Perioperative Risk Factors for Persistent Postsurgical Pain After Inguinal Hernia Repair: Systematic Review and Meta-Analysis

Persistent postsurgical pain (PPSP) is one of the most bothersome and disabling long-term complications after inguinal hernia repair surgery. Understanding perioperative risk factors that contribute to PPSP can help identify high-risk patients and develop risk-mitigation approaches. The objective of this study was to systematically review and meta-analyze risk factors that contribute to PPSP after inguinal hernia repair. The literature search resulted in 303 papers included in this review, 140 of which were used for meta-analyses. Our results suggest that younger age, female sex, preoperative pain, recurrent hernia, postoperative complications, and postoperative pain are associated with a higher risk of PPSP. Laparoscopic techniques reduce the PPSP occurrence compared to anterior techniques such as Lichtenstein repair, and tissue-suture techniques such as Shouldice repair. The use of fibrin glue for mesh fixation was consistently associated with lower PPSP rates compared to tacks, staples, and sutures. Considerable variability was observed with PPSP assessment and reporting methodology in terms of study design, follow-up timing, clarity of pain definition, as well as pain intensity or interference threshold. High or moderate risk of bias in at least one domain was noted in >75% of studies. These may limit the generalizability of our results. Future studies should assess and report comprehensive preoperative and perioperative risk factors for PPSP adjusted for confounding factors, and develop risk-prediction models to drive stratified PPSP-mitigation trials and personalized clinical decision-making. PERSPECTIVE: This systematic review and meta-analysis summarizes the current evidence on risk factors for persistent pain after inguinal hernia repair. The findings can help identify patients at risk and test personalized risk-mitigation approaches to prevent pain. PROSPERO REGISTRATION: htttps://www.crd.york.ac.uk/prospero/display_record.php?RecordID=154663.

The Role of the Cardiac Surgery Patient in Pain Management: The Patient Perspective

One and a half million cardiac surgeries are completed worldwide each year where undertreated postoperative pain increases the risk of patient morbidity and mortality. Patient-centered pain management is recommended to improve patient outcomes but there is insufficient information regarding how the patient views their role. The objective of this study is to explore cardiac surgery patients' perspectives on their role in postoperative pain management. This study used an interpretive phenomenological design and convenience sampling. Six participants who had undergone cardiac surgery were recruited from a cardiac rehabilitation program in Western Canada. The first author conducted semi-structured digitally recorded interviews. Sociodemographic characteristics and measures of anxiety and depression were also collected. Emergent thematic analysis of the qualitative data generated three themes: attitude, coping and care, and communication. The findings of this study address a gap in the literature with regard to patients' perceived roles in pain management. There is a complex relationship between patient attitude, coping and care, and communication which, in turn, influences how patients view their role within the pain management continuum. These themes contribute to the development of the patient role within the pain management continuum and form an integrated feedback loop. The patient's attitude contributes to their ability to cope with pain and participate in pain assessment and management. Furthermore, their ability to cope and desire to participate influences the development of their attitude. These findings may enhance providers' understanding of the patient's perspective and improve pain management outcomes.

The impact of pre-operative depression on pain outcomes after major surgery: a systematic review and meta-analysis

Symptoms of depression are common among patients before surgery. Depression may be associated with worse postoperative pain and other pain-related outcomes. This review aimed to characterise the impact of pre-operative depression on postoperative pain outcomes. We conducted a systematic review of observational studies that reported an association between pre-operative depression and pain outcomes after major surgery. Multilevel random effects meta-analyses were conducted to pool standardised mean differences and 95%CI for postoperative pain scores in patients with depression compared with those without depression, at different time intervals. A meta-analysis was performed for studies reporting change in pain scores from the pre-operative period to any time-point after surgery. Sixty studies (n = 501,962) were included in the overall review, of which 18 were eligible for meta-analysis. Pre-operative depression was associated with greater pain scores at < 72 h (standardised mean difference 0.97 (95%CI 0.37-1.56), p = 0.009, I2  = 41%; moderate certainty) and > 6 months (standardised mean difference 0.45 (95%CI 0.23-0.68), p < 0.001, I2  = 78%; low certainty) after surgery, but not at 3-6 months after surgery (standardised mean difference 0.54 (95%CI -0.06-1.15), p = 0.07, I2  = 83%; very low certainty). The change in pain scores from pre-operative baseline to 1-2 years after surgery was similar between patients with and without pre-operative depression (standardised mean difference 0.13 (95%CI -0.06-0.32), p = 0.15, I2  = 54%; very low certainty). Overall, pre-existing depression before surgery was associated with worse pain severity postoperatively. Our findings highlight the importance of incorporating psychological care into current postoperative pain management approaches in patients with depression.

Characterizing blood pressure trajectories in people living with HIV following antiretroviral therapy: A systematic review

OBJECTIVES

The advent of antiretroviral therapy (ART) has reduced AIDS-related morbidity and mortality among people living with HIV (PLWH). Due to increased survival, PLWH have now been found to be at risk of chronic conditions related to ageing, such as cardiovascular disease (CVD). Hypertension is common in PLWH and is a major risk factor for the development of CVD. We conducted a systematic literature review to evaluate the research evidence on longitudinal blood pressure (BP) trajectories following ART initiation in PLWH.

METHODS

We searched the following databases: PubMed, CINHAL, Scopus, and Web of Science (up to 15 March 2021) for peer-reviewed published studies that reported BP trajectories following ART initiation in PLWH. Three reviewers independently screened all studies by title and abstract. We included articles in English, published up to March 2021, that report office BP trajectories in PLWH initiating ART. A total of 10 publications met our inclusion criteria. Eight studies were prospective cohorts and two were retrospective.

RESULTS

Nine out of 10 studies in the literature reported an increase in systolic BP (4.7-10.0 mmHg in studies with a follow-up range of 6 months to 8 years, and 3.0-4.7 mmHg/year in time-averaged studies). In addition, four out of 10 studies reported increases in diastolic BP (2.3-8.0 mmHg for a 6 month to 6.8-year follow-up range and 2.3 mmHg/year).

CONCLUSION

Systolic BP consistently increases while diastolic BP changes are more heterogeneous following ART initiation in PLWH. However, the studies were highly variable with respect to population demographics, ART regimen and duration, and follow-up time. Nevertheless, given the risks of CVD complications, such as stroke, heart failure and myocardial infarction, associated with elevated BP, results highlight the importance of future research in this area. It will be important to better characterize BP trajectories over time, identify the most critical times for interventions to reduce BP, determine the long-term CVD consequences in PLWH with elevated BP, and understand how different ART regimens may or may not influence BP and CVD disease.

Psychological states could affect postsurgical pain after hemorrhoidectomy: A prospective cohort study

Background

Open hemorrhoidectomy is one of the standard procedures for grade IV hemorrhoids. Postsurgical pain is a common problem for patients. We aim to prospectively evaluate potential factors affecting postoperative pain among hemorrhoidectomy patients.

Methods

An observational study was conducted on 360 patients who had undergone Milligan-Morgan open hemorrhoidectomy. Details of the surgery and baseline information were recorded. Preoperative anxiety and depression were analyzed via the self-rating anxiety scale 20 (SAS-20) and self-rating depression scales 20 (SDS-20), respectively. Postoperative pain score was performed daily after surgery until the patient was discharged. The numerical pain score was evaluated by the visual analogue scale (VAS). The association between preoperative psychological states (anxiety or depression) and postoperative pain was analyzed using a generalized additive mixed model.

Results

A total of 340 patients eventually provided complete data and were included in our study. The average age was 43.3 ± 14.4 years, and 62.1% of patients were women. In total, 14.9% of patients had presurgical anxiety and 47.1% had presurgical depression. Postsurgical pain reached a peak point 1-2 days after surgery and went down to a very low level around 4-5 days after surgery. More excision of hemorrhoids could lead to more pain experience after surgery. Presurgical depression was associated with postsurgical pain. Patients who had presurgical depression had higher pain scores after surgery (2.3 ± 1.9 vs. 3.3 ± 1.9, p = 0.025).

Conclusion

Preoperative depression and the amount of excisional hemorrhoids are positively related to postsurgical pain.

Psychological Consequences Associated With Coronary Artery Bypass Graft Surgery: A Bibliometric Analysis

The current paper explores the mutual impact of psychological factors and cardiac surgery on each other using bibliometric analysis with the help of indicative cited publications, co-cited journals, and collaborations between countries, institutions, and authors. Citation analysis is an attractive methodology because it provides quantitative information that is readily acquired with electronic databases and that can be compared across topic areas. The bibliometric investigation was done using the PubMed database, Scopus, Web of Science, etc. with the help of appropriate MeSH words. Followed by an analysis of data with the help of CiteSpace 5.3.R4, Microsoft Excel 2016, and IBM SPSS Statistics 20.0 software (IBM Corp., Armonk, NY). The software extracts the number of scientific publications, citation frequency, and keyword trends. Relational figures and tables were obtained for data interpretation. The records of 259 articles were analyzed using bibliometric investigation which shows the increasing incidence of psychological consequences linked with coronary artery bypass grafting (CABG) surgery. This indicates that immediate management is required to overcome this. The present bibliometric study emphasizes the need for psychological screening and management of post-CABG patients. This will lay the path for organizing and prioritizing future research on vascular psychiatry and its early management.

The effect of the family presence on anxiety and agitation of patients under mechanical ventilation after open heart surgery: a randomized clinical trial

Background

Family-centered care has been considered as a philosophy of care. Family presence in intensive care units (ICUs), especially in the acute phase of the disease is controversial. This study has been carried out in order to determine the effect of the family presence on anxiety and agitation in patients undergoing coronary artery bypass grafting (CABG).

Materials and methods

In a clinical trial, 70 patients were randomly allocated into groups of experimental and control. In the experimental group, during the weaning process from the mechanical ventilation, a family member was present at the bedside. The degree of anxiety and Richmond’s Agitation and Sedation Scale (RASS) were compared in seven consecutive time stages, including the time of entry into the ICU, the first respiratory drive, the family entrance, 20 min and 1 h after the presence of the family member, the time of extubation, and 1 h after extubation.

Results

There was a significant difference between the two groups in the mean scores of the anxiety scale in the first (P =0.008), second (P=0.002), and third stages (P =0.005). This difference was not significant in the fourth to seventh stages (P>0.05). As the baseline anxiety levels were different, a covariate adjustment was used for comparisons between treatments, adjusting the main analyses for baseline anxiety levels. Analysis showed that groups were not different. Also, there was no significant difference in the mean scores of RASS between the two experimental and control groups at any of the seven stages (P> 0.05).

Conclusion

According to the findings of the present study, the presence of a family member does not reduce the level of anxiety and agitation of patients undergoing cardiac surgery. However, it can be concluded that this intervention is feasible in acute and complex situations after open heart surgeries.

Trial registration

This study has been registered in the Iranian Registry of Clinical Trials with the code IRCT201609014299N4.

Multidimensional Perioperative Recovery Trajectories in a Mixed Surgical Cohort: A Longitudinal Cluster Analysis Utilizing National Institutes of Health Patient-Reported Outcome Measurement Information System Measures

BACKGROUND

Pain trajectories have been described in numerous surgical settings where preoperative characteristics have been used to predict trajectory membership. Suboptimal pain intensity trajectories have been linked to poor longitudinal outcomes. However, numerous biopsychosocial modulators of postoperative pain may also have distinct longitudinal trajectories that may inform additional targets to improve postoperative recovery.

METHODS

Patients undergoing total joint arthroplasty, thoracic surgery, spine surgery, major abdominal surgery, or mastectomy completed Patient Reported Outcome Measurement Information System (PROMIS) measures and additional scales preoperatively and at 1 week, 2 weeks, 1 month, 3 months, and 6 months postoperatively. A k-means clustering for longitudinal data was utilized to explore and describe distinct pain impact (PROMIS Pain Interference and Physical Function) trajectories and associated changes in additional biopsychosocial measures. Follow-up analyses examined participant demographics and clinical characteristics associated with trajectory memberships.

RESULTS

Three postoperative biopsychosocial symptom clusters were identified across all patients (n = 402): low (35%), average (47%), and high (18%) performance cluster trajectories. Participants undergoing total knee arthroplasty (TKA), spinal surgery, reporting presurgical opioid use, and higher pain catastrophizing scale scores were found to be associated with the low performance trajectory. Patients within the low performance trajectory, while demonstrating small improvements by 6 months, remained mild to moderately impaired in both pain impact and physical health outcomes. Alternatively, participants in the average performance trajectory demonstrated improvement in pain impact to population norms compared to baseline and demonstrated continued improvement across physical and psychological outcomes. Patients within the high performance cluster started within population norms across all measures at baseline and returned to baseline or exceeded baseline values by 6 months postoperatively. Self-reported opioid utilization was significantly higher in the low performance cluster across all time points. While a larger proportion of average performance patients reported opioid utilization during the first postoperative month compared to the high performance cluster, no differences were detected at 6 months postoperatively between these 2 clusters.

CONCLUSIONS

These pain impact trajectories build upon previous unidimensional pain intensity trajectories and suggest that additional distinct biopsychosocial measures may have unique trajectories related to cluster assignment. Additionally, these findings highlight the importance of continued pain impact surveillance through the perioperative recovery period to detect patients at risk of experiencing a poor trajectory and subsequently poor longitudinal health outcomes.

Bupivacaine infiltration for acute postoperative pain management after cardiac surgery

BACKGROUND

Despite increased attention, acute and persistent post-operative pain are not treated efficiently and interventions against acute pain are therefore of clinical importance and should be welcomed.

AIMS AND OBJECTIVES

To evaluate the effectiveness of wound infiltration with 0.5% bupivacaine for pain management in the immediate post-operative period in patients that underwent cardiac surgery with sternotomy.

DESIGN

The study was performed employing a single-centre nonrandomized experimental design to evaluate a prospective cohort of patients recruited from June to December of 2017.

METHODS

A single-centre study with a non-randomized experimental design compared the pain perceived by 137 patients undergoing to cardiac surgery within which 68 patients who received infiltration of bupivacaine and 69 patients received infiltration with saline solution. Pain measures were made with the numeric rating scale (NRS) at 2, 12, 24, and 48 hours. Socio-demographic and clinical variables were included too and descriptive, bivariate, and multivariate logistic regression analyses were performed.

RESULTS

A statistically significant difference was found between the means of the NRS scores in favour of the intervention group. Cohen's d showed a significant effect size. NRS scores were grouped into NRS ≥4 or NRS <4 and similar results were found. Multivariate logistic regression analyses showed the absence of confounding factors that could call results into question.

CONCLUSION

Subcutaneous infiltration of 0.5% bupivacaine in the surgical site of patients who have undergone cardiac surgery showed clinically and statistically significant pain relief compared with patients who received saline infiltration throughout the first 12 hours after surgery. This intervention provides promising preliminary results that, alone or in conjunction with other nursing interventions, could constitute an important therapeutic tool for this area of nursing clinical practice.

The Impact of Nonpharmacological Interventions on Patient Experience, Opioid Use, and Health Care Utilization in Adult Cardiac Surgery Patients: Protocol for a Mixed Methods Study

BACKGROUND

Despite pharmacological treatments, patients undergoing cardiac surgery experience severe anxiety and pain, which adversely affect outcomes. Previous work examining pediatric and nonsurgical adult patients has documented the effectiveness of inexpensive, nonpharmacological techniques to reduce anxiety and pain as well as health care costs and length of hospitalization. However, the impact of nonpharmacological interventions administered by a dedicated comfort coach has not been evaluated in an adult surgical setting.

OBJECTIVE

This trial aims to assess whether nonpharmacological interventions administered by a trained comfort coach affect patient experience, opioid use, and health care utilization compared with usual care in adult cardiac surgery patients. This study has 3 specific aims: assess the effect of a comfort coach on patient experience, measure differences in inpatient and outpatient opioid use and postoperative health care utilization, and qualitatively evaluate the comfort coach intervention.

METHODS

To address these aims, we will perform a prospective, randomized controlled trial of 154 adult cardiac surgery patients at Michigan Medicine. Opioid-naive patients undergoing first-time, elective cardiac surgery via sternotomy will be randomized to undergo targeted interventions from a comfort coach (intervention) versus usual care (control). The individualized comfort coach interventions will be administered at 6 points: preoperative outpatient clinic, preoperative care unit on the day of surgery, extubation, chest tube removal, hospital discharge, and 30-day clinic follow-up. To address aim 1, we will examine the effect of a comfort coach on perioperative anxiety, self-reported pain, functional status, and patient satisfaction through validated surveys administered at preoperative outpatient clinic, discharge, 30-day follow-up, and 90-day follow-up. For aim 2, we will record inpatient opioid use and collect postdischarge opioid use and pain-related outcomes through an 11-item questionnaire administered at the 30-day follow-up. Hospital length of stay, readmission, number of days in an extended care facility, emergency room, urgent care, and an unplanned doctor's office visit will be recorded as the primary composite endpoint defined as total days spent at home within the first 30 days after surgery. For aim 3, we will perform semistructured interviews with patients in the intervention arm to understand the comfort coach intervention through a thematic analysis.

RESULTS

This trial, funded by Blue Cross Blue Shield of Michigan Foundation in 2019, is presently enrolling patients with anticipated manuscript submissions from our primary aims targeted for the end of 2020.

CONCLUSIONS

Data generated from this mixed methods study will highlight effective nonpharmacological techniques and support a multidisciplinary approach to perioperative care during the adult cardiac surgery patient experience. This study's findings may serve as the foundation for a subsequent multicenter trial and broader dissemination of these techniques to other types of surgery.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04051021; https://clinicaltrials.gov/ct2/show/NCT04051021.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/21350.

Preoperative Factors Associated with Remote Postoperative Pain Resolution and Opioid Cessation in a Mixed Surgical Cohort: Post Hoc Analysis of a Perioperative Gabapentin Trial

Background

Preoperative patient-specific risk factors may elucidate the mechanisms leading to the persistence of pain and opioid use after surgery. This study aimed to determine whether similar or discordant preoperative factors were associated with the duration of postoperative pain and opioid use.

Methods

In this post hoc analysis of a randomized, double-blind, placebo-controlled trial of perioperative gabapentin vs active placebo, 410 patients aged 18–75 years, undergoing diverse operations underwent preoperative assessments of pain, opioid use, substance use, and psychosocial variables. After surgery, a modified Brief Pain Inventory was administered over the phone daily up to 3 months, weekly up to 6 months, and monthly up to 2 years after surgery. Pain and opioid cessation were defined as the first of 5 consecutive days of 0 out of 10 pain or no opioid use, respectively.

Results

Overall, 36.1%, 19.8%, and 9.5% of patients continued to report pain, and 9.5%, 2.4%, and 1.7% reported continued opioid use at 3, 6, and 12 months after surgery. Preoperative pain at the future surgical site (every 1-point increase in the Numeric Pain Rating Scale; HR 0.93; 95% CI 0.87–1.00; P=0.034), trait anxiety (every 10-point increase in the Trait Anxiety Inventory; HR 0.79; 95% CI 0.68–0.92; P=0.002), and a history of delayed recovery after injury (HR 0.62; 95% CI 0.40–0.96; P=0.034) were associated with delayed pain cessation. Preoperative opioid use (HR 0.60; 95% CI 0.39–0.92; P=0.020), elevated depressive symptoms (every 5-point increase in the Beck Depression Inventory-II score; HR 0.88; 95% CI 0.80–0.98; P=0.017), and preoperative pain outside of the surgical site (HR 0.94; 95% CI 0.89–1.00; P=0.046) were associated with delayed opioid cessation, while perioperative gabapentin promoted opioid cessation (HR 1.37; 95% CI 1.06–1.77; P=0.016).

Conclusion

Separate risk factors for prolonged post-surgical pain and opioid use indicate that preoperative risk stratification for each outcome may identify patients needing personalized care to augment universal protocols for perioperative pain management and conservative opioid prescribing to improve long-term outcomes.

Trajectory Modelling Techniques Useful to Epidemiological Research: A Comparative Narrative Review of Approaches

Trajectory modelling techniques have been developed to determine subgroups within a given population and are increasingly used to better understand intra- and inter-individual variability in health outcome patterns over time. The objectives of this narrative review are to explore various trajectory modelling approaches useful to epidemiological research and give an overview of their applications and differences. Guidance for reporting on the results of trajectory modelling is also covered. Trajectory modelling techniques reviewed include latent class modelling approaches, ie, growth mixture modelling (GMM), group-based trajectory modelling (GBTM), latent class analysis (LCA), and latent transition analysis (LTA). A parallel is drawn to other individual-centered statistical approaches such as cluster analysis (CA) and sequence analysis (SA). Depending on the research question and type of data, a number of approaches can be used for trajectory modelling of health outcomes measured in longitudinal studies. However, the various terms to designate latent class modelling approaches (GMM, GBTM, LTA, LCA) are used inconsistently and often interchangeably in the available scientific literature. Improved consistency in the terminology and reporting guidelines have the potential to increase researchers' efficiency when it comes to choosing the most appropriate technique that best suits their research questions.

The Effect of Propofol Versus Volatile Anesthetics on Persistent Pain After Cardiac Surgery: A Randomized Controlled Trial

OBJECTIVES

Sternal incisions can generate persistent and intense post-sternotomy pain. Propofol has been shown to improve postoperative analgesia, but the preventive effect on persistent pain after cardiac surgery is unknown. The hypothesis of the present study was that intraoperative propofol-based anesthesia compared with volatile anesthesia could reduce the risk of chronic pain after cardiac surgery.

DESIGN

A single-center, two-arm, patient-and-evaluator-blinded, randomized controlled trial.

SETTING

A single major urban teaching and university hospital.

PATIENTS

Five-hundred adult patients undergoing cardiac surgery via sternotomy randomly were assigned. With six withdrawals from the study and five from surgery, 244 in the total intravenous anesthesia group and 245 in the volatile group were included in the modified intention-to-treat analysis.

INTERVENTIONS

Patients randomly were assigned to receive either propofol-based total intravenous anesthesia or volatile anesthesia during surgery.

MEASUREMENTS AND MAIN RESULTS

The primary outcomes were the incidence of pain at three, six, and 12 months after surgery defined as pain score >0 on the numeric rating scale. The secondary outcomes included acute pain, opioid use during the first 72 hours after surgery, and quality of life. The use of propofol did not significantly affect chronic pain at three months (55.4% v 52.9%, difference 2.5%, 95% confidence interval [CI] -6.6 to 11.6; p = 0.656), six months (35.5% v 37.5%, difference -2.0%, 95% CI -10.9 to 6.9; p = 0.657), or 12 months (18.2% v 20.7%, difference -2.5%, 95% CI -9.8 to 4.8; p = 0.495) compared with volatile anesthetics. Furthermore, there were no differences in acute pain score; morphine-equivalent consumption during the first 72 hours; and quality of life at three, six, and 12 months after surgery.

CONCLUSIONS

Intraoperative administration of propofol did not reduce persistent pain after cardiac surgery compared with volatile anesthetics.

[Factors Related to Persistent Postoperative Pain after Cardiac Surgery: A Systematic Review and Meta-Analysis]

PURPOSE

This study aimed at identifying factors related to persistent postoperative pain after cardiac surgery and estimating their effect sizes.

METHODS

The literature search and selection was conducted in four different databases (CINAHL, Cochrane Library, PubMed, and PQDT) using the Preferred Reporting Items for Systematic Review and Meta-Analysis Statement. A total of 14 studies met the inclusion criteria and were systematically reviewed. For the meta-analysis, R was used to analyze 30 effect sizes of for both individual and operative factors as well as publication biases from a total of nine studies.

RESULTS

The meta-analysis revealed that persistent postoperative pain after cardiac surgery was related to one individual factor (gender) and two operative factors (acute postoperative pain and use of the internal mammary artery). Operative factors (OR=5.26) had a larger effect size than individual factors (OR=1.53).

CONCLUSION

Female gender, acute pain after surgery, and use of the internal mammary artery are related factors to persistent postoperative pain. The development of interventions focusing on modifiable related factors, such as acute postoperative pain, may help to minimize or prevent PPP after cardiac surgery.

RELATIONSHIP OF ANXIETY AND PREOPERATIVE DEPRESSION WITH POST-OPERATIVE PAIN

ABSTRACT Objectiv:e to analyze the relationship of anxiety and depression in the preoperative period with the presence of pain in the postoperative period. Method: cohort study conducted at a university hospital in the state of Minas Gerais (Brazil), between february and July 2017, with 65 patients. A collection instrument was elaborated for the demographic and clinical characteristics. The Hospital Anxiety and Depression Scale was used to assess anxiety and depression; pain intensity was measured using the Verbal Numerical Scale. Data were submitted to descriptive and inferential statistical analysis. Results: according to demographic and clinical characteristics, most patients were female, with a median age of 44 years and surgical specialty of the digestive tract. In the preoperative period, 31 (47.7%) had anxiety, and nine (13.8%), depression. None of the patients reported pain immediately prior to surgery. The incidence of moderate to severe postoperative pain was 32 (49.2%) patients. There was a statistically significant difference in the distribution of patients with postoperative pain in relation to the presence or absence of preoperative anxiety (p value <0.001). There is no statistically significant difference in the distribution of patients with postoperative pain in relation to the presence or absence of preoperative depression (0.733). In multivariate analysis, preoperative anxiety was a predictive factor for postoperative pain. Depression was not a predictive factor of postoperative pain. Conclusion: It was demonstrated that, regardless of the demographic and clinical characteristics of the studied sample, the presence of anxiety in patients in the preoperative period is a predictive factor of postoperative pain.

Influence of volatile anesthesia versus total intravenous anesthesia on chronic postsurgical pain after cardiac surgery using the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials criteria: study protocol for a prospective randomized controlled trial

Background

Many patients develop chronic postsurgical pain (CPSP) after cardiac surgery, which interferes with their sleep, mood, and quality of life. Studies have suggested that propofol improves postoperative analgesia compared with volatile anesthetics, but its preventive effect on CPSP following cardiac surgery is still unknown. This study compares the incidence of CPSP following cardiac surgery for those receiving volatile anesthesia and those receiving propofol-based total intravenous anesthesia (TIVA) using criteria recommended by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT).

Methods/design

This is a prospective randomized controlled trial. In total, 500 adults undergoing cardiac surgery will be randomly allocated to the volatile or the TIVA group. The volatile group will receive sevoflurane or desflurane during surgery as general anesthesia. The TIVA group will receive propofol-based intravenous agents and no volatile agents during surgery. The primary outcomes will be the frequency of CPSP at 3 months, 6 months, and 1 year after surgery. In this case, CPSP is sternal or thoracic pain. It is defined as either (1) numerical rating scale (NRS) > 0 or (2) meeting all six IMMPACT criteria for CPSP. The IMMPACT criteria are validated pain instruments.

Discussion

To our knowledge, this is the first prospective randomized controlled trial to investigate the prevention of CPSP following cardiac surgery for patients receiving volatile anesthesia compared to those receiving propofol-based TIVA using validated pain instruments in accordance with the IMMPACT recommendations. This study will provide important information on which of these two anesthetic regimens is better for preventing CPSP after cardiac surgery.

Trial registration

Chictr.org.cn, ChiCTR1900020747. Registered on 16 January 2019.

Just how much does it cost? A cost study of chronic pain following cardiac surgery

OBJECTIVE

The study objective was to determine use of pain-related health care resources and associated direct and indirect costs over a two-year period in cardiac surgery patients who developed chronic post-surgical pain (CPSP).

METHODS

This multicentric observational prospective study recruited patients prior to cardiac surgery; these patients completed research assistant-administered questionnaires on pain and psychological characteristics at 6, 12 and 24 months post-operatively. Patients reporting CPSP also completed a one-month pain care record (PCR) (self-report diary) at each follow-up. Data were analyzed using descriptive statistics, multivariable logistic regression models, and generalized linear models with log link and gamma family adjusting for sociodemographic and pain intensity.

RESULTS

Out of 1,247 patients, 18%, 13%, and 9% reported experiencing CPSP at 6, 12, and 24 months, respectively. Between 16% and 28% of CPSP patients reported utilizing health care resources for their pain over the follow-up period. Among all CPSP patients, mean monthly pain-related costs were CAN$207 at 6 months and significantly decreased thereafter. More severe pain and greater levels of pain catastrophizing were the most consistent predictors of health care utilization and costs.

DISCUSSION

Health care costs associated with early management of CPSP after cardiac surgery seem attributable to a minority of patients and decrease over time for most of them. Results are novel in that they document for the first time the economic burden of CPSP in this population of patients. Longer follow-up time that would capture severe cases of CPSP as well as examination of costs associated with other surgical populations are warranted.

SUMMARY

Economic burden of chronic post-surgical pain may be substantial but few patients utilize resources. Health utilization and costs are associated with pain and psychological characteristics.

Persistent inflammatory pain alters sexually-motivated behavior in male rats

Urine from pro-œstrus female rodents evokes increased levels of sexually-motivated behaviors in males, including sniffing and scent marking of the urine spot as well as activation of brain reward regions. Stressors such as social defeat can adversely impact urine scent marking behavior in male rodents, an effect that can be mitigated with anti-depressant drugs. Persistent pain is also known to be a potent stressor, producing elevated levels of plasma corticosterone as well as reduced sucrose preference and reduced social interaction. However, the effect of persistent pain on sexually-motivated behavior is unknown. Here, we compared urine scent marking behavior in male rats for up to 3 weeks following intra-articular injection of Complete Freund’s Adjuvant (CFA) or sham injection. CFA-injected rats exhibited profound and ongoing deficits in static weight bearing capacity. CFA-induced persistent inflammatory pain increased plasma corticosterone levels and reduced urine scent marking behavior in male rats. Moreover, while the vast majority of injured rats showed decreased urine scent marking preference for the pro-œstrus female urine spot, male rats with higher baseline scent marking preference also exhibited higher post-injury scent marking preference, more sniffing behavior and lower levels of plasma corticosterone, compared to those with lower baseline scent marking preference. Overall, scent marking behavior may be an ethologically relevant behavioral predictor of persistent pain-induced stress in rats, representing a novel translational approach to understanding chronic pain comorbidities.

The psychology of chronic post-surgical pain: new frontiers in risk factor identification, prevention and management

In an era of considerable advances in anaesthesiology and pain medicine, chronic pain after major surgery continues to be problematic. This article briefly reviews the known psychological risk and protective factors associated with the development of chronic postsurgical pain (CPSP). We begin with a definition of CPSP and then explain what we mean by a risk/protective factor. Next, we summarize known psychological risk and protective factors for CPSP. Psychological interventions that target risk factors and may impact postsurgical pain are reviewed, including the acceptance and commitment therapy (ACT)-based approach to CPSP prevention and management we use in the Transitional Pain Service (TPS) at the Toronto General Hospital. Finally, we conclude with recommendations for research in risk factor identification and psychological interventions to prevent CPSP. Several pre-surgical psychological risk factors for CPSP have been consistently identified in recent years. These include negative affective constructs, such as anxiety symptoms, depressive symptoms, pain catastrophizing and general psychological distress. In contrast, relatively few studies have examined psychological protective factors for CPSP. Psychological interventions that target known psychological risk factors while enhancing protective psychological factors may reduce new incidence of CPSP. The primary goal of our ACT intervention is to teach patients a mindful way of responding to their postsurgical pain that empowers them to interrupt the negative cycle of pain, distress, behavioural avoidance and escalating opioid use that can limit functioning and quality of life while paradoxically amplifying pain over time. Early clinical outcome data suggest that patients who receive care from TPS physicians reduce their pain and opioid use, yet patients who also receive our ACT intervention have a larger decrease in daily opioid dose while reporting less pain interference and lower depression scores.