Ultrasound Mapping of Nerve Stimulator Response during Sciatic Nerve Blockade and Relation to Postoperative Pain Scores

1.1 Background and Purpose: Ultrasound guided sciatic nerve blockade has rapid onset but at 24 hours pain is greater than nerve stimulator techniques. Injection of the nerve branches or trunk and sub-sheath blockade increase success and reduce onset times but risk injury. This study mapped needle coordinates for sciatic nerve blockade with nerve stimulation and its relation to postoperative pain scores. 1.2 Method: Angle and distance of the needle tip and infusion catheter from the popliteal sciatic nerve at which stimulated plantar flexion occurred were measured. Pain scores at postanesthesia unit discharge and 24 hours were recorded. 1.3 Results: 81% of opioid naïve patients reported immediate analgesia and 20.8% at 24 hours. In opioid tolerant patients 56.8% reported immediate analgesia and 9.1% at 24 hours. Plantar flexion was observed with the needle in the posterior medial quadrant near the sciatic nerve. Opioid tolerant patients reported adequate analgesia when the needle was located more medially and proximally to the sciatic nerve. 1.4 Conclusion: Stimulated plantar flexion is isolated to a narrow angular range in the posterior medial quadrant adjacent to the sciatic nerve. Opioid tolerant patients report adequate analgesia if the needle and catheter are more medial and proximal to the nerve surface.

Differences in analgesia in opioid naïve and tolerant patients with sciatic nerve blockade following elective foot and ankle surgery

1.1 Introduction and Purpose: Adequate postoperative analgesia in the opioid tolerant with chronic non-malignant pain is challenging. Multimodal pain relief regimens include regional anesthesia but opioid tolerant patients report increased postoperative pain and opioid consumption. This study compared analgesia in opioid naïve and tolerant patients receiving postoperative sciatic nerve blockade for foot and ankle surgery. 1.2 Method: Preoperative pain scores, trauma, maintenance and intraoperative opioid doses and following postoperative sciatic nerve blockade, patient self-reported pain scores and opioid consumption at discharge from the post-anesthesia unit and 24 hours were recorded. 1.3 Results: 191 patients enrolled. 40.3% were opioid tolerant and 33% had lower extremity trauma. Preoperative, immediate and delayed postoperative pain scores and intraoperative, immediate and 24 hour postoperative consumption of opioids were increased in opioid tolerant patients. Trauma and continuous infusion in opioid naïve and tolerant groups did not result in differences in 24 hour opioid consumption. 1.4 Limitations: Small subgroups and use of the pain score limited the accuracy of results. 1.5 Conclusion: Opioid tolerant patients require greater analgesic doses following sciatic nerve blockade for foot and ankle surgery. 24 hour opioid consumption for opioid naïve and tolerant patients is neither influenced by lower extremity injury nor continuous infusion.

Potential for Cell-Transplant Therapy with Human Neuronal Precursors to Treat Neuropathic Pain in Models of PNS and CNS Injury: Comparison of hNT2.17 and hNT2.19 Cell Lines

Effective treatment of sensory neuropathies in peripheral neuropathies and spinal cord injury (SCI) is one of the most difficult problems in modern clinical practice. Cell therapy to release antinociceptive agents near the injured spinal cord is a logical next step in the development of treatment modalities. But few clinical trials, especially for chronic pain, have tested the potential of transplant of cells to treat chronic pain. Cell lines derived from the human neuronal NT2 cell line parentage, the hNT2.17 and hNT2.19 lines, which synthesize and release the neurotransmitters gamma-aminobutyric acid (GABA) and serotonin (5HT), respectively, have been used to evaluate the potential of cell-based release of antinociceptive agents near the lumbar dorsal (horn) spinal sensory cell centers to relieve neuropathic pain after PNS (partial nerve and diabetes-related injury) and CNS (spinal cord injury) damage in rat models. Both cell lines transplants potently and permanently reverse behavioral hypersensitivity without inducing tumors or other complications after grafting. Functioning as cellular minipumps for antinociception, human neuronal precursors, like these NT2-derived cell lines, would likely provide a useful adjuvant or replacement for current pharmacological treatments for neuropathic pain.

Spatiotemporal neuromodulation therapies engaging muscle synergies improve motor control after spinal cord injury.

Electrical neuromodulation of lumbar segments improves motor control after spinal cord injury in animal models and humans. However, the physiological principles underlying the effect of this intervention remain poorly understood, which has limited the therapeutic approach to continuous stimulation applied to restricted spinal cord locations. Here we developed stimulation protocols that reproduce the natural dynamics of motoneuron activation during locomotion. For this, we computed the spatiotemporal activation pattern of muscle synergies during locomotion in healthy rats. Computer simulations identified optimal electrode locations to target each synergy through the recruitment of proprioceptive feedback circuits. This framework steered the design of spatially selective spinal implants and real-time control software that modulate extensor and flexor synergies with precise temporal resolution. Spatiotemporal neuromodulation therapies improved gait quality, weight-bearing capacity, endurance and skilled locomotion in several rodent models of spinal cord injury. These new concepts are directly translatable to strategies to improve motor control in humans.

Injury prevention in Queensland : report to Queensland Injury Prevention Council

Injury is the fourth leading cause of death in Australia. Injury rates in Queensland are amongst the highest in Australia and 21.5% of people surveyed for this research reported that their lifestyle or that of an immediate family member had been permanently affected by injury. Injury results in over 40,000 hospital admissions and 200,000 attendances at hospital Emergency Departments in Queensland each year. Queensland's death rate from injuries is higher than the national average, with consistently higher rates of deaths related to transport injuries. Queensland statistics also show higher than national average rates of injuries due to falls, homicide and accidental drowning. (Pike, Muller, Baade & Ward, 2000) In 2000-01 injuries represented over $4 billion (or 8%) of total health system expenditure, and 185,000 disability-adjusted life years (DALYs), or 7% of the total morbidity burden of disease and injury in Australia in 2003. (Begg, Vos, Barker, Stevenson, Stanley & Lopez, 2007). Injury is one of seven key health areas identified by the Commonwealth, state and territory governments for priority attention as National Health Priority Areas

Teaching young people first aid skills to reduce injury

Background First aid given immediately after a motor vehicle crash can have considerable benefits. Less understood however is first aid training as a prevention strategy for reducing risk-taking. A first step is to understand whether first aid skills are associated with risk-taking and injury experiences. Further, students and teachers who undergo or deliver such training offer important perspectives about implementation. Aims The research has two aims: (i) to identify whether first aid knowledge is associated with road risk-taking and injury and (ii) to examine teachers’ and students’ experiences of first aid activities within a school-based injury prevention and control program. Method Participants were 173 Year 9s (47% male) who completed a survey which included demographic information, first aid knowledge and risk-taking behaviour and injury experiences. Focus groups were held with 8 teachers who delivered, and 70 students who participated in, a school-based injury prevention and control program. Results Results showed a relationship between greater first aid knowledge and reduced engagement in risk-taking and injury experiences. Both students and teachers reported favourably on first aid however teachers also acknowledged challenges in delivering practical activities. Discussion & Conclusion It appears that first aid can be implemented within the school setting, particularly at the Year 9 level, and that both students and teachers involved in such training identify multiple benefits and positive experiences with first aid training. In addition, the findings suggest that first aid knowledge could be an important part of a prevention program.

Reduction of Secondary Degeneration after Spinal Cord Injury by Acute Delivery of Proinflammatory Growth Factors

INTRODUCTION Inflammation is a protective attempt to facilitate the removal of damaged tissue and to initiate the healing response in other tissues. However, after spinal cord injury (SCI), this response is prolonged leading to secondary degeneration and glial scarring. Here, we investigate the potential of sustained delivery of pro-inflammatory factors vascular endothelial growth factor (VEGF) and platelet derived growth factor (PDGF) to increase early inflammatory events and promote inflammatory resolution. Method Animal ethics approval was obtained from the Queensland University of Technology. Adult Wistar-Kyoto rats (12-16 weeks old) were subjected to laminectomies and T10 hemisections. Animals were then randomised to treatment (implantation of osmotic pump (Alzet) loaded with 5ug VEGF & 5 ug PDGF) or control groups (lesion control or lesion plus pump delivering PBS). Rats were sacrificed at one month and the spinal cords were harvested and examined by immunohistology, using anti-neurofilament-200(NF200) and anti- ionized calcium binding adapter molecule 1 (Iba1). One way ANOVA was used for statistic analysis. Results At 1 month, active pump-treated cords showed a high level of axonal filament throughout the defects as compared to the control groups. The mean lesion size, as measured by NF200, was 0.47mm2 for the lesion control, 0.39mm2 for the vehicle control and 0.078mm2 for the active pump group. Significant differences were detected between the active pump group and the two control groups (AP vs LC p= 0.017 AG vs VC p= 0.004). Iba-1 staining also showed significant differences in the post-injury inflammatory response. Discussion We have shown that axons and activated microglia are co-located in the lesion of the treated cord. We hypothesise the delivery of VEGF/PDGF increases the local vessel permeability to inflammatory cells and activates these along with the resident microglia to threshold population, which ultimately resolved the prolonged inflammation. Here, we have shown that maintaining the inflammatory signals for at least 7 days improved the morphology of the injured cord. Conclusion This study has shown that boosting inflammation, by delivery VEGF/PDGF, in the early phase of SCI helps to reduce secondary degeneration and may promote inflammation resolution. This treatment may provide a platform for other neuro-regenrative therapies.

Targeting injury prevention strategies to adolescents of Pacific Islander descent : what will work?

Background: Ethnicity is rarely considered in injury prevention program development, even though this is known to impact on participation in injury risk behaviour. An understanding of injury, risk behaviour and risk and protective factors specific to adolescents of Pacific Islander descent will inform the development of prevention strategies appropriate to this group.----- Aims: To determine patterns of injury and associated risk behaviour among adolescents of Pacific Islander descent, and to understand the risk and protective factors that influence injury rates among this group.----- Methods: A total of 875 Year 9 students from five Queensland high schools completed a survey during health classes. Seventy-one students (n = 38 male) identified as Pacific Islander. The survey consisted of scales examining injury, risk taking behaviour, and relationships with family, school and police.----- Results: The leading causes of injury among adolescents of Pacific Islander descent were sports (48%) and transport (e.g. 45% reported bicycle injuries). Interpersonal violence related injuries were also relatively frequent, with 28% having been injured in a fight. Reports of alcohol use were relatively low (20% c.f. 40% of the remaining sample), however reports of other risk behaviours were relatively high (e.g. 43% c.f. 25% of remaining sample reported a group fight).----- Discussion and conclusions: Conclusions will be drawn regarding risk-related injuries reported by adolescents of Pacific Islander descent and those of other ethnic backgrounds. Additionally, risk and protective factors relating to family, school and police will be explored, in order to inform prevention strategies appropriate to this group.

The importance of school connectedness in adolescent risk taking and injury prevention

Background: Injury is the leading cause of mortality for young people in Australia (AIHW, 2008). Adolescent injury mortality is consistently associated with risk taking behaviour, including transport and interpersonal violence (AIHW, 2003), which often occurs in the context of alcohol and other substance use. A rapid increase in risk taking and injury through early to late adolescence highlights the need for effective school based interventions. Aim: The aim of the current research was to examine the relationship between school connectedness and adolescent risk and injury, in order to inform effective prevention approaches. School connectedness, or students’ feelings of belongingness to school, has been shown to be a critical protective factor in adolescence which can be targeted effectively through teacher interventions. Despite evidence linking low school connectedness with increased health risk behaviour, including substance use and violence, research has not yet addressed possible links between connectedness and a broader range of risk taking behaviours (e.g. transport risks) or injury. Method: This study involved background data collection to inform the development of an intervention. A total of 595 Year 9 students (aged 13-14 years) from 5 Southeast Queensland high schools completed questionnaires that included measures of school connectedness, risk taking behaviour, alcohol and other substance use, and injuries. Results: Increased school connectedness was found to be associated with fewer transport risk behaviours and with decreased alcohol and other substance use for both males and females. Similarly, increased school connectedness was associated with fewer passenger and motorcycle injuries for male participants. Both males and females with increased school connectedness reported fewer alcohol related injuries. Implications: These results indicate that school connectedness appears to have protective effects for early adolescence. These findings may also hold for older adolescents and indicate that it may be an important factor to target in school based risk and injury prevention programs. A school connectedness intervention is currently being designed, focusing on teacher professional development. The intervention will be implemented in conjunction with a curriculum based injury prevention program for Year 9 students and will be evaluated through a large scale cluster randomised trial involving 26 schools.