Manon Choinière

A systematic literature review of 10 years of research on sex/gender and experimental pain perception – Part 1: Are there really differences between women and men?

Summary Relatively limited support is provided to the hypothesis that healthy women have greater pain sensitivity than men in most experimental pain modalities. Abstract The purpose of this systematic review was to summarize and critically appraise the results of 10 years of human laboratory research on pain and sex/gender. An electronic search strategy was designed by a medical librarian and conducted in multiple databases. A total of 172 articles published between 1998 and 2008 were retrieved, analyzed, and synthesized. The first set of results (122 articles), which is presented in this paper, examined sex difference in the perception of laboratory‐induced thermal, pressure, ischemic, muscle, electrical, chemical, and visceral pain in healthy subjects. This review suggests that females (F) and males (M) have comparable thresholds for cold and ischemic pain, while pressure pain thresholds are lower in F than M. There is strong evidence that F tolerate less thermal (heat, cold) and pressure pain than M but it is not the case for tolerance to ischemic pain, which is comparable in both sexes. The majority of the studies that measured pain intensity and unpleasantness showed no sex difference in many pain modalities. In summary, 10 years of laboratory research have not been successful in producing a clear and consistent pattern of sex differences in human pain sensitivity, even with the use of deep, tonic, long‐lasting stimuli, which are known to better mimic clinical pain. Whether laboratory studies in healthy subjects are the best paradigm to investigate sex differences in pain perception is open to question and should be discussed with a view to enhancing the clinical relevance of these experiments and developing new research avenues.

The Canadian STOP-PAIN project - Part 1: Who are the patients on the waitlists of multidisciplinary pain treatment facilities?

PurposeThe Canadian STOP-PAIN Project assessed the human and economic burden of chronic pain in individuals on waitlists of Multidisciplinary Pain Treatment Facilities (MPTF). This article presents the patients’ bio-psycho-social profile.MethodsA sample of 728 patients was recruited from waitlists of eight university-affiliated MPTFs across Canada. Subjects completed validated questionnaires to: 1) assess the characteristics and impact of their pain; and 2) evaluate their emotional functioning and quality of life (QoL). Follow-up questionnaires were completed by a subgroup of 271 patients three months later.ResultsClose to 2/3 of the participants reported severe pain (≥xa07/10) that interfered substantially with various aspects of their daily living and QoL. Severe or extremely severe levels of depression were common (50.0%) along with suicidal ideation (34.6%). Patients agedxa0>xa060xa0yr were twice as likely to experience severe pain (≥xa07/10) as their younger counterparts (Pxa0=xa00.002). Patients with frequent sleep problems were more at risk of reporting severe pain (Pxa0≤xa00.003). Intense pain was also associated with a greater tendency to catastrophize (Pxa0<xa00.0001) severe depressive symptoms (Pxa0=xa00.003) and higher anger levels (Pxa0=xa00.016). Small but statistically significant changes in pain intensity and emotional distress were observed over a three-month wait time (all Pxa0<xa00.05).ConclusionThis study highlights the severe impairment that patients experience waiting for treatment in MPTFs. Knowing that current facilities cannot meet the clinical demand, it is clear that effective prevention/treatment strategies are needed earlier in primary and secondary care settings to minimize suffering and chronicity.RésuméObjectifLe projet canadien STOP-PAIN a évalué le fardeau humain et économique que représentait la douleur chronique des personnes se trouvant sur les listes d’attente des établissements pluridisciplinaires de traitement de la douleur (MPTF – Multidisciplinary Pain Treatment Facilities). Cet article présente le profil bio-psycho-social de ces patients.MéthodeUn échantillon de 728 patients a été recruté à partir des listes d’attente de huit MPTF affiliés à des universités partout au Canada. Les participants ont rempli des questionnaires validés afin dexa0: 1) évaluer les caractéristiques et l’impact de leur douleur; et 2) évaluer leur fonctionnement émotionnel et leur qualité de vie (QdV). Des questionnaires de suivi ont été remplis trois mois plus tard par un sous-groupe de 271 patients.RésultatsPrès de 2/3 des participants ont fait état d’une douleur grave (≥xa07/10) qui entravait considérablement différents aspects de leur vie quotidienne et de leur QdV. Des niveaux graves ou extrêmement graves de dépression étaient fréquents (50,0xa0%), tout comme les idées suicidaires (34,6xa0%). Les patients âgés dexa0>xa060 ans couraient un risque deux fois plus élevé de ressentir des douleurs graves (≥xa07/10) que les participants plus jeunes (Pxa0=xa00,002). Les patients ayant souvent des problèmes de sommeil couraient un risque plus élevé de faire état de douleur grave (Pxa0≤xa00,003). Une douleur intense était également associée à une tendance plus prononcée à la dramatisation (Pxa0<xa00,0001), à des symptômes de dépression grave (Pxa0=xa00,003) et à des niveaux plus élevés de colère (Pxa0=xa00,016). Des changements petits mais significatifs au niveau de l’intensité de la douleur et de la détresse émotionnelle ont été observés sur une période d’attente de trois mois (tous Pxa0<xa00,05).ConclusionCette étude met en évidence le handicap grave que les patients ressentent pendant qu’ils attendent d’être traités dans un MPTF. Sachant que les établissements actuels ne peuvent répondre à la demande clinique, il est clair que des stratégies de prévention et de traitement efficaces sont nécessaires plus tôt dans les cadres de soins primaires et secondaires afin de minimiser la souffrance et la chronicité.

The Canadian STOP-PAIN project – Part 2: What is the cost of pain for patients on waitlists of multidisciplinary pain treatment facilities?

PurposeThe Canadian STOP-PAIN Project was designed to document the human and economic burden of chronic pain in individuals on waitlists of Multidisciplinary Pain Treatment Facilities (MPTF). This paper describes the societal costs of their pain.MethodsA subgroup of 370 patients was selected randomly from The Canadian STOP-PAIN Project. Participants completed a self-administered costing tool (the Ambulatory and Home Care Record) on a daily basis for three months. They provided information about publicly financed resources, such as health care professional consultations and diagnostic tests as well as privately financed costs, including out-of-pocket expenditures and time devoted to seeking, receiving, and providing care. To determine the cost of care, resources were valued using various costing methods, and multivariate linear regression was used to predict total cost.ResultsOverall, the median monthly cost of care was

Predictors of suicidal ideation in chronic pain patients: An exploratory study

1,462 (CDN) per study participant. Ninety-five percent of the total expenditures were privately financed. The final regression model consisted of the following determinants: educational level, employment status, province, pain duration, depression, and health-related quality of life. This model accounted for 35% of the variance in total expenditure (Pxa0<xa00.001).ConclusionThe economic burden of chronic pain is substantial in patients on waitlists of MPTFs. Consequently, it is essential to consider this burden when making decisions regarding resource allocation and waitlist assignment for a MPTF. Resource allocation decision-making should include the economic implications of having patients wait for an assessment and for care.RésuméObjectifLe projet canadien STOP-PAIN a été élaboré afin de documenter le fardeau humain et économique que représentait la douleur chronique pour les personnes se trouvant sur les listes d’attente des établissements pluridisciplinaires de traitement de la douleur (MPTF – Multidisciplinary Pain Treatment Facilities). Cet article décrit les coûts sociétaux de leur douleur.MéthodeUn sous-groupe de 370 patients a été aléatoirement choisi parmi les participants au projet canadien STOP-PAIN. Les participants ont rempli quotidiennement un outil auto-administré de calcul des coûts (le fichier de soins ambulatoires et à domicile - Ambulatory and Home Care Record) pendant trois mois. Ils ont fourni des renseignements concernant les ressources financées par le secteur public, comme par exemple les consultations auprès de professionnels de la santé et les tests diagnostiques, ainsi que les coûts privés, notamment les sorties effectives d’argent et le temps consacré à chercher, recevoir et fournir des soins. Afin de déterminer le coût des soins, les ressources ont été estimées à l’aide de plusieurs méthodes de calcul des coûts, et une analyse par régression linéaire multivariée a été appliquée afin d’estimer le coût total.RésultatsGlobalement, le coût mensuel moyen des soins était de 1462xa0

Expectations predict chronic pain treatment outcomes.

(CDN) par participant à l’étude. Quatre-vingt-quinze pour cent des dépenses totales étaient prises en charge de façon privée. Le modèle de régression final était composé des déterminantes suivantesxa0: niveau d’éducation, situation d’emploi, province, durée de la douleur, dépression, et qualité de vie par rapport à la santé. Ce modèle a justifié 35xa0% de la variance des dépenses totales (Pxa0<xa00,001).ConclusionLe fardeau économique que représente la douleur chronique est substantiel pour les patients sur les listes d’attente des MPTF. Pour cette raison, il est nécessaire de tenir compte de ce fardeau lors de la prise de décision concernant l’attribution des ressources et l’affectation à la liste d’attente d’un MPTF. La prise de décision concernant l’attribution des ressources devrait inclure les implications économiques liées à l’attente des patients pour une évaluation de leur état et pour les soins.

Detecting pain in traumatic brain-injured patients with different levels of consciousness during common procedures in the ICU: typical or atypical behaviors?

Objectives:To explore whether chronic pain (CP) patients who report suicidal ideation (SI) present a distinctive profile with regard to their sociodemographic characteristics, physical health, psychological well-being, cognitions, and use of antidepressants, illicit drugs, and alcohol for pain relief. Methods:Eighty-eight CP patients completed self-administered questionnaires during their intake assessment at 3 pain clinics located in the province of Québec (Canada). Patients reporting active or passive SI on the Beck Depression Inventory were compared with patients reporting no SI. Between-group univariate analyses were performed using profile variables to compare patients with and without SI. Significant variables were then entered into multiple logistic regression analyses to identify significant independent predictors of SI. Results:Twenty-four percent of patients reported having had SI. Unemployed/disabled patients were 6 times more likely to report SI. Poor sleep quality was the only predictor of SI among the physical variables. For psychological well-being, depressive symptoms did not significantly predict SI. However, the poorer the patients perceived their mental health to be the more likely they were to report SI. Pain-related helplessness was the only predictor for SI among the cognitive variables. Patients who had used illicit drugs as a form of pain relief at any time since pain onset were 5 times more likely to report SI. Similar results were obtained for those who were on antidepressants. Discussion:Some factors associated with SI seem pain specific, whereas others are more generally associated with SI. Better identification and understanding of these factors is essential for the development of targeted suicide prevention programs for at-risk CP patients.

Pharmacotherapeutic management of chronic noncancer pain in primary care: lessons for pharmacists

Abstract Accumulating evidence suggests an association between patient pretreatment expectations and numerous health outcomes. However, it remains unclear if and how expectations relate to outcomes after treatments in multidisciplinary pain programs. The present study aims at investigating the predictive association between expectations and clinical outcomes in a large database of chronic pain patients. In this observational cohort study, participants were 2272 patients treated in one of 3 university-affiliated multidisciplinary pain treatment centers. All patients received personalized care, including medical, psychological, and/or physical interventions. Patient expectations regarding pain relief and improvements in quality of life and functioning were measured before the first visit to the pain centers and served as predictor variables. Changes in pain intensity, depressive symptoms, pain interference, and tendency to catastrophize, as well as satisfaction with pain treatment and global impressions of change at 6-month follow-up, were considered as treatment outcomes. Structural equation modeling analyses showed significant positive relationships between expectations and most clinical outcomes, and this association was largely mediated by patients global impressions of change. Similar patterns of relationships between variables were also observed in various subgroups of patients based on sex, age, pain duration, and pain classification. Such results emphasize the relevance of patient expectations as a determinant of outcomes in multimodal pain treatment programs. Furthermore, the results suggest that superior clinical outcomes are observed in individuals who expect high positive outcomes as a result of treatment.

Can Fluctuations in Vital Signs Be Used for Pain Assessment in Critically Ill Patients with a Traumatic Brain Injury

Purpose:Pain behaviors such as grimacing and muscle rigidity are recommended for pain assessment in nonverbal populations. However, these behaviors may not be appropriate for critically ill patients with a traumatic brain injury (TBI) depending on their level of consciousness (LOC). This study aimed to validate the use of behaviors for assessing pain of critically ill TBI adults with different LOC. Methods:Using a repeated measure within subject design, participants (N=45) were observed for 1 minute before (baseline), during, and 15 minutes after 2 procedures: (1) noninvasive blood pressure: NIBP (non-nociceptive); and (2) turning (nociceptive). A behavioral checklist combining 50 items from existing pain assessment tools and video recording were used to describe participants’ behaviors. Intrarater and interrater agreements of observed behaviors were also examined. Results:Overall, pain behaviors were observed more frequently during turning (median=4; T=−5.336; P⩽0.001) than at baseline (median=1), or during noninvasive blood pressure (median=0). TBI patients’ pain behaviors were mostly “atypical” and included uncommon responses such as flushing, sudden eye opening, eye weeping, and flexion of limbs. These behaviors were observed in ≥25.0% of TBI participants during turning independent of their LOC, and in 22.2% to 66.7% of conscious participants who reported the presence of pain. Agreements were >92% among and between the 2 raters. Conclusions:This study support previous findings that critically ill TBI patients could exhibit atypical behaviors when exposed to nociceptive procedures. As such, use of current recommended pain behaviors as part of standardized scales may not be optimal for assessing the analgesic needs of this vulnerable group.

Risk of Opioid Abuse and Biopsychosocial Characteristics Associated With This Risk Among Chronic Pain Patients Attending a Multidisciplinary Pain Treatment Facility.

Purpose Describe the pharmacotherapeutic management of primary-care patients with chronic noncancer pain, assess their satisfaction with pain treatment, and identify the determinants of their satisfaction. Methods A cohort study was conducted in Quebec (Canada). Patients reporting chronic noncancer pain with an average pain intensity of at least 4 on a 0–10 scale (10= worst possible pain) and having an active analgesic prescription from a primary-care physician were recruited. They completed a telephone interview and a self-administered questionnaire to document their pain, emotional well-being, satisfaction with treatment, and barriers/beliefs/attitudes about pain and its treatment. Information on pharmacotherapy was based on an administrative provincial database and pharmacies’ charts. Determinants of patients’ satisfaction were identified using multivariate linear regression models. Results Four hundred and eighty six patients participated. Their mean age was 58.4 years and they had had pain for a mean of 11.7 years (standard deviation, ±11.1) at an average pain intensity of 6.5 in the past week. Although 90% reported adverse gastrointestinal effects, 36.4% and 54.4% of these patients took no over-the-counter or prescribed medication for constipation or nausea, respectively. On a scale from 0–100, the mean overall satisfaction score was 64.7 (95% confidence interval [CI] =63.5–65.9). Patient satisfaction was low, particularly regarding the “information about pain and its treatment” (mean 50.6; 95% CI =47.6–53.7) and “treatment efficacy” (mean 53.6; 95% CI =51.5–55.6) subscales. The overall treatment satisfaction score decreased with more pain disability, probable depression and anxiety, more barriers to pain treatment, higher incidence of nausea, and use of over-the-counter analgesics. Conclusion In primary care, patients’ level of satisfaction with their pain treatment is not optimal. This study underlines how the expanded scope of practice of community pharmacists may allow them to play a pivotal role in providing information, discussing barriers to pain treatment, and monitoring pain disability, and by appropriately managing pharmacotherapy to optimize effectiveness while minimizing adverse effects.

Is the Quebec provincial administrative database a valid source for research on chronic non‐cancer pain?

Background. Many critically ill patients with a traumatic brain injury (TBI) are unable to communicate. While observation of behaviors is recommended for pain assessment in nonverbal populations, they are undetectable in TBI patients who are under the effects of neuroblocking agents. Aim. This study aimed to validate the use of vital signs for pain detection in critically ill TBI patients. Methods. Using a repeated measure within subject design, participants (N = 45) were observed for 1 minute before (baseline), during, and 15 minutes after two procedures: noninvasive blood pressure: NIBP (nonnociceptive) and turning (nociceptive). At each assessment, vital signs (e.g., systolic, diastolic, mean arterial pressure (MAP), heart rate (HR), respiratory rate (RR), capillary saturation (SpO2), end-tidal CO2, and intracranial pressure (ICP)) were recorded. Results. Significant fluctuations (P < 0.05) in diastolic (F = 6.087), HR (F = 3.566), SpO2 (F = 5.740), and ICP (F = 3.776) were found across assessments, but they were similar during both procedures. In contrast, RR was found to increase exclusively during turning (t = 3.933; P < 0.001) and was correlated to participants self-report. Conclusions. Findings from this study support previous ones that vital signs are not specific for pain detection. While RR could be a potential pain indicator in critical care, further research is warranted to support its validity in TBI patients with different LOC.