Nerve localization techniques for peripheral nerve block and possible future directions

Ultrasound guidance is now a standard nerve localization technique for peripheral nerve block (PNB). Ultrasonography allows simultaneous visualization of the target nerve, needle, local anesthetic injectate and surrounding anatomical structures. Accurate deposition of local anesthetic next to the nerve is essential to the success of the nerve block procedure. Unfortunately, due to limitations in the visibility of both needle tip and nerve surface, the precise relationship between needle tip and target nerve is unknown at the moment of injection. Importantly, nerve injury may result both from an inappropriately placed needle tip and inappropriately placed local anesthetic. The relationship between the block needle tip and target nerve is of paramount importance to the safe conduct of peripheral nerve block. This review summarizes the evolution of nerve localization in regional anesthesia, characterizes a problem faced by clinicians in performing ultrasound guided nerve block and explores the potential technological solutions to this problem

The effect of simulation-based training on initial performance of ultrasound-guided axillary brachial plexus blockade in a clinical setting – a pilot study

BACKGROUND: In preparing novice anesthesiologists to perform their first ultrasound-guided axillary brachial plexus blockade, we hypothesized that virtual reality simulation-based training offers an additional learning benefit over standard training. We carried out pilot testing of this hypothesis using a prospective, single blind, randomized controlled trial. METHODS: We planned to recruit 20 anesthesiologists who had no experience of performing ultrasound-guided regional anesthesia. Initial standardized training, reflecting current best available practice was provided to all participating trainees. Trainees were randomized into one of two groups; (i) to undertake additional simulation-based training or (ii) no further training. On completion of their assigned training, trainees attempted their first ultrasound-guided axillary brachial plexus blockade. Two experts, blinded to the trainees’ group allocation, assessed the performance of trainees using validated tools. RESULTS: This study was discontinued following a planned interim analysis, having recruited 10 trainees. This occurred because it became clear that the functionality of the available simulator was insufficient to meet our training requirements. There were no statistically significant difference in clinical performance, as assessed using the sum of a Global Rating Score and a checklist score, between simulation-based training [mean 32.9 (standard deviation 11.1)] and control trainees [31.5 (4.2)] (p = 0.885). CONCLUSIONS: We have described a methodology for assessing the effectiveness of a simulator, during its development, by means of a randomized controlled trial. We believe that the learning acquired will be useful if performing future trials on learning efficacy associated with simulation based training in procedural skills. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01965314. Registered October 17th 2013

A cross-sectional survey of anaesthesia-related expectations amongst patients awaiting upper limb trauma surgery

Background and aims: Little is known regarding patients’ anaesthesia-related expectations when presenting for upper limb trauma surgery. Methods: We conducted a prospective cross-sectional survey exploring prior anaesthetic experience, anaesthesia-related knowledge, anaesthesia expectations, the preoperative visit and factors likely to influence anaesthesia choice. The survey was completed by 192 patients. Results: Anaesthetists were identified as doctors by 52%; 53% were unaware of their planned anaesthesia; 58% indicated likely acceptance of regional anaesthesia. Information regarding anaesthesia originated mostly from surgeons (65%); 93% had not seen an anaesthetist at the time of the survey. Most believed anaesthesia involved ‘going to sleep’ (82%) and 71% expected to receive general anaesthesia. The preoperative anaesthesia visit was rated as important by 65% of patients. 78% indicated that provision of information would increase the likelihood of accepting regional anaesthesia. Reducing postoperative pain and nausea would influence 80% in choosing a regional technique. Conclusion: A knowledge deficit exists regarding anaesthesia modalities for upper limb trauma surgery

dtorsin, the Drosophila Ortholog of the Early-Onset Dystonia TOR1A (DYT1), Plays a Novel Role in Dopamine Metabolism

Dystonia represents the third most common movement disorder in humans. At least 15 genetic loci (DYT1-15) have been identified and some of these genes have been cloned. TOR1A (formally DYT1), the gene responsible for the most common primary hereditary dystonia, encodes torsinA, an AAA ATPase family protein. However, the function of torsinA has yet to be fully understood. Here, we have generated and characterized a complete loss-of-function mutant for dtorsin, the only Drosophila ortholog of TOR1A. Null mutation of the X-linked dtorsin was semi-lethal with most male flies dying by the pre-pupal stage and the few surviving adults being sterile and slow moving, with reduced cuticle pigmentation and thin, short bristles. Third instar male larvae exhibited locomotion defects that were rescued by feeding dopamine. Moreover, biochemical analysis revealed that the brains of third instar larvae and adults heterozygous for the loss-of-function dtorsin mutation had significantly reduced dopamine levels. The dtorsin mutant showed a very strong genetic interaction with Pu (Punch: GTP cyclohydrolase), the ortholog of the human gene underlying DYT14 dystonia. Biochemical analyses revealed a severe reduction of GTP cyclohydrolase protein and activity, suggesting that dtorsin plays a novel role in dopamine metabolism as a positive-regulator of GTP cyclohydrolase protein. This dtorsin mutant line will be valuable for understanding this relationship and potentially other novel torsin functions that could play a role in human dystonia

Disturbances of postural sway components in cannabis users

Introduction A prominent effect of acute cannabis use is impaired motor coordination and driving performance. However, few studies have evaluated balance in chronic cannabis users, even though density of the CB1 receptor, which mediates the psychoactive effects of cannabis, is extremely high in brain regions critically involved in this fundamental behavior. The present study measured postural sway in regular cannabis users and used rambling and trembling analysis to quantify the integrity of central and peripheral nervous system contributions to the sway signal. Methods Postural sway was measured in 42 regular cannabis users (CB group) and 36 non-cannabis users (N-CB group) by asking participants to stand as still as possible on a force platform in the presence and absence of motor and sensory challenges. Center of pressure (COP) path length was measured, and the COP signal was decomposed into rambling and trembling components. Exploratory correlational analyses were conducted between sway variables, cannabis use history, and neurocognitive function. Results The CB group had significantly increased path length and increased trembling in the anterior-posterior (AP) direction. Exploratory correlational analyses suggested that AP rambling was significantly inversely associated with visuo-motor processing speed. Discussion Regular cannabis use is associated with increased postural sway, and this appears to be predominantly due to the trembling component, which is believed to reflect the peripheral nervous system’s contribution to the sway signal

Ongoing life stressors and suicidal ideation among HIV-infected adults with depression

Suicidal ideation is the most proximal risk factor for suicide and can indicate extreme psychological distress; identification of its predictors is important for possible intervention. Depression and stressful or traumatic life events (STLEs), which are more common among HIV-infected individuals than the general population, may serve as triggers for suicidal thoughts

Improving Depression Among HIV-Infected Adults: Transporting the Effect of a Depression Treatment Intervention to Routine Care

Depression affects 20-30% of people with HIV. Randomized controlled trials (RCTs) have demonstrated the effectiveness of interventions to improve depression among HIV-infected adults, but typically have highly selected populations which may limit generalizability. Inverse probability of sampling weights (IPSW) are a recently proposed method to transport (or standardize) findings from RCTs to a specific external target population

Trauma history and depression predict incomplete adherence to antiretroviral therapies in a low income country.

As antiretroviral therapy (ART) for HIV becomes increasingly available in low and middle income countries (LMICs), understanding reasons for lack of adherence is critical to stemming the tide of infections and improving health. Understanding the effect of psychosocial experiences and mental health symptomatology on ART adherence can help maximize the benefit of expanded ART programs by indicating types of services, which could be offered in combination with HIV care. The Coping with HIV/AIDS in Tanzania (CHAT) study is a longitudinal cohort study in the Kilimanjaro Region that included randomly selected HIV-infected (HIV+) participants from two local hospital-based HIV clinics and four free-standing voluntary HIV counselling and testing sites. Baseline data were collected in 2008 and 2009; this paper used data from 36 month follow-up interviews (N = 468). Regression analyses were used to predict factors associated with incomplete self-reported adherence to ART. INCOMPLETE ART ADHERENCE WAS SIGNIFICANTLY MORE LIKELY TO BE REPORTED AMONGST PARTICIPANTS WHO EXPERIENCED A GREATER NUMBER OF CHILDHOOD TRAUMATIC EVENTS: sexual abuse prior to puberty and the death in childhood of an immediate family member not from suicide or homicide were significantly more likely in the non-adherent group and other negative childhood events trended toward being more likely. Those with incomplete adherence had higher depressive symptom severity and post-traumatic stress disorder (PTSD). In multivariable analyses, childhood trauma, depression, and financial sacrifice remained associated with incomplete adherence.\ud This is the first study to examine the effect of childhood trauma, depression and PTSD on HIV medication adherence in a low income country facing a significant burden of HIV. Allocating spending on HIV/AIDS toward integrating mental health services with HIV care is essential to the creation of systems that enhance medication adherence and maximize the potential of expanded antiretroviral access to improve health and reduce new infections

Providers' Attitudes Towards Treating Depression and Self-Reported Depression Treatment Practices in HIV Outpatient Care

Depression is highly prevalent among HIV-infected patients, yet little is known about the quality of HIV providers' depression treatment practices. We assessed depression treatment practices of 72 HIV providers at three academic medical centers in 2010–2011 with semi-structured interviews. Responses were compared to national depression treatment guidelines. Most providers were confident that their role included treating depression. Providers were more confident prescribing a first antidepressant than switching treatments. Only 31% reported routinely assessing all patients for depression, 13% reported following up with patients within 2 weeks of starting an antidepressant, and 36% reported systematically assessing treatment response and tolerability in adjusting treatment. Over half of providers reported not being comfortable using the full FDA-approved dosing range for antidepressants. Systematic screening for depression and best-practices depression management were uncommon. Opportunities to increase HIV clinicians' comfort and confidence in treating depression, including receiving treatment support from clinic staff, are discussed