Identifying At-Risk Subgroups for Acute Postsurgical Pain: A Classification Tree Analysis

Systematic Review of Methods for Individual Prediction of Postoperative Pain

Background: Acute postoperative pain is a common problem in clinical practice and merits attention considering its potential long-term adverse effects. This systematic review covers current knowledge on methods for individual prediction of postoperative pain. Methods: A systematic literature search was conducted using the PubMed, EMBASE, and CINAHL databases for original studies with adult patients published in English between 2016 and 2022. Inclusion required assessment of risk factors preoperatively and assessment of postoperative pain. No reviews, meta-analyses, or study protocols were included, nor studies with outcomes other than pain or where risk factor analysis was not performed preoperatively. A two peer-reviewed system was utilized using the screening and data collection tool Covidence, with a focus on new tools for preoperative pain prediction. The results were only analyzed qualitatively. Results: The search yielded 1950 abstracts to be screened. In total, 208 articles were subjected to full-text review, and 107 articles were included in the data synthesis of this review. The evaluated scientific methods were grouped and analyzed separately. Psychometric questionnaires and methods for quantitative sensory testing are still being studied. New methods proposed include the evaluation of pain induced by tourniquet inflation, venous cannulation, or pin-prick stimulation, the analgesia/nociception index, electroencephalographic recording, and other new equipment developed for this purpose. Conclusion: Various screening methods have been proposed to identify patients prone to postoperative pain. The focus has shifted from procedure-specific to individualized strategies to improve early management of pain. However, many traditional predictive methods still have a questionable role in clinical practice. Trial Registration: ClinicalTrials.gov identifier: CRD42022298479.

Exploring the relationship between pain intensity, self-management of pain and pain self-efficacy on post-operative pain on day 5 after cesarean section: A cross-sectional study in Mie prefecture in Japan

INTRODUCTION

Pain self-management among women who begin child-rearing after a cesarean section (CS) has not been ascertained. This study aimed to explore the relationship among pain intensity, self-management, and self-efficacy on post-operative day (POD) 5 after CS in postpartum women.

METHODS

A cross-sectional online survey was conducted on POD5 after CS. Participants were recruited through convenience sampling in Mie Prefecture, Japan, from August 2023 to April 2024. Pain was assessed using a numerical rating scale (NRS), both during activity and at rest, with higher scores indicating greater pain. Pain self-efficacy was assessed using the Japanese version of the Pain Self-Efficacy Questionnaire (PSEQ-J), and pain self-management was investigated. SPSS version 29.0 was used for data analysis, and p<0.05 was set as the significance level.

RESULTS

Data from 124 participants (valid response rate: 73.8%) were analyzed. The median (IQR) of the NRS was 4.5 (3-6) during activity and 2.0 (1-4) at rest. There were significant differences according to method of oral analgesia during activity (p<0.049) and at rest (p<0.015). Multiple regression analysis revealed that NRS scores at maximum pain after CS significantly influenced pain on POD5. However, the number of oral analgesics and PSEQ-J scores were not influenced (during activity: R2=0.21, p<0.001, at rest: R2=0.12, p<0.001).

CONCLUSIONS

Pain intensity during activity on POD5 was moderate and required pain-management. Acute post-operative pain-management was related to pain intensity on POD5, suggesting the importance of early post-operative pain control. Future studies are needed to examine the association between pain self-efficacy and other psychological factors.

Development of a nomogram for predicting acute pain among patients after abdominal surgery: A prospective observational study

AIMS

To develop a nomogram to provide a screening tool for recognising patients at risk of post-operative pain undergoing abdominal operations.

BACKGROUND

Risk prediction models for acute post-operative pain can allow initiating prevention strategies, which are valuable for post-operative pain management and recovery. Despite the increasing number of studies on risk factors, there were inconsistent findings across different studies. In addition, few studies have comprehensively explored predictors of post-operative acute pain and built prediction models.

DESIGN

A prospective observational study.

METHODS

A total of 352 patients undergoing abdominal operations from June 2022 to December 2022 participated in this investigation. A nomogram was developed for predicting the probability of acute pain after abdominal surgery according to the results of binary logistic regression. The nomogram's predictive performance was assessed by discrimination and calibration. Internal validation was performed via Bootstrap with 1000 re-samplings.

RESULTS

A total of 139 patients experienced acute post-operative pain following abdominal surgery, with an incidence of 39.49%. Age <60, marital status (unmarried, divorced, or widowed), consumption of intraoperative remifentanil >2 mg, indwelling of drainage tubes, poor quality sleep, high pain catastrophizing, low pain self-efficacy, and PCIA not used were predictors of inadequate pain control in patients after abdominal surgery. Using these variables, we developed a nomogram model. All tested indicators showed that the model has reliable discrimination and calibration.

CONCLUSIONS

This study established an online dynamic predictive model that can offer an individualised risk assessment of acute pain after abdominal surgery. Our model had good differentiation and calibration and was verified internally as a useful tool for risk assessment.

RELEVANCE TO CLINICAL PRACTICE

The constructed nomogram model could be a practical tool for predicting the risk of experiencing acute post-operative pain in patients undergoing abdominal operations, which would be helpful to realise personalised management and prevention strategies for post-operative pain.

REPORTING METHOD

The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines were adopted in this study.

PATIENT OR PUBLIC CONTRIBUTION

Before the surgery, research group members visited the patients who met the inclusion criteria and explained the purpose and scope of the study to them. After informed consent, they completed the questionnaire. The patients' pain scores (VAS) were regularly assessed and documented by the bedside nurse for the first 3 days following surgery. Other information was obtained from medical records.

Factors Associated With New Analgesic Requirements Following Critical Illness

BACKGROUND

Chronic opioid use represents a significant burden to global healthcare with adverse long-term outcomes. Elevated patient reported pain levels and analgesic prescriptions have been reported following discharge from critical care. We describe analgesic requirements following discharge from hospital and identify if a critical care admission is a significant factor for stronger analgesic prescriptions.

METHODS

This retrospective observational cohort study identified patients in the UK Biobank with a registered admission to any UK hospital between January 1, 2010 and December 31, 2015 and information on prescriptions drawn both prior to and following hospital discharge. Two matched cohorts were created from the dataset: critical care patients and hospital patients admitted without a critical care encounter. Outcomes were analgesic requirements following hospital discharge and factors associated with increased analgesic prescriptions. Multivariable logistic regression was used to identify factors associated with prescriptions from higher steps on the World Health Organization (WHO) analgesic ladder.

RESULTS

In total, 660 formed the total study population. Strong opioid prescriptions following discharge were significantly higher in the critical care cohort (P value <.001). Critical care admission (OR = 1.45) and increasing Townsend deprivation (OR = 1.04) index were significantly associated with increasing strength of analgesic prescriptions following discharge.

CONCLUSIONS

Critical care patients require stronger analgesic prescriptions in the 12 months following hospital discharge. Patients from areas of high socioeconomic deprivation may also be associated with increased analgesic requirements. Multidisciplinary support is required for patients who may be at risk of chronic opioid use and could be delivered within critical care recovery programs.

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.

Pain Sensitivity and Acute Postoperative Pain in Patients Undergoing Abdominal Surgery: The Mediating Roles of Pain Self-Efficacy and Pain Catastrophizing

BACKGROUND

Inadequately managed postoperative pain remains a common issue. Examining factors like pain sensitivity, pain catastrophizing, and pain self-efficacy can help improve postoperative pain management. While these factors have been identified as potential predictors of acute postoperative pain, their effects have been inconsistent. Few studies have explored the interactions between these factors.

AIM

To investigate the influence of preoperative pain sensitivity, pain catastrophizing, and pain self-efficacy on acute postoperative pain in abdominal surgery patients and to determine the mediating roles of pain catastrophizing and pain self-efficacy in the relationship between pain sensitivity and acute postoperative pain, as per the gate control theory.

METHODS

A total of 246 patients were enrolled in this study. General information was collected before surgery, and the Pain Sensitivity Questionnaire (PSQ), Pain Catastrophizing Scale (PCS), and Pain Self-Efficacy Questionnaire (PSEQ) were administered. After surgery, patients' average pain scores over the 24 hours were reported using the Numerical Rating Scale (NRS). Correlation analyses and a structural equation model were used to examine the relationships among these variables.

RESULTS

NRS scores over 3 during the 24 hours post-surgery were reported by 21.54% of patients. Postoperative acute pain was found to be associated with pain sensitivity (rs = 0.463, p < .001), pain catastrophizing (rs = 0.328, p < .001), and pain self-efficacy (rs = -0.558, p < .001). A direct effect on postoperative acute pain was exerted by pain sensitivity (effect = 0.250, p = .001), along with indirect effects through: (A) pain catastrophizing (effect = 0.028, p = .001); (B) pain self-efficacy (effect = 0.132, p = .001); and (C) the chain mediation of pain self-efficacy and pain catastrophizing (effect = 0.021, p = .008).

CONCLUSIONS

The severity of postoperative acute pain can be predicted by pain self-efficacy and pain catastrophizing, and the connection between moderate pain sensitivity and postoperative acute pain severity is mediated by them. Therefore, intervention programs aimed at boosting pain self-efficacy and reducing pain catastrophizing can enhance postoperative pain outcomes for abdominal surgery patients.

GGEM: Gender, Geography, and EMployment differences based on mobility levels among lower limb prosthesis users living in the United States

BACKGROUND

For individuals with a disability, an increase in functional mobility may improve their quality of life and well-being. Greater understanding is needed on how factors such as gender, geography, and employment may play a role in mobility levels among individuals with lower limb amputation.

OBJECTIVES

To assess the relationship between gender, geography, and employment status on mobility among lower limb prosthesis users.

METHODS

A cross-sectional analysis of 7,524 patient mobility outcomes completed across the United States was performed. The regression model included the independent variables, such as age, gender, region, employment status, and amputation level. Mobility was entered as the dependent variable.

RESULTS

Individuals who were employed had 3.6 times the odds of reaching increased mobility (Prosthetic Limb Users' Survey of Mobility ≥ 50) than those unemployed (odds ratio 3.56, 95% confidence interval 3.10-4.09). Gender and geography were significantly associated with mobility as well.

CONCLUSIONS

Being employed is associated with greater odds of reaching increased mobility. Addressing factors such as returning to employment may aid in improving mobility levels among prosthesis users.

Postoperative pain management in non-traumatic emergency general surgery: WSES-GAIS-SIAARTI-AAST guidelines

BACKGROUND

Non-traumatic emergency general surgery involves a heterogeneous population that may present with several underlying diseases. Timeous emergency surgical treatment should be supplemented with high-quality perioperative care, ideally performed by multidisciplinary teams trained to identify and handle complex postoperative courses. Uncontrolled or poorly controlled acute postoperative pain may result in significant complications. While pain management after elective surgery has been standardized in perioperative pathways, the traditional perioperative treatment of patients undergoing emergency surgery is often a haphazard practice. The present recommended pain management guidelines are for pain management after non-traumatic emergency surgical intervention. It is meant to provide clinicians a list of indications to prescribe the optimal analgesics even in the absence of a multidisciplinary pain team.

MATERIAL AND METHODS

An international expert panel discussed the different issues in subsequent rounds. Four international recognized scientific societies: World Society of Emergency Surgery (WSES), Global Alliance for Infection in Surgery (GAIS), Italian Society of Anesthesia, Analgesia Intensive Care (SIAARTI), and American Association for the Surgery of Trauma (AAST), endorsed the project and approved the final manuscript.

CONCLUSION

Dealing with acute postoperative pain in the emergency abdominal surgery setting is complex, requires special attention, and should be multidisciplinary. Several tools are available, and their combination is mandatory whenever is possible. Analgesic approach to the various situations and conditions should be patient based and tailored according to procedure, pathology, age, response, and available expertise. A better understanding of the patho-mechanisms of postoperative pain for short- and long-term outcomes is necessary to improve prophylactic and treatment strategies.

Mobility Analysis of AmpuTees (MAAT 4): classification tree analysis for probability of lower limb prosthesis user functional potential

Purpose: To develop a predictive model to inform the probability of lower limb prosthesis users' functional potential for ambulation.Materials and Methods: A retrospective analysis of a database of outcomes for 2770 lower limb prosthesis users was used to inform a classification and regression tree analysis. Gender, age, height, weight, body mass index adjusted for amputation, amputation level, cause of amputation, comorbid health status and functional mobility score [Prosthetic Limb Users Survey of Mobility (PLUS-M™)] were entered as potential predictive variables. Patient K-Level was used to assign dependent variable status as unlimited community ambulator (i.e., K3 or K4) or limited community/household ambulator (i.e., K1 or K2). The classification tree was initially trained from 20% of the sample and subsequently tested with the remaining sample.Results: A classification tree was successfully developed, able to accurately classify 87.4% of individuals within the model's training group (standard error 1.4%), and 81.6% within the model's testing group (standard error 0.82%). Age, PLUS-M™ T-score, cause of amputation and body weight were retained within the tree logic.Conclusions: The resultant classification tree has the ability to provide members of the clinical care team with predictive probabilities of a patient's functional potential to help assist care decisions.Implications for RehabilitationClassification and regression tree analysis is a simple analytical tool that can be used to provide simple predictive models for patients with a lower limb prosthesis.The resultant classification tree had an 81.6% (standard error 0.82%) accuracy predicting functional potential as an unlimited community ambulator (i.e., K3 or K4) or limited community/ household ambulator (i.e., K1 or K2) in an unknown group of 2770 lower limb prosthesis users.The resultant classification tree can assist with the rehabilitation team's care planning providing probabilities of functional potential for the lower limb prosthesis user.

Prospective Evaluation of Utilization Patterns and Prescribing Guidelines of Opioid Consumption Following Orthopedic Foot and Ankle Surgery

BACKGROUND

Overprescription of narcotic pain medication is a major culprit in the present opioid epidemic plaguing the United States. The current literature on lower extremity opioid usage has limitations and would benefit from additional study. The purpose of our study was to prospectively assess opioid consumption patterns following outpatient orthopedic foot and ankle procedures.

METHODS

Patients undergoing outpatient orthopedic foot and ankle procedures who met inclusion criteria had the following prospective information collected: patient demographics, preoperative health history, patient-reported outcomes, anesthesia type, procedure type, opioid prescription and consumption details. The morphine equivalent dose was calculated for each prescription and then converted to the equivalent of a 5-mg oxycodone "pill." Univariable analyses were performed to identify variables with a statistically robust association with opioid consumption for inclusion in a multivariable linear regression. A stepwise backward regression was then performed to identify independent predictors of opioid consumption. Postoperative opioid utilization was reported for 988 patients (mean age: 49 years).

RESULTS

Overall, patients consumed a median of 20 pills whereas the median number of pills prescribed was 40. This resulted in a utilization rate of 50% and 20 631 pills left unused. Independent factors associated with higher opioid consumption were anesthesia type ( P < .004), age <60 years ( P < .001), preoperative visual analog scale (VAS) pain report of >6 ( P = .008), and bony procedures ( P = .008); residual standard error 16.73 ( F_7,844=14.3, P < .001).

CONCLUSION

Our study found that patients who underwent orthopedic foot and ankle procedures were overprescribed narcotic medication by nearly twice the amount that was actually consumed. Although we identified 4 independent factors associated with opioid consumption, the large residual standard error suggests that there remains a substantial degree of unexplained variance of opioid consumption observed in the patient population. Physicians face a challenging task of setting appropriate protocols when balancing pain relief and generalizable guidelines.

LEVEL OF EVIDENCE

Level II, prospective observational cohort study.

Factor structure, correlates, and incremental validity of the Pain Appraisal Inventory-Short Form

We assessed the factor structure, correlates, and incremental validity of the Pain Appraisal Inventory in Chinese adult chronic pain samples. In an initial exploratory factor analysis sample (N = 301), the original two-component (threat, challenge) 16-item Pain Appraisal Inventory and a 10-item short form (Pain Appraisal Inventory-Short Form) were supported. Within a confirmatory factor analysis sample (N = 285), uniformly acceptable fits were observed only for the Pain Appraisal Inventory-Short Form. Furthermore, Pain Appraisal Inventory-Short Form threat and challenge subscales had significant correlations with conceptually related measures and added to prediction models for pain-related coping and adjustment, independent of other pain belief scales. Together, results indicated that the Pain Appraisal Inventory-Short Form has utility in Chinese chronic pain samples.