The transition from acute to persistent pain: the identification of distinct trajectories among women presenting to an emergency department

Pain assessment and management of adult patients in the Swedish EMS: a nationwide registry study

BACKGROUND

Pain is a frequent reason for contacting the Emergency Medical Services (EMS), and effective pain management constitutes one of its cornerstones. The aims of this study have been: (a) to describe the prevalence of pain intensity ratings in EMS care of patients with pain-related conditions; (b) to describe pain treatment in the EMS setting in terms of drugs administered and the proportion of patients receiving analgesics and (c) to investigate the relationship between patients' self-reported pain intensity and vital signs.

METHODS

This is a retrospective observational cohort study using data from 394,700 EMS missions conducted 2021 and 2022, as recorded in the Swedish Ambulance Registry. The study focused on patients who contacted the EMS due to pain, trauma, or injury. Pain intensity was recorded using the Numeric Rating Scale (NRS). NRS scores of 5-10 were considered as high-level pain and NRS ≤ 4 as low-level. Descriptive statistics were used to present categorical and continuous variables. Chi-square tests were applied for dichotomous variables, while Kruskal-Wallis tests were used for ordinal data. Logistic regression analysis was carried out to identify factors associated with pain intensity and analgesic treatment. p value < 0.001 was considered statistically significant.

RESULTS

Pain intensity was recorded in 23.6% of cases. Most patients rated their pain as high-level (NRS 5-10, 57.4% of those assessed). Analgesics were administered in 27.5% of cases, with higher administration rates observed when pain intensity was documented. Female sex, higher breathing rates, and higher systolic blood pressure were associated with higher pain intensity, while increasing age was associated with lower odds of reporting high-level pain intensity. No significant association was found between heart rate and pain intensity.

CONCLUSION

This 2-year cohort study highlights significant deficiencies in recorded pain assessment and management in the Swedish EMS. Only 22.5% of the patients had their pain assessed with a validated scale, while 27.5% received analgesics, although pain-related conditions were a common reason for contacting the EMS. The findings indicate a lack of systematic pain assessment which puts many patients at risk of insufficient pain relief.

Treating a common comorbidity: Pain outcomes following a 3-week cognitive processing therapy-based intensive treatment for posttraumatic stress disorder address

Posttraumatic stress disorder (PTSD) commonly co-occurs with pain and has been implicated in the maintenance of chronic pain. However, limited research has examined whether intervening for PTSD can hinder or optimize treatment outcomes for co-occurring pain and PTSD. In the present study, we examined changes in pain, PTSD, and depressive symptoms among 125 veterans completing a 3-week cognitive processing therapy (CPT)-based intensive treatment program (ITP) for PTSD. We also explored whether pretreatment pain interference predicted changes in PTSD and depressive symptom severity and whether larger changes in pain interference over the course of treatment were associated with larger changes in PTSD and depressive symptom severity. Linear mixed models revealed that participants' pain interference decreased throughout treatment, d = 0.15, p = .039. Higher levels of pretreatment pain interference were associated with higher PTSD, p = .001, and depressive symptom severity, p = .014, over time. Larger reductions in pain interference corresponded to more improvement in PTSD symptoms, β = -.03; p < .001, but not depressive symptoms. These findings indicate that ITPs for PTSD can reduce pain interferences, albeit to a small degree, and that reductions in pain interference can contribute to reductions in PTSD symptom severity. Future studies should examine which treatment components contribute to larger changes in symptom severity for veterans with co-occurring pain and PTSD.

Sex Differences in Pain and Its Treatment

Pain is a highly personal experience. Pain is often considered to be a purely neurologic phenomenon, but in actuality, it is a combination of both sensory and emotional experiences. This has sometimes been translated clinically toward a more mechanistic approach to the assessment and treatment of pain instead of one that does not discount pain mechanisms, but also is more inclusive of the need for humanism - considering the individual. In today's medical environment, more than ever before there is a significant amount of attention being paid to educating clinicians to better understand that several physiological, neurophysiological, and psychosocial factors can significantly impact responses to pain. The composition of these factors will be unique to that individual's life narrative, context, sex, and prior life experiences. Thus, the concept that a templated approach to pain assessment and pharmacotherapeutic treatment planning should not be expected to provide optimal patient satisfaction and treatment outcomes in the majority. The hypotheses that there may be sex-based differences in the pain experience in a variety of ways including pain sensitivity, tolerance to pain, threshold at which something becomes painful, and the effectiveness of endogenous pain modulation systems are not new and have been well represented in the literature. This chapter reviews important key findings in the scientific literature with respect to sex-based differences in pain and pain responses to experimentally induced painful stimuli, pain experienced in commonly occurring painful medical conditions, and variations in responses to pain treatments. Possible explanations to account for observed differences or similarities will also be discussed.

Relationship between systemic inflammation and recovery over 12 months after an acute episode of low back pain

BACKGROUND CONTEXT

Individual characteristics can influence outcomes after injury. Our previous work in individuals with early-acute low back pain (LBP) identified subgroups (clusters) with specific biopsychosocial features that recovered poorly or well by 6 months.

PURPOSE

This study extends on that work by revealing the short- and long-term trajectories of recovery and systemic inflammation of these participant clusters: (1) "inflammatory & poor sleep" (Cluster 1), "high TNF & depression" (Cluster 2), "high pain & high pain-related fear" (Cluster 3), and "low pain & low pain-related fear" (Cluster 4).

STUDY DESIGN/SETTING

Longitudinal cohort study.

PATIENT SAMPLE

Eighty-three individuals within 2 weeks of an acute episode of LBP - grouped into their a priori-defined cluster.

OUTCOME MEASURES

General participant characteristics (sex, age, body mass index, smoking history, previous LBP history); self-reported LBP (0-10 numerical rating scale, LBP-related disability (Roland-Morris Disability Questionnaire), depression (Center for Epidemiological Studies Depression Scale, pain catastrophizing (Pain Catastrophizing Scale), fear avoidance (Fear Avoidance Beliefs Questionnaire), pain self-efficacy (Pain Self-Efficacy Questionnaire), and sleep (Pittsburgh Sleep Quality Index); systemic inflammatory biomarkers (C-reactive protein [CRP], interleukin-6 [IL-6], interleukin-1β, tumor necrosis factor [TNF]).

METHODS

Participants provided blood for the measurement of CRP/cytokines, and completed questionnaires related to their pain/disability, psychological and sleep status. Blood measures were repeated 3-monthly for 9 months, and pain/disability were self-reported fortnightly for 12 months. Recovery (change in pain) and CRP/cytokines were longitudinally compared between clusters using mixed-models. Associations between baseline factors and follow-up CRP/cytokines levels were assessed with multiple regression.

RESULTS

Clusters 1 and 2 were associated, but oppositely, with recovery over the 12-months. Cluster 1 reported most recovery at every 3-monthly interval, whereas Cluster 2 reported least recovery. Cluster 1 had elevated CRP (and IL-6) at baseline that continued to decrease from 3 to 9 months. TNF was elevated early and persistently in Cluster 2. Baseline factors other than inflammation generally failed to predict follow-up inflammation.

CONCLUSIONS

Findings support the early role of CRP (and perhaps IL-6) in control of inflammation and recovery, and a pathological role of persistent TNF overexpression, which may be perpetuated by depressive-like behaviors.

Risk factors for low back pain outcome: Does it matter when they are measured?

BACKGROUND

The early identification of factors that increase risk of poor recovery from acute low back pain (LBP) is critical to prevent the transition to chronicity. Although most studies of risk factors for poor outcome in LBP tend to investigate the condition once it is already persistent, there is evidence to suggest that this differs from risk factors measured during the early-acute stage. This study aimed to identify early risk factors for poor outcome in the short- and long-term in individuals with acute LBP, and to compare this with factors identified at 3 months in the same cohort.

METHODS

One hundred and thirty-three individuals were recruited within 2 weeks of an acute LBP episode and completed questionnaires related to their sociodemographic, psychological, clinical and history/treatment status at baseline and 3 months later, and their pain-level fortnightly for 12 months.

RESULTS

Of the 133 participants recruited, follow-up data was provided by 120 at 3 months, 97 at 6 months, 85 at 9 months and 94 at 12 months. Linear regression identified various factors at baseline (acute phase) and 3 months later that predicted short- and long-term outcome (pain level, change in pain). Key findings were that: (1) depressive symptoms at baseline most consistently predicted worse outcome; (2) psychological factors in general at 3 months were more predictive of outcome than when measured at baseline; (3) early health care utilisation predicted better outcome, whereas use of pain medication later (3 months) predicted worse outcome; and (4) sex and BMI predicted outcome inconsistently over 12-months.

CONCLUSIONS

The results highlight the multidimensional nature of risk factors for poor outcome in LBP and the need to consider time variation in these factors.

The clinical course of neck pain: Are trajectory patterns stable over a 1-year period?

BACKGROUND

Recent studies with data-driven approaches have established common pain trajectories. It is uncertain whether these trajectory patterns are consistent over time, and if a shorter measurement period will provide accurate trajectories.

METHODS

We included 1,124 patients with non-specific neck pain in chiropractic practice. We classified patients into pre-defined trajectory patterns in each of four quarters of the follow-up year (persistent, episodic, and recovery) based on measures of pain intensity and frequency from weekly SMS. We explored the shifts between patterns and compared patients with stable and shifting patterns on baseline characteristics and clinical findings.

RESULTS

785 (70%) patients were in the same pattern in 1st and 4th quarters. Patients with episodic pattern in the 1st quarter shifted to other patterns more frequently than patients in the other patterns. A stable persistent pattern was associated with reduced function and higher scores on psychosocial factors. There was a decreased frequency of patients classified as persistent pattern (75% to 63%) and an increase of patients in recovery pattern (4% to 15%) throughout the four quarters. The frequency of patients classified as episodic remained relatively stable (21% to 24%).

CONCLUSIONS

We found an overall stability of the persistent pattern, and that episodic patterns have more potential for shifts. Shifts mostly occurred between patterns closest in pain variation. The deviation in pattern distribution compared with previous studies suggests that the duration of measurement periods has an impact on the results of the classification.

SIGNIFICANCE

Having persistent pain and having very minor pain is relatively stable over one year, while episodic pain has more potential for shifts. The duration of measurement periods appears to have an impact on the results of the classification. The given criteria resulted in a reduced frequency of episodic pattern due to shorter measurement periods. Our findings contribute to improved understanding and predicting NP using a combination of patient characteristics and trajectory patterns.