Pain perception: predictive value of sex, depression, anxiety, somatosensory amplification, obesity, and age

Association between psychological traits and occlusal tactile acuity of healthy individuals

OBJECTIVES

Tactile acuity is a somatosensory measure of the extent to which humans can discern tactile stimuli. It is influenced by how peripheral signals are processed centrally. In the oral cavity, Occlusal Tactile Acuity (OTA) is the ability to perceive minimal thicknesses between antagonist teeth. The aim of the current study was to assess the association between psychological traits and OTA of otherwise healthy individuals.

METHODS

Sixty-three volunteers (32 males; mean age ± SD: 24.6 ± 2.7 years) participated in this study. Somatosensory amplification, anxiety, depression, physical symptoms and pain catastrophizing were scored using questionnaires, and subgroups of severity were created per variable based on cut-offs. OTA was measured using 9 aluminium foils with thickness (ranging from 8 to 72 μm) and one sham test (without foil). Each thickness was tested 10 times in random order, the participants were instructed to report whether they felt the foil between their molars and the mean percentage of correct answers was computed. A linear mixed model was used with OTA as a dependent variable and psychological domain as an independent variable.

RESULTS

Significantly different OTA was observed among the anxiety subgroups (p = .003), supporting a decreased perception of thicknesses 24 and 32 μm (p = .018 and p < .001, respectively) in participants with moderate/severe anxiety compared to those with no/mild anxiety. Significantly different OTA was also observed among the pain catastrophizing subgroups (p = .008), showing decreased perception of thicknesses 32 and 40 μm (p < .001 and p = .007, respectively) in severe catastrophizing levels, compared to no/mild catastrophizing levels. No significant differences were observed for the other variables.

CONCLUSIONS

Healthy adults with increased anxiety or pain catastrophizing levels show decreased interdental acuity as compared to participants with minor or no psychological impairment.

Subjective cognitive concerns not related to objective impairment in patients with somatic symptom and related disorders

OBJECTIVES

Patients with Somatic Symptom and Related Disorders (SSRD) report subjective cognitive concerns, and research indicates that they show objective cognitive impairment. This study explored the value of subjective concerns flagging objective impairment. Furthermore, we investigated whether coping moderated this relationship, and the role of depressive symptomatology.

METHOD

In a cross-sectional design, objective impairment was measured with an extensive neuropsychological assessment; subjective concerns with the Cognitive Failure Questionnaire; coping styles with the Coping Inventory of Stressful Situations; and symptoms of depression with the Patient Health Questionnaire- 9.

RESULTS

The results show that subjective concerns are of limited value in signaling objective impairment in patients with SSRD. Regression analyses performed on data from 225 patients showed that symptoms of depression (β = .32) were the main predictor of subjective concerns, which were unrelated to objective impairment. Coping was not a moderator, but patients with emotion-oriented coping styles had more subjective concerns (β=.40), and conversely, patients with avoidance- and/or task-oriented coping styles had less (respectively, β=-.27 and β=-.24).

CONCLUSIONS

These results align with the Somatosensory Amplification Theory; patients with SSRD may amplify benign cognitive failures and experience them as intrusive, noxious, and more intense. In patients with SSRD, subjective cognitive concerns are more related to psychological constructs (symptoms of depression and coping styles) than to objective impairment.

Effect of injection pain and withdrawal movement of propofol and rocuronium in the induction of anaesthesia on postoperative pain outcomes in gynaecological laparoscopic surgery: a prospective observational study

INTRODUCTION

The experience and perception of pain may vary among individuals.This prospective cohort study aimed to determine the impact of injection pain/withdrawal movement of propofol and rocuronium in the induction of anaesthesia on postoperative pain outcomes in gynaecological laparoscopic surgery.

METHODS

A total of 100 patients aged 19-60 years received propofol and rocuronium injections for the induction of anaesthesia. The incidence of propofol injection pain (PIP) and rocuronium-induced withdrawal movement (RIWM), postoperative pain scores and total opioid consumption were evaluated, and the associations between PIP/RIWM and postoperative pain outcomes were determined.

RESULTS

Visual analogue scale (VAS) for pain after surgery and total opioid consumption after surgery were significantly higher in patients with PIP or RIWM than in patients without PIP or RIWM. The correlations of PIP/RIWM with VAS at 1 h, VAS at 24 h and total opioid consumption were significant and weakly positive ( r = 0.249, r = 0.234, r = 0.22 and r = 0.234, respectively). The RIWM correlated more positively with pain score compared to PIP at 1 h ( r = 0.408 vs. r = 0.234), PIP at 24 h ( r = 0.398 vs. r = 0.227) and with total opioid consumption for 48 h after surgery ( r = 0.457 vs. r = 0.234).

CONCLUSION

During anaesthesia induction, the occurrence of PIP and RIWM may predict the severity of postoperative pain and total opioid consumption, with RIWM emerging as a stronger predictor than PIP.

Patient satisfaction and patient accessibility in a small fiber neuropathy diagnostic service in the Netherlands: A single-center, prospective, survey-based cohort study

INTRODUCTION

Small fiber neuropathy (SFN) is a common cause of neuropathic pain in peripheral neuropathies. Good accessibility of diagnostics and treatment is necessary for an accurate diagnosis and treatment of SFN. Evidence is lacking on the quality performance of the diagnostic SFN service in the Netherlands. Our aim was to determine the patient satisfaction and -accessibility of the diagnostic SFN service, and to identify areas for improvement.

METHODS

In a single-center, prospective, survey-based cohort study, 100 visiting patients were asked to fill in the SFN patient satisfaction questionnaire (SFN-PSQ), with 10 domains and 51 items. Cut-off point for improvement was defined as ≥ 25% dissatisfaction on an item. A chi-square test and linear regression analyses was used for significant differences and associations of patient satisfaction.

RESULTS

From November 2020 to May 2021, 98 patients with SFN-related complaints filled in the online SFN-PSQ within 20 minutes. In 84% of the patients SFN was confirmed, average age was 55.1 (52.5-57.8) years and 67% was female. High satisfaction was seen in the domains 'Waiting List Period', Chest X-ray', 'Consultation with the Doctor or Nurse Practitioner (NP)', 'Separate Consultation with the Doctor or NP about Psychological Symptoms', and 'General' of the SFN service. Overall average patient satisfaction score was 8.7 (IQR 8-10) on a 1-to-10 rating scale. Main area for improvement was shortening the 8-week period for receiving the results of the diagnostic testing (p < 0.05). General health status was statistically significant associated with patient satisfaction (p < 0.05).

CONCLUSION

A good reflection of the high patient satisfaction and -accessibility of the SFN-service is shown, with important points for improvement. These results could help hospitals widely to optimize the logistic and diagnostic pathway of SFN analysis, benchmarking patient satisfaction results among the hospitals, and to improve the quality of care of comparable SFN services.

Prospective paired crossover evaluation of potential impact of investigator gender on perceived pain intensity early after acute or scheduled surgery

BACKGROUND

Postoperative pain is common but often difficult to assess, and there are many potential confounders. Over the last decades, the gender of investigator as well as participant has been found to influence pain perception in both preclinical and clinical studies. However, to our knowledge this has not been studied in various postoperative patients. Objectives of this study were to test the hypotheses that pain intensity levels early after acute or scheduled in- or out-hospital surgery are lower when evaluated by a female investigator, and higher when reported by a female patient.

METHODS

In this prospective observational paired crossover study, two investigators of opposite genders independently obtained individually reported pain intensity levels with a visual analogue scale in a mixed cohort of adult postoperative study patients at Skåne University Hospital in Malmö, Sweden.

RESULTS

In total, 245 (129 female) study patients were included and then one female excluded. The study patients rated their intensity of postoperative pain lower when evaluated by a female than by a male investigator (P = 0.006), where the male patients constituted the significant difference (P < 0.001). Pain intensity levels did not differ between female and male study patients (P = 0.210).

CONCLUSIONS

Main findings of lower pain intensity reported by males to a female than to a male investigator early after surgery in this paired crossover study in mixed postoperative patients, indicate that potential impact of investigator gender on pain perception should be considered and further evaluated in clinical bedside practice. Trial registration Retrospectively registered in the ClinicalTrials.gov research database on 24th June 2019 with TRN number NCT03968497.

Personality factors and cognitive functioning in patients with somatic symptom and related disorders

OBJECTIVE

Somatic symptom and related disorders (SSRD) are often complicated by cognitive symptoms, including reduced information processing speed, memory, and planning. Depression has been related to poor cognitive functioning in SSRD, but the role of underlying personality factors is poorly understood. This study investigates the association between personality factors (neuroticism, extraversion, openness, agreeableness, and conscientiousness) with cognitive functioning in patients with SSRD.

METHODS

Data from 366 patients with SSRD from a tertiary care expert center (mean age = 42.1 years (SD = 13.4), 59.6% women) were analyzed using a cross-sectional design. Neuropsychological assessments included measures of information processing speed, memory, attention, and executive function. Personality factors were assessed using the NEO-FFI and depressive symptoms using the PHQ-9.

RESULTS

Regression analyses showed associations between neuroticism with poorer performance on visual memory (B = -0.09, SE = 0.04, β = -0.14, p = .019), and planning (B = -0.09. SE = 0.02, β = -0.23, p < .001). Extraversion was also inversely associated with visual memory (B = -0.13, SE = 0.05, β = -0.18, p = .011) and planning (B = -0.07, SE = 0.03, β = -0.17, p = .021) and openness was associated with better visual memory (B = 0.17, SE = 0.05, β = 0.19, p = .002). These associations were attenuated but remained significant after adjusting for depressive symptoms.

CONCLUSION

Neuroticism, extraversion, and low openness were associated with lower cognitive functioning (particularly planning and visual memory) in patients with SSRD, which remained significant after taking depressive symptoms into account.

Protective and Risk Factors at the Intersection of Chronic Pain, Depression, Anxiety, and Somatic Amplification: A Latent Profile Approach

Objective

Research indicates a complex nexus between chronic pain, depression, anxiety, and somatic amplification (PDAS) symptoms, marked by high rates of co-morbidity and mutually maintaining mechanisms. Although recent frameworks have attempted to explain co-occurrence rates of pain and other comorbid disorders, the interrelations between PDAS and their impacts on pain outcomes have not been adequately examined with a person-centered approach. Using nationally representative data, this study assessed the heterogeneity in PDAS symptomatology and examined links among risk and protective factors in different profiles.

Methods

Data were derived from 1027 participants in the National Survey of Midlife Development in the United States (MIDUS) who completed telephone interviews or self-report measures that assessed PDAS, various sources of social supports (family, friends, spouses/partners, religion, coworkers, and supervisors), and the number of healthcare visits.

Results

We found heterogeneity in symptom severity rather than symptom type across classes over time. Regardless of comorbidity severity, people reported similar levels of somatic symptoms, which may help clinicians more effectively diagnose comorbidity issues among chronic pain patients. As PDAS symptomatology increased by group, the perceived levels of social support decreased. Membership in a higher symptom severity class was associated with being female, younger age, and an increase in medical, but not mental health visits.

Limitations

Limitations included the use of a cross-sectional design, reliance on self-report measures, and a sample largely comprised of Whites.

Conclusion

PDAS co-occurs across classes, which may relate to shared risk and protective factors. This study lays the foundation to investigate similar questions for overlapping symptoms that occur during the same period, which would shed light on whether—among middle to older age adults—these disorders are attributable to a common mechanism and if they may inform transdiagnostic treatments.

Diferenças de sexo e idade no limiar sensitivo para estimulação elétrica transcutânea

Resumo Introdução A dor é um dos principais sintomas preva-lentes na maioria das patologias. A estimulação elétrica ervosa transcutânea (TENS) se apresenta não apenas como medida terapêutica, como também um meio de quantificar a percepção neurossensitiva e dolorosa em pacientes com dores crônicas. Objetivo Avaliar a relação entre sexo e idade com os limiares neurossensitivos (limiar sensitivo e limiar de tolerância) na aplicação da corrente terapêutica TENS, em pacientes com dores crônicas. Métodos Foram selecionados 45 pacientes com dores crônicas (30 mulheres), com idade entre 24 e 87 anos. Cada paciente respondeu ao Questionário Individual, ao Questionário McGill de Dor (MPQ) e ao Inventário de Depressão de Beck (BDI). Posteriormente, aplicou-se a corrente elétrica TENS, pela qual foram analisados o limiar sensitivo e doloroso, bem como a percepção de acionamento das vias neurossensitivas para cada indivíduo. Os dados foram analisados pelo pacote SPSS 24.0 for Windows. Resultados Não houve correlação significativa (p > 0,05) entre possível diagnós-tico depressivo e a percepção da corrente pelos limiares de sensibilidade e dor. Em relação ao sexo, houve diferença significativa nos limiares sensitivos (p = 0,003) entre homens e mulheres. Já para a queixa de dor e limiar de dor, não foram observadas diferenças estatísticas entre os sexos (p > 0,05). Para as análises correlacionais, identificou-se correlação significativa (p = 0,05) entre as variáveis de índice de massa corporal e limiar de tolerância à dor (r = 0,68) para o sexo feminino e idade e limiar sensitivo (r = 0,65) paro o sexo masculino. Conclusão As diferenças identificadas entre os limiares de sensibilidade entre os sexos, onde as mulheres identificaram o estímulo elétrico significativamente primeiro que os homens, podem auxiliar nas doses de intensidade ou tipo de corrente terapêutica dos pacientes.

The Temporal Modulation of Nocebo Hyperalgesia in a Model of Sustained Pain

BACKGROUND

The direction and the magnitude of verbal suggestions have been shown to be strong modulators of nocebo hyperalgesia, while little attention has been given to the role of their temporal content. Here, we investigate whether temporal suggestions modulate the timing of nocebo hyperalgesia in an experimental model of sustained pain.

METHODS

Fifty-one healthy participants were allocated to one of three groups. Participants received an inert cream and were instructed that the agent had either hyperalgesic properties setting in after 5 (Nocebo 5, N5) or 30 (Nocebo 30, N30) minutes from cream application, or hydrating properties (No Expectation Group, NE). Pain was induced by the Cold Pressure Test (CPT) which was repeated before cream application (baseline) and after 10 (Test10) and 35 (Test35) minutes. Changes in pain tolerance and in HR at each test point in respect to baseline were compared between the three groups.

RESULTS

Tolerance change at Test 10 (Δ10) was greater in N5 (MED = -36.8; IQR = 20.9) compared to NE (MED = -5.3; IQR = 22.4; p < 0.001) and N30 (MED = 0.0; IQR = 23.1; p < 0.001), showing that hyperalgesia was only present in the group that expected the effect of the cream to set in early. Tolerance change at Test 35 (Δ35) was greater in N5 (MED = -36.3; IQR = 35.3; p = 0.002) and in N30 (MED = -33.3; IQR = 34.8; p = 0.009) compared to NE, indicating delayed onset of hyperalgesia in N30, and sustained hyperalgesia in N5. No group differences were found for HR.

CONCLUSIONS

Our study demonstrated that temporal expectations shift nocebo response onset in a model of sustained pain.

How Anxiety Our Adult Patients Before Venepuncture Procedure: A Study in UiTM Medical Centre Sungai Buloh (UiTMMC)

Background: Venepuncture is one of the commonest stressful invasive procedures in the health care setting. Unfortunately, to date, there was a lack of locally published studies that studied anxiety, especially before the procedure among adult patients. Hence, this study was conducted to determine the factors associated with the state and trait-anxiety among adult patients before the venepuncture procedure in UiTMMC. Methods: A cross-sectional pilot study was conducted among patients while waiting for a venepuncture procedure in March 2020. Patients aged 18 years old and above, Malaysian, able to understand English or Malay and had experienced venepuncture in UiTMMC were recruited. Malay validated version of the State-Trait-Anxiety-Inventory (STAI) Questionnaire was used to assess the anxiety level. Data were analysed using IBM SPSS Version 26.0, and multiple linear regression was used to determine the associated factors for state and trait-anxiety before the venepuncture procedure. Results: A total of 330 patients with a mean age of 46.34 ± 14.34 years participated in this study. The mean of the state-anxiety score was 38.02 ± 14.25 and the mean trait-anxiety score was 36.46 ± 11.47. The correlation between state-anxiety and trait-anxiety scores was highly significant (r=0.870, p<0.001). Factors associated with state-anxiety and trait-anxiety contributed with 72.6% and 58.5% variances, respectively. Conclusions: Adult patients who waiting for venepuncture in were average low state and trait anxiety scores. Although the associated factors were majority non-modifiable, this finding still can instil awareness to the health care workers who are dealing with needle procedurals.

Sex and age differences in sensory threshold for transcutaneous electrical stimulation

Abstract Introduction Pain is one of the main symptoms prevalent in most pathologies. Transcutaneous Electrical Nerve Stimulation (TENS) represents not only a therapeutic measure, but also a mean to quantify the neurosensory and pain perception in patients with chronic pain. Objective To evaluate the relationship between sex and age with neurosensory thresholds (sensory threshold and tolerance threshold) in the application of therapeutic current in patients with chronic pain. Methods Forty-five patients with chronic pain (30 women and 15 men) aged between 24 and 87 years were selected. Each patient answered the Individual Questionnaire, McGill Pain Questionnaire (MPQ) and Beck Depression Inventory (BDI). Subsequently, the electric current was applied, through which the sensory and pain thresholds were analyzed, as well as the perception of activation of the neurosensory pathways for each individual. Data were analyzed using the SPSS 24.0 for Windows. Results There was no significant correlation (p > 0.05) between a possible depressive diagnosis and the perception of current by the sensory and pain thresholds. Regarding sex, there was a significant difference in sensory thresholds (p = 0.003) between men and women, while no statistical differences were observed between sexes for pain complaint and pain threshold (p > 0.05). For the correlational analysis, a significant correlation (p = 0.05) was identified between the variables BMI and pain tolerance threshold (r = 0.68) for females and age and sensory threshold (r = 0.65) for males. Conclusion The sex and age variables are important in the measurement of TENS parameters because they lead to significant differences in sensory and pain thresholds.

Clinical and psychological factors in coronary heart disease patients with statin associated muscle side-effects

Background

To compare clinical and psychological factors among patients with self-perceived statin-associated muscle symptoms (SAMS), confirmed SAMS, and refuted SAMS in coronary heart disease patients (CHD).

Methods

Data were obtained from a cross-sectional study of 1100 CHD outpatients and a study of 71 CHD outpatients attending a randomized, double-blinded, placebo-controlled, crossover study to test effects of atorvastatin 40 mg/day on muscle symptom intensity. Clinical and psychosocial factors were compared between patients with and without SAMS in the cross-sectional study, and between patients with confirmed SAMS and refuted SAMS in the randomized study.

Results

Bilateral, symmetric muscle symptoms in the lower extremities during statin treatment were more prevalent in patients with confirmed SAMS compared to patients with refuted SAMS (75% vs. 41%, p = 0.01) in the randomized study. No significant differences in psychological factors (anxiety, depression, worry, insomnia, type D personality characteristics) were detected between patients with and without self-perceived SAMS in the cross-sectional study, or between patients with confirmed SAMS and refuted SAMS, in the randomized study.

Conclusions

Patients with confirmed SAMS more often present with bilateral lower muscle symptoms compared to those with refuted SAMS. Psychological factors were not associated with self-perceived SAMS or confirmed SAMS. A careful pain history and a search for alternative causes of muscle symptoms are likely to promote communication in patients with SAMS, and may reduce the risk for statin discontinuation.

Randomized cross-over evaluation of investigator gender on pain thresholds in healthy volunteers

Background and aims: This randomized cross-over study in healthy volunteers was designed primarily to evaluate the potential impact of investigator gender on electrical pain threshold (EPT) and corresponding pain intensity levels, and secondly to evaluate potential differences in those interventions between female and male study participants. Methods: Forty adult volunteers (22 females) were included. An electrical stimulation device was used to determine EPT levels (in pain magnitude scores) in series of three in each study participant - once by a female, and once by a male investigator - according to a predefined cross-over design schedule. Corresponding levels of pain intensity were scored on a visual analog scale (VAS) slide ruler. Results: Study data was obtained and analysed in all participants. Significantly higher EPT levels were determined by the female investigator compared with the male investigator (median 22 (IQR 12-31) vs. 8 (6-10) pain magnitude scores; p<0.0001), despite similar levels of reported pain intensity (1.9 (1.2-3.0) vs. 2.0 (1.1-3.4) VAS units; p>0.300). There were no differences in EPT levels between female and male subjects evaluated by female (p>0.300) and male (p=0.125) investigators, or between the first and second series of stimulation (p>0.300). Conclusions: Our finding of significantly higher EPT levels when study participants of both genders - despite no difference in reported pain intensity - were evaluated by a female than by a male investigator, indicates a potential impact of investigator gender on the individual perception of pain. Implications: By contributing to a better understanding of how individual pain threshold levels are potentially influenced by investigator gender, this study might facilitate future evaluation of pain conditions in both preclinical and clinical settings.

Chronic Pain and Mood Disorders in Asian Americans

Purpose: Pain and mood disorder frequently coexist. Yet, for Asian Americans (AAs), scant information about pain and mood disorder is available. Our aims were to compare (1) the rates of pain and mood disorders and (2) the magnitude of associations between pain and mood disorders between AAs and European Americans (EAs), and across different Asian subgroups. Methods: An analytical data was constructed from the Collaborative Psychiatric Epidemiology Studies (CPES), a representative sample of community-residing U.S. adults (n = 9,871). Pain morbidity was assessed by self-report. Mood disorders, including major depression and anxiety disorders, were assessed using the diagnostic interview. Analysis included descriptive statistics and multivariate logistic regression modeling. All analyses were weighted to approximate the U.S. populations, and controlled for sociodemographic and immigration characteristics. Results: Greater proportion of EAs, compared to AAs, endorsed lifetime pain (56.8% vs. 35.8%). Having life pain disorders elevated the likelihood of lifetime mood disorder by more than 2-folds (weight adjusted odds ratio (WAOR): 2.12, 95% CI: 1.77, 2.55). Having pain disorders over the past 12 months elevated the likelihood of mood disorder in the same time period by more than 3-folds (WAOR: 3.29, 95% CI: 2.02, 5.37) among AAs. The magnitude of the association between pain and psychiatric morbidity were greater in Vietnamese Americans compared to other AAs and EAs. Discussion: The conventional belief that rates of pain and mood disorders are greater in AAs than EAs may need to be further examined. Vietnamese Americans may be particularly vulnerable for experience of comorbid pain and mood disorders.

Office hysteroscopy in pre- and post-menopausal women: a predictive model

OBJECTIVES

To assess the variables associated with success of office hysteroscopy (OH) in pre-menopausal and post-menopausal women and to develop a clinical model for predicting the outcome of OH.

METHODS

This is a retrospective cohort study of consecutive patients (n = 3181) referred for an OH to a tertiary care university hospital between January 2018 and March 2020. Multivariate logistic regression analysis was used to investigate the variables for predicting the success of OH in all patients and in pre-menopausal and in post-menopausal patients separately. The logistic regression analysis of each variable was applied to develop a predictive model.

RESULTS

The overall success rate of the procedure was 92.2%; 95.4% in pre-menopausal women and 87.6% in post-menopausal women. In the general population, independent predictors of procedure success were previous vaginally delivery and hysteroscopy, while previous cervical or uterine surgery were associated with incomplete OH. In the pre-menopausal group, the independent predictors of failure were treatment with GnRH, estroprogestins and infertility. In 89% of cases, our developed model was able to predict whether an OH would be successful in a particular patient. ROC analysis showed an area under the curve of 0.8746 (95% CI: 0.85354-0.89557).

CONCLUSIONS

The present study demonstrates the development of a simple and reliable clinical model for the identification of both pre-menopausal and menopausal patients with a high chance of OH success.

Reducing the Pain Behind Opioid Prescribing in Primary Care

OBJECTIVE

To describe the efficacy of a comprehensive approach aimed at reducing opioid prescribing in an internal medicine resident clinic.

DESIGN

Retrospective observational study.

SETTING

Internal medicine primary care resident clinic at a large urban academic medical center.

SUBJECTS

All patients receiving opioid prescriptions from the primary care clinic.

METHODS

We reviewed pharmacy dispensing data for two hospital-affiliated pharmacies for resident primary care patients filling opioid prescriptions between July 2016 and July 2018. We instituted a comprehensive set of interventions that included resident education, limiting supervision of encounters for long-term opioid therapy (LTOT) to a fixed set of faculty champions, and providing alternate modalities for pain control. We calculated the change in number of opioid prescriptions dispensed, number of patients receiving opioid prescriptions, morphine milligram equivalents (MMEs) dispensed, and average per-patient daily MMEs dispensed.

RESULTS

We observed an average monthly reduction of 2.44% (P < 0.001) in the number of prescriptions dispensed and a 1.83% (P < 0.001) monthly reduction in the number of patients receiving prescriptions. Over the two-year period, there was a 74.3% reduction in total MMEs prescribed and a 66.5% reduction in the average MMEs prescribed per patient.

CONCLUSIONS

Our findings demonstrate a significant reduction in opioid prescribing after implementation of a comprehensive initiative. Although our study was observational in nature, we witnessed a nearly threefold decrease in opioid prescribing compared with national trends. Our results offer important insights for other primary care resident clinics hoping to engender safe prescribing practices and curb high-dose opioid prescribing.

Increased somatosensory amplification is associated with decreased pressure pain thresholds at both trigeminal and extra-trigeminal locations in healthy individuals

BACKGROUND

The diagnosis of temporomandibular disorders (TMD) is based on patient history and physical examination, and may require medical imaging. Masticatory muscle palpation is essential to make a diagnosis of TMD. However, the response of masticatory muscles to mechanical pressure stimuli depends on many physical and psychological factors.

OBJECTIVE

This study aimed at determining the impact of somatosensory amplification (SSA)-an estimate of somatic awareness and bodily hypervigilance-on pressure pain thresholds (PPTs) measured at both trigeminal and extra-trigeminal locations in healthy individuals.

METHODS

PPTs were measured at the right anterior temporalis and superficial masseter, and the thenar eminence of the right hand in one hundred healhty individuals (69F, 31M), divided in three groups based on their SSA scores: low (N = 32), intermediate (N = 34) and high (N = 34). General linear models were used to test between-group differences in PPTs including sex as a covariate. The level of significance was set at P < .05.

RESULTS

Individuals with high SSA had lower PPTs at the anterior temporalis than individuals with low (P = .006) and intermediate (P = .001) SSA. No significant between-group differences were found in PPTs measured at the masseter (P = .372). PPTs measured at the thenar eminence were significantly lower in the high than the low SSA group (P = .009). Females had lower PPTs at the masseter than males (P = .021) but not at other muscle locations (all P > .05).

CONCLUSION

Increased somatosensory amplification is associated with decreased pressure pain thresholds at both trigeminal and extra-trigeminal locations in healthy individuals. SSA could be a potential confounder while diagnosing TMD and evaluating treatment outcomes.

Comparison of Perioperative Renal Function Between Epidural and Intravenous Patient-Controlled Analgesia After Living-Donor Hepatectomy: A Retrospective Study

BACKGROUND

Sympathetic blockade associated with epidural analgesia was reported to be a risk factor for acute kidney injury (AKI) following liver resection. The purpose of this study was to compare the incidence of AKI after living-donor hepatectomies according to the type of patient-controlled analgesia (PCA).

METHODS

A total of 316 patients after living-donor hepatectomy were retrospectively analyzed; 148 patients in the epidural PCA group and 168 patients in the intravenous (IV) PCA group were evaluated. AKI was defined as an increase in serum creatinine ≥0.3 mg/dL, ie, 1.5-fold from the baseline, or a reduction in the urine output in the first 48 hours after surgery, based on the Acute Kidney Injury Network criteria. Logistic regression analysis was performed to identify the independent risk factors for AKI after living-donor hepatectomy.

RESULTS

Baseline characteristics were similar between the 2 groups except the age. Volumes of fluids and colloids administered intraoperatively were greater in the epidural PCA group (P < .001 and P = .006, respectively). The incidence of AKI did not show significant differences between the 2 groups (8.1% vs 7.1%; P = .747). In multivariate analysis, preoperative serum alanine transaminase level ≥50 U/L was identified as a risk factor for postoperative AKI. However, epidural PCA failed to be a risk factor for postoperative AKI.

CONCLUSIONS

The type of PCA did not affect the incidence of postoperative AKI after living-donor hepatectomy. Despite significant differences in the postoperative hemodynamics, the incidence of AKI was similar between 2 groups.

Temporal divergence of changes in pain and pain-free grip strength after manual acupuncture or electroacupuncture: an experimental study in people with lateral epicondylalgia

Background

The objective of this study was to examine, in individuals with lateral epicondylalgia (LE), the acute time course of acupuncture-induced hypoalgesia and change in pain-free grip strength (PFGS).

Methods

This was an experimental study, conducted at a single research center in Vancouver, BC. Twenty-one participants with unilateral LE lasting more than 6 weeks duration were enrolled. Participants received a single treatment of acupuncture (either electroacupuncture, 10–30 Hz, or manual acupuncture, assigned randomly). The primary outcome measure was pain level (0–10) during tendon loading (while making a fist) immediately after treatment, and over a 72 h follow-up period. Secondary outcome measures included pain-free grip strength (N).

Results

There was a small but statistically significant reduction in participants’ perceived pain level immediately after acupuncture (mean improvement of 1.2, 95% CI 0.45–1.9). This change in pain was not accompanied by a change in PFGS. No difference was observed between the two types of acupuncture at any time point.

Conclusions

The use of acupuncture or electroacupuncture, as administered in the current study, is unlikely to acutely enhance the ability of people with LE to engage in pain-free rehabilitation exercise.

Trial registration Registered February 25, 2015. ISRCTN14667535, http://www.isrctn.com/ISRCTN14667535

Electronic supplementary material

The online version of this article (doi:10.1186/s13020-017-0143-z) contains supplementary material, which is available to authorized users.