Current opinion in anaesthesiology
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Since the publication of original work on the transversus abdominis plane (TAP) block, the translation of the research into clinical practice has resulted in some 146 articles being published in peer-reviewed journals. However, there continues to be controversies over the best approach to be used. The introduction of ultrasound should have aided the development of this block, but in fact it has caused more questions to be asked. There are a number of reviews of the block already published, but were they published too early and what is our current understanding of the TAP block and its mechanisms of action? ⋯ The TAP block, in all its guises, is an effective analgesic tool, but what is the best approach? Randomized controlled trials comparing the TAP/RAFI blocks to epidural based analgesia are required.
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Curr Opin Anaesthesiol · Oct 2012
ReviewWhere should the tip of the needle be located in ultrasound-guided peripheral nerve blocks?
Data now exist describing the appropriate positioning of the needle tip and pattern of local anaesthetic spread after injection. The recent literature has been analysed in search of studies on the optimal procedure for common approaches centred on block efficacy, performance time, and safety. ⋯ The ultrasound appearance of nerves and target injections are better understood. The specific distributions of local anaesthetic spread that predict success are significantly different from one anatomical site to another. It seems advisable to avoid intraneural injection.
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Curr Opin Anaesthesiol · Oct 2012
ReviewLocal anesthetic 'in-situ' toxicity during peripheral nerve blocks: update on mechanisms and prevention.
Peripheral nerve blocks induce undesired side-effects linked to the toxicity of local anesthetics on neuron and myocytes via different cell targets. The effects of local anesthetics on these targets are now well known and summarized in this review. ⋯ Phenotypic analyses revealed that local anesthetics could induce histological damage with lesions ranging from local to extreme in skeletal muscle. Metabolic alterations were also described involving sarcoplasmic reticulum and calcium dysregulation, alteration of mitochondrial physiology and of oxidative phosphorylation with associated overproduction of harmful reactive oxygen species, typically leading to apoptosis or necrosis. Biochemical and cell biology investigations now indicate that local anesthetics interact with different molecular targets in mammalian cells as respiratory chain complex I or the prosurvival kinase Akt. Functional dysfunction in both muscle and neuron remains to be investigated with caution in patients, as local anesthetic toxicity remains under-evaluated. Likewise, the use of adapted local anesthetics in patients with particular diseases and neuromuscular disorder could further reduce the risk of undesired effect.We need to improve our practice, and the optimization of our clinical protocol could prevent from these side-effects. Lastly, experimental studies highlight the preventive effects of antioxidant drugs or of recombinant human erythropoietin but the pharmacokinetic feature of such strategies remain to be evaluated.
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Curr Opin Anaesthesiol · Oct 2012
ReviewOptimizing the safety and practice of ultrasound-guided regional anesthesia: the role of echogenic technology.
Significant improvements have been made in the quality of ultrasound imaging, and it is now much easier to see nerves. However, the key to safe ultrasound-guided regional anesthesia is to be able to direct the needle to the target. This relies on good needle visibility. We review the recent advances that have been made in this crucial area. ⋯ Good echogenic needles should increase safety, efficacy, and simplicity, and hopefully further drive the adoption of ultrasound-guided techniques, to the benefit of our patients.
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Curr Opin Anaesthesiol · Oct 2012
ReviewUpdates in the management of intracranial pressure in traumatic brain injury.
Traumatic brain injury remains a common and often debilitating event across the world, producing significant burdens upon health and social care. Effective neurocritical care coupled with timely and appropriate neurosurgical intervention can produce significant improvements in patient outcome. There remains controversy about how best to manage intracranial pressure on the ICU; we review the recent literature addressing a number of key variables. ⋯ The role of the neurointensivist in outcome for patients who suffer severe traumatic brain injury is key. Targeted therapies are allowing early detection and manipulation of brain ischaemia leading to more individualized treatment.