Comparative Randomized Study Between Pulsed Radiofrequency and Suprascapular Nerve Block for the Treatment of Chronic Shoulder Pain.

OBJECTIVES: The primary objective of this study was to compare pain intensity after pulsed radiofrequency (RF) or suprascapular nerve block for the treatment of chronic shoulder pain. The secondary objectives were to compare the shoulder range of motion and supplementary analgesic requirement. METHODS: This randomized and prospective study included 40 patients, with chronic shoulder pain allocated into 2 groups. One group underwent pulsed RF, and the other group was submitted to block (B) of the suprascapular nerve, guided by ultrasound. They were assessed for 12 weeks regarding pain intensity, the need for analgesia supplementation, and shoulder range of motion. Side effects were recorded. RESULTS: Pain intensity on movement was lower in the RF group after 2, 4, and 8 weeks. At rest, pain intensity was lower in group RF than in group B after 12 weeks. Pain intensity was lower than before the procedure at all times evaluated, in both groups. There was no difference between groups in the range of motion. There was a need for tramadol supplementation in 1 patient in group RF and 2 in group B. Adverse effects observed were local pain (RF: 1), hematoma (RF: 1; B: 1), and lipothymia (B: 2). DISCUSSION: Pulsed RF on the suprascapular nerve promoted an analgesic effect for 12 weeks. Regarding the intensity of pain on movement and at rest, there was a trend toward a better effect with RF than with nerve blockage treatment. In both groups, there was a reduction in pain intensity without serious adverse effects.

Randomized Clinical Trial Comparing Quadratus Lumborum Block and Intrathecal Morphine for Postcesarean Analgesia.

OBJECTIVE: To compare the efficacy of quadratus lumborum (QL) block and intrathecal morphine (M) for postcesarean delivery analgesia. METHODS: Thirty-one pregnant women with ≥ 37 weeks of gestation submitted to elective cesarean section were included in the study. They were randomly allocated to either the QL group (12.5 mg 0.5% bupivacaine for spinal anesthesia and 0.3 ml/kg 0.2% bupivacaine for QL block) or the M group (12.5 mg bupivacaine 0.5% and 100 mcg of morphine in spinal anesthesia). The visual analog scale of pain, consumption of morphine and tramadol for pain relief in 48 hours, and side effects were recorded. RESULTS: Median pain score and/or pain variation were higher in the morphine group than in the QL group (p = 0.02). There was no significant difference in the consumption of morphine or tramadol between groups over time. Side effects such as pruritus, nausea, and vomiting were observed only in the morphine group. CONCLUSION: Quadratus lumborum block and intrathecal morphine are effective for analgesia after cesarean section. Patients undergoing QL block had lower postoperative pain scores without the undesirable side effects of opioids such as nausea, vomiting, and pruritus.

OBJETIVO: Comparar a eficácia do bloqueio do quadrado lombar (QL) e da morfina intratecal (M) na analgesia pós-cesariana. MéTODOS: Trinta e uma gestantes com ≥ 37 semanas de gestação submetidas a cesariana eletiva foram incluídas no estudo. Eles foram alocados aleatoriamente no grupo QL (12,5 mg de bupivacaína a 0,5% para raquianestesia e 0,3 ml/kg de bupivacaína a 0,2% para bloqueio de QL) ou no grupo M (12,5 mg de bupivacaína a 0,5% e 100 mcg de morfina na raquianestesia). A escala visual analógica de dor, consumo de morfina e tramadol para alívio da dor em 48 horas e efeitos colaterais foram registrados. RESULTADOS: A mediana do escore de dor e/ou variação da dor foi maior no grupo morfina do que no grupo QL (p = 0,02). Não houve diferença significativa no consumo de morfina ou tramadol entre os grupos ao longo do tempo. Efeitos colaterais como prurido, náuseas e vômitos foram observados apenas no grupo morfina. CONCLUSãO: O bloqueio QL e a morfina intratecal são eficazes para analgesia após cesariana. Os pacientes submetidos ao bloqueio do QL apresentaram menores escores de dor pós-operatória sem os efeitos colaterais indesejáveis dos opioides, como náuseas, vômitos e prurido.

An alternative approach for blocking the superior trunk of the brachial plexus evaluated by a single arm clinical trial

Abstract Background Interscalene brachial plexus block is associated with phrenic nerve paralysis. The objective of this study was to evaluate an alternative approach to interscalene brachial plexus blocks in terms of efficacy, grade of motor and sensory blockade, and phrenic nerve blockade. Methods The study was prospective and interventional. The ten living patients studied were 18 to 65 years old, ASA physical status I or II, and submitted to correction of rotator cuff injury. A superior trunk blockade was performed at the superior trunk below the omohyoid muscle, without blocking the phrenic nerve. The needle was advanced below the prevertebral layer until contacting the superior trunk. In order to guarantee the correct positioning of the needle tip, an intracluster pattern of the spread was visualized. The block was performed with 5 mL of 0.5% bupivacaine in ten patients. In the six cadavers, 5 mL of methylene blue was injected. Diaphragmatic excursion was assessed by ultrasonography of the ipsilateral hemidiaphragm. In three patients, pulmonary ventilation was evaluated with impedance tomography. Pain scores and analgesic consumption were assessed in the recovery room for 6 hours after the blockade. Results In the six cadavers, methylene blue didn't reach the phrenic nerve. Ten patients underwent arthroscopic surgery, and no clinically phrenic nerve paralysis was observed. No patient reported pain during the first 6 hours. Conclusions This study suggests that this new superior trunk approach to block the superior trunk may be an alternative technique to promote analgesia for shoulder surgery in patients with impaired respiratory function.

Randomized Clinical Trial Comparing Quadratus Lumborum Block and Intrathecal Morphine for Postcesarean Analgesia / Ensaio Clínico Randomizado Comparando Bloqueio do Quadrado Lombar e Morfina Intratecal Para Analgesia Pós-cesariana

Abstract Objective To compare the efficacy of quadratus lumborum (QL) block and intrathecal morphine (M) for postcesarean delivery analgesia. Methods Thirty-one pregnant women with ≥ 37 weeks of gestation submitted to elective cesarean section were included in the study. They were randomly allocated to either the QL group (12.5 mg 0.5% bupivacaine for spinal anesthesia and 0.3 ml/kg 0.2% bupivacaine for QL block) or the M group (12.5 mg bupivacaine 0.5% and 100 mcg of morphine in spinal anesthesia). The visual analog scale of pain, consumption of morphine and tramadol for pain relief in 48 hours, and side effects were recorded. Results Median pain score and/or pain variation were higher in the morphine group than in the QL group (p = 0.02). There was no significant difference in the consumption of morphine or tramadol between groups over time. Side effects such as pruritus, nausea, and vomiting were observed only in the morphine group. Conclusion Quadratus lumborum block and intrathecal morphine are effective for analgesia after cesarean section. Patients undergoing QL block had lower postoperative pain scores without the undesirable side effects of opioids such as nausea, vomiting, and pruritus.

Resumo Objetivo Comparar a eficácia do bloqueio do quadrado lombar (QL) e da morfina intratecal (M) na analgesia pós-cesariana. Métodos Trinta e uma gestantes com ≥ 37 semanas de gestação submetidas a cesariana eletiva foram incluídas no estudo. Eles foram alocados aleatoriamente no grupo QL (12,5 mg de bupivacaína a 0,5% para raquianestesia e 0,3 ml/kg de bupivacaína a 0,2% para bloqueio de QL) ou no grupo M (12,5 mg de bupivacaína a 0,5% e 100 mcg de morfina na raquianestesia). A escala visual analógica de dor, consumo de morfina e tramadol para alívio da dor em 48 horas e efeitos colaterais foram registrados. Resultados A mediana do escore de dor e/ou variação da dor foi maior no grupo morfina do que no grupo QL (p = 0,02). Não houve diferença significativa no consumo de morfina ou tramadol entre os grupos ao longo do tempo. Efeitos colaterais como prurido, náuseas e vômitos foram observados apenas no grupo morfina. Conclusão O bloqueio QL e a morfina intratecal são eficazes para analgesia após cesariana. Os pacientes submetidos ao bloqueio do QL apresentaram menores escores de dor pós-operatória sem os efeitos colaterais indesejáveis dos opioides, como náuseas, vômitos e prurido.

An alternative approach for blocking the superior trunk of the brachial plexus evaluated by a single arm clinical trial.

BACKGROUND: Interscalene brachial plexus block is associated with phrenic nerve paralysis. The objective of this study was to evaluate an alternative approach to interscalene brachial plexus blocks in terms of efficacy, grade of motor and sensory blockade, and phrenic nerve blockade. METHODS: The study was prospective and interventional. The ten living patients studied were 18 to 65 years old, ASA physical status I or II, and submitted to correction of rotator cuff injury. A superior trunk blockade was performed at the superior trunk below the omohyoid muscle, without blocking the phrenic nerve. The needle was advanced below the prevertebral layer until contacting the superior trunk. In order to guarantee the correct positioning of the needle tip, an intracluster pattern of the spread was visualized. The block was performed with 5.ßmL of 0.5% bupivacaine in ten patients. In the six cadavers, 5.ßmL of methylene blue was injected. Diaphragmatic excursion was assessed by ultrasonography of the ipsilateral hemidiaphragm. In three patients, pulmonary ventilation was evaluated with impedance tomography. Pain scores and analgesic consumption were assessed in the recovery room for 6.ßhours after the blockade. RESULTS: In the six cadavers, methylene blue didn...t reach the phrenic nerve. Ten patients underwent arthroscopic surgery, and no clinically phrenic nerve paralysis was observed. No patient reported pain during the first 6.ßhours. CONCLUSIONS: This study suggests that this new superior trunk approach to block the superior trunk may be an alternative technique to promote analgesia for shoulder surgery in patients with impaired respiratory function.

Chemical Ablation of Genicular Nerve with Phenol for Pain Relief in Patients with Knee Osteoarthritis: A Prospective Study.

BACKGROUND: Radiofrequency ablation of the genicular nerve is performed for knee osteoarthritis (KOA) when conservative treatment is not effective. Chemical ablation may be an alternative, but its effectiveness and safety have not been examined. The objective of this prospective open-label cohort study is to evaluate the effectiveness and safety of ultrasound-guided chemical neurolysis for genicular nerves with phenol to treat patients with chronic pain from KOA. METHODS: Forty-three patients with KOA with pain intensity score (Numeric Rating Scale, NRS) ≥ 4, and duration of pain of more than 6 months were considered for enrollment. Ultrasound-guided diagnostic blocks of genicular nerves (superomedial, inferomedial, and superolateral) with 1.5 mL of 0.25% bupivacaine at each site were performed. Those who reported more than 50% reduction in NRS went on to undergo chemical neurolysis, using 1.5 mL 7% glycerated phenol in each genicular nerve. NRS and Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores were assessed before intervention and at 2 weeks and 1, 2, 3, and 6 months following the intervention. RESULTS: NRS and WOMAC scores improved at all time points. Mean pain intensity improved from 7.2 (95% confidence interval [CI]: 6.8 to 7.7) at baseline to 4.2 (95%CI: 3.5 to 5.0) at 6-month follow-up (P < 0.001). Composite WOMAC score improved from 48.7 (95%CI: 43.3 to 54.2) at baseline to 20.7 (95%CI: 16.6 to 24.7) at 6-month follow-up (P < 0.001). Adverse events did not persist beyond 1 month and included local pain, hypoesthesia, swelling, and bruise. CONCLUSION: Chemical neurolysis of genicular nerves with phenol provided efficacious analgesia and functional improvement for at least 6 months in most patients with a low incidence of adverse effects.

Peripheral nerve block and rebound pain: literature review / Bloqueio de nervos periféricos e dor rebote: revisão de literatura

Abstract Background and objectives: To investigate, describe, and assess the phenomenon of "rebound pain" as a clinically relevant problem in anesthetic practice. Content: The phenomenon of "rebound pain" has been demonstrated and described as a very severe pain, which occurs after a peripheral nerve block resolution with the recovery of sensitivity. The incidence of rebound pain is unknown. Usually, it occurs between 12 and 24 hours after surgery and, adversely affecting sleep quality. It is not yet possible to establish a mechanism as a definitive cause or trigger factor of rebound pain. Studies suggest that rebound pain is a side effect of peripheral nerve blocks, despite their effectiveness in pain control. Currently, the extent and clinical significance of rebound pain cannot be well determined due to the lack of large prospective studies. Conclusion: Rebound pain assessment should always be considered in clinical practice, as it is not a rare side effect of peripheral nerve blocks. There are still many challenging questions to be answered about rebound pain, so large prospective studies are needed to address the issue. For prevention, the use of peripheral nerve block techniques that avoid nerve damage and adequate perioperative analgesia associated with patient education on the early administration of analgesics, even during the period of analgesia provided by peripheral nerve block, is recommended. A better understanding of the "rebound pain" phenomenon, its pathophysiology, associated risk factors, and long-term consequences may help in developing more effective preventive strategies.

Resumo Justificativa e objetivos: Investigar, descrever e avaliar o fenômeno da "dor rebote" como um problema clinicamente relevante na prática anestésica. Conteúdo: O fenômeno da "dor rebote" foi demonstrado e descrito como uma dor muito intensa que ocorre após a resolução do bloqueio de nervo periférico com o retorno da sensibilidade. A incidência de dor rebote é desconhecida. Normalmente ela ocorre entre 12 a 24 horas após a cirurgia e afeta negativamente a qualidade do sono. Ainda não é possível estabelecer um mecanismo como causa definitiva ou fator desencadeante da dor rebote. Estudos sugerem que a dor rebote seja um efeito colateral dos bloqueios de nervos periféricos, apesar destes terem eficácia no controle álgico. Atualmente, a extensão e a significância clínica da dor rebote não podem ser bem determinadas, devido à falta de grandes estudos prospectivos. Conclusão: A avaliação da dor rebote deve ser sempre considerada na prática clínica, pois não é um efeito colateral raro dos bloqueios de nervo periféricos. Ainda existem muitas questões desafiadoras a serem respondidas sobre a dor rebote, portanto fazem-se necessários amplos estudos prospectivos sobre a temática. Para a sua prevenção recomenda-se o uso de técnicas de bloqueio de nervo periférico que evitem a lesão do nervo e uma adequada analgesia perioperatória associada à orientação do paciente sobre a administração precoce de analgésicos mesmo na vigência da analgesia proporcionada pelo bloqueio de nervo periférico. A melhor compreensão do fenômeno "dor rebote", sua fisiopatologia, seus fatores de risco associados e suas consequências em longo prazo poderá ajudar na elaboração de estratégias preventivas mais eficazes.

Ultrasound-guided selective nerve blocks for trigger finger surgeries to maintain flexion/extension of fingers - Case series / Bloqueios seletivos guiados por ultrassom para cirurgias de dedo em gatilho para manutenção da flexão/extensão dos dedos - Série de casos

Abstract Background: A patient's ability to move his/her fingers during hand surgery may be helpful to surgeons because it allows the effectiveness of the intervention evaluation and prediction of hand function in the postoperative period. The purpose of this case series is to demonstrate the efficacy of an ultrasound-guided peripheral nerve block technique to maintain the hand flexor and extensor muscles motor function and discuss the benefits of the technique for trigger finger surgery. Case report: Ten patients scheduled to undergo trigger finger surgery were selected. The goal was to maintain flexion and extension of the fingers during the procedure. Thus, ultrasound-guided ulnar, radial, and medial nerve block was performed in the distal third of the forearm, at 5-7 cm proximal to the wrist. The block was performed with 5 mL of 0.375% bupivacaine on each nerve. All procedures were uneventfully performed maintaining the flexion and extension of the fingers. In two cases, it was observed that the motricity maintenance and the patients' ability to move their fingers when requested allowed the success of the surgical procedure after the third intraoperative evaluation. Conclusion: This case series shows that it is possible to maintain the motor function of the hand flexor and extensor muscles to perform finger trigger surgeries using specific ultrasound-guided distal blocks.

Resumo Justificativa: A capacidade de um paciente mover os dedos durante a cirurgia da mão pode ser útil para o cirurgião porque permite a avaliação da eficácia da intervenção e a predição da função da mão no pós-operatório. O objetivo desta série de casos é demonstrar a eficácia de uma técnica de bloqueio de nervo periférico guiado por ultrassom na manutenção da função motora dos músculos flexores e extensores da mão e discutir os benefícios da técnica para cirurgias de liberação de dedo em gatilho. Relato de caso: Foram selecionados 10 pacientes em programação para cirurgia de liberação de dedo em gatilho. O objetivo era manter a flexão e a extensão dos dedos durante o procedimento. Dessa forma, o bloqueio dos nervos ulnar, radial e mediano, guiados por ultrassom, foi feito no terço distal do antebraço, 5 a 7 cm proximais ao punho. O bloqueio foi feito com 5 mL de bupivacaína a 0,375% em cada nervo. Todos os procedimentos foram feitos sem complicações e com manutenção da flexão e extensão dos dedos. Em dois casos, observou-se que a manutenção da motricidade e a capacidade dos pacientes de mover os dedos quando solicitado permitiu o sucesso do procedimento cirúrgico após a terceira avaliação intraoperatória. Conclusão: Esta série de casos mostra que é possível manter a função motora dos músculos flexores e extensores da mão em cirurgias de liberação de dedo em gatilho por meio de bloqueios distais específicos guiados por ultrassom.

[Ultrasound-guided selective nerve blocks for trigger finger surgeries to maintain flexion/extension of fingers - Case series]. / Bloqueios seletivos guiados por ultrassom para cirurgias de dedo em gatilho para manutenção da flexão/extensão dos dedos ­ Série de casos.

BACKGROUND: A patient's ability to move his/her fingers during hand surgery may be helpful to surgeons because it allows the effectiveness of the intervention evaluation and prediction of hand function in the postoperative period. The purpose of this case series is to demonstrate the efficacy of an ultrasound-guided peripheral nerve block technique to maintain the hand flexor and extensor muscles motor function and discuss the benefits of the technique for trigger finger surgery. CASE REPORT: Ten patients scheduled to undergo trigger finger surgery were selected. The goal was to maintain flexion and extension of the fingers during the procedure. Thus, ultrasound-guided ulnar, radial, and medial nerve block was performed in the distal third of the forearm, at 5-7cm proximal to the wrist. The block was performed with 5mL of 0.375% bupivacaine on each nerve. All procedures were uneventfully performed maintaining the flexion and extension of the fingers. In two cases, it was observed that the motricity maintenance and the patients' ability to move their fingers when requested allowed the success of the surgical procedure after the third intraoperative evaluation. CONCLUSION: This case series shows that it is possible to maintain the motor function of the hand flexor and extensor muscles to perform finger trigger surgeries using specific ultrasound-guided distal blocks.

Ultrasound-guided peripheral nerve blocks in anticoagulated patients - case series / Bloqueios de nervos periféricos guiados por ultrassom em pacientes anticoagulados - série de casos

Abstract Background and objectives: The advent of ultrasound has brought many benefits to peripheral nerve blocks. It includes both safety and effectiveness, given the possibility of visualizing the neurovascular structures and the needle during the procedure. Despite these benefits, there is no consensus in the literature on the use of this technique in anticoagulated patients or with other coagulation disorders. Moreover, peripheral blocks vary in depth, spreadability, and possibility of local compression. However, few societies take it into account when drawing up its recommendations, establishing a single recommendation for performing peripheral blocks, regardless of the route used. The objective of this series is to expand the discussion on peripheral nerve block in anticoagulated patients. Case reports: This series reports 9 cases of superficial peripheral nerve blocks guided by ultrasound in patients with primary or secondary dyscrasias. All blocks were performed by experienced anesthesiologists in the management of ultrasound, and there was no bruising or neurological injuries in the cases. Conclusions: This case series support the discussion on conducting surface peripheral nerve blocks and easy local knowledge as the axillary, interscalene, femoral, saphenous or popliteal in anticoagulated patients, on dual antiaggregation therapy and/or with other coagulation disorders, provided that guided by ultrasound and performed by an anesthesiologist with extensive experience in guided nerve blocks. However, larger series should be performed to prove the safety of the technique for these patients.

Resumo Justificativa e objetivos: O advento da ultrassonografia trouxe inúmeros benefícios para os bloqueios de nervos periféricos. Agregou tanto segurança quanto eficácia, dada a possibilidade de visualização de estruturas neurovasculares e da agulha durante o procedimento. Apesar desses benefícios, não há consenso na literatura sobre o uso da técnica em pacientes anticoagulados ou com outros distúrbios da coagulação. Além disso, os bloqueios periféricos variam com relação à profundidade, expansibilidade e possibilidade de compressão local. Porém, poucas sociedades levam isso em consideração para elaborar suas recomendações, estabelecem um recomendação única para bloqueios periféricos, independentemente da via usada. O objetivo desta série é ampliar a discussão sobre bloqueio de nervos periféricos em pacientes anticoagulados. Relato de casos: Esta série relata 9 casos de bloqueios de nervos periféricos superficiais guiados por ultrassonografia em pacientes com discrasias primárias ou secundárias. Todos os bloqueios foram feitos por anestesiologistas experientes no manejo do ultrassom, que não foram observados hematomas ou lesões neurológicas nos casos. Conclusões: A série de casos em questão ajuda a discussão sobre bloqueios periféricos superficiais e de fácil compressão local, como o axilar, interescalênico, femoral, safeno ou poplíteo, em pacientes anticoagulados, duplamente antiagregados e/ou com outros distúrbios da coagulação desde que guiados por ultrassom e feitos por anestesiologista com vasta experiência em bloqueios guiados. Entretanto, maiores séries devem ser feitas para comprovar a segurança da técnica para esses pacientes.

[Ultrasound-guided peripheral nerve blocks in anticoagulated patients - case series]. / Bloqueios de nervos periféricos guiados por ultrassom em pacientes anticoagulados ­ série de casos.

BACKGROUND AND OBJECTIVES: The advent of ultrasound has brought many benefits to peripheral nerve blocks. It includes both safety and effectiveness, given the possibility of visualizing the neurovascular structures and the needle during the procedure. Despite these benefits, there is no consensus in the literature on the use of this technique in anticoagulated patients or with other coagulation disorders. Moreover, peripheral blocks vary in depth, spreadability, and possibility of local compression. However, few societies take it into account when drawing up its recommendations, establishing a single recommendation for performing peripheral blocks, regardless of the route used. The objective of this series is to expand the discussion on peripheral nerve block in anticoagulated patients. CASE REPORTS: This series reports 9 cases of superficial peripheral nerve blocks guided by ultrasound in patients with primary or secondary dyscrasias. All blocks were performed by experienced anesthesiologists in the management of ultrasound, and there was no bruising or neurological injuries in the cases. CONCLUSIONS: This case series support the discussion on conducting surface peripheral nerve blocks and easy local knowledge as the axillary, interscalene, femoral, saphenous or popliteal in anticoagulated patients, on dual antiaggregation therapy and/or with other coagulation disorders, provided that guided by ultrasound and performed by an anesthesiologist with extensive experience in guided nerve blocks. However, larger series should be performed to prove the safety of the technique for these patients.

Ultrasound-guided peripheral nerve blocks in anticoagulated patients - case series.

BACKGROUND AND OBJECTIVES: The advent of ultrasound has brought many benefits to peripheral nerve blocks. It includes both safety and effectiveness, given the possibility of visualizing the neurovascular structures and the needle during the procedure. Despite these benefits, there is no consensus in the literature on the use of this technique in anticoagulated patients or with other coagulation disorders. Moreover, peripheral blocks vary in depth, spreadability, and possibility of local compression. However, few societies take it into account when drawing up its recommendations, establishing a single recommendation for performing peripheral blocks, regardless of the route used. The objective of this series is to expand the discussion on peripheral nerve block in anticoagulated patients. CASE REPORTS: This series reports 9 cases of superficial peripheral nerve blocks guided by ultrasound in patients with primary or secondary dyscrasias. All blocks were performed by experienced anesthesiologists in the management of ultrasound, and there was no bruising or neurological injuries in the cases. CONCLUSIONS: This case series support the discussion on conducting surface peripheral nerve blocks and easy local knowledge as the axillary, interscalene, femoral, saphenous or popliteal in anticoagulated patients, on dual antiaggregation therapy and/or with other coagulation disorders, provided that guided by ultrasound and performed by an anesthesiologist with extensive experience in guided nerve blocks. However, larger series should be performed to prove the safety of the technique for these patients.

Minimum effective concentration of bupivacaine for axillary brachial plexus block guided by ultrasound / Concentração mínima efetiva de bupivacaína para o bloqueio do plexo braquial via axilar guiado por ultrassom / Concentración mínima efectiva de bupivacaína para el bloqueo del plexo braquial vía axilar guiado por ecografía

INTRODUCTION: The use of ultrasound in regional anesthesia allows reducing the dose of local anesthetic used for peripheral nerve block. The present study was performed to determine the minimum effective concentration (MEC90) of bupivacaine for axillary brachial plexus block. METHODS: Patients undergoing hand surgery were recruited. To estimate the MEC90, a sequential up-down biased coin method of allocation was used. The bupivacaine dose was 5 mL for each nerve (radial, ulnar, median, and musculocutaneous). The initial concentration was 0.35%. This concentration was changed by 0.05% depending on the previous block; a blockade failure resulted in increased concentration for the next patient; in case of success, the next patient could receive or reduction (0.1 probability) or the same concentration (0.9 probability). Surgical anesthesia was defined as driving force ≤2 according to the modified Bromage scale, lack of thermal sensitivity and response to pinprick. Postoperative analgesia was assessed in the recovery room with numeric pain scale and the amount of drugs used within 4 h after the blockade. RESULTS: MEC90 was 0.241% [R 2: 0.978, confidence interval: 0.20-0.34%]. No patient, with successful block, reported pain after 4 h. CONCLUSION: This study demonstrated that ultrasound guided axillary brachial plexus block can be performed with the use of low concentration of local anesthetics, increasing the safety of the procedure. Further studies should be conducted to assess blockade duration at low concentrations. .

INTRODUÇÃO: O uso do ultrassom na anestesia regional permite a redução da dose de anestésico local utilizada para o bloqueio de nervos periféricos. O presente estudo foi conduzido com o objetivo de determinar a concentração mínima efetiva (CME90) de bupivacaína para o bloqueio do plexo braquial via axilar (BPVA). MÉTODOS: Pacientes submetidos a cirurgias da mão foram recrutados. Foi usado um método de alocação "biased coin" seqüencial "up-down" para estimar a CME90. A dose de bupivacaína foi de 5 mL para cada nervo (radial, ulnar, mediano e musculocutâneo). A concentração inicial de era 0,35%. Essa concentração era alterada em 0,05% dependendo do bloqueio anterior: a falha do bloqueio resultava em aumento da concentração para o próximo paciente; no caso de sucesso, o próximo paciente poderia receber ou redução (probabilidade de 0,1) ou mesma concentração (probabilidade 0,9). A anestesia cirúrgica foi definida como força motora ≤ 2 segundo a escala de Bromage modificada, ausência de sensibilidade térmica e de resposta ao pinprick. A analgesia pós-operatória foi verificada na sala de recuperação anestésica com escala numérica de dor e a quantidade de analgésicos utilizados até 4 horas após o bloqueio. RESULTADOS: A CME90 foi de 0,241% [R2: 0,978, Intervalo de Confiança: 0,20%-0,34%]. Além disso, nenhum paciente com sucesso do bloqueio apresentou dor após 4 horas. CONCLUSÃO: Este estudo demonstrou que pode-se realizar o BPVA guiado por ultrassom utilizando-se baixas concentrações de anestésico local, aumentando a segurança do procedimento. Novos estudos devem ser realizados para avaliar a duração de bloqueios com baixas concentrações. .

INTRODUCCIÓN: El uso de la ecografía en la anestesia regional permite la reducción de la dosis de anestésico local utilizada para el bloqueo de nervios periféricos. El presente estudio fue llevado a cabo con el objetivo de determinar la concentración mínima efectiva (CME90) de bupivacaína para el bloqueo del plexo braquial vía axilar. MÉTODOS: Fueron reclutados pacientes sometidos a cirugías de la mano. Se usó un método de ubicación "biased coin" secuencial "up-down" para estimar la CME90. La dosis de bupivacaína fue de 5 mL para cada nervio (radial, cubital, mediano y musculocutáneo). La concentración inicial era de un 0,35%. Esa concentración era alterada en un 0,05% dependiendo del bloqueo anterior: El fallo del bloqueo revertía en un aumento de la concentración al próximo paciente; en caso de éxito, el próximo paciente podría recibir o una reducción (probabilidad de 0,1) o la misma concentración (probabilidad 0,9). La anestesia quirúrgica fue definida como fuerza motora ≤ 2 según la escala de Bromage modificada, ausencia de sensibilidad térmica y de respuesta al pinprick (test del pinchazo de la aguja). La analgesia postoperatoria fue verificada en la sala de recuperación anestésica con la escala numérica de dolor y la cantidad de analgésicos utilizados hasta 4 h después del bloqueo. RESULTADOS: La CME90 fue del 0,241% [R2: 0,978, intervalo de confianza: 0,20-0,34%]. Además, ningún paciente con éxito en el bloqueo tuvo dolor después de 4 h. CONCLUSIÓN: Este estudio demostró que se puede realizar el bloqueo del plexo braquial vía axilar guiado por ecografía utilizando bajas concentraciones de anestésico local, aumentando la seguridad del procedimiento. Nuevos estudios deben ser realizados para calcular la duración de bloqueos con bajas concentraciones. .

[Minimum effective concentration of bupivacaine for axillary brachial plexus block guided by ultrasound]. / Concentração mínima efetiva de bupivacaína para o bloqueio do plexo braquial via axilar guiado por ultrassom.

INTRODUCTION: The use of ultrasound in regional anesthesia allows reducing the dose of local anesthetic used for peripheral nerve block. The present study was performed to determine the minimum effective concentration (MEC90) of bupivacaine for axillary brachial plexus block (ABPB). METHODS: Patients undergoing hand surgery were recruited. To estimate the MEC90, a sequential up-down biased coin method of allocation was used. The bupivacaine dose was 5mL for each nerve (radial, ulnar, median, and musculocutaneous). The initial concentration was 0.35%. This concentration was changed by 0.05% depending on the previous block: a blockade failure resulted in increased concentration for the next patient; in case of success, the next patient could receive or reduction (0.1 probability) or the same concentration (0.9 probability). Surgical anesthesia was defined as driving force ≤ 2 according to the modified Bromage scale, lack of thermal sensitivity and response to pinprick. Postoperative analgesia was assessed in the recovery room with numeric pain scale and the amount of drugs used within 4hours after the blockade. RESULTS: MEC90 was 0.241% [R2: 0.978, confidence interval: 0.20%-0.34%]. No successful block patient reported pain after 4hours. CONCLUSION: This study demonstrated that ultrasound guided ABPB can be performed with the use of low concentration of local anesthetics, increasing the safety of the procedure. Further studies should be conducted to assess blockade duration at low concentrations.

Minimum effective concentration of bupivacaine for axillary brachial plexus block guided by ultrasound.

INTRODUCTION: The use of ultrasound in regional anesthesia allows reducing the dose of local anesthetic used for peripheral nerve block. The present study was performed to determine the minimum effective concentration (MEC90) of bupivacaine for axillary brachial plexus block. METHODS: Patients undergoing hand surgery were recruited. To estimate the MEC90, a sequential up-down biased coin method of allocation was used. The bupivacaine dose was 5 mL for each nerve (radial, ulnar, median, and musculocutaneous). The initial concentration was 0.35%. This concentration was changed by 0.05% depending on the previous block; a blockade failure resulted in increased concentration for the next patient; in case of success, the next patient could receive or reduction (0.1 probability) or the same concentration (0.9 probability). Surgical anesthesia was defined as driving force ≤ 2 according to the modified Bromage scale, lack of thermal sensitivity and response to pinprick. Postoperative analgesia was assessed in the recovery room with numeric pain scale and the amount of drugs used within 4h after the blockade. RESULTS: MEC90 was 0.241% [R(2): 0.978, confidence interval: 0.20-0.34%]. No patient, with successful block, reported pain after 4h. CONCLUSION: This study demonstrated that ultrasound guided axillary brachial plexus block can be performed with the use of low concentration of local anesthetics, increasing the safety of the procedure. Further studies should be conducted to assess blockade duration at low concentrations.

Determination of the minimum effective volume of 0.5% bupivacaine for ultrasound-guided axillary brachial plexus block.

BACKGROUND AND OBJECTIVE: The use of ultrasound for needle correct placement and local anesthetic spread monitoring helped to reduce the volume of local anesthetic required for peripheral nerve blocks. There are few studies of the minimum effective volume of local anesthetic for axillary brachial plexus block. The aim of this study was to determine the minimum effective volume (VE90) of 0.5% bupivacaine with epinephrine (1:200,000) for ultrasound guided ABPB. METHOD: Massey and Dixon's up-and-down method was used to calculate the minimum effective volume. The initial dose was 5 mL per nerve (radial, median, ulnar, and musculocutaneous). In case of blockade failure, the volume was increased to 0.5 mL per nerve. A successful blockade resulted in decreased volume of 0.5 mL per nerve to the next patient. Successful blockade was defined as a motor block ≤2, according to the modified Bromage scale; lack of thermal sensitivity; and response to pinprick. The achievement of five cases of failure followed by success cases was defined as criterion to complete the study. RESULTS: 19 patients were included in the study. The minimum effective volume (VE90) of 0.5% bupivacaine with 1:200,000 epinephrine was 1.56 mL (95% CI, 0.99-3.5) per nerve. CONCLUSION: This study is in agreement with some other studies, which show that it is possible to achieve surgical anesthesia with low volumes of local anesthetic for ultrasound-guided peripheral nerve blocks.

Determinacao do volume minimo efetivo de bupivacaina 0,5% para bloqueio do plexo braquial por via axilar guiado por ultrassom / Determination of the minimum effective volume of 0.5% bupivacaine for ultrasound-guided axillary brachial plexus block / Determinacion del volumen minimo efectivo de bupivacaina al 0,5% para el bloqueo del plexo braquial por via axilar guiado por ultrasonido

Justificativa e objetivo: o uso do ultrassom para acompanhar o correto posicionamento da agulha e a dispersão do anestésico local permitiu a redução do volume de anestésico local necessário para o bloqueio de nervos periféricos. Existem poucos trabalhos sobre o volume mínimo efetivo de anestésico local para o bloqueio do plexo braquial via axilar (BPVA). Este estudo foi conduzido com o objetivo de determinar o volume mínimo efetivo (VE90) de bupivacaína 0,5% comadrenalina (1:200.000) para o BPVA guiado por ultrassom. Método: o método up-and-down proposto por Massey e Dixon foi usado para o cálculo do volume mínimo efetivo. A dose inicial foi de 5 ml por nervo (radial, mediano, ulnar e musculocutâneo). No caso de falha do bloqueio, o volume era aumentado em 0,5 mL por nervo. O sucesso do bloqueio resultava na diminuição do volume em 0,5 mL por nervo para o paciente subsequente. O sucesso do bloqueio foi definido como bloqueio da função motora ≤ 2 segundo a escala de Bromage modificada, ausência de sensibilidade térmica e de resposta ao pinprick. Foi definido como critério para término do estudo a obtenção de cinco casos de falha seguidos de casos de sucesso. Resultados: foram incluídos 19 pacientes no estudo. O volume mínimo efetivo (VE90) de bupi-vacaína 0,5% com 1:200.000 de adrenalina foi de 1,56 ml (IC 95% 0,99-3,5) por nervo. Conclusão: este trabalho corrobora alguns estudos que mostram que é possível obter anestesia cirúrgica com baixos volumes de anestésico local para bloqueios de nervo periférico guiados por ultrassom. .

Background and objective: The use of ultrasound for needle correct placement and local anesthetic spread monitoring helped to reduce the volume of local anesthetic required for peripheral nerve blocks. There are few studies of the minimum effective volume of local anesthetic for axillary brachial plexus block. The aim of this study was to determine the minimum effective volume (VE90) of 0.5% bupivacaine with epinephrine (1:200,000) for ultrasound guided ABPB. Method: Massey and Dixon's up-and-down method was used to calculate the minimum effective volume. The initial dose was 5 mL per nerve (radial, median, ulnar, and musculocutaneous). In case of blockade failure, the volume was increased to 0.5 mL per nerve. A successful blockade resulted in decreased volume of 0.5 mL per nerve to the next patient. Successful blockade was defined as a motor block ≤2, according to the modified Bromage scale; lack of thermal sensitivity; and response to pinprick. The achievement of five cases of failure followed by success cases was defined as criterion to complete the study. Results: 19 patients were included in the study. The minimum effective volume (VE90) of 0.5% bupivacaine with 1:200,000 epinephrine was 1.56 mL (95% CI, 0.99-3.5) per nerve. Conclusion: This study is in agreement with some other studies, which show that it is possible to achieve surgical anesthesia with low volumes of local anesthetic for ultrasound-guided peripheral nerve blocks. .

Justificación y objetivo: el uso del ultrasonido para acompanar el correcto posicionamiento de la aguja y la dispersión del anestésico local ha permitido la reducción del volumen de anestésico local necesario para el bloqueo de los nervios periféricos. Existen pocos trabajos sobre el volumen mínimo efectivo de anestésico local para el bloqueo del plexo braquial vía axilar. Este estudio fue llevado a cabo con el objetivo de determinar el volumen mínimo efectivo (VE90) de bupivacaína al 0,5% con adrenalina (1:200.000) para el bloqueo del plexo braquial vía axilar guiado por ultrasonido. Método: el método up-and-down propuesto por Massey y Dixon fue usado para el cálculo del volumen mínimo efectivo. La dosis inicial fue de 5mL por nervio (radial, mediano, cubital y musculocutáneo). En el caso de fallo en el bloqueo, el volumen se aumentaba a 0,5 mL por nervio. El éxito del bloqueo traía la disminución del volumen en 0,5 mL por nervio para el paciente posterior. El éxito del bloqueo se definió como bloqueo de la función motora < 2 según la escala de Bromage modificada, ausencia de sensibilidad térmica y de respuesta al pinprick. Quedó definido como criterio para el término del estudio la obtención de 5 casos de fallo seguidos de casos de éxito. Resultado: se incluyeron 19 pacientes en el estudio. El volumen mínimo efectivo (VE90) de bupivacaína al 0,5% con 1:200.000 de adrenalina fue de 1,56 mL (IC 95%: 0,99-3,5) por nervio. Conclusiones: este trabajo corrobora algunos estudios que muestran que se puede obtener la anestesia quirúrgica con bajos volúmenes de anestésico local para bloqueos de nervio periférico guiados por ultrasonido. .

Hipertermia maligna no Brasil: análise da atividade do hotline em 2009 / Malignant hyperthermia in Brazil: analysis of hotline activity in 2009 / Hipertermia maligna en Brasil: análisis de la actividad del hotline en 2009

JUSTIFICATIVA E OBJETIVOS: Hipertermia maligna (HM) é doença farmacogenética, com reação hipermetabólica anormal a anestésicos halogenados e/ou relaxantes musculares despolarizantes. Desde 1991 há um serviço hotline de atendimento telefônico para HM no Brasil, disponível 24 horas por dia, em São Paulo. Este artigo analisa a atividade do serviço brasileiro de hotline para HM em 2009. MÉTODOS: Análise prospectiva de todas chamadas telefônicas paria maligna (HM) é doença farmacogenética, com reação hipermetabólica anormal a anestésicos halogenados e/ou relaxantes musculares despolarizantes. Desde 1991 há um serviço hotline de atendimento telefônico para HM no Brasil, disponível 24 horas por dia, em São Paulo. Este art go analisa a at vidade do serviço brasileiro de hotline para HM em 2009a o serviço brasileiro de hotline para HM, de janeiro a dezembro de 2009. RESULTADOS: Foram recebidas 22 ligações; 21 provenientes do Sul-Sudeste do Brasil e uma do Norte. Quinze eram pedidos de informações gerais sobre HM. Sete foram suspeitas de crises agudas de HM, das quais duas não foram consideradas como HM. Nas cinco crises compatíveis com HM, todos os pacientes receberam anestésicos inalatórios halogenados (2 isoflurano, 3 sevoflurano) e um usou também succinilcolina; havia quatro homens e uma mulher, com média de idade de 18 anos (2-27). Problemas descritos nas cinco crises de HM: taquicardia (cinco), aumento do gás carbônico expirado (quatro), hipertermia (três), acidemia (um), rabdomiólise (um) e mioglobinúria (um). Um paciente recebeu dantrolene. Todos os cinco pacientes com crises de HM foram seguidos em unidade de terapia intensiva e recuperaram-se sem sequelas. A suscetibilidade à HM foi posteriormente confirmada em dois pacientes por meio do teste de contratura muscular in vitro. CONCLUSÕES: O número de chamadas por ano no serviço brasileiro de hotline para HM ainda é reduzido. As características das crises foram similares às descritas em outros países. É preciso aumentar o conhecimento sobre HM no Brasil.

BACKGROUND AND OBJECTIVES: Malignant hyperthermia (MH) is a pharmacogenetic disease that causes abnormal hypermetabolic reaction to halogenated anesthetics and/or depolarizing muscle relaxants. In Brazil, there is a hotline telephone service for MH since 1991, available 24 hours a day in São Paulo. This article analyzes the activity of the Brazilian hotline service for MH in 2009. METHODS: Prospective analysis of all phone calls made to the Brazilian hotline service for MH from January to December 2009. RESULTS: Twenty-two phone calls were received: 21 from the South/Southeast region of Brazil and one from the North region. Fifteen calls were requests for general information about MH. Seven were about suspected MH acute episodes, two of which were not considered as MH. In five episodes compatible with MH, all patients received halogenated volatile anesthetics (2, isoflurane; 3, sevoflurane) and one also used succinylcholine; there were four men and one woman, with a mean age of 18 years (2-27). The problems described in the five MH episodes were tachycardia (5), increased expired carbon dioxide (4), hyperthermia (3), acidemia (1), rhabdomyolysis (1), and myoglobinuria (1). One patient received dantrolene. All five patients with MH episodes were follow-up in the intensive care unit and recovered without sequelae. Susceptibility to MH was later confirmed in two patients by in vitro muscle contracture test. CONCLUSIONS: The number of calls per year in the Brazilian hotline service for MH is still low. The characteristics of MH episode were similar to those reported in other countries. The knowledge of MH in Brazil needs to be increased.

JUSTIFICATIVA Y OBJETIVOS: La Hipertermia Maligna (HM) es una enfermedad farmacogenética, con una reacción hipermetabólica anormal a los anestésicos halogenados y/o relajantes musculares despolarizantes. Desde 1991 existe un servicio hotline de atención telefónica para la HM en Brasil a disposición las 24 horas del día en São Paulo. Este artículo analiza la actividad del servicio brasileño de hotline para la HM en el 2009. MÉTODOS: Análisis prospectivo de todas las llamadas telefónicas realizadas al servicio brasileño de hotline para la HM, desde enero a diciembre de 2009. RESULTADOS: Se recibieron 22 llamadas; 21 provenientes del Sur y Sudeste de Brasil y una del Norte. Quince eran solicitudes de informaciones generales sobre la HM. Siete fueron sobre sospechas de crisis agudas de HM, de las cuales dos no fueron consideradas como HM. En las cinco crisis compatibles con la HM, todos los pacientes recibieron anestésicos inhalatorios halogenados (2 isoflurano, 3 sevoflurano) y uno también usó succinilcolina. Había cuatro hombres y una mujer, con un promedio de edad de 18 años (2-27). Los problemas descritos en las cinco crisis de HM: taquicardia (cinco), aumento del gas carbónico espirado (cuatro), hipertermia (tres), acidemia (uno), rabdomiólisis (uno) y mioglobinuria (uno). Un paciente recibió dantrolene. Todos los cinco pacientes con crisis de HM recibieron acompañamiento en la unidad de cuidados intensivos y se recuperaron sin secuelas. La susceptibilidad a la HM fue posteriormente confirmada en dos pacientes por medio del test de la contractura muscular in vitro. CONCLUSIONES: El número de llamadas por año al servicio brasileño de hotline para la HM todavía es pequeño. Las características de las crisis fueron similares a las descritas en otros países. Es necesario aumentar el conocimiento que se tiene sobre la HM en Brasil.

Malignant hyperthermia in Brazil: analysis of hotline activity in 2009.

BACKGROUND AND OBJECTIVES: Malignant hyperthermia (MH) is a pharmacogenetic disease that causes abnormal hypermetabolic reaction to halogenated anesthetics and/or depolarizing muscle relaxants. In Brazil, there is a hotline telephone service for MH since 1991, available 24 hours a day in São Paulo. This article analyzes the activity of the Brazilian hotline service for MH in 2009. METHODS: Prospective analysis of all phone calls made to the Brazilian hotline service for MH from January to December 2009. RESULTS: Twenty-two phone calls were received: 21 from the South/Southeast region of Brazil and one from the North region. Fifteen calls were requests for general information about MH. Seven were about suspected MH acute episodes, two of which were not considered as MH. In five episodes compatible with MH, all patients received halogenated volatile anesthetics (2, isoflurane; 3, sevoflurane) and one also used succinylcholine; there were four men and one woman, with a mean age of 18 years (2-27). The problems described in the five MH episodes were tachycardia (5), increased expired carbon dioxide (4), hyperthermia (3), acidemia (1), rhabdomyolysis (1), and myoglobinuria (1). One patient received dantrolene. All five patients with MH episodes were follow-up in the intensive care unit and recovered without sequelae. Susceptibility to MH was later confirmed in two patients by in vitro muscle contracture test. CONCLUSIONS: The number of calls per year in the Brazilian hotline service for MH is still low. The characteristics of MH episode were similar to those reported in other countries. The knowledge of MH in Brazil needs to be increased.