Best practice in radiofrequency denervation of the lumbar facet joints: a consensus technique.

BACKGROUND: Radiofrequency denervation is used to treat selected people with low back pain. Recent trials have been criticised for using a sub-optimal intervention technique. OBJECTIVES: To achieve consensus on a best practice technique for administering radiofrequency denervation of the lumbar facet joints to selected people with low back pain. STUDY DESIGN: A consensus of expert professionals in the area of radiofrequency denervation of the lumbar facet joints. METHODS: We invited a clinical member from the 30 most active UK departments in radiofrequency pain procedures and two overseas clinicians with specific expertise to a 1 day consensus meeting. Drawing on the known anatomy of the medial branch, the theoretical basis of radiofrequency procedures, a survey of current practice and collective expertise, delegates were facilitated to reach consensus on the best practice technique. RESULTS: The day was attended by 24 UK and international clinical experts. Attendees agreed a best practice technique for the conduct of radiofrequency denervation of the lumbar facet joints. LIMITATIONS: This consensus was based on a 1 day meeting of 24 clinical experts who attended and took part in the discussions. The agreed technique has not been subject to input from a wider community of experts. CONCLUSIONS: Current best practice for radiofrequency denervation has been agreed for use in a UK trial. Group members intend immediate implementation in their respective trusts. We propose using this in a planned Randomised Controlled Trial (RCT) of radiofrequency denervation for selected people with low back pain.

Chronic postsurgical pain and cancer: the catch of surviving the unsurvivable.

PURPOSE OF REVIEW: Chronic postsurgical pain (CPSP) is an important and well recognized cause of much long-term suffering, which in some cases may be preventable and affects many people living with cancer. Unfortunately, general consensus is lacking as to how best reduce the risk of developing CPSP. RECENT FINDINGS: Cancer is now not always a short-lived, fatal disease and is now moving towards a chronic illness. Poorly managed perioperative pain is the greatest risk factor for CPSP. Recent trials have examined preventive strategies for CPSP associated with breast surgery and thoracotomy, two operations used in cancer treatment. Standard antinociceptive drugs, 5% lidocaine patches and ketamine do not prevent CPSP. The evidence for gabapentinoids is conflicting. Intravenous lidocaine and, separately, regional anaesthesia appear beneficial. SUMMARY: Well-managed pain, irrespective of technique, reduces the risk of CPSP. The literature is inconclusive regarding an 'optimal approach.' Regional anaesthesia, intravenous lidocaine and the aggressive management of perioperative pain using multimodal analgesia including antineuropathic pain agents such as gabapentinoids and certain antidepressants are recommended. Clinicians should not rely on general anaesthesia, opioids, NSAIDs and ketamine to prevent CPSP. A blanket approach using gabapentinoids for all patients undergoing major surgery is not indicated. Instead, the presence of perioperative neuropathic pain should be checked for regularly.

Prognosis of diffuse axonal injury with traumatic brain injury.

BACKGROUND: Determine the prognostic impact of magnetic resonance imaging (MRI)-defined diffuse axonal injury (DAI) after traumatic brain injury (TBI) on functional outcomes, quality of life, and 3-year mortality. METHODS: This retrospective single center cohort included adult trauma patients (age > 17 years) admitted from 2006 to 2012 with TBI. Inclusion criteria were positive head computed tomography with brain MRI within 2 weeks of admission. Exclusion criteria included penetrating TBI or prior neurologic condition. Separate ordinal logistic models assessed DAI's prognostic value for the following scores: (1) hospital-discharge Functional Independence Measure, (2) long-term Glasgow Outcome Scale-Extended, and (3) long-term Quality of Life after Brain Injury-Overall Scale. Cox proportional hazards modeling assessed DAI's prognostic value for 3-year survival. Covariates included age, sex, race, insurance status, Injury Severity Score, admission Glasgow Coma Scale Score, Marshall Head computed tomography Class, clinical DAI on MRI (Y/N), research-level anatomic DAI Grades I-III (I, cortical; II, corpus callosum; III, brainstem), ventilator days, time to follow commands, and time to long-term follow-up (for logistic models). RESULTS: Eligibility criteria was met by 311 patients, who had a median age of 40 years (interquartile range [IQR], 23-57 years), Injury Severity Score of 29 (IQR, 22-38), intensive care unit stay of 6 days (IQR, 2-11 days), and follow-up of 5 years (IQR, 3-6 years). Clinical DAI was present on 47% of MRIs. Among 300 readable MRIs, 56% of MRIs had anatomic DAI (25% Grade I, 18% Grade II, 13% Grade III). On regression, only clinical (not anatomic) DAI was predictive of a lower Functional Independence Measure score (odds ratio, 2.5; 95% confidence interval, 1.28-4.76], p = 0.007). Neither clinical nor anatomic DAI were related to survival, Glasgow Outcome Scale-Extended, or Quality of Life after Brain Injury-Overall Scale scores. CONCLUSION: In this longitudinal cohort, clinical evidence of DAI on MRI may only be useful for predicting short-term in-hospital functional outcome. Given no association of DAI and long-term TBI outcomes, providers should be cautious in attributing DAI to future neurologic function, quality of life, and/or survival. LEVEL OF EVIDENCE: Epidemiological, level III; Therapeutic, level IV.

A national survey of pain clinics within the United Kingdom and Ireland focusing on the multidisciplinary team and the incorporation of the extended nursing role.

Inconsistencies in the availability and quality of pain service provision have been noted nationally, as have lengthy waiting times for appointments and lack of awareness of the Pain Clinic role. The 2013 NHS England report stated that specialist pain services must offer multispecialty and multidisciplinary pain clinics. This national survey of multidisciplinary pain service provision in the United Kingdom and Ireland provides a snapshot of pain service provision in order to review and highlight what variations exist in multidisciplinary team (MDT) provision and working patterns. A common perception among clinicians is that financial pressures have led to alternate ways of staff utilisation with variable degrees of success. The survey included 143 pain clinics, focusing principally on MDT working patterns, MDT composition and adoption of the extended role. The results identified that the majority of Pain Clinics utilise the MDT approach. However, provision of critical components such as regular MDT meetings is highly variable as is the composition of the MDT itself and also working patterns of the individual clinicians. The survey reports the successful use of the extended roles for specialist nurses in follow up clinics. In contrast, the survey highlights that a large proportion of clinicians surveyed have reservations about both the effectiveness and the safety of utilising specialist nurses in the extended role to see new referrals of complex pain patients to pain clinics. This survey underlines the essential requirement for incorporation of greater MDT working locally and nationally and allocation of appropriate resources to facilitate this.

Mitochondrial dysfunction in an animal model of diabetic neuropathy is associated with a reduction of neurosteroid synthesis.

Background: Recent work in a model of diabetic neuropathy revealed that layer 2/3 cortical pyramidal neurones of the pain pathway exhibited reduced endogenous neurosteroid modulation of the GABA AR and exogenously applied neurosteroids had an exaggerated impact. It is postulated that this is related to reduced precursor synthesis, due to mitochondrial dysfunction in diabetic neuropathy. Benzodiazepines are also known to activate neurosteroidogenesis by binding to mitochondrial translocator protein (TSPO). This study explored the differential effect of diazepam on GABA AR modulation via neurosteroidogenesis in diabetic and wild type (WT) mice. Methods: Whole-cell patch-clamp technique was used on slices of neural tissue. Electrophysiological recordings were obtained from layer 2/3 cortical pyramidal neurons of the pain pathway from mice with type-II diabetic neuropathy ( ob/ob) and WT controls aged 60-80 days. Results: There was a key difference in the response of the WT and ob/ob cortical neurons to simultaneous incubation with diazepam and flumazenil. In contrast, diazepam and the 5a-reductase inhibitor finasteride, individually or in combination, produced the same response in both strains. Conclusions: The exaggerated effect of diazepam on GABAergic inhibitory tone in the ob/ob, despite the presence of the GABA AR benzodiazepine antagonist flumazenil is likely observed due to physiological upregulation of key neurosteroidogenic enzymes in response to the reduced pregnenolone synthesis by the mitochondria. By increasing pregnenolone via TSPO activation, it is possible to promote enhanced neurosteroidogenesis and increase GABAergic inhibitory tone via an alternate route. In diabetic neuropathic pain, mitochondrial dysfunction may play an important role. Enhancing the GABAergic neurosteroid tone could be of potential therapeutic benefit.

Tracheostomy risk factors and outcomes after severe traumatic brain injury.

OBJECTIVE: To determine risk factors associated with tracheostomy placement after severe traumatic brain injury (TBI) and subsequent outcomes among those who did and did not receive a tracheostomy. METHODS: This retrospective cohort study compared adult trauma patients with severe TBI (n = 583) who did and did not receive tracheostomy. A multivariable logistic regression model assessed the associations between age, sex, race, insurance status, admission GCS, AIS (Head, Face, Chest) and tracheostomy placement. Ordinal logistic regression models assessed tracheostomy's influence on ventilator days and ICU LOS. To limit immortal time bias, Cox proportional hazards models assessed mortality at 1, 3 and 12-months. RESULTS: In this multivariable model, younger age and private insurance were associated with increased probability of tracheostomy. AIS, ISS, GCS, race and sex were not risk factors for tracheostomy placement. Age showed a non-linear relationship with tracheostomy placement; likelihood peaked in the fourth decade and declined with age. Compared to uninsured patients, privately insured patients had an increased probability of receiving a tracheostomy (OR = 1.89 [95% CI = 1.09-3.23]). Mortality was higher in those without tracheostomy placement (HR = 4.92 [95% CI = 3.49-6.93]). Abbreviated injury scale-Head was an independent factor for time to death (HR = 2.53 [95% CI = 2.00-3.19]), but age, gender and insurance were not. CONCLUSIONS: Age and insurance status are independently associated with tracheostomy placement, but not with mortality after severe TBI. Tracheostomy placement is associated with increased survival after severe TBI.

ICU sedation with dexmedetomidine after severe traumatic brain injury.

OBJECTIVE: To comprehensively describe the use of dexmedetomidine in a single institutional series of adult ICU patients with severe TBI. This study describes the dexmedetomidine dosage and infusion times, as well as the physiological parameters, neurological status and daily narcotic requirements before, during and after dexmedetomidine infusion. METHODS: This study identified 85 adult patients with severe TBI who received dexmedetomidine infusions in the Trauma ICU at Vanderbilt University Medical Center between 2006-2010. Demographic, haemodynamic, narcotic use and sedative use data were systematically obtained from the medical record and analysed for changes associated with dexmedetomidine infusion. RESULTS: During infusion with dexmedetomidine, narcotic and sedative use decreased significantly (p < 0.001 and p < 0.05). Median MAP, SBP, DBP and HR also decreased significantly during infusion when compared to pre-infusion values (p < 0.001). Despite the use of dexmedetomidine, RASS and GCS scores improved from pre-infusion to infusion time periods. CONCLUSIONS: The findings demonstrate that initiation of dexmedetomidine infusion is not associated with a decline in neurological functioning in adults with severe TBI. Although there was an observed decrease in haemodynamic parameters during infusion with dexmedetomidine, the change was not clinically significant and the requirements for narcotics and additional sedatives were minimized.

Neurosteroids are reduced in diabetic neuropathy and may be associated with the development of neuropathic pain.

INTRODUCTION: Peripheral and central sensitisation are implicated in the development of neuropathic pain. Hypersensitivity of pain pathway neurons has been described in animal models of diabetic neuropathy, which is postulated to be related to an imbalance between inhibitory and excitatory signals within the spinal cord. GABAergic neurons within the pain pathway are vital for the transmission of painful stimuli to higher centres. A developmental change in the rate of exponential decay of GABAergic synaptic events has been observed in other types of neurons and this may be associated with fluctuations in endogenous neurosteroid tone.  Methods: The whole-cell patch-clamp technique was used on slices of neural tissue. Electrophysiological recordings were obtained from wild type mice between the ages of 6 and 80 days in the spinal cord, the nucleus reticularis of the thalamus and the cerebral cortex. Recordings were also obtained from mice with diabetic neuropathy (ob/ob and db/db) between the ages of 60 and 80 days. Behavioural experiments were performed to examine mechanical and thermal nociception. RESULTS: Electrophysiological recordings from cortical pain pathway neurons from mature type-2 diabetic mice revealed that the endogenous neurosteroid tone is reduced compared to control. However, selected neurosteroid compounds had a more pronounced effect on the GABA A receptors of these diabetic mice. ob/ob mice exhibit mechanical hyperalgesia and allodynia, which was reduced by neurosteroids applied exogenously. CONCLUSIONS: The reduced endogenous neurosteroid tone in ob/ob mice may be linked to their hypersensitivity. Neurosteroids may exert analgesic effects in pathological pain states by attempting to restore the physiological GABAergic inhibitory tone.

Cervical spine collar clearance in the obtunded adult blunt trauma patient: a systematic review and practice management guideline from the Eastern Association for the Surgery of Trauma.

BACKGROUND: With the use of the framework advocated by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group, our aims were to perform a systematic review and to develop evidence-based recommendations that may be used to answer the following PICO [Population, Intervention, Comparator, Outcomes] question:In the obtunded adult blunt trauma patient, should cervical collar removal be performed after a negative high-quality cervical spine (C-spine) computed tomography (CT) result alone or after a negative high-quality C-spine CT result combined with adjunct imaging, to reduce peri-clearance events, such as new neurologic change, unstable C-spine injury, stable C-spine injury, need for post-clearance imaging, false-negative CT imaging result on re-review, pressure ulcers, and time to cervical collar clearance? METHODS: Our protocol was registered with the PROSPERO international prospective register of systematic reviews on August 23, 2013 (REGISTRATION NUMBER: CRD42013005461). Eligibility criteria consisted of adult blunt trauma patients 16 years or older, who underwent C-spine CT with axial thickness of less than 3 mm and who were obtunded using any definition.Quantitative synthesis via meta-analysis was not possible because of pre-post, partial-cohort, quasi-experimental study design limitations and the consequential incomplete diagnostic accuracy data. RESULTS: Of five articles with a total follow-up of 1,017 included subjects, none reported new neurologic changes (paraplegia or quadriplegia) after cervical collar removal. There is a worst-case 9% (161 of 1,718 subjects in 11 studies) cumulative literature incidence of stable injuries and a 91% negative predictive value of no injury, after coupling a negative high-quality C-spine CT result with 1.5-T magnetic resonance imaging, upright x-rays, flexion-extension CT, and/or clinical follow-up. Similarly, there is a best-case 0% (0 of 1,718 subjects in 11 studies) cumulative literature incidence of unstable injuries after negative initial imaging result with a high-quality C-spine CT. CONCLUSION: In obtunded adult blunt trauma patients, we conditionally recommend cervical collar removal after a negative high-quality C-spine CT scan result alone. LEVEL OF EVIDENCE: Systematic review, level III.

Neurologic Functional and Quality of Life Outcomes after TBI: Clinic Attendees versus Non-Attendees.

This investigation describes the relationship between TBI patient demographics, quality of life outcome, and functional status outcome among clinic attendees and non-attendees. Of adult TBI survivors with intracranial hemorrhage, 63 attended our TBI clinic and 167 did not attend. All were telephone surveyed using the Extended-Glasgow Outcome Scale (GOSE), the Quality of Life after Brain Injury (QOLIBRI) scale, and a post-discharge therapy questionnaire. To determine risk factors for GOSE and QOLIBRI outcomes, we created multivariable regression models employing covariates of age, injury characteristics, clinic attendance, insurance status, post-discharge rehabilitation, and time from injury. Compared with those with severe TBI, higher GOSE scores were identified in individuals with both mild (odds ratio [OR]=2.0; 95% confidence interval [CI]: 1.1-3.6) and moderate (OR=4.7; 95% CI: 1.6-14.1) TBIs. In addition, survivors with private insurance had higher GOSE scores, compared with those with public insurance (OR=2.0; 95% CI: 1.1-3.6), workers' compensation (OR=8.4; 95% CI: 2.6-26.9), and no insurance (OR=3.1; 95% CI: 1.6-6.2). Compared with those with severe TBI, QOLIBRI scores were 11.7 points (95% CI: 3.7-19.7) higher in survivors with mild TBI and 17.3 points (95% CI: 3.2-31.5) higher in survivors with moderate TBI. In addition, survivors who received post-discharge rehabilitation had higher QOLIBRI scores by 11.4 points (95% CI: 3.7-19.1) than those who did not. Survivors with private insurance had QOLIBRI scores that were 25.5 points higher (95% CI: 11.3-39.7) than those with workers' compensation and 16.8 points higher (95% CI: 7.4-26.2) than those without insurance. Because neurologic injury severity, insurance status, and receipt of rehabilitation or therapy are independent risk factors for functional and quality of life outcomes, future directions will include improving earlier access to post-TBI rehabilitation, social work services, affordable insurance, and community resources.

Summary of: Developing professional status: an investigation into the working patterns, working relationships and vision for the future of UK clinical dental technicians.

AIMS: To investigate the working patterns and patient base of registered clinical dental technicians (CDTs); their relationships with dentists and other professionals in the dental team; their willingness to work within the NHS and their expectations for the future as a new professional group.Methods Face-to-face qualitative interviews of registered CDTs, selected because of their geographic representation and mode of working, informed the development of a postal questionnaire survey of all early registrants with the General Dental Council (GDC). Results The majority of CDTs reported working part-time, often combining clinical practice with their role as a dental technician. They reported both positive and negative working relationships with dentists and dental technicians, demonstrating collaboration and/or competition depending on whether the scope of CDTs was respected and patient care was shared or lost. CDTs role in the NHS was limited because they did not have the status of becoming a recognised provider of dental care. There was a desire to expand their scope of practice in future. Conclusion CDTs are embracing their new status as an occupational group within dentistry. Core features of becoming a professional group were exhibited including the importance of social and financial status and the need to negotiate their current and future roles in the healthcare system [corrected].

Opportunities for the dental team arising out of the new arrangements for primary dental care.

Many changes are occurring in the delivery of dental care to patients as a result of the implementation of a series of Government initiatives to improve the services to patients throughout the National Health Service (NHS). Dentistry is no exception, and the whole dental team should benefit from new opportunities that have opened up as a result of these changes. This paper outlines a number of these initiatives, and describes some of the potential opportunities that may develop for each group within the dental team. Many of these changes are already in the pipeline, many depend on funding, and many depend on a change in the mindset of established organisations and institutions to think 'outside the box'. The author believes that none of the changes outlined or discussed in this paper challenge the position or status of any group; however, they do require all members of the dental team to examine the way in which they work, to look at the evidence base for these ways of working, and then perhaps look for innovative solutions to the employment, training and development of all members of the team.

Long-term calorie restriction reduces proton leak and hydrogen peroxide production in liver mitochondria.

Calorie restriction (CR) without malnutrition increases maximal life span in diverse species. It has been proposed that reduction in energy expenditure and reactive oxygen species (ROS) production could be a mechanism for life span extension with CR. As a step toward testing this theory, mitochondrial proton leak, H2O2 production, and markers of oxidative stress were measured in liver from FBNF1 rats fed control or 40% CR diets for 12 or 18 mo. CR was initiated at 6 mo of age. Proton leak kinetics curves, generated from simultaneous measures of oxygen consumption and membrane potential, indicated a decrease in proton leak after 18 mo of CR, while only a trend toward a proton leak decrease was observed after 12 mo. Significant shifts in phosphorylation and substrate oxidation curves also occurred with CR; however, these changes occurred in concert with the proton leak changes. Metabolic control analysis indicated no difference in the overall pattern of control of the oxidative phosphorylation system between control and CR animals. At 12 mo, no significant differences were observed between groups for H2O2 production or markers of oxidative stress. However, at 18 mo, protein carbonyl content was lower in CR animals, as was H2O2 production when mitochondria were respiring on either succinate alone or pyruvate plus malate in the presence of rotenone. These results indicate that long-term CR lowers mitochondrial proton leak and H2O2 production, and this is consistent with the idea that CR may act by decreasing energy expenditure and ROS production.

Influence of mitochondrial membrane fatty acid composition on proton leak and H2O2 production in liver.

Mitochondrial membrane fatty acid composition has been proposed to play a role in determining mitochondrial proton leak rate. The purpose of this study was to determine if feeding rats diets with different fatty acid sources produces changes in liver proton leak and H(2)O(2) production. Six-month-old male FBNF(1) rats were fed diets with a primary fat source of either corn or fish oil for a 6-month period. As expected, diet manipulations produced substantial differences in mitochondrial fatty acid composition. These changes were most striking for 20:4n6 and 22:6n3. However, proton leak and phosphorylation kinetics as well as lipid and protein oxidative damage were not different (P > 0.10) between fish and corn oil groups. Metabolic control analysis, however, did show that control of both substrate oxidation and phosphorylation was shifted away from substrate oxidation reactions to increased control by phosphorylation reactions in fish versus corn oil groups. Increased mitochondrial H(2)O(2) production was observed in corn versus fish oil-fed rats when mitochondria were respiring on succinate alone or on either succinate or pyruvate/malate in the presence of antimycin A. These results show that mitochondrial H(2)O(2) production and the regulation of oxidative phosphorylation are altered in liver mitochondria from rats consuming diets with either fish or corn oil as the primary lipid source.