first postoperative day using pre-operative variables. Secondary analyses included the use of peri-operative variables. Data from 17,079 patients undergoing major surgery were included. Severe pain was reported by 3140 (18.4%) patients; this was more prevalent in females, patients with cancer or insulin-dependent diabetes, current smokers and in those taking baseline opioids. Our final model included 25 pre-operative predictors with an optimism-corrected c-statistic of 0.66 and good calibration (mean absolute error 0.005, p = 0.35). Decision-curve analysis suggested an optimal cut-off value of 20-30% predicted risk to identify high-risk individuals. Potentially modifiable risk factors included smoking status and patient-reported measures of psychological well-being. Non-modifiable factors included demographic and surgical factors. Discrimination was improved by the addition of intra-operative variables (likelihood ratio χ2 496.5, p < 0.001) but not by the addition of baseline opioid data. On internal validation, our pre-operative prediction model was well calibrated but discrimination was moderate. Performance was improved with the inclusion of peri-operative covariates suggesting pre-operative variables alone are not sufficient to adequately predict postoperative pain.

Transitional Pain Medicine; New Era, New Opportunities, and New Journey

Chronic postsurgical pain (CPSP), also known as persistent postsurgical pain (PPSP), is pain that develops or increases in intensity after a surgical procedure and lasts more than 3 months. Transitional pain medicine is the medical field that focuses on understanding the mechanisms of CPSP and defining risk factors and developing preventive treatments. Unfortunately, one significant challenge is the risk of developing opioid use dependence. Multiple risk factors have been discovered, with the most common, and modifiable, being uncontrolled acute postoperative pain; preoperative anxiety and depression; and preoperative site pain, chronic pain, and opioid use.

Managing Post-Operative Pain in Orthopedic Patients: An International Comparison

Introduction

Opioids play a crucial role in post-operative pain management in America, but not in some other countries. We sought to determine if a discrepancy in opioid use between the United States (U.S.) and Romania, a country that administers opioids in a conservative fashion, would show in subjective pain control differences.

Methods

Between May 23, 2019, and November 23, 2019, 244 Romanian patients and 184 American patients underwent total hip arthroplasty or the surgical treatment of the following fractures: bimalleolar ankle, distal radius, femoral neck, intertrochanteric, and tibial-fibular. Opioid and non-opioid analgesic medication use and subjective pain scores during the first and second 24 hours after surgery were analyzed.

Results

Subjective pain scores for the first 24 hours were higher among patients in Romania compared to the U.S. (p < 0.0001), but Romanians reported lower pain scores than U.S. patients in the second 24-hours (p < 0.0001). The quantity of opioids given to U.S. patients did not differ significantly based on sex (p = 0.4258) or age (p = 0.0975). However, females reported higher pain scores than male patients following the studied procedures (p = 0.0181). No sex-based differences in pain scores were noted among Romanian patients.

Conclusions

Higher pain scores in American females, despite equivalent amounts of narcotics to their male counterparts, and the absence of a difference in Romanians suggested that the current American post-operative pain regimen may be tailored to the needs of male patients. In addition, it pointed to the impacts of gender, compared to sex, in pain experiences. Future research should look for the safest, most efficacious pain regimen suitable for all patients.

Subjective Assessments and Serum Cortisol Levels as Risk Factors of Pain Persistence in the Late Postoperative Period in Old and Oldest-Old Patients

Postoperative pain is one of the most common postoperative complications, resulting in significant burdens and adverse outcomes among patients, notably the frailest ones. Predicting the likelihood of intense postoperative pain can help optimize a patient's recovery. The aims of this study were to build a prognostic model of pain persistence in elderly and senile patients in the late postoperative period, based on clinical and laboratory parameters of the early postoperative period, and to evaluate the potential for the model's application. The study included 201 male and female patients who had undergone surgery of any type from September 2019 to August 2020. The patients were divided into three groups: senile patients, elderly patients, and young patients (control group). All of the examined patients were measured for fasting cortisol on the mornings of the first and seventh days following surgery. A statistically significant increase in the probability of pain persistence in the late postoperative period with the increasing age of the patient was found. Age, pain severity scores on the seventh day after surgery, and cortisol concentration in the blood on the first day after surgery, are of prognostic value for the risk of persistence of postoperative-pain syndrome.

Bones, groans and sending patients home: Perioperative opioid-related harm reduction strategy utilisation in a regional New South Wales (NSW) hospital

OBJECTIVE

Perioperative initiation of opioids continues to be a major contributor to chronic use, misuse and diversion in regional areas. There is considerable effort to mitigate harm through avoiding excessive prescribing and reducing the risk of persistent postoperative opioid use. Improving perioperative documentation practices has been reported to ensure appropriate opioid initiation and de-escalation. It has not been established whether these strategies are utilised in regional hospitals.

METHODS

A retrospective observational study of perioperative opioid prescribing and documentation practices in Goulburn Base Hospital, a regional centre in the Southern New South Wales (NSW) Local Health District. Data were collected from 110 records and validated for adult patients undergoing elective total knee replacement (TKR) or total hip replacement (THR) from 12 January 2020 to 13 January 2021.

OUTCOME MEASURES

To observe perioperative opioid prescribing and utilisation of harm reduction strategies in a regional hospital.

RESULTS

65% of patients were opioid naïve (ON). Preoperative pain assessments and patient education were completed in 23% and 15% of records, respectively. Postoperative opioids were prescribed for 99% of patients, with 74% prescribed a slow-release (SR) formulation. 50% of patients were discharged with an SR prescription. Inadequate postoperative pain control was reported in 21% of patients. Of the 103 patients prescribed opioids on discharge, only 20% included a de-escalation plan and only 35% of discharge summaries included dose and quantity of opioids supplies.

CONCLUSIONS

This study has identified underutilisation of perioperative harm reduction strategies despite the potential to improve appropriate initiation and de-escalation of opioids. These findings highlight opportunities for improvement in regional hospitals.

Effect of acute pain on the association between preoperative cognitive impairment and postoperative delirium: a secondary analysis of three trials

BACKGROUND

The association between preoperative cognitive impairment, postoperative pain, and postoperative delirium in older patients after noncardiac surgery is not known.

METHODS

This was a secondary analysis of datasets from three previous studies. Patients aged ≥55 yr who underwent elective noncardiac surgery were enrolled. Preoperative cognitive impairment was defined as Mini-Mental State Examination <27. Pain intensity with movement was assessed using an 11-point numeric rating scale at 12-h intervals during the first 72 h after surgery; time-weighted average (TWA) pain score was calculated. Primary outcome was the occurrence of delirium within the first 5 postoperative days. Mediation analysis was used to investigate the relationships between cognitive impairment, pain score, and delirium.

RESULTS

A total of 1497 patients were included. Prevalence of preoperative cognitive impairment was 40.3% (603/1497). Patients with cognitive impairment suffered higher TWA pain score within 72 h (4 [3-5] vs 3 [2-5], P=0.004) and more delirium within 5 days (12.9% [78/603] vs 4.9% [44/894], P<0.001) when compared with those without. Total and direct associations between cognitive impairment and delirium were (adjusted β) 8.3% (95% confidence interval [CI], 4.8-12.0%; P<0.001) and 7.8% (95% CI, 4.4-12.0%; P<0.001), respectively. A significant indirect association with acute pain was observed between cognitive impairment and delirium (adjusted β=0.4%; 95% CI, 0.1-1.0%; P=0.006), accounting for 4.9% of the total effect.

CONCLUSIONS

The association between preoperative cognitive impairment and delirium is significantly mediated by acute pain in patients after noncardiac surgery. Considering the small effect size, clinical significance of this mediation effect requires further investigation.

Fairness in the prediction of acute postoperative pain using machine learning models

Introduction

Overall performance of machine learning-based prediction models is promising; however, their generalizability and fairness must be vigorously investigated to ensure they perform sufficiently well for all patients.

Objective

This study aimed to evaluate prediction bias in machine learning models used for predicting acute postoperative pain.

Method

We conducted a retrospective review of electronic health records for patients undergoing orthopedic surgery from June 1, 2011, to June 30, 2019, at the University of Florida Health system/Shands Hospital. CatBoost machine learning models were trained for predicting the binary outcome of low (≤4) and high pain (>4). Model biases were assessed against seven protected attributes of age, sex, race, area deprivation index (ADI), speaking language, health literacy, and insurance type. Reweighing of protected attributes was investigated for reducing model bias compared with base models. Fairness metrics of equal opportunity, predictive parity, predictive equality, statistical parity, and overall accuracy equality were examined.

Results

The final dataset included 14,263 patients [age: 60.72 (16.03) years, 53.87% female, 39.13% low acute postoperative pain]. The machine learning model (area under the curve, 0.71) was biased in terms of age, race, ADI, and insurance type, but not in terms of sex, language, and health literacy. Despite promising overall performance in predicting acute postoperative pain, machine learning-based prediction models may be biased with respect to protected attributes.

Conclusion

These findings show the need to evaluate fairness in machine learning models involved in perioperative pain before they are implemented as clinical decision support tools.

Knowing the Enemy Is Halfway towards Victory: A Scoping Review on Opioid-Induced Hyperalgesia

Opioid-induced hyperalgesia (OIH) is a paradoxical effect of opioids that is not consensually recognized in clinical settings. We conducted a revision of clinical and preclinical studies and discuss them side by side to provide an updated and renewed view on OIH. We critically analyze data on the human manifestations of OIH in the context of chronic and post-operative pain. We also discuss how, in the context of cancer pain, though there are no direct evidence of OIH, several inherent conditions to the tumor and chemotherapy provide a substrate for the development of OIH. The review of the clinical data, namely in what concerns the strategies to counter OIH, emphasizes how much OIH rely mechanistically on the existence of µ-opioid receptor (MOR) signaling through opposite, inhibitory/antinociceptive and excitatory/pronociceptive, pathways. The rationale for the maladaptive excitatory signaling of opioids is provided by the emerging growing information on the functional role of alternative splicing and heteromerization of MOR. The crossroads between opioids and neuroinflammation also play a major role in OIH. The latest pre-clinical data in this field brings new insights to new and promising therapeutic targets to address OIH. In conclusion, although OIH remains insufficiently recognized in clinical practice, the appropriate diagnosis can turn it into a treatable pain disorder. Therefore, in times of scarce alternatives to opioids to treat pain, mainly unmanageable chronic pain, increased knowledge and recognition of OIH, likely represent the first steps towards safer and efficient use of opioids as analgesics.

The influence of involving patients in postoperative pain treatment decisions on pain-related patient-reported outcomes: A STROBE-compliant registering observational study

The evidence regarding the influence of allowing patients to participate in postoperative pain treatment decisions on acute pain management is contradictory. This study aimed to identify the role of patient participation in influencing pain-related patient-reported outcomes (PROs). This is a cross-sectional study. The data were provided by PAIN OUT (www.pain-out.eu). A dataset specific to adult Chinese patients undergoing orthopedic surgery was selected. The PROs were assessed on postoperative day 1. The patient participant was assessed using an 11-point scale. Participants who reported >5 were allocated to the "participation" group, and those who reported ≤5 were allocated to the "nonparticipation" group. A 1:1 propensity score matching was conducted. The primary outcome was the desire for more pain treatment. All other items of PROs were the secondary outcomes comprising pain intensity, interference of pain with function, emotional impairment, adverse effects, and other patient perception. From February 2014 to November 2020, 2244 patients from 20 centers were approached, of whom 1804 patients were eligible and 726 pairs were matched. There was no significant difference between the groups in the desire for more pain treatment either before (25.4% vs 28.2%, risk ratio [95% CI]: 0.90 [0.77, 1.05], P = .18) or after matching (26.7% vs 28.8%, risk ratio [95% CI]: 0.93 [0.79, 1.10], P = .43). After matching, patients in the participation group reported significantly better PROs, including pain intensity (less time spent in severe pain [P < .01]), emotional impairment (less anxiety [P < .01]), interference with function (less interference with sleep [P < .01]), adverse effects (less drowsiness [P = .01]), and patient perception (more pain relief [P < .01] and more satisfaction [P < .01]), than the nonparticipation group. Patient participation in pain treatment decisions was associated with improved pain experience but failed to mitigate the desire for more treatment.

A novel methodology to integrate outcomes regarding perioperative pain experience into a composite score: prediction model development and validation

BACKGROUND

An integrated score that globally assesses perioperative pain experience and rationally weights each component has not yet been developed.

METHODS

A development dataset specific to adult Chinese patients undergoing orthopedic surgery was obtained from PAIN OUT (1985 qualified patients of 2244). A more recent validation dataset obeying the same conditions was obtained from the Chinese Anesthesia Shared-database Platform (1004 qualified patients of 1032). Outcomes were assessed using the International Pain Outcomes Questionnaire (IPO-Q), which comprises key patient-level outcomes of perioperative pain management, including pain experience and perceptions of care. Using principal component analysis and regression models, a composite score was inferred to integrate pain experience. The discrimination of the composite score for dissatisfaction and desire for more pain treatment was compared with that of the worst pain score.

RESULTS

A composite score was developed from the 12 items of the IPO-Q regarding pain experience. The weight for calculating the composite score was worst pain 11, least pain 17, time spent in severe pain 11, interference with activity in bed 9, interference with breathing deeply or coughing 10, interference with sleep 9, anxiety 12, helplessness 12, nausea 0, drowsiness 2, itch 5, and dizziness 2. In external validation, the composite score indicated superior discrimination to the worst pain in predicting dissatisfaction (P<0.001) and desire for more pain treatment (P<0.001).

CONCLUSIONS

This study introduced a methodology to integrate outcomes regarding perioperative pain experience into a composite score, which was based on the weight of each item.

Multimodal prediction of pain and functional outcomes 6 months following total knee replacement: a prospective cohort study

BACKGROUND

Knee osteoarthritis (OA) is among the most common and disabling persistent pain conditions, with increasing prevalence and impact around the globe. In the U.S., the rising prevalence of knee OA has been paralleled by an increase in annual rates of total knee arthroplasty (TKA), a surgical treatment option for late-stage knee OA. While TKA outcomes are generally good, post-operative trajectories of pain and functional status vary substantially; a significant minority of patients report ongoing pain and impaired function following TKA. A number of studies have identified sets of biopsychosocial risk factors for poor post-TKA outcomes (e.g., comorbidities, negative affect, sensory sensitivity), but few prospective studies have systematically evaluated the unique and combined influence of a broad array of factors.

METHODS

This multi-site longitudinal cohort study investigated predictors of 6-month pain and functional outcomes following TKA. A wide spectrum of relevant biopsychosocial predictors was assessed preoperatively by medical history, patient-reported questionnaire, functional testing, and quantitative sensory testing in 248 patients undergoing TKA, and subsequently examined for their predictive capacity.

RESULTS

The majority of patients had mild or no pain at 6 months, and minimal pain-related impairment, but approximately 30% reported pain intensity ratings of 3/10 or higher. Reporting greater pain severity and dysfunction at 6 months post-TKA was predicted by higher preoperative levels of negative affect, prior pain history, opioid use, and disrupted sleep. Interestingly, lower levels of resilience-related "positive" psychosocial characteristics (i.e., lower agreeableness, lower social support) were among the strongest, most consistent predictors of poor outcomes in multivariable linear regression models. Maladaptive profiles of pain modulation (e.g., elevated temporal summation of pain), while not robust unique predictors, interacted with psychosocial risk factors such that the TKA patients with the most pain and dysfunction exhibited lower resilience and enhanced temporal summation of pain.

CONCLUSIONS

This study underscores the importance of considering psychosocial (particularly positively-oriented resilience variables) and sensory profiles, as well as their interaction, in understanding post-surgical pain trajectories.

Postdischarge pain, nausea and patient satisfaction after diagnostic and breast-conserving ambulatory surgery for breast cancer: A cross-sectional study

BACKGROUND

The aims of this study were to assess first day postdischarge pain, nausea and patient satisfaction in ambulatory breast cancer surgical patients, after diagnostic and breast conserving procedures.

METHODS

A total of 781 women, aged 18-85 years were included in this prospective, cross-sectional study. All patients received standardized multimodal pain prophylaxis with paracetamol, COX-II inhibitor, dexamethasone and wound infiltration with local anaesthetics. Nausea prophylaxis was provided with ondansetron. Most patients received general anaesthesia with propofol and remifentanil. Data were collected using a validated questionnaire during telephone follow-up on the first postoperative day.

RESULTS

The response rate was 94.5%. NRS ≥ 4 was reported by 5.3% at rest, by 17% during activity and by 30.7% as the worst pain score. Young age was strongly associated with more pain both at rest, during activity and regarding worst pain since discharge. Postdischarge nausea was present in 17.8%, and vomiting in 1.2%. High pain score during activity and higher level of worst pain, were associated with nausea. There was no association between nausea and age, type of anaesthesia, surgical procedure or pain at rest. Patient satisfaction was high (97.8%-99.7%) regarding information, time for discharge and overall satisfaction.

CONCLUSION

Pain scores and incidence of nausea were generally low on the day after surgery. Young age was a strong predictor for postdischarge pain. A high worst pain score and high pain score during the activity were associated with postdischarge nausea. Patient satisfaction was high.

CE: Assessing Movement-Evoked Pain

ABSTRACT

One of the most common and nuanced tasks that nurses perform is pain assessment, particularly in acute postoperative settings where frequent reassessments are needed. Most assessments are limited to obtaining a pain intensity score with little attention paid to the conditions necessitating the assessment or the factors contributing to the pain. Pain is frequently assessed during rest, but seldom during periods of movement or activity, which is a crucial omission given that acute postoperative movement-evoked pain (MEP) is intense and a common barrier to healing and restoration of function. In addition to physical limitations, MEP can impede cognitive, emotional, and social functioning in ways that can contribute to chronic pain, mood disorders, and disability. Professional and regulatory standards are moving away from a focus on pain intensity to an emphasis on its context, impact on function, and associated distress. Thus, there are many driving forces compelling nurses to integrate MEP assessments into practice to expedite the restoration of biopsychosocial functioning in postoperative patients. The authors discuss the clinical significance of a MEP assessment as well as protocols and tools for completing such assessments.

Chronic Pain Prevalence and Factors Associated With High Impact Chronic Pain following Total Joint Arthroplasty: An Observational Study

Hip, knee, and shoulder arthroplasty are among the most frequently performed orthopaedic procedures in the United States. High impact and bothersome chronic pain rates following total joint arthroplasty (TJA) are unknown; as are factors that predict these chronic pain outcomes. This retrospective observational study included individuals that had a TJA from January 2014 to January 2020 (n = 2,638). Pre-operative and clinical encounter information was extracted from the electronic health record and chronic pain state was determined by email survey. Predictor variables included TJA location, number of surgeries, comorbidities, tobacco use, BMI, and pre-operative pain intensity. Primary outcomes were high impact and bothersome chronic pain. Rates of high impact pain (95% CI) were comparable for knee (9.8-13.3%), hip (8.3-11.8%) and shoulder (7.6-16.3%). Increased risk of high impact pain included non-white race, two or more comorbidities, age less than 65 years, pre-operative pain scores 5/10 or higher, knee arthroplasty, and post-operative survey completion 24 months or less. Rates of bothersome chronic pain (95% CI) were also comparable for knee (24.9-29.9%) and hip (21.3-26.3%) arthroplasty; but higher for shoulder (26.9-39.6%). Increased risk of bothersome chronic pain included non-white race, shoulder arthroplasty, knee arthroplasty, current or past tobacco use, and being female. PERSPECTIVE: In this cohort more than 1/3rd of individuals reported high impact or bothersome chronic pain following TJA. Non-white race and knee arthroplasty were the only two variables associated with both chronic pain outcomes.

Prognostic prediction models for chronic postsurgical pain in adults: a systematic review

ABSTRACT

Chronic postsurgical pain (CPSP) affects an estimated 10% to 50% of adults depending on the type of surgical procedure. Clinical prediction models can help clinicians target preventive strategies towards patients at high risk for CPSP. Therefore, the objective of this systematic review was to identify and describe existing prediction models for CPSP in adults. A systematic search was performed in MEDLINE, Embase, PsychINFO, and the Cochrane Database of Systematic Reviews in March 2020 for English peer-reviewed studies that used data collected between 2000 and 2020. Studies that developed, validated, or updated a prediction model in adult patients who underwent any surgical procedure were included. Two reviewers independently screened titles, abstracts, and full texts for eligibility; extracted data; and assessed risk of bias using the Prediction model Risk of Bias Assessment Tool. The search identified 2037 records; 28 articles were reviewed in full text. Fifteen studies reporting on 19 prediction models were included; all were at high risk of bias. Model discrimination, measured by the area under receiver operating curves or c-statistic, ranged from 0.690 to 0.816. The most common predictors identified in final prediction models included preoperative pain in the surgical area, preoperative pain in other areas, age, sex or gender, and acute postsurgical pain. Clinical prediction models may support prevention and management of CPSP, but existing models are at high risk of bias that affects their reliability to inform practice and generalizability to wider populations. Adherence to standardized guidelines for clinical prediction model development is necessary to derive a prediction model of value to clinicians.

Opioid Analgesics and Persistent Pain After an Acute Pain Emergency Department Visit: Evidence from a Cohort of Suspected Urolithiasis Patients

BACKGROUND

Severe acute pain is still commonly treated with opioid analgesics in the United States, but this practice could prolong the duration of pain.

OBJECTIVES

Estimate the risk of experiencing persistent pain after opioid analgesic use after emergency department (ED) discharge among patients with suspected urolithiasis.

METHODS

We analyzed data collected for a longitudinal, multicenter clinical trial of ED patients with suspected urolithiasis. We constructed multilevel models to estimate the odds ratios (ORs) of reporting pain at 3, 7, 30, or 90 days after ED discharge, using multiple imputation to account for missing outcome data. We controlled for clinical, demographic, and institutional factors and used weighting to account for the propensity to be prescribed an opioid analgesic at ED discharge.

RESULTS

Among 2413 adult ED patients with suspected urolithiasis, 62% reported persistent pain 3 days after discharge. Participants prescribed an opioid analgesic at discharge were OR 2.51 (95% confidence interval [CI] 1.82-3.46) more likely to report persistent pain than those without a prescription. Those who reported using opioid analgesics 3 days after discharge were OR 2.24 (95% CI 1.77-2.84) more likely to report pain at day 7 than those not using opioid analgesics at day 3, and those using opioid analgesics at day 30 had OR 3.25 (95% CI 1.96-5.40) greater odds of pain at day 90.

CONCLUSIONS

Opioid analgesic prescription doubled the odds of persistent pain among ED patients with suspected urolithiasis. Limiting opioid analgesic prescribing at ED discharge for these patients might prevent persistent pain in addition to limiting access to these medications.

Association of Nutritional Risk Index With Postoperative Pain Outcomes in Elderly Patients Undergoing Gastrointestinal Surgeries: A Retrospective Cohort Study

Background: Malnutrition is a major health problem, which is common in hospitalized elderly patients and is associated with an increased risk of morbidity and mortality. However, studies on malnutrition and its effect on postoperative pain outcomes in elderly patients have been largely neglected. Here we investigated the relationship between nutritional risk and postoperative pain outcomes in elderly patients.

Methods: Between April 1, 2012, and August 31, 2015, 734 elderly patients (≥65 years) who underwent gastrointestinal surgeries were recruited and assigned into two groups according to geriatric nutritional risk index (GNRI). All patients received standard anesthesia procedures and postoperative patient-controlled analgesia for 48 h. The preoperative epidemiology data and postoperative outcome data including pain intensities at rest and movement, the cumulative consumption of analgesics and its common side effects were recorded.

Results: The total number of patients with high nutritional risk (GNRI < 92) was 533 out of 734 (72.62%). When compared with low nutritional risk individuals (GNRI ≥ 92), the incidence of inadequate analgesia was significantly higher in elderly patients with GNRI < 92 at different time points. In addition, the cumulative consumption of analgesics was also significantly higher in elderly patients with GNRI < 92 at 0–6 h postoperatively. Through logistic regression analysis, high nutritional risk (OR = 3.113, 95% CI: 1.661–5.834, P < 0.001) and female gender (OR = 0.606, 95% CI: 0.394–0.932, P = 0.023) were identified as significant predictors for postoperative inadequate analgesia. Further sensitivity analyses showed high nutritional risk as a predictor for postoperative inadequate analgesia was more prominent in female patients and early elderly patients. Moreover, 88 was determined as an optimal cut-off value of GNRI for postoperative inadequate analgesia using receiver operating characteristic curve analysis.

Conclusion: High nutritional risk is associated with poor postoperative pain outcomes in gastrointestinal elderly patients. Preoperative nutritional evaluation using simple nutritional screening instruments (e.g., GNRI) with the new suggested cut-off value (GNRI = 88) might be included as a standard procedure in routine clinical practice among these patients for postoperative analgesia.

Erector Spinae Plane Block versus Continuous Perineural Local Anesthetic Infusion for Postoperative Pain Control After Supraclavicular Decompression for Neurogenic Thoracic Outlet Syndrome: A Matched Case-Control Comparison

OBJECTIVE

The purpose of this study was to determine if single injection erector spinae plane blocks are associated with improved pain control, opioid use, numbness, length of stay, or patient satisfaction compared to intraoperatively placed continuous perineural infusion of local anesthetic after decompression of neurogenic thoracic outlet syndrome.

METHODS

This is a retrospective cohort study at a tertiary academic center of eighty patients that underwent supraclavicular decompression for thoracic outlet syndrome between May 2019 and January 2020. Forty consecutive patients treated with single-injection preoperative erector spinae plane blocks were retrospectively compared to 40 age- and gender-matched controls treated with continuous perineural infusion.

RESULTS

The primary outcome of mean pain scores was not significantly different between the erector spinae and perineural infusion groups over the three-day study period (4.2-5.3 vs 3.0-5.1 P=0.08). On post-operative day 0, mean pain scores were significantly higher in the erector spinae group (4.2 vs 3.0, P=0.02). While statistically significant, the score was still lower in the erector spinae group on day 0 than on day 1,2, or 3 in either group. Opioid use, nausea, length of stay and patient satisfaction were also similar. Upper extremity numbness was significantly less severe in the erector spinae group (36% vs 73% moderate-extreme, P=0.03) at 6-month follow-up.

CONCLUSIONS

Seventy-two-hour perineural local anesthetic infusion did not provide superior analgesia compared to preoperative single-injection erector spinae blocks. Furthermore, there was significantly less long-term postoperative numbness associated with erector spinae blocks compared to perineural local anesthetic infusion.

Waking Up in Pain: a prospective unselected cohort study of pain in 3702 patients immediately after surgery in the Danish Realm

BACKGROUND

Acute and persistent pain after surgery is well described. However, no large-scale studies on immediate postoperative pain in the operating room (OR) exist, hindering potential areas of research to improve clinical outcomes. Thus, we aimed to describe the occurrence and severity of immediate postoperative pain in a large, unselected cohort.

METHODS

This was a prospective cohort study, encompassing all procedures in 31 public hospitals in the Danish Realm, during a 5-day period including the weekend. Data on procedures and anesthesia were collected and the main outcome was occurrence of moderate or severe pain in the OR. Secondary outcomes included pain, sedation and nausea in the OR or during the first 15 min in the postanesthesia care unit (PACU) including relevant risk factors. Descriptive and logistic regression statistics were used.

RESULTS

A total of 3675 procedures were included for analysis (87% inclusion rate). Moderate or severe pain occurred in 7.4% (95% CI 6.5% to 8.3%) of cases in the OR immediately after awakening, rising to 20.2% in the OR and/or PACU. Large intraprocedure and interprocedure variations occurred (0.0%-37.5%), and in 20% of cases with epidural-general anesthesia patients experienced moderate or severe pain. Independent risk factors were female sex, younger age, preoperative pain, daily opioid use and major surgical procedures.

CONCLUSION

Moderate or severe pain in the immediate postoperative phase occurred in 20% of all cases with procedure and anesthesiological technique variations, suggesting a need for identification of relevant procedure-specific risk factors and development of preventive treatments.

TRIAL REGISTRATION NUMBER

RoPR ID 43191.

Age- and Sex-Graded Data Evaluation of Vaccination Reactions after Initial Injection of the BNT162b2 mRNA Vaccine in a Local Vaccination Center in Germany

A high vaccination rate of older and particularly chronically ill people against coronavirus disease-2019 (COVID-19) is likely one of the most important factors in containing the pandemic. When Germany’s vaccination campaign started on December 2020, vaccination prioritization was initially carried out starting with older population groups. Side effect rates in 1065 individuals who had received the first dose of the messenger ribonucleic acid (mRNA) vaccine BNT162b2 Tozinameran from BioNTech/Pfizer three weeks earlier were examined retrospectively. An age- and gender-graded data analysis showed clear age and gender differences with regard to vaccine-related adverse effects. In 77% of all individuals over 80 years of age, no local or systemic side effects were reported after the first vaccination, whereas in the age group up to 80 years, only 37% showed no side effects. In the whole study population, 64% of females and 73% of males reported no adverse effects. The initial vaccination with mRNA vaccine BNT162b2 shows an overall low profile of side effects. Particularly in those over 80 years, an extraordinarily good tolerance with equally good effectiveness is evident. The sex comparison showed that women suffer more often from adverse vaccination reactions. In order to achieve sufficient herd immunity, both age- and gender-dependent vaccination reactions and any difference in the maintenance of immunity should be considered in future vaccination strategies.

Identification of preoperative predictors for acute postsurgical pain and for pain at three months after surgery: a prospective observational study

Identifying patients at risk is the start of adequate perioperative pain management. We aimed to identify preoperative predictors for acute postsurgical pain (APSP) and for pain at 3 months after surgery to develop prediction models. In a prospective observational study, we collected preoperative predictors and the movement-evoked numerical rating scale (NRS-MEP) of postoperative pain at day 1, 2, 3, 7, week 1, 6 and 3 months after surgery from patients with a range of surgical procedures. Regression analyses of data of 2258 surgical in- and outpatients showed that independent predictors for APSP using the mean NRS-MEP over the first three days after surgery were hospital admittance, female sex, higher preoperative pain, younger age, pain catastrophizing, anxiety, higher score on functional disability, highest categories of expected pain, medical specialty, unknown wound size, and wound size > 10 cm compared to wound size ≤ 10 cm (RMSE = 2.11). For pain at three months, the only predictors were preoperative pain and a higher score on functional disability (RMSE = 1.69). Adding pain trajectories improved the prediction of pain at three months (RMSE = 1.37). Our clinically applicable prediction models can be used preoperatively to identify patients at risk, as well as in the direct postoperative period.

AAAPT Diagnostic Criteria for Acute Thoracic Surgery Pain

Patients undergoing thoracic surgery experience particular challenges for acute pain management. Availability of standardized diagnostic criteria for identification of acute pain after thoracotomy and video assisted thoracic surgery (VATS) would provide a foundation for evidence-based management and facilitate future research. The Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership with the United States Food and Drug Administration, the American Pain Society (APS), and the American Academy of Pain Medicine (AAPM) formed the ACTTION-APS-AAPM Pain Taxonomy (AAAPT) initiative to address absence of acute pain diagnostic criteria. A multidisciplinary working group of pain experts was invited to develop diagnostic criteria for acute thoracotomy and VATS pain. The working group used available studies and expert opinion to characterize acute pain after thoracotomy and VATS using the 5-dimension taxonomical structure proposed by AAAPT (i.e., core diagnostic criteria, common features, modulating factors, impact/functional consequences, and putative mechanisms). The resulting diagnostic criteria will serve as the starting point for subsequent empirically validated criteria. PERSPECTIVE ITEM: This article characterizes acute pain after thoracotomy and VATS using the 5-dimension taxonomical structure proposed by AAAPT (ie, core diagnostic criteria, common features, modulating factors, impact and/or functional consequences, and putative mechanisms).

Psychophysical predictors of experimental muscle pain intensity following fatiguing calf exercise

Musculoskeletal pain affects approximately 20% of the population worldwide and represents one of the leading causes of global disability. As yet, precise mechanisms underlying the development of musculoskeletal pain and transition to chronicity remain unclear, though individual factors such as sleep quality, physical activity, affective state, pain catastrophizing and psychophysical pain sensitivity have all been suggested to be involved. This study aimed to investigate whether factors at baseline could predict musculoskeletal pain intensity to an experimental delayed onset of muscle soreness (DOMS) pain model. Demographics, physical activity, pain catastrophizing, affective state, sleep quality, isometric force production, temporal summation of pain, and psychophysical pain sensitivity using handheld and cuff algometry were assessed at baseline (Day-0) and two days after (Day-2) in 28 healthy participants. DOMS was induced on Day-0 by completing eccentric calf raises on the non-dominant leg to fatigue. On Day-2, participants rated pain on muscle contraction (visual analogue scale, VAS, 0-10cm) and function (Likert scale, 0–6). DOMS resulted in non-dominant calf pain at Day-2 (3.0±2.3cm), with significantly reduced isometric force production (P<0.043) and handheld pressure pain thresholds (P<0.010) at Day-2 compared to Day-0. Linear regression models using backward selection predicted from 39.3% (P<0.003) of VAS to 57.7% (P<0.001) of Likert score variation in DOMS pain intensity and consistently included cuff pressure pain tolerance threshold (P<0.01), temporal summation of pain (P<0.04), and age (P<0.02) as independent predictive factors. The findings indicate that age, psychological and central pain mechanistic factors are consistently associated with pain following acute muscle injury.

Predictors of maximal postoperative pain at rest in adult patients undergoing elective surgery - A multicenter observational study

The aim of this prospective cohort study was to assess the maximum intensity of postoperative pain at rest in 620 adults after an elective surgery as well as to determine demographic and clinical predictors of pain. The Hospital Anxiety and Depression Scale was used to evaluate the preoperative mental condition of the patient. Preoperative and postoperative pain were assessed at rest based on the Numeric Rating Scale (range: 0-10). The total median maximum intensity of pain was 3 (interquartile range: 1-5). The linear regression model for the maximum intensity of postoperative pain was statistically significant and very well fitted - the coefficient of determination was 62%. Preoperative anxiety, pain, cancer, a medical history of thyroid (vs abdominal) surgery, and an operation resulting in major (vs moderate) tissue injury have a positive impact on the maximum intensity of postoperative pain. Eye surgery and lower limb operations gave lower scores than abdominal surgery. The early identification of these predictors in patients at risk for postoperative pain will help in preparing an individual pain management plan.

A Bibliometric Analysis of Published Literature in Postoperative Pain in Elderly Patients in Low- and Middle-Income Countries

Postoperative pain (POP) remains a major challenge for surgeons and anesthesiologists worldwide, especially in low- and middle-income countries. Elderly patients are at higher risk for undertreatment of pain. Despite that, there is a paucity of papers addressing POP among this population in developing countries. This study aimed to provide a bibliometric analysis of the literature concerning postoperative pain in elderly patients from low- and middle-income countries. It was performed an extensive search of papers on this subject through the Web of Science and Scopus database using a series of uniterms and, including publications from 2001 to 2021. Publication quality was assessed by using total citation frequency, average citations per item and other citation indexes. Citation indexes were low, with the highest reaching 15 citations. In conclusion, few studies of postoperative pain in the elderly in countries with medium and low income, indicating a need that has not yet been met for this population and in these areas of the world. The published studies were not specifically aimed at the elderly, had limited impact, low international visibility. They were not epidemiological studies and are not robust, weakening knowledge and decision-making towards policies directed at this vulnerable population.

Sleep Well and Recover Faster with Less Pain-A Narrative Review on Sleep in the Perioperative Period

Sleep disturbance, pain, and having a surgical procedure of some kind are all very likely to occur during the average lifespan. Postoperative pain continues to be a prevalent problem and growing evidence supports the association between pain and sleep disturbances. The bidirectional nature of sleep and pain is widely acknowledged. A decline in sleep quality adds a risk for the onset of pain and also exacerbates existing pain. The risk factors for developing insomnia and experiencing severe pain after surgery are quite similar. The main aim of this narrative review is to discuss why it is important to be aware of sleep disturbances both before and after surgery, to know how sleep disturbances should be assessed and monitored, and to understand how better sleep can be supported by both pharmacological and non-pharmacological interventions.

An Interactive Pain Application (MServ) Improves Postoperative Pain Management

Background

Most patients have moderate or severe pain after surgery. Opioids are the cornerstone of treating severe pain after surgery but cause problems when continued long after discharge. We investigated the efficacy of multifunction pain management software (MServ) in improving postoperative pain control and reducing opioid prescription at discharge.

Methods

We recruited 234 patients to a prospective cohort study into sequential groups in a nonrandomised manner, one day after major thoracic or urological surgery. Group 1 received standard care (SC, n = 102), group 2 were given a multifunctional device that fed back to the nursing staff alone (DN, n = 66), and group 3 were given the same device that fed back to both the nursing staff and the acute pain team (DNPT, n = 66). Patient-reported pain scores at 24 and 48 hours and patient-reported time in severe pain, medications, and satisfaction were recorded on trial discharge. Findings. Odds of having poor pain control (>1 on 0–4 pain scale) were calculated between standard care (SC) and device groups (DN and DNPT). Patients with a device were significantly less likely to have poor pain control at 24 hours (OR 0.45, 95% CI 0.25, 0.81) and to report time in severe pain at 48 hours (OR 0.62, 95% CI 0.47–0.80). Patients with a device were three times less likely to be prescribed strong opioids on discharge (OR 0.35, 95% CI 0.13 to 0.95). Interpretation. Using an mHealth device designed for pain management, rather than standard care, reduced the incidence of poor pain control in the postoperative period and reduced opioid prescription on discharge from hospital.

Big Data in Studying Acute Pain and Regional Anesthesia

The digital transformation of healthcare is advancing, leading to an increasing availability of clinical data for research. Perioperative big data initiatives were established to monitor treatment quality and benchmark outcomes. However, big data analyses have long exceeded the status of pure quality surveillance instruments. Large retrospective studies nowadays often represent the first approach to new questions in clinical research and pave the way for more expensive and resource intensive prospective trials. As a consequence, the utilization of big data in acute pain and regional anesthesia research has considerably increased over the last decade. Multicentric clinical registries and administrative databases (e.g., healthcare claims databases) have collected millions of cases until today, on which basis several important research questions were approached. In acute pain research, big data was used to assess postoperative pain outcomes, opioid utilization, and the efficiency of multimodal pain management strategies. In regional anesthesia, adverse events and potential benefits of regional anesthesia on postoperative morbidity and mortality were evaluated. This article provides a narrative review on the growing importance of big data for research in acute postoperative pain and regional anesthesia.

Confirmatory factor analysis of the International Pain Outcome questionnaire in surgery

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The reliability and validity of International Pain Outcome questionnaire Spanish adaptation is confirmed in a large heterogeneous sample. Factor scores can be used as a global outcome analysis tool.

Background:

Choosing perioperative suitable treatments requires reliable and valid outcome measurements. The International Pain Outcome (IPO) questionnaire has been widely used for quality improvement and research purposes within the PAIN-OUT network that has collected more than 550,000 data sets of postoperative patients in 200 hospitals worldwide. Our aim is to confirm psychometric properties of the Spanish version of the IPO questionnaire and its invariance by pain predictors.

Method:

Sample included 4014 participants within a large age range, who underwent different surgical procedures. Confirmatory factor analysis (CFA) assessed internal structure, considering invariance by sex, age, procedure, smoking, obesity, affective disorder, and chronic pain. Incremental predictive validity of factor scores on question would have liked more pain treatment and opioid requirement was also estimated with logistic binary regression.

Results:

Confirmatory factor analysis verified original structure in 3 factors measuring pain intensity and interference (F1), adverse effects (F2), and perceptions of care (F3), with good internal consistency. Multigroup CFA analysis confirmed invariance by assessed pain predictors. Good incremental predictive capacity to identify would have liked more pain treatment was achieved.

Conclusion:

Our study confirms the factor structure, supports reliability, and adds some evidence of convergent validity of the Spanish adaptation of the IPO questionnaire. The sum of scores in its main factors serves a global outcome analysis tool. Low scores in F1 and F2 with high scores in F3 would indicate optimal quality of care.