7,169 research outputs found

    Lower extremity near-infrared spectroscopy after popliteal block for orthopaedic foot surgery

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    BACKGROUND: Noninvasive measurement of cutaneous tissue oxygenation using near-infrared spectroscopy (NIRS) has become common in peri-operative care. Following institution of peripheral nerve blocks, neurovascular alterations in the blocked region have been described. OBJECTIVE: The primary aim of this study encompassed the assessment of the influence of a popliteal block on changes in regional oxygen saturation (SrO(2)), and the location of most prominent changes. METHOD: We conducted a prospective randomised controlled trial. Hundred twenty patients who received a popliteal block for foot surgery were included. Popliteal block was performed under echographic guidance. The patients were randomized in 3 groups according to the location of the SrO(2) electrodes on the legs. Bilateral SrO(2) measurements were performed simultaneously. SrO(2) in the operated leg and in the control leg was measured at baseline and 1, 5, 10, 15, and 30 minutes after the perineural injection. We quantified the evolution in SrO(2) by calculating over time the differences in SrO(2) values between the operated and control leg (=ΔSrO(2)). RESULTS: At 30 minutes, ΔSrO(2) increased significantly (p<0.05) at the plantar side of the foot (11.3% ± 2.9%), above the ankle (4.9% ± 1.3%) and the popliteal fossa (3.6% ± 1.2%). CONCLUSION: At 30 minutes after institution of the popliteal block, ΔSrO(2) was most prominent at the plantar side of the foot as compared with measurement performed above the ankle or under the knee

    Is resistance to ischaemia of motor axons in diabetic subjects due to membrane depolarization?

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    The reasons for the resistance to ischaemia of peripheral nerves in diabetics are not well understood. We have now explored whether axonal depolarization underlies this phenomenon, as has previously been proposed. Resistance to ischaemia was determined by the new method of “threshold tracking”. This method revealed an increase in excitability of the peroneal nerve at the popliteal fossa during ischaemia, and a decrease in excitability in the post-ischaemic period. The extent of these alterations in 28 type 1 diabetics without peripheral neuropathy showed a strong correlation with the mean blood glucose concentrations during the last 24 h before examination. To test whether the ischaemic resistance was related to membrane potential, we also measured axonal superexcitability in 11 selected diabetics, since it has been shown that post-spike changes in excitability depend on membrane potential. Changes in excitability of the peroneal nerve were measured in the period between 10 and 30 msec following a conditioning supramaximal compound action potential. Under resting conditions, no differences in the post-spike superexcitability were found between controls and diabetics, despite striking differences in their responses to a 10-min pressure cuff. These observations indicate that membrane depolarization is not involved in the resistance to ischaemia of motor axons in diabetic subjects

    Sciatic neuropathy with preserved sensory nerve action potentials, a case series

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    Background: Sciatic neuropathy is differentiated from lumbosacral radiculopathy based on the finding of abnormal sensory nerve action potentials (SNAPs). Cases of sciatic neuropathy with intact SNAPS have not been well described. Methods: A retrospective analysis of 12 patients with sciatic neuropathy in a single institution. Results: We describe 12 patients in whom a sciatic neuropathy was diagnosed based on a combination of history, physical exam, radiological and electrodiagnostic (EDX) findings. Lower extremity SNAPs were found to be within normal range in all patients, although SNAP amplitude asymmetry between both sides was observed in 3. Included patients were young (mean age of 40.3 years) and mostly female (9 patients). Conclusions: Sciatic neuropathy may occur with a relative sparing of sensory fibers. Recognition of this group of patients should help to avoid making a misdiagnosis of lumbosacral radiculopathy

    Clathrin structure characterized with monoclonal antibodies. I. Analysis of multiple antigenic sites.

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    Three monoclonal antibodies that react with previously undefined antigenic determinants on the clathrin molecule have been produced and characterized. They were isolated from a fusion between myeloma cells and popliteal lymphocytes from SJL mice that had received footpad injections of human brain clathrin. This protocol was chosen to favor the production of antibodies to poorly immunogenic proteins and thereby increase the repertoire of anti-clathrin monoclonal antibodies. One antibody (X16) reacts preferentially with the heavier of the two clathrin light chains (LCa) when it is not associated with heavy chain. This specificity is different from that of the anti-LCa antibody, CVC.6, which has preferential reactivity with heavy chain-associated LCa. In addition, X16 and CVC.6 bound simultaneously to LCa, confirming that they react with different sites. The other two antibodies produced, X19 and X22, react with two different determinants on the clathrin heavy chain, based on immunoprecipitation, Western blot, and binding studies. Competitive binding studies with anti-clathrin monoclonal antibodies showed that they define a total of five distinct antigenic determinants on bovine clathrin

    Additional femoral catheter in combination with popliteal catheter for analgesia after major ankle surgery

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    Background The contribution of the saphenous nerve in pain after major ankle surgery is unknown. The aim of this study was to evaluate its contribution in this context. Methods Fifty patients were included in this prospective, randomized, controlled study. In all patients [Group P (popliteal) and Group F (popliteal+femoral)], a popliteal catheter was placed before operation and ropivacaine 0.5% (30 ml) administered via this catheter; major ankle surgery was then performed under spinal anaesthesia. In Group PF patients, an additional femoral catheter was sited before operation and ropivacaine 0.5% (10 ml) administered. Six hours after spinal anaesthesia (defined as T0), a continuous infusion of ropivacaine 0.3% (14 ml h−1) was started through the popliteal catheter until T24. Then, the concentration was reduced to 0.2% until T48. Patients in Group PF received continuous ropivacaine 0.2% (5 ml h−1) through the femoral catheter from T0 to T48. I.V. morphine patient-controlled analgesia was used as a rescue analgesia. Pain at rest, pain with movement, adverse effects, and i.v. morphine consumption were assessed. Pain at rest and on movement was evaluated 6 months after operation. Results Pain at rest was comparable in the two groups. In Group PF, patients had significantly reduced pain during movement in the postoperative period (P=0.01) and 6 months after operation (P=0.03). Morphine consumption was significantly reduced in Group PF at T0-T24 and T24-T48 (P=0.01). Adverse effects were comparable in both groups. Conclusions The addition of continuous femoral catheter infusion of ropivacaine to a continuous popliteal catheter infusion improved postoperative analgesia during movement after major ankle surgery. This effect was still present 6 months after surger

    Estudio comparativo del bloqueo anestésico del nervio ciático con ropivacaína 0,5% por vía medio-femoral versus poplítea lateral

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    Introducción: El bloqueo anestésico/analgésico del nervio ciático por vía medio-femoral es una técnica nueva que se ha utilizado para la analgesia postoperatoria de la cirugía de rodilla. Su mayor ventaja es que se puede realizar en decúbito supino, evitando el decúbito prono necesario en otras técnicas de abordaje, y que obliga al paciente a soportar dolor durante su realización. Objetivo: El objetivo de este estudio fue comparar la eficacia, tiempo de latencia y grado de aceptación del paciente entre el bloqueo anestésico/analgésico del nervio ciático realizado por vía medio-femoral y el bloqueo ciático lateral a nivel poplíteo en pacientes sometidos a cirugía de la extremidad inferior. Métodos: En este estudio de tipo aleatorio y prospectivo, se incluyeron 63 pacientes que iban a ser intervenidos quirúrgicamente de la extremidad inferior. En el grupo PB 32 pacientes recibieron un bloqueo ciático lateral a nivel poplíteo, mientras que en el grupo MF 31 pacientes recibieron el mismo bloqueo pero a nivel medio-femoral lateral. En ambos grupos la dosis de anestésico local administrada fue de 30 mi de ropivacaína al 0,5%. Resultados: La calidad del bloqueo fue similar en ambos grupos. Los tiempos de latencia del bloqueo (desde el final del bloqueo al inicio de su efecto) tanto sensitivo como motor fueron significativamente menores en el grupo MF que en el grupo PB (tabla 2). Sin embargo no hubo diferencia estadística en la duración del bloqueo sensitivo y motor entre ambos grupos. NO hubo tampoco diferencia en la dificultad de realización del bloqueo entre ellos. El grado de molestia para el paciente durante la inserción de la aguja de bloqueo fue similar. La tolerancia al manguito de isquemia fue mejor en el grupo MF, pero sin llegar a niveles de significación estadística. Medicina Balear 2004; 18-25 Conclusión: El abordaje medio-femoral del nervio ciático para cirugía de tobillo y pie, proporciona una anestesia eficaz comparable al abordaje poplíteo lateral. Esta nueva técnica es simple y segura, y proporciona una analgesia postoperatoria tan efectiva como la obtenida con el abordaje poplíteo lateral

    Cравнение эффективности блокады седалищного нерва, выполняемой под уз-контролем тремя доступами: чрезъягодичным, подъягодичным и подколенным

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    АНЕСТЕЗИЯСЕДАЛИЩНЫЙ НЕРВПЕРИФЕРИЧЕСКАЯ БЛОКАДАСЕНСОРНЫЙ БЛОКМОТОРНЫЙ БЛОКУЗ-КОНТРОЛЬПОДЪЯГОДИЧНЫЙ ДОСТУППОДКОЛЕННЫЙ ДОСТУПЧРЕЗЪЯГОДИЧНЫЙ ДОСТУППОСЛЕОПЕРАЦИОННЫЙ ПЕРИО
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