Sex Differences, Sleep Disturbance and Risk of Persistent Pain Associated With Groin Hernia Surgery: A Nationwide Register-Based Cohort Study

Sex Disparities in Opioid Prescription and Administration on a Hospital Medicine Service

INTRODUCTION

Decisions to prescribe opioids to patients depend on many factors, including illness severity, pain assessment, and patient age, race, ethnicity, and gender. Gender and sex disparities have been documented in many healthcare settings, but are understudied in inpatient general medicine hospital settings.

OBJECTIVE

We assessed for differences in opioid administration and prescription patterns by legal sex in adult patient hospitalizations from the general medicine service at a large urban academic center.

DESIGNS, SETTING, AND PARTICIPANTS

This study included all adult patient hospitalizations discharged from the acute care inpatient general medicine services at the University of California, San Francisco (UCSF) Helen Diller Medical Center at Parnassus Heights from 1/1/2013 to 9/30/2021.

MAIN OUTCOME AND MEASURES

The primary outcomes were (1) average daily inpatient opioids received and (2) days of opioids prescribed on discharge. For both outcomes, we first performed logistic regression to assess differences in whether or not any opioids were administered or prescribed. Then, we performed negative binomial regression to assess differences in the amount of opioids given. We also performed all analyses on a subgroup of hospitalizations with pain-related diagnoses.

RESULTS

Our study cohort included 48,745 hospitalizations involving 27,777 patients. Of these, 24,398 (50.1%) hospitalizations were female patients and 24,347 (49.9%) were male. Controlling for demographic, clinical, and hospitalization-level variables, female patients were less likely to receive inpatient opioids compared to male patents (adjusted OR 0.87; 95% CI 0.82, 0.92) and received 27.5 fewer morphine milligram equivalents per day on average (95% CI - 39.0, - 16.0). When considering discharge opioids, no significant differences were found between sexes. In the subgroup analysis of pain-related diagnoses, female patients received fewer inpatient opioids.

CONCLUSIONS

Female patients were less likely to receive inpatient opioids and received fewer opioids when prescribed. Future work to promote equity should identify strategies to ensure all patients receive adequate pain management.

Impact of patient's sex on groin hernia repair: A systematic review and meta-analysis

BACKGROUND

Groin hernia repair (GHR) is a performed procedure worldwide, with approximately 20 million surgeries carried out each year. Despite being less common in females, there is a lack of research on how sex influences the outcomes of GHR. This systematic review and meta-analysis aim to assess how patient sex impacts results in GHR.

METHODS

We performed a systematic review and meta-analysis according to Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. We searched for studies up to October 2023 in MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials. The studies included focused on sex outcomes for both robotic and open GHR procedures. Data extraction and quality assessment were conducted using the Risk of Bias in Non-Randomized Studies - Of Interventions tool. Our statistical analysis was performed using the metafor package in RStudio.

RESULTS

After screening a total of 3917 articles, we identified 29 studies that met our criteria, comprising a total of 1,236,694 patients. Among them, 98,641 (7.98%) patients were females. Our findings showed that females had higher rates of hernia recurrence (RR 1.28), chronic pain (RR 1.52), and surgical site infections (SSIs) (RR 1.46) compared to males. Females showed a lower tendency to undergo minimally invasive surgery (MIS) with a relative risk of 0.82 (95% CI 0.69-0.97; p = 0.02).

CONCLUSION

Females tend to face higher rates of complications after GHR such as an elevated risk of chronic pain, recurrence, and surgical site infections (SSI). Moreover, they undergo fewer MIS options compared to males. These results underscore the importance of research to enhance outcomes for women undergoing GHR.

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.

Microglial voltage-dependent anion channel 1 signaling modulates sleep deprivation-induced transition to chronic postsurgical pain

STUDY OBJECTIVES

This study verified that sleep deprivation before and after skin/muscle incision and retraction (SMIR) surgery increased the risk of chronic pain and investigated the underlying roles of microglial voltage-dependent anion channel 1 (VDAC1) signaling.

METHODS

Adult mice received 6 hours of total sleep deprivation from 1 day prior to SMIR until the third day after surgery. Mechanical and heat-evoked pain was assessed before and within 21 days after surgery. Microglial activation and changes in VDAC1 expression and oligomerization were measured. Minocycline was injected to observe the effects of inhibiting microglial activation on pain maintenance. The VDAC1 inhibitor 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) and oligomerization inhibitor VBIT-4 were used to determine the roles of VDAC1 signaling on microglial adenosine 5' triphosphate (ATP) release, inflammation (IL-1β and CCL2), and chronicity of pain.

RESULTS

Sleep deprivation significantly increased the pain duration after SMIR surgery, activated microglia, and enhanced VDAC1 signaling in the spinal cord. Minocycline inhibited microglial activation and alleviated sleep deprivation-induced pain maintenance. Lipopolysaccharide (LPS)-induced microglial activation was accompanied by increased VDAC1 expression and oligomerization, and more VDAC1 was observed on the cell membrane surface compared with control. DIDS and VBIT-4 rescued LPS-induced microglial ATP release and IL-1β and CCL2 expression. DIDS and VBIT-4 reversed sleep loss-induced microglial activation and pain chronicity in mice, similar to the effects of minocycline. No synergistic effects were found for minocycline plus VBIT-4 or DIDS.

CONCLUSIONS

Perioperative sleep deprivation activated spinal microglia and increases the risk of chronic postsurgical pain in mice. VDAC1 signaling regulates microglial activation-related ATP release, inflammation, and chronicity of pain.

Presurgical sleep and pain behaviors predict insomnia symptoms and pain after total knee arthroplasty: a 12-month longitudinal, observational study

OBJECTIVE

Up to 40% of individuals who undergo total knee arthroplasty (TKA) experience some degree of pain following surgery. Presurgical insomnia has been identified as a predictor of postsurgical pain; however, modifiable presurgical behaviors related to insomnia have received minimal attention. The objective of the present study was to develop a 2-item sleep and pain behavior scale (SP2) to investigate a maladaptive sleep and pain behavior and is a secondary analysis of a larger, parent study.

METHODS

Patients (N = 109) completed SP2 at baseline and 12 months and questionnaires assessing sleep and pain at baseline (pre-TKA), 6 weeks, 3, 6, and 12 months post-TKA. SP2 demonstrated adequate preliminary psychometric properties.

RESULTS

As hypothesized, even after controlling for baseline insomnia, pain, anxiety and other covariates, baseline SP2 predicted insomnia symptom severity at 6 weeks (β = 2.828), 3 (β = 2.140), 6 (β = 2.962), and 12 months (β = 1.835) and pain at 6 weeks (β = 6.722), 3 (β = 5.536), and 6 months (β = 7.677) post-TKA (P < .05). Insomnia symptoms at 6-weeks post-TKA mediated the effect of presurgical SP2 on pain at 3 (95% CI: 0.024-7.054), 6 (95%CI: 0.495-5.243), and 12 months (95% CI: 0.077-2.684).

CONCLUSIONS

This provides preliminary evidence that patients who cope with pain by retiring to their bed and bedroom have higher rates of post-surgical insomnia and pain and supports efforts to target this maladaptive sleep and pain behavior to reduce postsurgical pain.

Female Groin Hernia Repairs in the Swedish Hernia Register 1992-2022: A Review With Updates

Introduction: Groin hernias in women is much less common than in men; it constitutes only 9% of all groin hernia operations. Historically, studies have been performed on men and the results applied to both genders. However, prospectively registered operations within national registers have contributed to new knowledge regarding groin hernias in women. The aim of this paper was to investigate and present a body of literature based upon the Swedish Hernia Register together with recent data from the register's annual report. Patients and Methods: PubMed and Embase were searched for studies based on the Swedish Hernia Register between 1992 and 2023. Based on the initial reading of abstracts, studies that presented results separately for women were selected and read. Recent data were acquired from the 2022 annual report of the Swedish Hernia Register. Results: A total of 73 studies of interest were identified. Of these, 52 included women, but only 19 presented separate results for women. Four themes emerged and were analysed further: emergency surgery and mortality, femoral hernias, the risk of reoperation for recurrence, and chronic pain following female groin hernia repairs. Discussion: Studies from the Swedish Hernia Register clearly describe that both the presentation of hernias and outcomes after repair differ significantly between the two genders. The differences that have been identified over the years have been incorporated into the national guidelines. Register data indicates that the guidelines have been implemented and are fairly well adhered to. As a result, significant improvements in outcomes regarding recurrences have been made for women with groin hernias in Sweden.

Predictors of Chronic Pain in Elderly Patients Undergoing Total Knee and Hip Arthroplasty: A Prospective Observational Study

BACKGROUND

Chronic postsurgical pain (CPSP) after total knee arthroplasty and total hip arthroplasty (TKA and THA) is an important clinical problem in which many factors play a role. The risk factors for CPSP in elderly individuals are currently unknown. Therefore, our aim was to predict the risk factors for CPSP after TKA and THA and to provide help regarding early screening and interventions for elderly individuals at risk.

METHODS

In this prospective observational study, we collected and analyzed 177 TKA patients and 80 THA patients. Based on pain results at the 3-month follow-up, they were divided into the no chronic postsurgical pain and CPSP groups, respectively. The preoperative baseline conditions, including pain intensity (Numerical Rating Scale) and sleep quality (Pittsburgh Sleep Quality Index), as well as intraoperative and postoperative factors, were compared. Factors with P < .05 were included in binary regression analyses to establish prediction models for CPSP after TKA and THA.

RESULTS

The prevalence of CPSP was 20.9% after TKA and 7.5% after THA. The preoperative sleep disorders were an independent risk factor of CPSP after TKA, but no risk factors of CPSP after THA were identified.

CONCLUSION

This study indicated that the prevalence of CPSP after TKA was significantly higher than after THA, and that preoperative sleep disorders were an independent risk factor for CPSP after TKA, which may aid clinicians in screening people at risk for CPSP for primary prevention.

Development and validation of a nomogram for postoperative sleep disturbance in adults: a prospective survey of 640 patients undergoing spinal surgery

BACKGROUND

Postoperative sleep disturbance (PSD) is a prevalent clinical complication that may arise due to various factors. The purpose of this investigation is to identify the risk factors for PSD in spinal surgery and establish a risk prediction nomogram.

METHODS

The clinical records of individuals who underwent spinal surgery from January 2020 to January 2021 were gathered prospectively. The least absolute shrinkage and selection operator (LASSO) regression, along with multivariate logistic regression analysis, was employed to establish independent risk factors. A nomogram prediction model was devised based on these factors. The nomogram's effectiveness was evaluated and verified via the receiver operating characteristic (ROC) curve, calibration plot, and decision curve analysis (DCA).

RESULTS

A total of 640 patients who underwent spinal surgery were analyzed in this investigation, among which 393 patients experienced PSD with an incidence rate of 61.4%. After conducting LASSO regression and logistic regression analyses using R software on the variables in training set, 8 independent risk factors associated to PSD were identified, including female, preoperative sleep disorder, high preoperative anxiety score, high intraoperative bleeding volume, high postoperative pain score, dissatisfaction with ward sleep environment, non-use of dexmedetomidine and non-use of erector spinae plane block (ESPB). The nomogram and online dynamic nomogram were constructed after incorporating these variables. In the training and validation sets, the area under the curve (AUC) in the receiver operating characteristic (ROC) curves were 0.806 (0.768-0.844) and 0.755 (0.667-0.844), respectively. The calibration plots indicated that the mean absolute error (MAE) values in both sets were respectively 1.2% and 1.7%. The decision curve analysis demonstrated the model had a substantial net benefit within the range of threshold probabilities between 20% and 90%.

CONCLUSIONS

The nomogram model proposed in this study included eight frequently observed clinical factors and exhibited favorable accuracy and calibration.

TRIAL REGISTRATION

The study was retrospectively registered with the Chinese Clinical Trial Registry (ChiCTR2200061257, 18/06/2022).

Significant factors influencing chronic postoperative inguinal pain: A conditional time-dependent observational cohort study

BACKGROUND

Inguinal hernia (IH) repair is a common surgical procedure. Focus has shifted from recurrences to chronic postoperative inguinal pain (CPIP). To assess the natural course of CPIP and identify patient factors influencing the onset of CPIP, an observational registry-based study was performed.

MATERIALS AND METHODS

Data prospectively collected from the Club-Hernie national database was retrieved from 2011 until 2021. Patients who underwent elective surgery for inguinal hernia were divided in an irrelevant pain group and relevant pain group. Relevant pain at one year and two years were compared with patients with irrelevant pain at all-time points (preoperatively, one month, one year and two years). Quality of life questions were compared between relevant pain at one year and two years.

RESULTS

4.016 patients were included in the analysis. Mean age was 65.1 years, 90.3% of patients was male. Factors correlated with CPIP onset were age, gender, ASA, recurrent surgery, surgical technique, nerve handling and fixation type. Relevant pain at one month was a greater risk for CPIP than preoperative pain (12.3% vs 3.6%). In the majority of patients (83.2%) CPIP was ameliorated at two years. Hernia related complaints differed significantly between CPIP at one year and two years.

CONCLUSION

Postoperative pain after one month was a greater risk factor for CPIP development than preoperative pain. CPIP at one year seems to have a different pain etiology than CPIP at two years. Patient and surgical factors influence the onset of CPIP at one year, however the natural course of these complaints shows great decline at two years, largely without reinterventions.

[Pain and quality of life after laparoscopic transabdominal preperitoneal hernioplasty with different ways of fixing the peritoneum. Results of early completion randomized clinical trial]

OBJECTIVE

To compare and statistically evaluate the severity of pain syndrome and quality of life depending on the method of fixation of the parietal peritoneum during laparoscopic hernia repair (suture fixation or the use of tack fixation).

METHODS

A randomized clinical trial was conducted from May to June 2021 at the Lomonosov Moscow State University Medical Center. It was planned to observe patients for a year. In the first group, the fixation of the parietal peritoneum was performed using suture fixation, in the second group, the peritoneal flap was fixed using a fixation device. In the course of statistical data processing, it was planned to study the dependence of the duration of the operation, the severity of the pain syndrome in the early postoperative period, the frequency of complications, the quality of life of patients in the postoperative period on the chosen method of the fixation of the parietal peritoneum.

RESULTS

At the initial stage of the study, 8 patients with inguinal hernias were selected in the first group during randomization, and 6 patients were selected in the second group. Each patient of the second group in the early postoperative period had a more pronounced local pain, protective muscle tension in the projection of fixation of the parietal peritoneum with tacks, which was accompanied by negative psychoemotional reactions, an increase in the dose of analgesic drugs. Due to the revealed features of the early postoperative period in patients of second group, it was considered unethical and inappropriate to continue the study within the protocol.

CONCLUSION

The results obtained do not allow us to draw statistically supported conclusions. The solution of the problem of the peritoneal flap fixation method is possible in two ways: abandoning stapler fixation in favor of suture or conducting additional clinical studies with an analysis of the impact of the choice of peritoneal fixation technique not only on acute and chronic postoperative pain, but on quality of life in the early and delayed postoperative periods.