Annales françaises d'anesthèsie et de rèanimation
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How does general anesthesia (GA) work? Anesthetics are pharmacological agents that target specific central nervous system receptors. Once they bind to their brain receptors, anesthetics modulate remote brain areas and end up interfering with global neuronal networks, leading to a controlled and reversible loss of consciousness. This remarkable manipulation of consciousness allows millions of people every year to undergo surgery safely most of the time. ⋯ During the last decade, the exponential progress in neuroscience and neuro-imaging led to a significant step in the understanding of the neural correlates of consciousness, with direct consequences for clinical anesthesia. Far from shutting down all brain activity, anesthetics lead to a shift in the brain state to a distinct, highly specific and complex state, which is being increasingly characterized by modern neuro-imaging techniques. There are several clinical consequences and challenges that are arising from the current efforts to dissect GA mechanisms: the improvement of anesthetic depth monitoring, the characterization and avoidance of intra-operative awareness and post-anesthesia cognitive disorders, and the development of future generations of anesthetics.
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Ann Fr Anesth Reanim · Feb 2014
ReviewConsequences of brain damage in the public debate regarding the end of life. The mediatic prism: A reflection of reality?
For the last 20 years or so, conflicts on life-support have become the object of widespread media coverage. By focusing public opinion on the alleged physicians' unreasonable obstinacy, these publicized cases impact social debates on life-support. By these, they justify claims for the legalization of assisted suicide, specifically the practice of termination of life by lethal injection. ⋯ As it turns out, the publicized filter does not reflect the true reality of cases involving unreasonable care. Specific procedures could aid in notifying the existence of such situations. The role of health care professionals (excluding physicians) appears to play an essential part in preventing these situations from happening.
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Ann Fr Anesth Reanim · Feb 2014
ReviewAssessing consciousness in coma and related states using transcranial magnetic stimulation combined with electroencephalography.
Thanks to advances in medical care, an increased number of patients recover from coma. However, some remain in vegetative/unresponsive wakefulness syndrome or in a minimally conscious state. Detection of awareness in severely brain-injured patients is challenging because it relies on behavioral assessments, which can be affected by motor, sensory and cognitive impairments of the patients. ⋯ We will then describe a non-invasive technique, transcranial magnetic stimulation combined with high-density electroencephalography (TMS-EEG), which has allowed us to detect the presence or absence of consciousness in different physiological, pathological and pharmacological states. Some potential underlying mechanisms of the loss of consciousness will then be discussed. In conclusion, TMS-EEG is highly promising in identifying markers of consciousness at the individual level and might be of great value for clinicians in the assessment of consciousness.
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When a severe traumatic brain-injured patient arrives to hospital, fear of failure and definite opinions about the outcome modify early care and provoke self-fulfilling prophecies. It is obvious that working on prognosis is not only useful to inform relatives but also permits to maintain a high level of care, key for a better outcome. Mortality is high (40-50%) if deaths in the first days are not excluded. ⋯ Studies with complex statistical methodology give a good estimated probability of bad outcome but must be confirmed by more validation studies. Progress will come from a better understanding of physiopathology. Focuses on processing chain, rapid multi-monitoring, biomarkers, and investigations in MRI and TDI will help to establish opportunities for treatments and to determine limits.
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Ann Fr Anesth Reanim · Feb 2014
ReviewCritical appraisal of organ procurement under Maastricht 3 condition.
The ethics committee of the French Society of Anesthesia and Intensive Care (Sfar) has been requested by the French Biomedical Agency to consider the issue of organ donation in patients after the decision to withdraw life-supportive therapies has been taken. This type of organ donation is performed in the USA, Canada, the United Kingdom, the Netherlands and Belgium. The three former countries have published recommendations formalizing procedures and operations. ⋯ According to French regulations concerning organ procurement in brain-dead patients, the committee stresses the need to restrict this specific way of procurement to severely brain-injured patients, once confirmatory investigations predicting a catastrophic prognosis have been performed. This suggests that the nature of the confirmatory investigation required should be formalized by the French Biomedical Agency on behalf of the French parliamentarians, which should help preserve population trust regarding organ procurement and provide a framework for medical decision. This text has been endorsed by the Sfar.