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.

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.

Non-invasive haemodynamic monitoring with Clearsight in patients undergoing spinal anaesthesia for total hip replacement. A prospective observational cohort study.

BACKGROUND: Patients undergoing elective primary total hip replacement and spinal anesthesia may encounter significant hemodynamic instability Objective: The study is aimed at observing the haemodynamic modifications after spinal anaesthesia during total hip replacement in patients managed to "preload independence" with goal directed fluid therapy (GDFT) and monitored non-invasively with Clearsight. METHODS: Thirty patients, aged 50-80 years, with an American Society of Anaesthesiologists' (ASA) score II-III, undergoing elective primary total hip replacement and spinal anaesthesia were enrolled. Patients were monitored with the EV1000 platform and the Clearsight finger-cuff and managed with a goal directed fluid therapy. RESULTS: The 79% of the population showed preload independence at baseline. After spinal, the 93% did not show a significant mean arterial pressure reduction. In our population, 79% reported a decrease >10% of the stroke volume during surgery, while 66% in the Recovery Room. Patients showed an improvement in mean arterial pressure, systemic vascular resistances indexed (SVRI), stroke volume (SV) and stroke volume indexed (SVI) at spinal resolution compared to baseline. CONCLUSIONS: Our cohort population showed hemodynamic stability throughout the study period, with increased SV and decreased SVRI at spinal resolution compared to basal values. Further randomized prospective studies are advocated in the same setting.

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.

Morphine sulfate abuse-deterrent formulations for the treatment of chronic pain.

INTRODUCTION: Abuse-deterrent formulations have been developed to reduce inappropriate opioid use. The aim of this paper is to review existing literature about currently available morphine abuse-deterrent formulations. Areas covered: The US FDA has currently attributed an 'abuse-deterrent formulation' label to two different morphine compounds: an agonist/antagonist combination, and a morphine formulation with physical barrier. The combination of morphine sulfate and naltrexone showed bioequivalence with extended release morphine. Naltrexone was found in low levels or non-detectable in most of the patients. If the capsules are tampered, the orally available naltrexone would be released, causing a decreased euphoria expected by the use of morphine. The application of physical and chemical barriers to the active compound aims at preventing manipulation of the opioid tablet. This abuse-deterrent formulation obtained with a physical barrier did not reduce drug liking compared to ER morphine. Expert commentary: Available data from literature suggest that both formulations may offer an alternative with lower abuse potential in the treatment of chronic pain. Nevertheless, current evidence suggests that only a little percentage of abusers may stop abusing drugs as result of reformulation. More post-marketing studies are advocated to evaluate the real impact of abuse-deterrent formulations.

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.

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.

Iontophoretic transdermal fentanyl for the management of acute perioperative pain in hospitalized patients.

INTRODUCTION: Intravenous (I.V.) morphine administered through a patient-controlled system currently represents the gold standard treatment for moderate to severe acute postoperative pain. To fix the limitations showed by the available I.V. patient-controlled analgesia (PCA) systems that may restrict its use in the clinical practice a needle-free, iontophoretic, fentanyl patient-controlled transdermal system has been developed and recently approved by the United States Food and Drug Administration (FDA) and by the European Medicines Agency (EMA). AREAS COVERED: This review aims at describing the technology, pharmacology and clinical efficacy of fentanyl iontophoretic transdermal system (ITS) in the treatment of acute pain. A literature search was conducted in the PUBMED database using the term 'fentanyl iontophoretic transdermal system' through September 2015 and results from the main clinical trials are discussed. EXPERT OPINION: In 2015, the appropriate treatment of acute pain after surgery is still a challenge and it represents a primary goal in the care of the surgical patient. When regional analgesia techniques are not applicable and systemic analgesia is required, patient controlled systems represent the standard of care for opioid administration. The fentanyl ITS presents several potential advantages compared to the currently used PCA devices. In particular, it does not require intravenous lines and eliminates the potential for drug administration errors, observed with manually programmed standard PCA devices. Nevertheless, further studies are needed to address eventual inter-individual variability especially for opioid tolerant patients.