Reliability of the Buttock Applied Strain Test to Diagnose Radicular Pain in Patients With Low Back Pain.

BACKGROUND: Low-back pain (LBP) pathophysiological conditions include nociceptive back pain, somatic referred pain, radicular pain (RP), and radiculopathy. Differential diagnosis is challenging; guidance may come from patients' thorough clinical history and physical examination and, particularly for lumbar RP, from the evaluation of subjective responses of injured lumbar nerves to a strain applied at the buttock (buttock applied strain [BUAS] test). METHODS: In a sample of 395 consecutive patients with LBP, sensitivity, specificity, and prior probability (positive predictive values [PPVs] and negative predictive values [NPVs]) of the BUAS test were evaluated against 2 reference tests: the straight leg raising test (SLRT) and the painDETECT (PD) questionnaire. Multinomial logistic regression (MLR) and χ2 analyses were used to evaluate the BUAS test outcomes' dependence upon independent variables (gender, age group, pain localization, SLRT outcomes, and PD outcomes). Cohen's kappa statistic was used to assess inter-rater agreement. RESULTS: Compared with the PD questionnaire, the BUAS test showed a sensitivity of 92%, specificity of 100%, PPV of 100%, and NPV of 82%; compared with the SLRT, the BUAS test showed a sensitivity of 82%, NPV of 82%, specificity of 40%, and PPV of 40%. Inter-rater agreement of Cohen's kappa was 0.911. Significant associations were found between BUAS test outcomes and pain localization, SLRT outcomes, and PD outcomes, but not with the predictors gender or age group. MLR showed significant congruent relationships between BUAS test and PD outcomes. CONCLUSION: Among patients with LBP, the BUAS test showed satisfactory sensitivity, specificity, prior probability, and inter-rater reliability; thus, it may be considered a useful adjunctive tool to diagnose RP in patients with LBP. For more generalized results, more research, in clinical settings other than pain clinics, is needed.

Dialyzability of Oxycodone and Its Metabolites in Chronic Noncancer Pain Patients with End-Stage Renal Disease.

OBJECTIVES: Opioids are the preferred analgesic drugs to treat severe chronic pain conditions among dialysis patients; however, knowledge about their dialyzability features is limited. Oxycodone is increasingly used for the treatment of chronic pain conditions as oral controlled release (CR) tablets; however, evidence about this drug and its metabolites' dialyzability is lacking. METHODS: We assessed, during 4-hour dialysis sessions, the effect of standard hemodialysis (HD) and online hemodiafiltration (HDF) methods on the plasma concentration of oxycodone and its metabolites in n = 20 chronic pain patients with end-stage renal disease who were stably treated with oral CR oxycodone. Chromatographic techniques were used to evaluate the studied compounds' plasma concentrations at three different time points during dialysis. RESULTS: Mean plasma concentrations of oxycodone and noroxycodone in the sample showed an overall reduction trend over time, but it was less enhanced for noroxycodone. Mean reduction in oxycodone and noroxycodone arterial concentrations was significant and higher with HDF (54% and 27%, respectively) than with HD (22% and 17%, respectively). Analysis of the regression of these compounds' clearance on their increasing arterial concentration showed a more stable and linear clearance prediction with HDF (roughly 85 mL/min); with HD, for increasing arterial concentration, clearance of oxycodone decreased while noroxycodone clearance increased. DISCUSSION: While no oxymorphone or noroxymorphone metabolites were detected, limited dialyzability of oxycodone and noroxycodone was documented along with insignificant postdialysis pain increment. This evidence will contribute toward considerations as to the safety of the use of oxycodone in dialysis patients in the future.

The Occipital Nerves Applied Strain Test to Support Occipital Neuralgia Diagnosis.

INTRODUCTION: Occipital neuralgia (ON) is a disabling cephalalgia form with demanding diagnostic workflow. We report the description and reliability analyses of the occipital nerves-applied strain (ONAS) test for occipital neuralgia (ON) early-stage diagnosis in cephalalgia patients. METHODS: In a retrospective and observational study, we evaluated, among n = 163 consecutive cephalalgia patients, the sensitivity, specificity, and prior probability [positive (PPV) and negative (NPV) predictive values] of the ONAS test against two reference tests (occipital nerve anesthetic block and the painDETECT questionnaire). Multinomial logistic regression (MLR) and χ2 analyses verified the ONAS test outcome's dependence upon independent variables (gender, age, pain site, block test, and painDETECT outcomes). We assessed inter-rater agreement with Cohen's kappa statistic. RESULTS: ONAS test showed sensitivity and specificity of 81 and 18%, respectively, against the painDETECT and of 94 and 46%, respectively, against the block test. PPV was > 70% against both tests, while NPV was 81% against the block test and 26% against the painDETECT. Interrater agreement Cohen's kappa was excellent. Significant association (χ2 analyses) and relationship (MLR) were found only between ONAS test and pain site but not with the other independent predictors. CONCLUSIONS: The ONAS test showed satisfactory reliability among cephalalgia patients; thus, it might be considered a valuable early stage tool for ON diagnosis in these patients.

We report the description and reliability features of an occipital neuralgia diagnostic tool. The latter is based on the assertion that applying a strain on putatively compromised occipital nerves prompts abnormal nerve discharges and subjective pain reactions and thus may reveal occipital neuralgia. Among 163 cephalalgia patients, the test showed sensitivity and specificity of 81 and 18%, respectively, against the painDETECT questionnaire and 94 and 46%, respectively, against the occipital nerves' block test. Interrater agreement was excellent, and significant associations and relationships were found only between the tool and congruent pain site but not with the other independent predictors. This tool may help clinicians' early detection of occipital neuralgia in cephalalgia patients.

Evidence for the BUAS-test ability to diagnose lumbar radicular pain.

BACKGROUND: Differential diagnosis of low back pain (LBP) is complex and a prominent issue at all health-care levels; guidance may come from patients' history cues and clinical examination signs. Human and animal studies report that diagnosis of lumbar radicular pain (LRP) may come from evaluating subjective responses of injured lumbar nerves to a strain applied at the buttock. The Buttock Applied Strain (BUAS-test) test may guide the differential diagnosis of LBP. Following an ex-adiuvantibus criterion, clinical improvement of LRP, diagnosed with the BUAS-test and congruently treated, may support this test diagnostic ability. METHODS: Among 258 LRP patients, who, upon first visit (V1), tested positive on the BUAS-test (with/without positive Straight Leg Raising Test, SLRT), the effect of gabapentin prescription on painDETECT (PD) questionnaire and Brief Pain Inventory (BPI) outcomes was quantified in the follow-up visit (V2). To support BUAS-test diagnostic ability, we hypothesized that, at V2, >50% of the sample would present negative PD outcome, significant (t-test) and ⩾2 points V2-V1 differences for each of the BPI-item's score. We used multinomial logistic regression (MLR) and χ2 analyses to evaluate the PD-V2 outcomes' dependence upon independent variables. RESULTS: Of the sample, 77% reported a negative PD-V2 outcome. V2-V1 differences of all BPI items were significant and >2 points. PD-V2 outcomes showed significant associations with SLRT-V1 and PD-V1, respectively, but not with gender, age group or pain site. MLR showed a significant relationship between SLRT-V1 and PD-V2 outcomes. CONCLUSION: Among LRP patients, diagnosed by the BUAS-test and treated with gabapentin, all prespecified endpoints were reached. These results may be considered a piece of ex-adiuvantibus evidence for the BUAS-test ability to diagnose LRP. While positive BUAS-test implies potential LRP, the co-presence with positive SLRT may imply a severer LRP condition. Further prospective research, in different settings and direct clinical measures, is needed.

Opioid-induced constipation in mixed chronic pain patients: Prevalence and predictors analysis.

OBJECTIVES: Assessment of opioid-induced constipation (OIC) prevalence and relationship with demographic, clinical, and drug predictors in our daily practice. DESIGN: Observational and retrospective study. SETTING: Chronic pain (CP) center of Bologna's Teaching Hospital, Italy. SUBJECTS: Mixed consecutive CP opioid-user outpatients (n = 128). MAIN OUTCOME MEASURE(S): OIC was assessed with the Bowel Function Index (BFI) in three consecutive visits. Absolute difference and Student's t-test were used to compare BFI scores. Predictors (opioid compound and type, morphine-equivalent daily-dose [MEDD], and laxatives) were retrieved from the patients' charts. BFI and predictors relationships were checked by multinomial logistic regression (MLR); independent predictors of BFI scores were assessed with χ2 analysis. RESULTS: Of the 384 evaluations, 85 percent were on strong opioids with a MEDD range of 11-50 mg per day in the majority (60 percent) and 64 percent showed moderate constipation; 42 percent did not use laxatives while 24 percent used macrogol with significant decrease in the BFI. MLR showed that oxycodone was associated with a risk for moderate constipation. Lactulose and glycerin suppositories were associated with severe constipation. Non-opioid users and cancer patients were associated with normal bowel function and severe constipation, respectively. CONCLUSIONS: OIC was found in almost all evaluations of weak or strong opioidusers (97 percent); moderate to severe OIC was found in 72 percent of the evaluations. Cancer patients were associated with severe constipation. Macrogol was superior to other laxatives. In our experience, macrogol relieved constipation in those on the combination of oxycodone and naloxone and in those on fentanyl patches. Lactulose and glycerol suppositories were associated with severe constipation.

Development and performance of a diagnostic/prognostic scoring system for breakthrough pain.

OBJECTIVES: Variable prevalence and treatment of breakthrough pain (BTP) in different clinical contexts are partially due to the lack of reliable/validated diagnostic tools with prognostic capability. We report the statistical basis and performance analysis of a novel BTP scoring system based on the naïve Bayes classifier (NBC) approach and an 11-item IQ-BTP validated questionnaire. This system aims at classifying potential BTP presence in three likelihood classes: "High," "Intermediate," and "Low." METHODS: Out of a training set of n=120 mixed chronic pain patients, predictors associated with the BTP likelihood variables (Pearson's χ2 and/or Fisher's exact test) were employed for the NBC planning. Adjusting the binary classification to a three-likelihood classes case enabled the building of a scoring algorithm and to retrieve the score of each predictor's answer options and the Patient's Global Score (PGS). The latter medians were used to establish the NBC thresholds, needed to evaluate the scoring system performance (leave-one-out cross-validation). RESULTS: Medians of PGS in the "High," "Intermediate," and "Low" likelihood classes were 3.44, 1.53, and -2.84, respectively. Leading predictors for the model (based on score differences) were flair frequency (ΔS=1.31), duration (ΔS=5.25), and predictability (ΔS=1.17). Percentages of correct classification were 63.6% for the "High" and of 100.0% for either the "Intermediate" and "Low" likelihood classes; overall accuracy of the scoring system was 90.9%. CONCLUSION: The NBC-based BTP scoring system showed satisfactory performance in classifying potential BTP in three likelihood classes. The reliability, flexibility, and simplicity of this statistical approach may have significant relevance for BTP epidemiology and management. These results need further impact studies to generalize our findings.

Development, validation and psychometric properties of a diagnostic/prognostic tool for breakthrough pain in mixed chronic-pain patients.

BACKGROUND/OBJECTIVE: Breakthrough pain (BTP) shows variable prevalence in different clinical contexts of cancer and non-cancer patients. BTP diagnostic tools with demonstrated reliability, validation and prognostic capability are lacking. We report the development, psychometric and validation properties of a diagnostic/prognostic tool, the IQ-BTP, for BTP recognition, its likelihood and clinical features among chronic-pain (CP) patients. PATIENTS: n=120 consecutive mixed cancer/non-cancer CP in/outpatients. Development, psychometric analyses and formal validation included: Face/Content validity (by 'experts' opinion and assessing the relationship between the IQ-BTP classes and criteria derived from BTP operational-case-definition); Construct validity, by Principle Component Analysis (PCA); and the strength of Spearman correlation between IQ-BTP classes and the Brief Pain Inventory (BPI) items; Reliability, by Cronbach's alpha statistics. Associations with clinical/demographic moderators were assessed applying χ(2) analysis. RESULTS: Potential-BTP was found in 36.7% of patients (38.4% of non-cancer and 32.4% of cancer patients). Among these the likelihood for BTP diagnosis was 'high' in 25%, 'intermediate' in 41% and, 'low' 34% of patients. Analyses showed significant differences between IQ-BTP classes and between the latter BPI pain-item scores. Correlation between IQ-BTP classes and BPI items was moderate. PCA and scree test identified 3 components accounting for 62.3% of the variance. Cronbach's alpha was 0.71. CONCLUSIONS: The IQ-BTP showed satisfactory psychometric and validation properties. With adequate feasibility it enabled the allocating of cancer/non-cancer CP patients in three prognostic classes. Results are sufficient to warrant a subsequent impact study of the IQ-BTP as prognostic model and screening tool for BTP in both CP populations.

Medical Evidence Influence on Inpatients and Nurses Pain Ratings Agreement.

Biased pain evaluation due to automated heuristics driven by symptom uncertainty may undermine pain treatment; medical evidence moderators are thought to play a role in such circumstances. We explored, in this cross-sectional survey, the effect of such moderators (e.g., nurse awareness of patients' pain experience and treatment) on the agreement between n = 862 inpatients' self-reported pain and n = 115 nurses' pain ratings using a numerical rating scale. We assessed the mean of absolute difference, agreement (κ-statistics), and correlation (Spearman rank) of inpatients and nurses' pain ratings and analyzed congruence categories' (CCs: underestimation, congruence, and overestimation) proportions and dependence upon pain categories for each medical evidence moderator (χ (2) analysis). Pain ratings agreement and correlation were limited; the CCs proportions were further modulated by the studied moderators. Medical evidence promoted in nurses overestimation of low and underestimation of high inpatients' self-reported pain. Knowledge of the negative influence of automated heuristics driven by symptoms uncertainty and medical-evidence moderators on pain evaluation may render pain assessment more accurate.

Lasting Prolonged-Release Tapentadol for Moderate/Severe Non-Cancer Musculoskeletal Chronic Pain.

INTRODUCTION: Despite opioids' recognized role in the treatment of moderate/severe musculoskeletal chronic pain, their long-term benefits need investigation. We explored the lasting analgesic efficacy, tolerability, influence on life quality, and chronicity stage of the novel prolonged release (PR) opioid, tapentadol, in 30 outpatients. METHODS: We evaluated patients' pain intensity and relief (Numerical Rating Scale; NRS), adverse effects, sleep quality, treatment satisfaction, health status (12-questions Health-Survey; SF-12), chronicity stage (Italian Mainz Pain-Staging System; I-MPSS) at 10, 30, 60, and 90 days after tapentadol prescription. RESULTS: At follow-ups, the investigated outcomes showed an overall statistically significant (Wilcoxon signed-rank test) improvement and remained stable over time, as did the health status and chronicity stage. Adverse effects were limited, transitory, and tolerable. CONCLUSIONS: Twelve weeks of PR tapentadol in outpatients with moderate/severe chronic musculoskeletal pain showed satisfactory analgesic efficacy and tolerability, and had a positive influence on life quality and chronicity stage. The results are robust enough to warrant a subsequent study with a larger sample and a longer observation period.

Psychometric properties and validation of the Italian version of the Mainz pain staging system as a tool for pain-patients referral selection.

RATIONALE, AIMS AND OBJECTIVES: Indications are lacking on which patient to refer to pain facilities. Pain-chronicity stage and outcome prognosis may be used for such aims. The Mainz pain-staging system (MPSS) classifies pain patients in three chronicity stages that respectively require more extensive management. We explored the psychometric and validation properties of its Italian version towards its application as screening/referral tool. METHODS: I-MPSS was administered to n=120 mixed non-cancer-pain outpatients. Psychometric analyses and formal validation included: content validity, by assessing the hypothesis of an existing relationship between the I-MPSS classes and criteria derived from an operational case definition of chronic pain; construct validity, by principle component analysis (PCA); the autonomous construct of the I-MPSS was assessed by the strength of the Spearman correlation between its classes and the brief pain inventory (BPI) items; and reliability, by applying Cronbach's alpha statistics. Associations between psychosocial moderators and the I-MPSS were assessed applying χ(2) analyses. RESULTS: Quantitative and qualitative analyses showed significant differences between I-MPSS classes for health care and drug utilization; BPI item scores significantly differed between the classes; Spearman correlation between I-MPSS classes and BPI items was mostly moderate or mild. PCA and scree test identified four components accounting for 63.7% of the variance. Cronbach's alpha was 0.842. CONCLUSIONS: The I-MPSS showed satisfactory psychometric and validation properties. With adequate feasibility, it enabled the screening of mixed non-cancer-pain outpatients in three chronicity/prognostic stages. Results are sufficient to warrant its use for a subsequent impact study as a prognostic model and screening tool for referring pain patients.

Opioid titration with sustained-release oxycodone and immediate-release morphine for moderate/severe cancer pain: a pilot assessment of the CoDem protocol.

OBJECTIVES: Opioid titration is the first challenging stage for rapid control of moderate/severe cancer pain. Evidence shows that sustained-release formulations may be used for opioid titration. We set a pilot assessment of the efficacy and tolerability of our in-house protocol (continuous and on demand opioids [CoDem]) of the association of sustained-release oxycodone and immediate-release morphine as rescue dose for opioid titration/rotation in opioid-naïve (NAOP, n = 13), tolerant to weak (WOP, n = 20), or strong opioids (STOP, n = 44) in-patients with moderate/severe cancer pain. METHODS: Observational and retrospective analysis of cancer in-patients treated for ≥7 days with the CoDem protocol. OUTCOME MEASURES: Pain intensity (patients self-reported pain with numerical rating scale [NRS] under static [NRSs] and dynamic [NRSd] conditions), amount of drug consumption, opioid adverse effects, and patient satisfaction. EFFICACY ENDPOINTS: In more than 50 percent of the patients and in <72 hours, steady NRSs and NRSd score reduction of at least two points, NRSs ≤ 3 and NRSd ≤4; and mean daily morphine consumption < mean of one rescue dose and t1:t6 ratio of mean oxycodone daily dose < 1:2. RESULTS: Endpoints were reached within 24 hours both within the sample and subgroups. Only NAOP patients reached NRSd ≤ 4 endpoint within 48 hours. Against moderate and transient adverse effects, most patients (84.4 percent) found pain treatment to be good or excellent. CONCLUSIONS: The CoDem protocol was shown to be effective and reasonably tolerated for titration for moderate/severe cancer pain relief in both opioid-naïve or opioid-tolerant cancer in-patients. This pilot assessment warrants prospective and comparative studies with larger samples for more generalized results.