Age and preoperative pain are major confounders for sex differences in postoperative pain outcome: A prospective database analysis

Development and internal validation of a clinical risk tool to predict chronic postsurgical pain in adults: a prospective multicentre cohort study

ABSTRACT

Chronic postsurgical pain (CPSP) is a highly prevalent condition. To improve CPSP management, we aimed to develop and internally validate generalizable point-of-care risk tools for preoperative and postoperative prediction of CPSP 3 months after surgery. A multicentre, prospective, cohort study in adult patients undergoing elective surgery was conducted between May 2021 and May 2023. Prediction models were developed for the primary outcome according to the International Association for the Study of Pain criteria and a secondary threshold-based CPSP outcome. Models were developed with multivariable logistic regression and backward stepwise selection. Internal validation was conducted using bootstrap resampling, and optimism was corrected by shrinkage of predictor weights. Model performance was assessed by discrimination and calibration. Clinical utility was assessed by decision curve analysis. The final cohort included 960 patients, 16.3% experienced CPSP according to the primary outcome and 33.6% according to the secondary outcome. The primary CPSP model included age and presence of other preoperative pain. Predictors in the threshold-based models associated with an increased risk of CPSP included younger age, female sex, preoperative pain in the surgical area, other preoperative pain, orthopedic surgery, minimally invasive surgery, expected surgery duration, and acute postsurgical pain intensity. Optimism-corrected area-under-the-receiver-operating curves for preoperative and postoperative threshold-based models were 0.748 and 0.747, respectively. These models demonstrated good calibration and clinical utility. The primary CPSP model demonstrated fair predictive performance including 2 significant predictors. Derivation of a generalizable risk tool with point-of-care predictors was possible for the threshold-based CPSP models but requires independent validation.

Attitudes and Experiences of Patients Regarding Gender-Specific Aspects of Pain Management

BACKGROUND

Biological, pharmacological, and socio-cultural aspects influence gender-specific effects in pain management.

METHODS

Gender-specific aspects of pain management were assessed in a rural outpatient center via semi-structured patient interview: (i) general gender aspects (total population) from 1 = "fully disagree" to 5 = "fully agree"; and (ii) individual pain (matched pairs) via numeric analog scale (NAS) from 0 = "no pain" to 10 = "maximum pain". Patient charts were assessed for pain management (WHO-ladder).

RESULTS

In total, 113 patients were enrolled (59.18 [SD: 12.76] years, 46% female, 54% male, 0% diverse), and 42 were matched into female-male pairs. (i) Women and men agreed that men and women should be treated equally despite biological differences (median: 5 [women] vs. 5 [men]; p = 0.789). As a reason for gender-specific aspects, "medication concentration" was reported more frequently by women (p = 0.038) and "no answer" by men (p = 0.014). (ii) Mean value (SD) of pain (NAS) was 4.0 (SD 2.3) for women and 3.3 (SD 2.6) for men (p = 0.215) with a positive correlation between pain management escalation (WHO-ladder) and the pain score (NAS) only in men (r = 0.704, p = 0.001). Women rather reported an influence of adverse drug reactions on treatment contentment than men (p = 0.042).

CONCLUSIONS

Although patients pleaded for gender-independent equal treatment, gender-specific differences in pain therapy were found.

Gender roles as predictive factors on labor pain: a cross-sectional study

Labor is a complex, subjective experience, and all factors that influence pain should be considered to ensure a comprehensive evaluation. This study aimed to determine whether gender roles were predictive of labor pain. The study has a descriptive and cross-sectional design. It was carried out in a delivery room of a city hospital in Turkey between September 2019 and September 2020. The study sample consisted of 231 primiparous women presenting for labor and delivery. Data were gathered with a descriptive characteristics form, Visual Analogue Scale and The Bem Sex-Role Inventory. Descriptive statistics and simple regression analysis were employed to analyze the obtained data. Regression analysis demonstrated that gender roles were predictive of labor pain in the latent, active, and transitional stages, but not in the second stage. Gender roles were most responsible for labor pain in the latent phase. Results of the study revealed that gender roles may be useful variables to predict women's labor pain, and contributed to the relevant literature. Nurses and midwives offering care for labor pain should consider gender roles as a factor affecting labor pain. It is also necessary to individualize the supporting care given during labor.

Pain Predictors in Patients in the Postanesthesia Care Unit

PURPOSE

To analyze the effects of pain-predicting factors on patients in the postanesthesia care unit (PACU).

DESIGN

This is an observational and prospective study.

METHODS

This study was conducted at a University Hospital in the state of Minas Gerais (Brazil). To collect data on demographic, clinical, and surgical factors, a collection instrument was devised. The verbal numerical scale was employed to measure pain levels before and after surgery in the PACU. A path analysis was used to assess a predictive model.

FINDINGS

A total of 226 patients were included in this study. The incidence of pain in the PACU was 31.9%. A model with demographic, clinical, and surgical variables was tested. The final model, after including modification indices, obtained results that indicated an acceptable data fit (comparative fit index = 0.996; root mean square error of approximation = 0.08). Age (being young), sex (being a woman), oncological diagnosis as an indication for the surgical procedure, type of surgery (surgery of the digestive system), duration of surgery (longer surgeries), and high intraoperative doses of opioids were predictive variables for pain in the PACU.

CONCLUSIONS

This study's findings provide support for pain management in the PACU. Furthermore, the results of this research can be used to anticipate the occurrence of acute postoperative pain and personalized perioperative analgesia needs.

Red-Haired People's Altered Responsiveness to Pain, Analgesics, and Hypnotics: Myth or Fact?-A Narrative Review

Red hair has been linked to altered sensitivity to pain, analgesics, and hypnotics. This alteration may be impacted by variants in the melanocortin-1 receptor (MC1R) gene, which are mainly found in redheads. The aim of this narrative review was to explore and present the current state of knowledge on red hair and its plausible associations with altered responsiveness to pain, analgesics, and hypnotics. Structured searches in the PubMed, CINAHL Complete, and Scopus electronic databases were conducted. Evidence suggests that women with red hair have an increased sensitivity to pain. Conversely, data also indicate a higher pain tolerance in homozygous carriers of MC1R variant alleles. Varied responses to analgesia have been reported, with both increased analgesic responsiveness in homozygous carriers of MC1R variant alleles and less analgesia in redheads. Data indicate an increased need for hypnotics in redheads. However, failed attempts to find statistical associations between red hair and altered responsiveness to hypnotics are also evident. Even though there seems to be an association between red hair and an altered responsiveness to pain, analgesics, and/or hypnotics, the results of this narrative review are inconclusive. Further research studies with larger populations and MC1R testing are needed.

The Problem of Pain in Rheumatology: Variations in Case Definitions Derived From Chronic Pain Phenotyping Algorithms Using Electronic Health Records

OBJECTIVE

The aim of this study was to investigate and compare different case definitions for chronic pain to provide estimates of possible misclassification when researchers are limited by available electronic health record and administrative claims data, allowing for greater precision in case definitions.

METHODS

We compared the prevalence of different case definitions for chronic pain (N = 3042) in patients with autoimmune rheumatic diseases. We estimated the prevalence of chronic pain based on 15 unique combinations of pain scores, diagnostic codes, analgesic medications, and pain interventions.

RESULTS

Chronic pain prevalence was lowest in unimodal pain phenotyping algorithms: 15% using analgesic medications, 18% using pain scores, 21% using pain diagnostic codes, and 22% using pain interventions. In comparison, the prevalence using a well-validated phenotyping algorithm was 37%. The prevalence of chronic pain also increased with the increasing number (bimodal to quadrimodal) of phenotyping algorithms that comprised the multimodal phenotyping algorithms. The highest estimated chronic pain prevalence (47%) was the multimodal phenotyping algorithm that combined pain scores, diagnostic codes, analgesic medications, and pain interventions. However, this quadrimodal phenotyping algorithm yielded a 10% overestimation of chronic pain compared to the well-validated algorithm.

CONCLUSION

This is the first empirical study to our knowledge that shows that established common modes of phenotyping chronic pain can lead to substantially varying estimates of the number of patients with chronic pain. These findings can be a reference for biases in case definitions for chronic pain and could be used to estimate the extent of possible misclassifications or corrections in using datasets that cannot include specific data elements.

Influence of a chronic beta-blocker therapy on perioperative opioid consumption - a post hoc secondary analysis

BACKGROUND

Beta-blocker (BB) therapy plays a central role in the treatment of cardiovascular diseases. An increasing number of patients with cardiovascular diseases undergoe noncardiac surgery, where opioids are an integral part of the anesthesiological management. There is evidence to suggest that short-term intravenous BB therapy may influence perioperative opioid requirements due to an assumed cross-talk between G-protein coupled beta-adrenergic and opioid receptors. Whether chronic BB therapy could also have an influence on perioperative opioid requirements is unclear.

METHODS

A post hoc analysis of prospectively collected data from a multicenter observational (BioCog) study was performed. Inclusion criteria consisted of elderly patients (≥ 65 years) undergoing elective noncardiac surgery as well as total intravenous general anesthesia without the use of regional anesthesia and duration of anesthesia ≥ 60 min. Two groups were defined: patients with and without BB in their regular preopreative medication. The administered opioids were converted to their respective morphine equivalent doses. Multiple regression analysis was performed using the morphine-index to identify independent predictors.

RESULTS

A total of 747 patients were included in the BioCog study in the study center Berlin. 106 patients fulfilled the inclusion criteria. Of these, 37 were on chronic BB. The latter were preoperatively significantly more likely to have arterial hypertension (94.6%), chronic renal failure (27%) and hyperlipoproteinemia (51.4%) compared to patients without BB. Both groups did not differ in terms of cumulative perioperative morphine equivalent dose (230.9 (BB group) vs. 214.8 mg (Non-BB group)). Predictive factors for increased morphine-index were older age, male sex, longer duration of anesthesia and surgery of the trunk. In a model with logarithmised morphine index, only gender (female) and duration of anesthesia remained predictive factors.

CONCLUSIONS

Chronic BB therapy was not associated with a reduced perioperative opioid consumption.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov ( NCT02265263 ) on the 15.10.2014 with the principal investigator being Univ.-Prof. Dr. med. Claudia Spies.

Pain After Outpatient Surgical Procedures

BACKGROUND

Approximately 8.1 million outpatient surgical procedures were performed in Germany in 2021. Little is known about the quality of postoperative pain treatment in the outpatient sector.

METHODS

The AQS1 project comprises a combined survey of patients and staff in the framework of quality control for ambulatory surgery. The primary endpoint of this study was the prevalence of relevant incisional pain (≥ 4/10 on the numerical rating scale) up to postoperative day 3. Secondary endpoints included prognostic variables for pain and pain-associated outcomes, based on the AQS1 patient questionnaire. Moreover, mixed regression models were used to analyze potential prognostic variables and associations of pain with other outcomes (study registration number DRKS00028052).

RESULTS

Data from 330 008 patients were evaluated (from 1 July 2001 to 31 December 2021). The overall prevalence of relevant incisional pain up to postoperative day 3 was 22.5%, with major differences between different types of procedure (3.2%-51.2%). Pain was most common after hemorrhoid surgery (51.2%) and the laparoscopic lysis of large and small bowel adhesions (45.4%). The main associations of relevant pain were with younger age (odds ratio [OR] 1.87, 95% confidence interval [1.82; 1.91]), early postoperative pain (1.34, [1.30; 1.39]), inadequate provision of analgesics (2.90, [2.71; 3.09]), and surgical wound infections (2.60, [2.43; 2.78]). Patients with pain reported lower overall satisfaction with the procedure and a longer inability to work.

CONCLUSION

These data have not been tested for representativeness. They can serve as a point of departure for the optimization of individualized perioperative pain therapy and for the planning of prospective studies.

The Effect of Preoperative Exposure to Benzodiazepines on Opioid Consumption After One and Two-level Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

Investigate the relationship between preoperative benzodiazepine exposure and postoperative opioid use in patients undergoing primary 1 or 2-level anterior cervical discectomy and fusion (ACDF).

BACKGROUND

Little is known about the effect of preoperative benzodiazepine exposure on postoperative opioid use in spine surgery.

PATIENTS AND METHODS

Patients undergoing primary 1 or 2-level ACDF at a single institution from February 2020 to November 2021 were identified through electronic medical records. The prescription drug monitoring program was utilized to record the name, dosage, and quantity of preoperative benzodiazepines/opioids filled within 60 days before surgery and postoperative opioids 6 months after surgery. Patients were classified as benzodiazepine naïve or exposed according to preoperative usage, and postoperative opioid dose and duration were compared between groups. Regression analysis was performed for outcomes that demonstrated statistical significance, adjusting for preoperative opioid use, age, sex, and body mass index.

RESULTS

Sixty-seven patients comprised the benzodiazepine-exposed group whereas 90 comprised the benzodiazepine-naïve group. There was no significant difference in average daily morphine milligram equivalents between groups (median: 96.0 vs 65.0, P = 0.11). The benzodiazepine-exposed group received postoperative opioids for a longer duration (median: 32.0 d vs 12.0 d, P = 0.004) with more prescriptions (median: 2.0 vs 1.0, P = 0.004) and a greater number of pills (median: 110.0 vs 59.0, P = 0.007). On regression analysis, preoperative benzodiazepine use was not significantly associated with postoperative opioid duration [incidence rate ratio (IRR): 0.93, P = 0.74], number of prescriptions (IRR: 1.21, P = 0.16), or number of pills (IRR: 0.89, P = 0.58).

CONCLUSIONS

While preoperative benzodiazepine users undergoing primary 1 or 2-level ACDF received postoperative opioids for a longer duration compared with a benzodiazepine naïve cohort, preoperative benzodiazepine use did not independently contribute to this observation. These findings provide insight into the relationship between preoperative benzodiazepine use and postoperative opioid consumption.

LEVEL OF EVIDENCE

Level III.

Acupuncture Effect on Analgesic Consumption and Cortisol Levels Following Total Knee Arthroplasty: A Randomized Controlled Trial

Objective

Pain following total knee arthroplasty (TKA) is common. Various modalities of treating orthopedic postoperative pain (POP) exist; however, the optimal management of POP remains unclear. The purpose of this study was to examine acupuncture's effect on postoperative analgesic consumption and cortisol levels in patients undergoing TKA.

Materials and Methods

In this randomized controlled trial, 80 patients scheduled for elective TKA surgery were recruited and randomly assigned to 2 groups: (1) an intervention group, receiving acupuncture treatment on days 1 and 2 in addition to standard POP management (n = 40) and a control group, who received standard POP management only (n = 40).

Results

There was no statistical difference between the groups in analgesic consumption on days 1 and 3 postoperatively. On day 5 postoperatively, lower analgesic consumption was seen in the intervention group, compared to the control group. However, this difference was not statistically significant (1.4 versus 2.3, respectively; P = 0.215). There was no statistical difference between the groups in cortisol levels on day 1 postoperatively. In contrast, on day 2 postoperatively, cortisol level was significantly lower in the intervention group, compared to the control group (296 nmol/L versus 400 nmol/L, respectively; P < 0.05).

Conclusions

The findings suggest that acupuncture may have some effect on patients' analgesic consumption short-term after TKA. Further studies with larger samples are required for establishing these results.This trial was registered at ClinicalTrials.gov (Registration #: NCT03415204).

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.

Change in perioperative neutrophil-lymphocyte ratio as a potential predictive biomarker for chronic postsurgical pain and quality of life: an ambispective observational cohort study

Introduction

Accurate and accessible predictors of chronic postsurgical pain (CPSP) to identify high-risk postsurgical patients are prerequisite for preventive and interventional strategies. We investigated the incidence and risk factors of CPSP after abdominal surgery, with a focus on plasma immunological markers.

Materials and methods

This was a retrospective analysis of patients who underwent abdominal surgery under general anesthesia at a tertiary center between January 2021 and January 2022. The preoperative demographics, laboratory test data, and surgical factors of the participants were collected from the electronic medical record system. Postoperative pain intensity and living conditions at 1 year after discharge from the hospital were assessed via a phone survey. Univariate and multivariate analyses were used to explore independent risk factors associated with CPSP.

Results

A total of 968 patients were included, and 13.53% (n = 131 of 968) of patients reported CPSP 1 year after surgery. Patients with older age, open surgery, higher American Association of Anesthesiologists classification, patient-controlled intravenous analgesia application, longer surgery duration, higher postoperative absolute neutrophil count, and neutrophil-lymphocyte ratio (NLR), lower postoperative absolute lymphocyte count, and higher white blood cell count, were more likely to suffer from CPSP. A changed ratio of NLR (postoperative to preoperative) ≥ 5 significantly correlated with CPSP, moderate to severe pain, maximum numeric rating score since discharge from the hospital, and affected quality of life.

Discussion

The changed ratio of NLR could be used for the early identification of patients at risk for CPSP and affect the quality of life to alert the clinician to undertake further assessment.

Synaptic Plasticity in the Pain-Related Cingulate and Insular Cortex

Cumulative animal and human studies have consistently demonstrated that two major cortical regions in the brain, namely the anterior cingulate cortex (ACC) and insular cortex (IC), play critical roles in pain perception and chronic pain. Neuronal synapses in these cortical regions of adult animals are highly plastic and can undergo long-term potentiation (LTP), a phenomenon that is also reported in brain areas for learning and memory (such as the hippocampus). Genetic and pharmacological studies show that inhibiting such cortical LTP can help to reduce behavioral sensitization caused by injury as well as injury-induced emotional changes. In this review, we will summarize recent progress related to synaptic mechanisms for different forms of cortical LTP and their possible contribution to behavioral pain and emotional changes.

The influence of preoperative anxiety on postoperative pain in patients undergoing cardiac surgery

Patients undergoing cardiac surgery represent a challenge in terms of pain management due to multiple factors relating to the patients and to the procedure itself. Our aim was to identify the influence of levels of preoperative anxiety on postoperative pain in patients undergoing cardiac surgery and explore associations between preoperative anxiety, postoperative pain, analgesic requirements, and sex. We present a prospective cohort study of 116 patients undergoing cardiac surgery between January and April 2020. Preoperative anxiety was evaluated using the State-Trait Anxiety Inventory and the amount of morphine needed to keep pain intensity below 4 on the verbal numerical rating scale was recorded for 48 h post-surgery. Given the extracorporeal circulation time, type of surgery and body surface, it was observed that every percentile increase in preoperative state anxiety led to an extra 0.068 mg of morphine being administered. For each extra year of age, the amount of morphine needed decreased by 0.26 mg, no difference was observed between men and women in terms of preoperative anxiety or postoperative analgesics requirements. It may be concluded that in cardiac surgery, postoperative analgesic requirements increased with higher levels of preoperative state anxiety and decreased for every extra year of age.

No Gender Differences in Pain Perception and Medication after Lumbar Spine Sequestrectomy—A Reanalysis of a Randomized Controlled Clinical Trial

Background: Gender issues have received increasing attention in clinical research of the past years, and biological sex has been introduced as a moderating variable in experimental pain perception. However, in clinical studies of acute pain and gender, there are conflicting results. In particular, there are limited data on the impact of gender differences after spinal sequestrectomy. The aim of this work is to examine gender differences in postoperative pain and pain medication consumption in an inpatient clinical setting. Methods: Data of a completed double-blind RCT was subdivided by gender and reanalyzed by means of an analysis of variance in repeated measures. Outcomes included pain severity measured on a VAS, affective (SES-A) and sensory pain perception (SES-S) and morphine equivalent doses (MED) of analgesics after spinal sequestrectomy. Results: In total, 42 female (47.73%) and 46 male (52.27%) patients were analyzed. No differences in pain severity (VAS: Gender × Time F = 0.35; (df = 2, 86); p = 0.708), affective and sensory pain perception (SES-A: Gender × Time F = 0.08; (df = 2, 86); p = 0.919; SES-S: Gender × Time F = 0.06; (df = 2, 86); p = 0.939) or post-operative opioid use between men and women (MEDs: Gender × Time F = 1.44; (df = 2, 86); p = 0.227) could be observed. Conclusions: This reanalysis of an RCT with respect to gender differences is to our knowledge the first attempt to investigate the role of gender in pain perception and medication after lumbar spine sequestrectomy. In contrast to other studies, we were not able to show significant differences between male and female patients in all pain-related outcomes. Apart from well-established pain management, psychological reasons such as gender-specific response biases or the observer effect might explain our results. Trial registration: The study was registered as a regulatory phase IV study at the German Clinical Trials Register (DRKS), an open-access online register for clinical trials conducted in Germany (Reg-No: DRKS00007913).

Pain management of nalbuphine and sufentanil in patients admitted intensive care unit of different ages

Background

Pain relief for patients in the intensive care unit (ICU) can improve treatment outcomes and reduce the burden on doctors and nurses. This study aims to report the clinical analgesic and sedative effects of nalbuphine and sufentanil on ICU patients.

Methods

This study retrospectively analyzed the medical records of 87 critically ill patients who received nalbuphine or sufentanil infusion in the ICU, including demographic data, diagnosis, Acute Physiology and Chronic Health Evaluation (APACHE) II, Critical Care Pain Observation Tool (CPOT), Richmond Agitation-Sedation Scale (RASS), systolic and diastolic blood pressure, heart rate and blood oxygen saturation (SpO2). The primary outcomes of this study were CPOT and RASS scores. The secondary outcomes were hemodynamic changes, including systolic blood pressure, diastolic blood pressure, heart rate, and SpO2. The adverse events recorded during pain management, such as hypoxemia, respiration depression and bradycardia, were also collected and analyzed.

Results

None of the patients in both groups experienced episode of hypoxemia, respiration depression and bradycardia. However, age-stratified analyses showed that nalbuphine has a better analgesic effect than sufentanil for patients aged ≤ 60 (P < 0.05). In contrast, sufentanil showed a better analgesic effect than nalbuphine for patients aged > 60 ( P < 0.05). Furthermore, nalbuphine has a significantly better sedative effect than sufentanil for patients aged ≤ 60 (P < 0.05).

Conclusion

ICU patients of different age groups may be suitable for different analgesics. For patients under the age of 60, nalbuphine has better analgesia and sedation than sufentanil, and does not cause respiratory depression and drastic hemodynamic changes.

Is There a Neuropathic-Like Component to Endometriosis-Associated Pain? Results From a Large Cohort Questionnaire Study

Background: Pain is one of the primary symptoms of endometriosis, a chronic inflammatory condition characterised by the presence of endometrial tissue outside the uterus. Endometriosis-associated pain is commonly considered as nociceptive in nature, but its clinical presentation suggests that it might have neuropathic-like properties in a subgroup of patients.

Methods: This is a cross sectional study using an online survey. The survey was distributed by patient support websites. The survey was composed of validated questionnaires assessing pain symptoms, psychological measures and questions about number of surgeries.

Main Results: We had 1,417 responses which met the inclusion criteria. Using standard painDETECT cut-off scores, we found that pain was classified as neuropathic in 40% of patients and as mixed neuropathic/nociceptive in a further 35%. In line with observations in other neuropathic conditions, the neuropathic subgroup reported higher pain intensities, greater psychological distress and cognitive impairment. Neuropathic pain was also more likely in those with more surgeries to the abdomen and a longer history of pain. As revealed by a cluster analysis, those with a neuropathic pain component could further be divided into two subgroups based on their sensory profile.

Conclusions: The data presented here indicate that endometriosis-associated pain includes a neuropathic-like component in a substantial proportion of women. Although further investigation is required, our finding challenges the current conceptualisation of endometriosis-associated pain as nociceptive and advocates for a new perspective on this type of pain, which is so debilitating to a large number of women.

Patients' Active Participation in Postoperative Pain Management in an Urban Hospital of Vietnam: Implications for Patient Empowerment

Active participation in pain management is vital to improve postoperative pain outcomes. However, this issue has not been fully examined in Vietnam. This study aimed to examine the active participation of patients in pain management after surgery, as well as explore its effect on acute postoperative pain.

A hospital-based survey on 245 patients after surgery was conducted. Information about demographic and clinical characteristics, pain intensity and active participation in pain management was collected. Multivariate regression models were utilized to determine the associations.

53.9% of patients reported that they were informed about the postoperative pain relief method before surgery. One-third (33.5%) of patients selected preferred pain relief methods; 46.1% reported that they asked physicians when feeling pain immediately after surgery; 49.8% asked physicians when pain was not relieved after taking medications, and 52.2% asked physicians for their current pain in the time of interview. Age and occupation were found to be positively associated with active participation score. Patients being informed about the postoperative pain relief method before surgery had 0.87 points higher than those not receiving explanation (Coef. = 0.87; 95%CI = 0.49-1.26). Patients with high active participation scores were more likely to have pain improvement (OR = 3.41, 95%CI = 2.37-4.92).

This study highlights a low level of active participation in postoperative pain management among Vietnamese patients. Routinely providing information about pain control before surgery, and encouraging patients to actively participate in pain management are essential to improve postoperative pain outcomes.

Factors affecting sufentanil consumption for intravenous controlled analgesia after hepatectomy: retrospective analysis

Background

Pain control after hepatectomy is usually achieved by opioids. There are significant individual differences in the amount of opioids used after hepatectomy, and the metabolism of opioids is liver-dependent. The purpose of our study was to explore the possible risk factors for opioid consumption during the first 48 h after surgery.

Methods

In a retrospective study design involving 562 patients undergoing open or laparoscopic hepatectomy, all patients were treated with intravenous patient-controlled analgesia (IV-PCA) along with continuous and bolus doses of sufentanil for a duration of 48 h after surgery during the time period of August 2015 and February 2019. The primary endpoint was high sufentanil consumption 48 h after hepatectomy, and patients were divided into two groups: those with or without a high PCA sufentanil dosage depending on the third quartile (Q3). The secondary endpoint was the effect of a high PCA sufentanil dosage on various possible clinical risk factors. The relevant parameters were collected, and correlation and multivariate regression analyses were performed.

Results

The median operation time was 185 min (range, 115–250 min), and the median consumption of sufentanil 48 h after the operation was 91 μg (IQR, 64.00, 133.00). Factors related to the consumption of sufentanil at 48 h after hepatectomy included age, operation time, blood loss, intraoperative infusion (red blood cells and fresh-frozen plasma), pain during movement after surgery (day 1 and day 2), preoperative albumin, and postoperative blood urea nitrogen. Age (≤ 60 and > 60 years), extent of resection (minor hepatic resection and major hepatic resection), surgical approach (laparoscope and open) and operation time (min) were independent risk factors for sufentanil consumption at 48 h postoperatively.

Conclusion

Age younger than 60 years, major hepatic resection, an open approach and a longer operation are factors more likely to cause patients to require higher doses of sufentanil after hepatectomy, and the early identification of such patients can increase the efficacy of perioperative pain management.

Relationship Between Quality of Care and Patient Care Outcomes for Postoperative Pain in Major Orthopedic Surgery: Analytical and Cross-Sectional Study

The quality of care provided for the management of postoperative pain and patient outcomes are key criteria for healthcare institutions. This study aimed to determine the relationship between the quality of care provided for the alleviation of postoperative pain experienced among patients undergoing major orthopedic surgery and the patient care outcomes. The study was designed as an analytical and cross-sectional study. The rates of pain severity and sleep interference, activity interference, affective experiences, and adverse effects due to postoperative pain were higher in female patients than in male patients. A significant positive correlation was identified between the quality of postoperative pain care and the perception of care (p < .05). Implementing nursing interventions to improve pain management and increase the quality of care appears to be vital elements for reducing adverse effects caused by pain and increasing the satisfaction with postoperative pain care.

Inhibiting endocytosis in CGRP+ nociceptors attenuates inflammatory pain-like behavior

The advantage of locally applied anesthetics is that they are not associated with the many adverse effects, including addiction liability, of systemically administered analgesics. This therapeutic approach has two inherent pitfalls: specificity and a short duration of action. Here, we identified nociceptor endocytosis as a promising target for local, specific, and long-lasting treatment of inflammatory pain. We observed preferential expression of AP2α2, an α-subunit isoform of the AP2 complex, within CGRP⁺/IB4^- nociceptors in rodents and in CGRP⁺ dorsal root ganglion neurons from a human donor. We utilized genetic and pharmacological approaches to inhibit nociceptor endocytosis demonstrating its role in the development and maintenance of acute and chronic inflammatory pain. One-time injection of an AP2 inhibitor peptide significantly reduced acute and chronic pain-like behaviors and provided prolonged analgesia. We evidenced sexually dimorphic recovery responses to this pharmacological approach highlighting the importance of sex differences in pain development and response to analgesics.

The authors show the endocytotic adaptor subunit called AP2A2 is differentially expressed in CGRP⁺ nociceptors. Locally inhibiting nociceptor endocytosis with a lipidated AP2 inhibitor peptide reduces acute and chronic pain-like behaviour in mice and rats, indicating prolonged analgesia.

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.

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.

Sex differences in the consumption of over-the-counter analgesics among amateur volleyball players

Background

Compared with the normal adult population, athletes of several sport disciplines, such as endurance sports, ball sports, cycling and swimming, have higher use of over-the-counter analgesics (OTC analgesics). The aim of this study was to describe the epidemiology of OTC analgesic use in volleyball players as a typical competitive sport discipline. One particular focus was placed on the analysis whether the athletes’ use of OTC analgesics was influenced by their performance motivation.

Methods

A cross-sectional survey among amateur volleyball players was carried out using a web-based sports questionnaire. The study included athletes of both sexes, 18 years and older, currently playing in a German volleyball league. The athletes’ sport-related complaints were evaluated regarding the use of OTC analgesics. The use of OTC analgesics by athletes was compared with their performance motivation, based on the „Achievement Motives Scale - Sport” (AMS-Sport) questionnaire.

Results

The analysis of 114 completed questionnaires of amateur athletes revealed that the use of OTC analgesics was sex dependent, with a higher prevalence of use in female players (60%) versus male players (38%). The main reasons for consumption of OTC analgesics were pain in the head, knee and shoulder. The most frequently taken drug was ibuprofen, most often taken at competitions and over a period of 4 years (median). The analysis of the AMS-Sport questionnaire revealed that a logistic regression model for estimating the probability of drug use can be explained by the factors hope of success and years of playing practise in female players but not male players. In females, an increase in the factor hope of success resulted in a lower probability of OTC analgesic use, while an increase in years of playing practise resulted in a higher probability of use.

Conclusion

The average duration that volleyball players in this study took OTC analgesics was higher than that of the German population, and OTC analgesic use was more prevalent in female than male volleyball players. Thus, to reduce the prevalence of OTC analgesic use, educational programs should be implemented in sports teams; and, to reduce direct and indirect social pressure, sports teams should also receive sex-specific psychological support.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13102-021-00273-5.

National Trends in Opioid Prescriptions Following Outpatient Otologic Surgery, 2005-2017

OBJECTIVE

To describe opioid stewardship in ambulatory otologic surgery from 2005 to 2017.

STUDY DESIGN

Descriptive study of US private insurance claims.

SETTING

Nationwide deidentified private insurance claims database (Clinformatics DataMart; Optum).

METHODS

A total of 17,431 adult opioid-naïve outpatients were included in the study. Patients were identified from CPT-4 codes (Current Procedural Terminology, Fourth Edition) as having undergone middle ear or mastoid surgery. Multiple regression was used to determine sociodemographic and geographic predictors of postoperative morphine milligram equivalents (MMEs) prescribed, including procedure type, year of procedure, age, sex, education, income level, and geographic region of the United States.

RESULTS

The mean prescribed perioperative dose over the examined period was 203.03 MMEs (95% CI, 200.27-205.79; 5-mg hydrocodone pill equivalents, 40.61). In multivariate analysis, patients undergoing mastoid surgery were prescribed more opioids than those undergoing middle ear surgery (mean difference, 39.89 MME [95% CI, 34.37-45.41], P < .01; 5-mg hydrocodone pill equivalents, 8.0). Men were prescribed higher doses than women (mean difference, 15.39 [95% CI, 9.87-20.90], P < .01; 5-mg hydrocodone pill equivalents, 3.1). Overall MMEs prescribed by year demonstrates a sharp drop in MMEs from 2015 to 2017.

CONCLUSION

While the amount of opioids prescribed perioperatively has declined in recent years, otologists should continue to be cognizant of potential overprescribing in light of previous studies of patients' relatively low opioid intake.

Impact of the Timing of Rocuronium Injection after Propofol Administration on Temporal Summation of Pain in Gynecologic Laparoscopic Surgery: A Prospective and Controlled Study

Purpose

Temporal summation of pain, which is defined as the perception of greater pain evoked by repetitive painful stimuli, varies among individuals. This study aimed at determining the impact of the timing of rocuronium after induction with propofol on the temporal summation of pain.

Methods

One hundred patients aged 19–60 years underwent gynecologic laparoscopic surgery. Patients were randomly assigned to one of the two groups: group PRi received immediate injections of rocuronium after propofol administration and group PRd received rocuronium injections when the bispectral index score (BIS) decreased to <60 after propofol administration. The grade of rocuronium-induced withdrawal movement (RIWM) according to the timing of propofol injection, the incidence and severity of propofol injection pain (PIP), rescue analgesics, visual analog scale (VAS) score after surgery for postoperative pain, patient-controlled analgesia (PCA) opioid consumption, association between PIP and the grade of RIWM, and associations between PIP, the grade of RIWM, and postoperative pain outcomes were measured.

Results

The differences between the incidence and severity of PIP in the two groups were not significant. The grade of the RIWM in the PRd group was significantly reduced compared with the PRi group. Rescue analgesics, severity for postoperative pain, and PCA opioid consumption were not significant. Correlations between the incidence and severity of PIP and the grade of RIWM were weakly negative. Correlations between the grade of RIWM and pain outcomes were moderately positive, but correlations between the severity for PIP and the postoperative pain outcomes were negligible.

Conclusion

The timing of rocuronium administration after propofol injection played a role in reducing RIWM. The grade of RIWM was significantly related to pain outcomes compared with the severity of PIP. Therefore, delayed rocuronium injection after induction with propofol reduced temporal summation of pain.

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.

A Prospective Evaluation of Postoperative Opioid Use in Otologic Surgery

OBJECTIVE

To prospectively evaluate opioid consumption following adult outpatient otologic surgery.

STUDY DESIGN

Prospective observational.

SETTING

Single-tertiary referral center.

PATIENTS

Patients scheduled for otologic surgery who did not have a history of chronic opioid use were recruited between February 2018 and February 2019.

INTERVENTIONS AND MAIN OUTCOME MEASURES

Opioid consumption was queried using telephone or in-person surveys administered between postoperative days 5 and 15. Patient demographics, surgical details, and opioid prescription patterns were abstracted from medical records. Opioid distribution was determined by querying records maintained by the California Department of Justice through a state-wide prescription drug monitoring program mandated since 2016.

RESULTS

Seventy patients were prescribed an average of 68.9 ± 31.8 mg of morphine equivalents (MME) and consumed 47.3 ± 42.9 MME over 2.4 ± 2.3 days postoperatively. Patients who received a postauricular incision were prescribed significantly more than those who underwent transcanal procedures (86.2 vs 55.9 MME; t test, p < 0.001), consumed significantly more (72.2 vs 28.6 MME; t test, p < 0.001), and for a significantly longer duration (3.4 vs 1.6 days; t test, p = 0.001). In the postauricular group, there was no significant difference in consumption between mastoidectomy and nonmastoidectomy subgroups (64.9 vs 89.2 MME; t test, p = 0.151). Eighty percent of transcanal patients consumed 50 MME (10 pills) or less, while 80% of postauricular patients consumed 80 MME (16 pills) or less.

CONCLUSIONS

Patients in our cohort consumed approximately 3/4 of the prescribed opioids. Those with postauricular incisions used significantly more than those with transcanal incisions. Postoperative opioid prescription recommendations should be tailored according to the extent of surgery.

Qualitative sex differences in pain processing: emerging evidence of a biased literature

Although most patients with chronic pain are women, the preclinical literature regarding pain processing and the pathophysiology of chronic pain has historically been derived overwhelmingly from the study of male rodents. This Review describes how the recent adoption by a number of funding agencies of policies mandating the incorporation of sex as a biological variable into preclinical research has correlated with an increase in the number of studies investigating sex differences in pain and analgesia. Trends in the field are analysed, with a focus on newly published findings of qualitative sex differences: that is, those findings that are suggestive of differential processing mechanisms in each sex. It is becoming increasingly clear that robust differences exist in the genetic, molecular, cellular and systems-level mechanisms of acute and chronic pain processing in male and female rodents and humans.

Sex Comparisons in Opioid Use and Pain After Colorectal Surgery Using Enhanced Recovery Protocols

BACKGROUND

Differences in nociception and use of opioids between sexes are of particular interest, considering higher rates of persistent opioid use among women after surgery. Although enhanced recovery protocols (ERPs) have improved postoperative pain control in colorectal surgery, sex-based comparisons of inpatient opioid use after surgery in an ERP remain understudied.

METHODS

This retrospective study analyzed data from adults after colorectal surgery using an ERP at a single hospital between 2015 and 2017. The main outcome was the rate of opioid consumption measured as oral morphine equivalents per inpatient day. Poisson regression determined association between sex and opioid consumption, accounting for early discharge, using inverse probability weighting and adjusting for covariates that retained significance on univariate analysis. Linear regression assessed the association between sex and pain scores on postoperative days 0-5 adjusting for covariates.

RESULTS

Of 588 patients included, 43% were men and 57% were women. In the unadjusted model, malignancy, prehospital psychiatric medication and analgesic use, tobacco, ileostomy creation, operative time, and postoperative complications were associated with increased opioid consumption. In multivariate analyses, prehospital opioid and nonopioid analgesic use, operative time, anastomotic leak, and postoperative ileus remained significantly associated with increased inpatient opioid consumption. However, there was no significant association between sex and opioid use in crude or adjusted analysis (incidence rate ratio: 1.09; 95% confidence interval: 0.90, 1.32). Women reported higher average daily pain scores (coefficient: 0.29; 95% confidence interval: 0.04, 0.55) in adjusted analyses.

CONCLUSIONS

Among patients undergoing colorectal surgery using an ERP, sex-based differences exist in pain scores but not early postoperative opioid consumption. Identification of intragroup differences in postoperative pain and opioid use among patients managed with an ERP serves as targets for customization and enhancement of current protocols. Furthermore, incongruence between reported pain and analgesic administration may have important implications for sex-related differences in persistent opioid use.

Sex difference in synaptic plasticity in the anterior cingulate cortex of adult mice

Sex differences in certain types of pain sensitivity and emotional responses have been previously reported. Synaptic plasticity is a key cellular mechanism for pain perception and emotional regulation, including long-term potentiation (LTP) and long-term depression (LTD). However, it is unclear whether there is a sex difference at synaptic level. Recent studies indicate that excitatory transmission and plasticity in the anterior cingulate cortex (ACC) are critical in chronic pain and pain related emotional responses. In the present study, we used 64-channel multielectrode (MED64) system to record synaptic plasticity in the ACC of male and female adult mice. We found that there was no significant difference in theta-burst stimulation (TBS)-induced LTP between female and male mice. Furthermore, the recruitment of inactive channels was also not different. For LTD, we found that LTD was greater in slices of ACC in male mice than female mice. Our results demonstrate that LTP in the ACC does not show any sex-related difference.

Is There Gender Discrimination in Acute Renal Colic Pain Management? A Retrospective Analysis in an Emergency Department Setting

BACKGROUND

Pain is a widespread problem, affecting both men and women; studies have found that women in the emergency department receive analgesic medication and opioids less often compared with men.

AIMS

The aim of this study was to examine the administration and management of analgesics by the medical/paramedical staff in relation to the patients' gender, and thereby to examine the extent of gender discrimination in treating pain.

DESIGN

This is a single-center retrospective cohort study that included 824 patients.

SETTINGS

Emergency department of tertiary hospital in Israel.

PARTICIPANTS/SUBJECTS

The patients stratified by gender to compare pain treatments and waiting times between men and women in renal colic complaint.

METHODS

As an acute pain model, we used renal colic with a nephrolithiasis diagnosis confirmed by imaging. We recorded pain level by Visual Analog Scale (VAS) scores and number of VAS examinations. Time intervals were calculated between admissions to different stations in the emergency department. We recorded the number of analgesic drugs administered, type of drugs prescribed, and drug class (opioids or others).

RESULTS

A total of 824 patients (414 women and 410 men) participated. There were no significant differences in age, ethnicity, and laboratory findings. VAS assessments were higher in men than in women (6.43 versus 5.90, p = .001, respectively). More men than women received analgesics (68.8% versus 62.1%, p = .04, respectively) and opioids were prescribed more often for men than for women (48.3 versus 35.7%, p = .001). The number of drugs prescribed per patient was also higher in men compared with women (1.06 versus 0.93, p = .03). A significant difference was found in waiting time length from admission to medical examination between non-Jewish women and Jewish women.

CONCLUSIONS

We found differences in pain management between genders, which could be interpreted as gender discrimination. Yet these differences could also be attributed to other factors not based on gender discrimination but rather on gender differences.

Quality of postoperative pain management in Ethiopia: A prospective longitudinal study

Background

The annual number of surgical operations performed is increasing throughout the world. With this rise in the number of surgeries performed, so too, the challenge of effectively managing postoperative pain. In Africa, there are scanty data available that make use of multi-center data to characterize the quality of postoperative pain management. In this study using a longitudinal data, we have attempted to characterize the quality of postoperative pain management; among patients scheduled for major elective orthopedic, gynecologic and general surgery.

Methods

This prospective longitudinal study evaluated the quality of postoperative pain management in patients undergoing elective general, gynecologic, and orthopedic surgery. We quantified the prevalence of moderate to severe postoperative pain with the International Pain Outcome Questionnaire and the corresponding adequacy of treatment with the pain management index. At four time points after surgery, we estimated pain severity, its physical and emotional interference, and patient satisfaction.

Results

Moderate to severe postoperative pain was present in 88.2% of patients, and pain was inadequately treated in 58.4% of these patients. Chronic pain (β = 0.346, 95% CI: 0.212, 0.480) predicted patients’ worst pain intensity. Gender was not associated with the worst pain intensity or percentage of time spent in severe pain. Patient’s pain intensity did not predicted the level of satisfaction.

Conclusions

The prevalence of moderate to severe postoperative pain and its functional interference is high in Ethiopian patients. The treatment provided to patients is inadequate and not in line with international recommendations and standards.

Preoperative predictors of poor acute postoperative pain control: a systematic review and meta-analysis

OBJECTIVES

Inadequate postoperative pain control is common and is associated with poor clinical outcomes. This study aimed to identify preoperative predictors of poor postoperative pain control in adults undergoing inpatient surgery.

DESIGN

Systematic review and meta-analysis DATA SOURCES: MEDLINE, Embase, CINAHL and PsycINFO were searched through October 2017.

ELIGIBILITY CRITERIA

Studies in any language were included if they evaluated postoperative pain using a validated instrument in adults (≥18 years) and reported a measure of association between poor postoperative pain control (defined by study authors) and at least one preoperative predictor during the hospital stay.

DATA EXTRACTION AND SYNTHESIS

Two reviewers screened articles, extracted data and assessed study quality. Measures of association for each preoperative predictor were pooled using random effects models.

RESULTS

Thirty-three studies representing 53 362 patients were included in this review. Significant preoperative predictors of poor postoperative pain control included younger age (OR 1.18 [95% CI 1.05 to 1.32], number of studies, n=14), female sex (OR 1.29 [95% CI 1.17 to 1.43], n=20), smoking (OR 1.33 [95% CI 1.09 to 1.61], n=9), history of depressive symptoms (OR 1.71 [95% CI 1.32 to 2.22], n=8), history of anxiety symptoms (OR 1.22 [95% CI 1.09 to 1.36], n=10), sleep difficulties (OR 2.32 [95% CI 1.46 to 3.69], n=2), higher body mass index (OR 1.02 [95% CI 1.01 to 1.03], n=2), presence of preoperative pain (OR 1.21 [95% CI 1.10 to 1.32], n=13) and use of preoperative analgesia (OR 1.54 [95% CI 1.18 to 2.03], n=6). Pain catastrophising, American Society of Anesthesiologists status, chronic pain, marital status, socioeconomic status, education, surgical history, preoperative pressure pain tolerance and orthopaedic surgery (vs abdominal surgery) were not associated with increased odds of poor pain control. Study quality was generally high, although appropriate blinding of predictor during outcome ascertainment was often limited.

CONCLUSIONS

Nine predictors of poor postoperative pain control were identified. These should be recognised as potentially important factors when developing discipline-specific clinical care pathways to improve pain outcomes and to guide future surgical pain research.

PROSPERO REGISTRATION NUMBER

CRD42017080682.

High-fat diet exacerbates postoperative pain and inflammation in a sex-dependent manner

Obesity is often associated with increased pain, but little is known about the effects of obesity and diet on postoperative pain. In this study, effects of diet and obesity were examined in the paw incision model, a preclinical model of postoperative pain. Long-Evans rats were fed high-fat diet (40% calories from butter fat) or low-fat normal chow. Male rats fed high-fat diet starting 6 weeks before incision (a diet previously shown to induce markers of obesity) had prolonged mechanical hypersensitivity and an overall increase in spontaneous pain in response to paw incision, compared with normal chow controls. Diet effects in females were minor. Removing high-fat diet for 2 weeks before incision reversed the diet effects on pain behaviors, although this was not enough time to reverse high-fat diet-induced weight gain. A shorter (1 week) exposure to high-fat diet before incision also increased pain behaviors in males, albeit to a lesser degree. The 6-week high-fat diet increased macrophage density as examined immunohistochemically in lumbar dorsal root ganglion even before paw incision, especially in males, and sensitized responses of peritoneal macrophages to lipopolysaccharide stimuli in vitro. The nerve regeneration marker growth-associated protein 43 (GAP43) in skin near the incision (day 4) was higher in the high-fat diet group, and wound healing was delayed. In summary, high-fat diet increased postoperative pain particularly in males, but some diet effects did not depend on weight gain. Even short-term dietary manipulations, that do not affect obesity, may enhance postoperative pain.

Hypertension and Postoperative Pain: A Prospective Observational Study

Objectives

The relationship between pain and hypertension is of great pathophysiological and clinical interest in the pain field, but the mechanism is poorly understood. This study used the postoperative patient-controlled analgesia (PCA) dose and the visual analysis scale (VAS) score to assess the relationship between pain and hypertension.

Methods

In this prospective study in a single-center hospital, 200 participants were enrolled and divided into three groups: normotensive group, hypertension without treatment group, and hypertension with treatment group. The participants scheduled for elective inhalational general anesthesia were interviewed at hospital admission.

Results

A significant difference was observed in analgesic dosage on postoperative days 1, 2, and 3 between the female normotensive group and female hypertension with treatment group (independent-samples, one-way analysis of covariance, age, and weight as covariates:P=0.021, 0.014, 0.032). No significant differences in the VAS scores and PCA dosages were observed between the male normotensive group and any one of the male hypertensive groups.

Conclusion

We agree that hypertensive hypoanalgesia exists in some experimental settings. The mechanism linking postoperative pain and hypertension is far more complex than we initially believed. Therefore, more studies are required to investigate the roles that antihypertensive drugs, sex, and psychological stress play. Antihypertensive drugs may play a crucial role in mediating the relationship between pain and hypertension. Psychosocial factors were discussed but were not examined.

Orthopedic Professionals' Recognition and Knowledge of Pain and Perceived Barriers to Optimal Pain Management at Five Hospitals

Pain is a challenge for orthopedic healthcare professionals (OHCP). However, pain studies examined the competencies of a single OHCP category, did not consider various pain management domains or barriers to optimal pain service, and are deficient across the Arabic Eastern Mediterranean region. We surveyed OHCP's recognition and knowledge of pain and perceived barriers to optimal pain service (361 OHCP, five hospitals). Chi square compared doctors' (n = 63) vs. nurses/physiotherapists' (n = 187) views. In terms of pain recognition, more nurses had pain management training, confidently assessed pediatric/elderly pain, were aware of their departments' pain protocols, and felt that their patients receive proper pain management. More doctors comfortably prescribed opiate medications and agreed that some nationalities were more sensitive to pain. For pain knowledge, more nurses felt patients are accurate in assessing their pain, vital signs are accurate in assessing children's pain, children feel less pain because of nervous system immaturity, narcotics are not preferred due respiratory depression, and knew pre-emptive analgesia. As for barriers to optimal pain service, less nurses agreed about the lack of local policies/guidelines, knowledge, and skills; time to pre-medicate patients; knowledge about medications; complexity of the clinical environment; and physicians being not comfortable prescribing pain medication. We conclude that doctors required confidence in pain, especially pediatric and geriatric pain, using vital signs in assessing pain and narcotics use. Their most perceived barriers were lack of local policies/guidelines and skills. Nurses required more confidence in medications, caring for patients on narcotics, expressed fewer barriers than doctors, and the complexity of the clinical environment was their highest barrier. Educational programs with clinical application could improve OHCPs' pain competencies/clinical practices in pain assessment and administration of analgesics.