5. Sacroiliac joint pain.

INTRODUCTION: Sacroiliac (SI) joint pain is defined as pain localized in the anatomical region of the SI joint. The reported prevalence of SI joint pain among patients with mechanical low back pain varies between 15% and 30%. METHODS: In this narrative review, the literature on the diagnosis and treatment of SI joint pain was updated and summarized. RESULTS: Patient's history provides clues on the source of pain. The specificity and sensitivity of provocative maneuvers are relatively high when three or more tests are positive, though recent studies have questioned the predictive value of single or even batteries of provocative tests. Medical imaging is indicated only to rule out red flags for potentially serious conditions. The diagnostic value of SI joint infiltration with local anesthetic remains controversial due to the potential for false-positive and false-negative results. Treatment of SI joint pain ideally consists of a multidisciplinary approach that includes conservative measures as first-line therapies (eg, pharmacological treatment, cognitive-behavioral therapy, manual medicine, exercise therapy and rehabilitation treatment, and if necessary, psychological support). Intra- and extra-articular corticosteroid injections have been documented to produce pain relief for over 3 months in some people. Radiofrequency ablation (RFA) of the L5 dorsal ramus and S1-3 (or 4) lateral branches has been shown to be efficacious in numerous studies, with extensive lesioning strategies (eg, cooled RFA) demonstrating the strongest evidence. The reported rate of complications for SI joint treatments is low. CONCLUSIONS: SI joint pain should ideally be managed in a multidisciplinary and multimodal manner. When conservative treatment fails, corticosteroid injections and radiofrequency treatment can be considered.

Study Design Characteristics and Endpoints for Enriched Enrollment Randomized Withdrawal Trials for Chronic Pain Patients: A Systematic Review.

Enriched enrollment randomized withdrawal (EERW) pain trials are designed to include only responders with considerable pain relief without unacceptable side effects into the randomized phase. There are no recommendations for primary endpoints in such trials. Our objective was to propose recommendations based on assessment of trial characteristics, endpoints and effect sizes in EERW pain trials. We conducted a systematic review by searching electronic databases up to June 2020 for EERW trials comparing an analgesic with a placebo in adults suffering from chronic pain. A total of 28 trials met our criteria, involving 13662 patients in the open or single-blind phase and 7937 patients in the double-blind phase. As primary endpoint 18 trials used pain intensity measured with the visual analogue scale (VAS) or the 11-point numerical rating scale (NRS); 1 trial used a 4-point NRS. Loss of therapeutic response (LTR) was used in 1 trial and time to LTR was used in 8 trials as primary endpoint. Definitions of time to LTR differed considerably between trials. Only 2 out of 8 trials using time to LTR as primary endpoint reported the percentage of patients experiencing a minimum pain relief of 50%, compared to 14 out of 18 trials using NRS or VAS. Due to the complexity and diversity of time to LTR in EERW pain trials, we propose to use the NRS as primary endpoint with conservative imputation methods, and to use time to LTR as secondary endpoint.

Use of antithrombotics at the end of life: an in-depth chart review study.

BACKGROUND: Antithrombotics are frequently prescribed for patients with a limited life expectancy. In the last phase of life, when treatment is primarily focused on optimizing patients' quality of life, the use of antithrombotics should be reconsidered. METHODS: We performed a secondary analysis of a retrospective review of 180 medical records of patients who had died of a malignant or non-malignant disease, at home, in a hospice or in a hospital, in the Netherlands. All medication prescriptions and clinical notes of patients using antithrombotics in the last three months of life were reviewed manually. We subsequently developed case vignettes based on a purposive sample, with variation in setting, age, gender, type of medication, and underlying disease. RESULTS: In total 60% (n=108) of patients had used antithrombotics in the last three months of life. Of all patients using antithrombotics 33.3 % died at home, 21.3 % in a hospice and 45.4 % in a hospital. In total, 157 antithrombotic prescriptions were registered; 30 prescriptions of vitamin K antagonists, 60 of heparins, and 66 of platelet aggregation inhibitors. Of 51 patients using heparins, 32 only received a prophylactic dose. In 75.9 % of patients antithrombotics were continued until the last week before death. Case vignettes suggest that inability to swallow, bleeding complications or the dying phase were important factors in making decisions about the use of antithrombotics. CONCLUSIONS: Antithrombotics in patients with a life limiting disease are often continued until shortly before death. Clinical guidance may support physicians to reconsider (dis)continuation of antithrombotics and discuss this with the patient.

Placebo effects in low back pain: A systematic review and meta-analysis of the literature.

BACKGROUND AND OBJECTIVE: The current treatments of primary musculoskeletal low back pain (LBP) have a low to moderate efficacy, which might be improved by looking at the contribution of placebo effects. However, the size of true placebo effects in LBP is unknown. Therefore, a systematic review and meta-analysis were executed of randomized controlled trials investigating placebo effects in LBP. DATABASES AND DATA TREATMENT: The study protocol was registered in the international prospective register of systematic reviews Prospero (CRD42019148745). A literature search (in PubMed, Embase, The Cochrane Library, CINAHL and PsycINFO) up to 2021 February 16th yielded 2,423 studies. Two independent reviewers assessed eligibility and risk of bias. RESULTS: Eighteen studies were eligible for the systematic review and 5 for the meta-analysis. Fourteen of the 18 studies were clinical treatment studies, and 4 were experimental studies specifically assessing placebo effects. The clinical treatment studies provided varying evidence for placebo effects in chronic LBP but insufficient evidence for acute and subacute LBP. Most experimental studies investigating chronic LBP revealed significant placebo effects. The meta-analysis of 5 treatment studies investigating chronic LBP depicted a significant moderate effect size of placebo for pain intensity (SMD = 0.57) and disability (SMD = 0.52). CONCLUSIONS: This review shows a significant contribution of placebo effects to chronic LBP symptom relief in clinical and experimental conditions. The meta-analysis revealed that placebo effects can influence chronic LBP intensity and disability. However, additional studies are required for more supporting evidence and evidence for placebo effects in acute or subacute LBP. SIGNIFICANCE: This systematic review and meta-analysis provides evidence of true placebo effects in low back pain (LBP). It shows a significant contribution of placebo effects to chronic LBP symptom relief. The results highlight the importance of patient- and context-related factors in fostering treatment effects in this patient group. New studies could provide insight into the potential value of actively making use of placebo effects in clinical practice.

Physicians' Opinions on Anticoagulant Therapy in Patients with a Limited Life Expectancy.

Patients with a limited life expectancy have an increased risk of thromboembolic and bleeding complications. Anticoagulants are often continued until death, independent of their original indication. We aimed to identify the opinions of physicians about the use of anticoagulants at the end of life. A mixed-method research design was used. A secondary analysis was performed on data from a vignette study and an interview study. Participants included general practitioners and clinical specialists. Physicians varied in their opinions: some would continue and others would stop anticoagulants at the end of life because of the risk of thromboembolic or bleeding complications. The improvement or preservation of patients' quality of life was a reason for both stopping and continuing anticoagulants. Other factors considered in the decision-making were the types of anticoagulant, the indication for which the anticoagulant was prescribed, underlying diseases, and the condition and life expectancy of the patient. Factors that made decision-making difficult were the lack of evidence on either strategy, uncertainty about patients' life expectancy, and the fear of harming patients. Which decision was eventually made seems largely dependent on the choice of the patient. In conclusion, there is a substantial variation in physicians' opinions regarding the use of anticoagulants in patients with a limited life expectancy. Physicians agree that the primary goal of medical care at end of life is the improvement or preservation of patients' quality of life. An important barrier to decision-making is the lack of evidence about the risks and benefits of stopping anticoagulants.

Role of nurses in medication management at the end of life: a qualitative interview study.

BACKGROUND: Patients in the last phase of their lives often use many medications. Physicians tend to lack awareness that reviewing the usefulness of medication at the end of patients' lives is important. The aim of this study is to gain insight into the perspectives of patients, informal caregivers, nurses and physicians on the role of nurses in medication management at the end of life. METHODS: Semi-structured interviews were conducted with patients in the last phase of their lives, in hospitals, hospices and at home; and with their informal caregivers, nurses and physicians. Data were qualitatively analyzed using the constant comparative method. RESULTS: Seventy-six interviews were conducted, with 17 patients, 12 informal caregivers, 15 nurses, 20 (trainee) medical specialists and 12 family physicians. Participants agreed that the role of the nurse in medication management includes: 1) informing, 2) supporting, 3) representing and 4) involving the patient, their informal caregivers and physicians in medication management. Nurses have a particular role in continuity of care and proximity to the patient. They are expected to contribute to a multidimensional assessment and approach, which is important for promoting patients' interest in medication management at the end of life. CONCLUSIONS: We found that nurses can and should play an important role in medication management at the end of life by informing, supporting, representing and involving all relevant parties. Physicians should appreciate nurses' input to optimize medication management in patients at the end of life. Health care professionals should recognize the role the nurses can have in promoting patients' interest in medication management at the end of life. Nurses should be reinforced by education and training to take up this role.

Pain Pressure Threshold in the Region of the Sacroiliac Joint in Patients Diagnosed with Sacroiliac Joint Pain.

BACKGROUND: Although the prevalence of sacroiliac joint (SIJ) pain is relatively high (15 - 30%), there is no unambiguous reference standard to diagnose SIJ pain. Pressure tenderness in the SIJ region is used for diagnostic purposes, but the clinimetric properties of this procedure remain to be determined. OBJECTIVES: The aim of this study is to determine the reliability of pain pressure threshold (PPT) measurements in the SIJ region and the difference in PPTs in the SIJ region between healthy volunteers and PPTs in patients with SIJ pain. STUDY DESIGN: Prospective cohort study. SETTING: Outpatient pain clinic VU University Medical Center. METHODS: Forty-one healthy volunteers and 31 patients diagnosed with SIJ pain were included. PPTs were obtained from 5 measurement points in the region of the SIJ with a pressure pain algometer using a standardized protocol. The inter-rater reliability of this method was calculated by means of the Intraclass Correlation Coefficients (ICC) of individual assessment performed by 2 individual raters of SIJs of healthy volunteers on both sides. PPTs of healthy volunteers were compared to those of the affected side in patients with SIJ pain. RESULTS: PPT measurement showed moderate to good inter-rater reliability (ICC 0.6 - 0.82).The median PPTs of 5 points was comparable for both sides in healthy volunteers (right: 8.5 kg/cm2 [IQR 6.0 - 10.0]; left 8.3 kg/cm2 (5.8 - 10.0]). Median PPTs for the affected sides of patients with SIJ pain were significantly lower compared to the same side of healthy volunteers (right: 2.4 kg/cm2 [IQR 2.2 - 3.2, n = 15]; left: 2.5 kg/cm2 [2.3 - 3.2, n = 16]; P < 0.001 for both sides). LIMITATIONS: Only the SIJ on one side of was measured in patients with SIJ pain, where both sides would be desirable. CONCLUSIONS: Pressure pain algometry appears to be a reliable method to establish differences in PPTs between healthy volunteers and patients with SIJ pain. The diagnostic accuracy of this test should be investigated further.

The use of observational scales to monitor symptom control and depth of sedation in patients requiring palliative sedation: a systematic review.

BACKGROUND: Palliative sedation is the intentional lowering of consciousness of a patient in the last phase of life to relieve suffering from refractory symptoms such as pain, delirium and dyspnoea. AIM: In this systematic review, we evaluated the use of monitoring scales to assess the degree of control of refractory symptoms and/or the depth of the sedation. DESIGN: A database search of PubMed and Embase was performed up to January 2010 using the search terms 'palliative sedation' OR 'terminal sedation'. DATA SOURCES: Retro- and prospective studies as well as reviews and guidelines containing information about monitoring of palliative sedation, written in the English, German or Dutch language were included. RESULTS: The search yielded 264 articles of which 30 were considered relevant. Most studies focused on monitoring refractory symptoms (pain, fatigue or delirium) or the level of awareness to control the level of sedation. Four prospective and one retrospective study used scales validated in other settings: the Numeric Pain Rating Scale, the Visual Analogue Scale, the Memorial Delirium Assessment Scale, the Communication Capacity Scale and Agitation Distress Scale. Only the Community Capacity Scale was partially validated for use in a palliative sedation setting. One guideline described the use of a scale validated in another setting. CONCLUSIONS: A minority of studies reported the use of observational scales to monitor the effect of palliative sedation. Future studies should be focused on establishing proper instruments, most adequate frequency and timing of assessment, and interdisciplinary evaluation of sedation depth and symptom control for palliative sedation.

13. Sacroiliac joint pain.

The sacroiliac joint accounts for approximately 16% to 30% of cases of chronic mechanical low back pain. Pain originating in the sacroiliac joint is predominantly perceived in the gluteal region, although pain is often referred into the lower and upper lumbar region, groin, abdomen, and/ or lower limb(s). Because sacroiliac joint pain is difficult to distinguish from other forms of low back pain based on history, different provocative maneuvers have been advocated. Individually, they have weak predictive value, but combined batteries of tests can help ascertain a diagnosis. Radiological imaging is important to exclude "red flags" but contributes little in the diagnosis. Diagnostic blocks are the diagnostic gold standard but must be interpreted with caution, because false-positive as well as false-negative results occur frequently. Treatment of sacroiliac joint pain is best performed in the context of a multidisciplinary approach. Conservative treatments address the underlying causes (posture and gait disturbances) and consist of exercise therapy and manipulation. Intra-articular sacroiliac joint infiltrations with local anesthetic and corticosteroids hold the highest evidence rating (1 B+). If the latter fail or produce only short-term effects, cooled radiofrequency treatment of the lateral branches of S1 to S3 (S4) is recommended (2 B+) if available. When this procedure cannot be used, (pulsed) radiofrequency procedures targeted at L5 dorsal ramus and lateral branches of S1 to S3 may be considered (2 C+).

Possible nociceptive structures in the sacroiliac joint cartilage: An immunohistochemical study.

The sacroiliac joint (SI joint) is a known source of low back pain. In the absence of validated physical signs and imaging studies, the diagnosis of SI joint pain can be secured by positive response to SI joint intra-articular infiltration with local anesthetics. The current anatomical and histological knowledge concerning intra-articular structures of the sacroiliac joint is insufficient to explain the efficacy of this infiltration. Consequently, this study was undertaken to detect the intra-articular presence of substance P and calcitonin gene-related peptide (CGRP) positive nerve fibers, providing indirect evidence of nociceptive innervation of the SI joint. Free-floating sections, obtained from iliac and sacral cartilage and subchondral bone of the SI joint and adjacent ligamentous tissue, of 10 human cadavers were studied immunohistochemically. Tissue of nine human cadavers showed the presence of substance P and CGRP immunoreactivity in the superficial layer of sacral and iliac cartilage, and the surrounding ligamentous structures. Subchondral bone reacted weakly to the antisera used. These findings support the view that the SI joint may be capable of intra-articular nociception and may explain the positive response to the intra-articular deposition of local anesthetic.

Diagnostic validity of criteria for sacroiliac joint pain: a systematic review.

UNLABELLED: A systematic literature review was conducted to determine the diagnostic validity of the criteria for sacroiliac (SI) joint pain as proposed by the International Association for the Study of Pain (IASP). Databases were searched up to September 2007. Quality of the studies was assessed using a Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. Sensitivity, specificity, and diagnostic odds ratios (DOR) were calculated together with 95% confidence intervals (CI). Statistical pooling was conducted for results of provocative tests. Eighteen studies were included. Five studies examined the pattern of SI joint pain, whereas another 5 examined stressing test specific for SI joint pain. None of the studies evaluated the diagnostic validity of the SI joint infiltration or the diagnostic validity of the IASP criteria set as a whole. In all studies, the SI joint selective infiltration was used as a gold standard; however, the technique, medications, and required pain relief after the infiltration varied considerably between the studies. Taking the double infiltration technique as reference test, the pooled data of the thigh thrust test (DOR, 18.461; CI, 5.82 to 58.53), compression test (DOR, 3.88; CI, 1.7 to 8.9), and 3 or more positive stressing tests (DOR, 17.16; CI, 7.6 to 39) showed discriminative power for diagnosing SI joint pain. PERSPECTIVE: This review of clinical studies focused on the diagnostic validity of the IASP criteria for diagnosing SI joint pain. A meta-analysis showed that the thigh thrust test, the compression test, and 3 or more positive stressing tests have discriminative power for diagnosing SI joint pain. Because a gold standard for SI joint pain diagnosis is lacking, the diagnostic validity of tests related to the IASP criteria for SI joint pain should be regarded with care.

Nociceptive nerve fibers in the sacroiliac joint in humans.

BACKGROUND AND OBJECTIVES: A positive response to sacroiliac joint intra-articular infiltration with local anesthetics is used to confirm sacroiliac joint pain. However, current anatomical and histological knowledge concerning the anatomy of pain perception within the sacroiliac joint intra- and peri-articular structures is insufficient to explain the efficacy of this infiltration, because of the use of unspecific histochemical visualization techniques. METHODS: In this study, immunohistochemistry for calcitonin gene-related peptide (CGRP) and substance P was used to trace nociceptive fibers and receptors in the anterior and interosseous sacroiliac ligaments obtained from 5 human cadavers without history of sacroiliac joint pain. RESULTS: Microscopic analysis of stained slides showed presence of CGRP and substance P immunoreactive fibers. Thick, wavy, formed bundles were observed in dense and loose connective tissue, whereas single, beaded nerve fibers, occasionally ramified, were observed more frequently in the dense connective tissue and next to blood vessels. Based on their morphologic features, these immunoreactive structures were classified as receptors type IV. Additionally, receptors type II were found in anterior and interosseous ligaments, which contained CGRP or substance P immunoreactive free nerve endings. CONCLUSIONS: We conclude that the presence of CGRP and substance P immunoreactive fibers in the normal anterior capsular ligament and interosseous ligament provides a morphological and physiological base for pain signals originating from these ligaments. Therefore, diagnostic infiltration techniques for sacroiliac joint pain should consider extra- as well as intra-articular approaches.