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.

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.

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

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 to 24hours 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.

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.

Randomized prospective study of three different techniques for ultrasound-guided axillary brachial plexus block / Estudo prospectivo randomizado de três diferentes técnicas para o bloqueio do plexo braquial via axilar guiado por ultrassom

Abstract Introduction Randomized prospective study comparing two perivascular techniques with the perineural technique for ultrasound-guided axillary brachial plexus block (US-ABPB). The primary objective was to verify if these perivascular techniques are noninferior to the perineural technique. Method 240 patients were randomized to receive the techniques: below the artery (BA), around the artery (AA) or perineural (PN). The anesthetic volume used was 40 mL of 0.375% bupivacaine. All patients received a musculocutaneous nerve blockade with 10 mL. In BA technique, 30 mL were injected below the axillary artery. In AA technique, 7.5 mL were injected at 4 points around the artery. In PN technique, the median, ulnar, and radial nerves were anesthetized with 10 mL per nerve. Results Confidence interval analysis showed that the perivascular techniques studied were not inferior to the perineural technique. The time to perform the blockade was shorter for the BA technique (300.4 ± 78.4 s, 396.5 ± 117.1 s, 487.6 ± 172.6 s, respectively). The PN technique showed a lower latency time (PN - 655.3 ± 348.9 s; BA - 1044 ± 389.5 s; AA - 932.9 ± 314.5 s), and less total time for the procedure (PN - 1132 ± 395.8 s; BA - 1346.2 ± 413.4 s; AA - 1329.5 ± 344.4 s). BA technique had a higher incidence of vascular puncture (BA - 22.5%; AA - 16.3%; PN - 5%). Conclusion The perivascular techniques are viable alternatives to perineural technique for US-ABPB. There is a higher incidence of vascular puncture associated with the BA technique.

Resumo Introdução Estudo prospectivo randomizado, compara duas técnicas perivasculares com a técnica perineural para o bloqueio do plexo braquial via axilar guiado por ultrassom (BPVA-USG). Objetivo primário foi verificar se essas técnicas perivasculares são não inferiores à técnica perineural. Método Foram randomizados 240 pacientes para receber as técnicas: abaixo da artéria (TA), ao redor da artéria (TR) ou perineural (PN). O volume de anestésico usado foi 40 ml de bupivacaína 0,375%. Em todos os pacientes, fez-se o bloqueio do nervo musculocutâneo com 10 ml. Na técnica TA, injetaram-se 30 ml abaixo da artéria axilar. Na técnica TR, injetaram-se 7,5 ml em quatro pontos ao redor da artéria. Na técnica PN, os nervos mediano, ulnar e radial foram anestesiados com 10 ml por nervo. Resultados Análise dos intervalos de confiança mostrou que as técnicas perivasculares estudadas não são inferiores à técnica perineural. A técnica TA apresentou menor tempo para o bloqueio (300,4 ± 78,4 seg; 396,5 ± 117,1 seg; 487,6 ± 172,6 seg; respectivamente). A técnica PN apresentou menor tempo de latência (PN - 655,3 ± 348,9 seg; TA - 1044 ± 389,5 seg; TR - 932,9 ± 314,5 seg) e menor tempo total de procedimento (PN - 1132 ± 395,8 seg; TA -1346,2 ± 413,4 seg; TR 1329,5 ± 344,4 seg). A técnica TA apresentou maior incidência de punção vascular (TA - 22,5%, TR - 16,3%; PN - 5%). Conclusão As técnicas perivasculares são opções viáveis à técnica perineural para o BPVA-USG. Ressalta-se maior incidência de punção vascular associada à técnica TA.

[Randomized prospective study of three different techniques for ultrasound-guided axillary brachial plexus block]. / Estudo prospectivo randomizado de três diferentes técnicas para o bloqueio do plexo braquial via axilar guiado por ultrassom.

INTRODUCTION: Randomized prospective study comparing two perivascular techniques with the perineural technique for ultrasound-guided axillary brachial plexus block (US-ABPB). The primary objective was to verify if these perivascular techniques are noninferior to the perineural technique. METHOD: 240 patients were randomized to receive the techniques: below the artery (BA), around the artery (AA) or perineural (PN). The anesthetic volume used was 40mL of 0.375% bupivacaine. All patients received a musculocutaneous nerve blockade with 10mL. In BA technique, 30mL were injected below the axillary artery. In AA technique, 7.5mL were injected at 4 points around the artery. In PN technique, the median, ulnar, and radial nerves were anesthetized with 10mL per nerve. RESULTS: Confidence interval analysis showed that the perivascular techniques studied were not inferior to the perineural technique. The time to perform the blockade was shorter for the BA technique (300.4±78.4sec, 396.5±117.1sec, 487.6±172.6sec, respectively). The PN technique showed a lower latency time (PN - 655.3±348.9sec; BA -1044±389.5sec; AA-932.9±314.5sec), and less total time for the procedure (PN-1132±395.8sec; BA -1346.2±413.4sec; AA 1329.5±344.4sec). BA technique had a higher incidence of vascular puncture (BA - 22.5%; AA - 16.3%; PN - 5%). CONCLUSION: The perivascular techniques are viable alternatives to perineural technique for US-ABPB. There is a higher incidence of vascular puncture associated with the BA technique.