Anestesia regional y periférica guiada por ultrasonido en el paciente critico

El presente trabajo es un capítulo de libro titulado “Anestesia Regional y Periférica Guiada por Ultrasonido en el Paciente Crítico” que será incluido en la última edición del libro “Manual de Ultrasonido en Terapia Intensiva y Emergencias” cuyo editor es el Doctor José de Jesús Rincón Salas y que será publicado por la Editorial Prado de México para distribución latinoamericana desde dicho país. Por solicitud del editor y teniendo en cuenta el enfoque del libro, el presente trabajo está dirigido a estudiantes de formación, médicos graduados y especialistas en las áreas de cuidado intensivo, anestesiología, dolor, medicina interna y medicina de urgencias. Tiene como propósito empapar de conocimientos necesarios y prácticos en anestesia regional a personas que usualmente no han tenido contacto con la anestesia regional, pues desafortunadamente sólo en los últimos años ha sido posible que la anestesia regional haya comenzado a salir de las salas de cirugía, ámbito donde ha estado confinada tradicionalmente. El lenguaje utilizado es sencillo y el capítulo ha sido escrito para que sea fácil de leer y consultar, dejando así mensajes muy claros sobre la utilidad, viabilidad e implicaciones que tiene el uso de anestesia regional guiada por ultrasonido en cuidado intensivo. Los autores esperamos que de esta manera, el presente capítulo permita continuar superando los obstáculos que se interponen entre los invaluables beneficios de la anestesia regional y los pacientes de cuidado intensivo que necesitan de ella.

Effects of action observation on corticospinal excitability: muscle specificity, direction, and timing of the mirror response

Many human behaviours and pathologies have been attributed to the putative mirror neuron system, a neural system that is active during both the observation and execution of actions. While there are now a very large number of papers on the mirror neuron system, variations in the methods and analyses employed by researchers mean that the basic characteristics of the mirror response are not clear. This review focuses on three important aspects of the mirror response, as measured by modulations in corticospinal excitability: (1) muscle specificity, (2) direction, and (3) timing of modulation. We focus mainly on electromyographic (EMG) data gathered following single-pulse transcranial magnetic stimulation (TMS), because this method provides precise information regarding these three aspects of the response. Data from paired-pulse TMS paradigms and peripheral nerve stimulation (PNS) are also considered when we discuss the possible mechanisms underlying the mirror response. In this systematic review of the literature, we examine the findings of 85 TMS and PNS studies of the human mirror response, and consider the limitations and advantages of the different methodological approaches these have adopted in relation to discrepancies between their findings. We conclude by proposing a testable model of how action observation modulates corticospinal excitability in humans. Specifically, we propose that action observation elicits an early, non-specific facilitation of corticospinal excitability (at around 90 ms from action onset), followed by a later modulation of activity specific to the muscles involved in the observed action (from around 200 ms). Testing this model will greatly advance our understanding of the mirror mechanism and provide a more stable grounding on which to base inferences about its role in human behaviour.

Role of spinal microglia in myositis-induced central sensitisation: An immunohistochemical and behavioural study in rats

There is increasing evidence that spinal glial cells play an important role in chronic pain states. However, so far no data on the role of microglia in muscle pain are available. The aim of the present study was to investigate the involvement of spinal microglial cells in chronic muscle pain. In a rat model of chronic muscle inflammation (injection of complete Freunds adjuvant into the gastrocnemius-soleus muscle) alterations of microglia were visualized with quantitative OX-42 immunohistochemistry in the dorsal horn of the segments L4 and L5 12 days after induction of inflammation. In behavioural experiments the influence of chronic intrathecally applied minocycline - a specific microglia inhibitor - or an antibody against tumour necrosis factor-alpha (TNF-alpha: a cytokine released from microglia) on pain-related behaviour was investigated after 1, 3, 6, and 12 days. The immunhistochemical data show that in the deep laminae of the spinal dorsal horn microglial cells reacted with morphological changes to the muscle inflammation. Following inflammation, the mean boundary length surrounding the OX-42 immunostained area was significantly shorter. This indicates that microglial cells were activated by the myositis and withdrew their processes. Chronic intrathecal administration of minocycline or anti TNF-alpha with an osmotic mini-pump largely normalised the inflammation-induced changes in spontaneous exploratory behaviour and attenuated the hypersensitivity to mechanical stimulation. Both the immunohistochemical and behavioural data show that spinal microglial cells are involved in nociceptive processes in the cause of a chronic muscle inflammation. (C) 2008 European Federation of International Association for the Study of Pain Chapters. Published by Elsevier Ltd. All rights reserved.

TRPV1 receptors are involved in protein nitration and Muller cell reaction in the acutely axotomized rat retina

We report here the protein expression of TRPV1 receptor in axotomized rat retinas and its possible participation in mechanisms involved in retinal ganglion cell (RGC) death. Adult rats were subjected to unilateral, intraorbital axotomy of the optic nerve, and the retinal tissue was removed for further processing. TRPV1 total protein expression decreased progressively after optic nerve transection, reaching 66.2% of control values 21 days after axotomy. The number of cells labeled for TRPV1 in the remnant GCL decreased after 21 days post-lesion (to 63%). Fluoro-jade B staining demonstrated that the activation of TRPV1 in acutely-lesioned eyes elicited more intense neuronal degeneration in the GCL and in the inner nuclear layer than in sham-operated retinas. A single intraocular injection of capsazepine (100 mu M), a TRPV1 antagonist, 5 days after optic nerve lesion, decreased the number of GFAP-expressing Muller cells (72.5% of control values) and also decreased protein nitration in the retinal vitreal margin (75.7% of control values), but did not affect lipid peroxidation. Furthermore, retinal explants were treated with capsaicin (100 mu M), and remarkable protein nitration was then present, which was reduced by blockers of the constitutive and inducible nitric oxide synthases (7-NI and aminoguanidine, respectively). TRPV1 activation also increased GFAP expression, which was reverted by both TRPV1 antagonism with capsazepine and by 7-NI and aminoguanidine. Given that Muller cells do not express TRPV1, we suppose that the increased GFAP expression in these cells might be elicited by TRPV1 activation and by its indirect effect upon nitric oxide overproduction and peroxynitrite formation. We incubated Fluorogold pre-labeled retinal explants in the presence of capsazepine (1 mu M) during 48 h. The numbers of surviving RGCs stained with fluorogold and the numbers of apoptotic cells in the GCL detected with TUNEL were similar in lesioned and control retinas. We conclude that TRPV1 receptor expression decreased after optic nerve injury due to death of TRPV1-containing cells. Furthermore, these data indicate that TRPV1 might be involved in intrinsic protein nitration and Muller cell reaction observed after optic nerve injury. (C) 2010 Elsevier Ltd. All rights reserved.

Efeitos da eletroestimulação percutânea na incontinência urinária e qualidade de vida pós-prostatectomia: registro de seis casos

Introduction: Radical prostatectomy surgery is the best treatment currently adopted by detecting prostate cancer. The urinary incontinence is one more common and difficult to treat postoperative complications, which causes a negative impact on quality of life of the individual prostatectomy . The surface electrical nerve stimulation involves the transmission of electrical impulses from an external stimulator for peripheral nerve through surface electrodes attached to skin. It is an easy and efficient technique, widely used for pain relief, rehabilitation and muscle strengthening. Objective: To analyze the effect of T10-L2 percutaneous electrical stimulation, in individuals with urinary incontinence who underwent radical prostatectomy by the laparoscopic technique. Methods: Six patients had previously undergone radical prostatectomy were submitted to 20 sections of surface electrical stimulation with frequency of 4 Hz, pulse width of 1ms during 20 minutes. All subjects fillid a quality of life - International Consultation on Incontinence Questionnaire- Short FormI - ICIQ-SF questionnaire evaluating. Results: Results showed reduction in the use of the number of pads, number of leaks before and after treatment, and reduced voiding frequency and consequent improvement in quality of life. No side effects were reported. Conclusion: Percutanous electrical stimulation in T10-L2 may be an effective technique to treat urinary incontinence (UI) after radical prostatectomy video laparoscopy

Complicações neurológicas determinadas pela anestesia subaracnóidea

JUSTIFICATIVA E OBJETIVOS: Complicações neurológicas da anestesia subaracnóidea, apesar de raras, podem determinar seqüelas importantes. O objetivo deste estudo é apresentar estas complicações com a finalidade de esclarecer os fatores desencadeantes, o que facilita o diagnóstico das lesões. CONTEÚDO: São apresentadas as seguintes complicações: lesão de nervo desencadeada pela agulha e cateter, cefaléia pós-punção, síndrome da artéria espinhal anterior, hematoma espinhal, meningite bacteriana, meningite asséptica, aracnoidite adesiva, síndrome da cauda eqüina e sintomas neurológicos transitórios. CONCLUSÕES: O conhecimento dos fatores desencadeantes de complicações neurológicas determinadas pela anestesia subaracnóidea pode prevenir as lesões, diagnosticar e tratar mais precocemente e, desse modo, mudar o prognóstico das mesmas.

Manejo da dor inguinal crônica pós-hernioplastia (inguinodinia)

A dor inguinal crônica pós-herniorrafia é uma situação preocupante, pois aproximadamente 10% dos pacientes submetidos à hernioplastia inguinal apresenta os sintomas, que com frequência limita a capacidade física. A etiopatogênese está relacionada a uma periostite do púbis (dor somática) e mais frequentemente à lesão nervosa (dor neuropática). É importante distinguir clinicamente entre os dois tipos de dor, pois o tratamento pode ser diferente. O médico deve estabelecer uma rotina diagnóstica e de tratamento, sendo que a maior parte dos pacientes necessitarão de terapêutica cirúrgica. A prevenção desta condição é de grande importância e pode levar a uma menor incidência da síndrome. Algumas medidas são fundamentais, como evitar pontos ou clipes no periósteo do púbis, usar criteriosamente as próteses e identificar os nervos da região inguinal. Esta última medida é certamente a mais importante na prevenção da dor crônica e implica em conhecimento profundo da anatomia e o uso de uma técnica aprimorada.

Ação neuro-muscular do veneno crotálico: dados preliminares

Estudamos 6 pacientes, 2 cães e um coelho com intoxicação crotálica. Avaliamos a condução nervosa periférica sensitiva e motora, a transmissão neuromuscular e eletromiografias. As biópsias de músculo foram processadas por histoquímica. Os 6 pacientes apresentaram mononeuropatia sensitiva no nervo periférico adjacente ao local da inoculação do veneno e encontramos evidências histoquímicas de miopatia mitocondrial. Os defeitos da transmissão neuromuscular foram mínimos. A maioria dos autores admite que veneno crotálico determina síndrome miastênica. Nossos achados indicam que ptose palpebral, facies miastênico e fraqueza muscular observados após acidente crotálico, correspondem provavelmente a miopatia mitocondrial, muitas vezes transitória e reversível.

Leprosy patients: neurotrophic factors and axonal markers in skin lesions

Neurotrofinas são fatores de crescimento com papel fundamental na fisiopatologia neural. Esses mediadores modulam funcionalmente fibras nociceptivas. Mudanças em sua expressão têm sido relacionadas à perda precoce da nocicepção na hanseníase. Este estudo investigou a expressão de NGF, BDNF e NT3 em nervos dérmicos de pacientes hansenianos. A caracterização de fibras nervosas não mielinizadas foi feita por p75NTR e marcadores axonais NF-L e PGP 9.5. Os parâmetros clínicos de dano neural foram avaliados por monofilamentos Semmes-Wenstein. Nossos achados demonstram diminuição de NGF nos pacientes dimorfos em comparação aos controles. Resultados similares foram observados para PGP 9.5 (dimorfos: p<0,001; virchowianos: p<0,05) e NF-L (virchowianos: p<0.05), sugerindo degeneração avançada das terminações nervosas na hanseníase multibacilar. Foi observada correlação positiva entre p75NTR e PGP 9.5, indicando associação entre células de Schwann e axônios em fibras nervosas não mielinizadas. Os resultados indicam que o desequilíbrio na expressão das neurotrofinas pode participar do dano neural periférico.

A inadequação dos valores dos limites de tolerância biológica para a prevenção da intoxicação profissional pelo chumbo no Brasil

São revisados os trabalhos que, a partir de 1975,estudaram a ocorrência de manifestações neurológicas centrais e periféricas em trabalhadores ocupacionalmente expostos ao chumbo, que apresentavam níveis de exposição supostamente insuficientes para causarem Saturnismo. A partir da revisão realizada é sugerido que os limites de tolerância biológica utilizados em nosso meio para firmar o diagnóstico de intoxicação profissional pelo chumbo devam ser revistos. Tal sugestão baseia-se na existência de evidências bem estabelecidas que apontam disfunções da condução nervosa periférica e central, além de alterações de várias funções nervosas superiores, em trabalhadores profissionalmente expostos ao chumbo que apresentam indicadores de efeito biológico e indicadores de exposição inferiores aos limites estabelecidos pela legislação brasileira.

Tratamento cirúrgico da fratura-avulsão da inserção tibial do L.C.P. do joelho: experiência de 21 casos

Avaliamos 21 pacientes, sendo 16 pacientes do sexo masculino e 5 do feminino, com idade média de 30 anos, foram submetidos à tratamento cirúrgico da fratura-avulsão do LCP. em 57% dos casos a lesão foi secundária a acidente motociclístico e 19% a acidente automobilístico. em 72% dos casos foi identificada uma lesão na face anterior do joelho. O tratamento cirúrgico consistiu na abordagem posterior do joelho e fixação do fragmento ósseo com parafuso e arruela em 18 casos; e amarrilhas trans-ósseas em 3 casos, onde o fragmento ósseo era muito pequeno. em 91% dos casos, a cirurgia foi realizada dentro dos primeiros 15 dias apos a lesão. Os pacientes foram avaliados objetivamente (teste de gaveta posterior) e subjetivamente (Escala de Lysholm), apos um seguimento pós-operatório mínimo de 12 meses. A análise estatística não mostrou diferença significativa, ao nível de 5%, entre as avaliações objetiva e subjetiva. A ausência de lesão ligamentar periférica pode ter contribuído para que os resultados clínicos pós-operatórios tenham avaliação subjetiva satisfatória; entretanto, a presença de uma posteriorização tibial residual sugere que a fratura-avulsão do ligamento cruzado posterior deve ser abordada não como uma lesão óssea pura, mas sim, como uma lesão ósteo-ligamentar.

Assessment of brachial plexus blockade in chickens by an axillary approach

Objective To assess the brachial plexus block in chickens by an axillary approach and using a peripheral nerve stimulator.Study design Prospective, randomized, double-blinded study.Animals Six, 84-week old, female chickens.Methods Midazolam (1 mg kg(-1)) and butorphanol (1 mg kg(-1)) were administered into the pectoralis muscle. Fifteen minutes later, the birds were positioned in lateral recumbency and following palpation of the anatomic landmarks, a catheter was inserted using an axillary approach to the brachial plexus. Lidocaine or bupivacaine (1 mL kg(-1)) was injected after plexus localization by the nerve stimulator. Sensory function was tested before and after blockade (carpus, radius/ulna, humerus and pectoralis muscle) in the blocked and unblocked wings. The latency to onset of motor and sensory block and the duration of sensory block were recorded. A Friedman nonparametric one-way repeated-measures ANOVA was used to compare scores from baseline values over time and to compare the differences between wings at each time point.Results A total of 18 blocks were performed with a success rate of 66.6% (12/18). The latency for motor block was 2.8 +/- 1.1 and 3.2 +/- 0.4 minutes for lidocaine and bupivacaine, respectively. The latencies for and durations of the sensory block were 6.0 +/- 2.5 and 64.0 +/- 18.0 and 7.8 +/- 5.8 and 91.6 +/- 61.7 minutes for lidocaine and bupivacaine, respectively. There was no statistical difference between these times for lidocaine or bupivacaine. Sensory function was not abolished in nonblocked wings.Conclusions and clinical relevance The brachial plexus block was an easy technique to perform but had a high failure rate. It might be useful for providing anesthesia or postoperative analgesia of the wing in chickens and exotic avian species that have similar wing anatomy.

Neuropathy of Gastrointestinal Chagas' Disease: Immune Response to Myelin Antigens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Latero-terminal neurorrhaphy without removal of the epineural sheath. Experimental study in rats.

Termino-lateral neurorrhaphies have been used up to the beginning of this century. After this period, they have no longer been reported. We tested the efficacy of a new type of latero-terminal neurorrhaphy and evaluated the role of the epineural sheath. A group of 10 rats had the fibular nerve sectioned and the distal ending was sutured to the lateral face of the tibial nerve without removing the epineurium. All experiments were made on the right side, the left one remaining untouched in half of the animals of each group. The other half were denervated by sectioning and inverting the endings of the fibular nerves. In this way, tibial cranial muscles were either normal or denervated in the left side and reinnervated through latero-terminal neurorrhaphy in the right side. After 7.7 months, the animals were subjected to electrophysiological tests, sacrificed, and the nerves and muscles were taken for histological exams. A response of the tibial cranial muscle was obtained in 75% of the animals. The distal ending of the fibular nerve showed an average of 498 nerve fibers. The average areas of the reinnervated tibial cranial muscles were (mu 2):841.30 for M2n and 1798.33 for M2d. We concluded that the termino-lateral neurorrhaphy was functional, conducting electrical stimuli and allowing the passage of axons from the lateral surface of a healthy nerve, to reconstitute the distal segment of a sectioned nerve. The presence of the epineurium was no impediment to axonal regeneration or to the passage of electrical stimuli.(ABSTRACT TRUNCATED AT 250 WORDS)

Distúrbios neurológicos em trabalhadores com baixos níveis de chumbo no sangue. I: Neuropatia periférica

This is a cross-sectional study with a randomized choice of individuals aiming at studying the validity of the Brazilian biological exposure limits applied to lead level in the blood (PbB) and delta-aminolevulinic acid in the urine (ALAU), which are 60 μg/dl and 10 mg/g.creat., respectively. For this purpose, twenty workers, whose PbB and ALAU values have been below these limits over the past two years, were selected at random at a battery production plant in the State of S. Paulo, Brazil. The workers were submitted to a peripheral nerve conduction study. The results were compared with those obtained for workers of a control group also chosen at random. The lead workers showed a decrease in the velocity conduction of the radial nerves. Comparing this group with a randomized control group, a significant difference was observed (p-value = 0.0067). The results suggest that the Brazilian biological exposure limits above should be rearranged.