Intraoperative peripheral nerve injury in colorectal surgery. An update.

Intraoperative peripheral nerve injury during colorectal surgery procedures is a potentially serious complication that is often underestimated. The Trendelenburg position, use of inappropriately padded armboards and excessive shoulder abduction may encourage the development of brachial plexopathy during laparoscopic procedures. In open colorectal surgery, nerve injuries are less common. It usually involves the femoral plexus associated with lithotomy position and self-retaining retractor systems. Although in most cases the recovery is mostly complete, treatment consists of physical therapy to prevent muscular atrophy, protection of hypoesthesic skin areas and analgesics for neuropathic pain. The aim of the present study is to review the incidence, prevention and management of intraoperative peripheral nerve injury.

High resolution neurography of the brachial plexus by 3 Tesla magnetic resonance imaging.

The study of the structures that make up the brachial plexus has benefited particularly from the high resolution images provided by 3T magnetic resonance scanners. The brachial plexus can have mononeuropathies or polyneuropathies. The mononeuropathies include traumatic injuries and trapping, such as occurs in thoracic outlet syndrome due to cervical ribs, prominent transverse apophyses, or tumors. The polyneuropathies include inflammatory processes, in particular chronic inflammatory demyelinating polyneuropathy, Parsonage-Turner syndrome, granulomatous diseases, and radiation neuropathy. Vascular processes affecting the brachial plexus include diabetic polyneuropathy and the vasculitides. This article reviews the anatomy of the brachial plexus and describes the technique for magnetic resonance neurography and the most common pathologic conditions that can affect the brachial plexus.

[Complications in brachial plexus surgery]. / Complicaciones de la cirugía del plexo braquial.

OBJECTIVE: Although traumatic brachial plexus injuries are relatively rare in trauma patients, their effects on the functionality of the upper limb can be very disabling. The authors' objective was to assess the complications in a series of patients operated for brachial plexus injuries. MATERIAL AND METHOD: This was a retrospective evaluation of patients operated on by the authors between August 2009 and March 2013. RESULTS: We performed 36 surgeries on 33 patients. The incidence of complications was 27.7%. Of these, only 1 (2.7%) was considered serious and associated with the procedure (iatrogenic injury of brachial artery). There was another serious complication (hypoxia in patients with airway injury) but it was not directly related to the surgical procedure. All other complications were considered minor (wound dehiscence, hematoma, infection). There was no mortality in our series. CONCLUSIONS: The complications in our series are similar to those reported in the literature. Serious complications (vascular, neural) are rare and represent less than 5% in all the different series. Given the rate of surgical complications and the poor functional perspective for a brachial plexus injury without surgery, we believe that surgery should be the treatment of choice.

[Brachial plexus compression from supraclavicular encapsulated fat necrosis. A case report]. / Plexopatía braquial compresiva por necrosis grasa encapsulada supraclavicular. Caso clínico.

We report the case of a 44-year-old male, lacking clinical history of previous illness, who had surgery at our hospital to treat a mass in the supraclavicular space. The patient presented with a 1-month progressive distal paresis of the left arm. The histo-pathological examination of the mass revealed an encapsulated fat necrosis. Fat necrosis is characterised by cystic architecture, encapsulation with fat necrosis within, and inflammatory infiltration of its walls. Neural structure compression secondary to this tumour mass is very rare. Fat necrosis is more frequent in the lower limbs, in areas exposed to trauma. This article is the first report of brachial plexus compression due to supraclavicular fat necrosis.

[Ipsilateral brachial plexus C7 root transfer. Presentation of a case and a literature review]. / Transferencia ipsilateral de la raíz C7 del plexo braquial. A propósito de un caso y revisión de la literatura.

The C7 root in brachial plexus injuries has been used since 1986, since the first description by Gu at that time. This root can be used completely or partially in ipsilateral or contralateral lesions of the brachial plexus. A review of the literature and the case report of a 21-month-old girl with stab wounds to the neck and section of the C5 root of the right brachial plexus are presented. A transfer of the anterior fibres of the ipsilateral C7 root was performed. At 9 months there was complete recovery of abduction and external rotation of the shoulder.

[Myxoid/round cell liposarcoma of the brachial plexus]. / Liposarcoma mixoide de células redondas de plexo braquial.

Myxoid/round cell liposarcoma is a soft tissue sarcoma that is extremely rare in the brachial plexus. We report a case of a myxoid/round cell liposarcoma originating in the brachial plexus that was surgically resected and evolved well, with no deficit or recurrence after 2 years of follow-up. To date, there has been no other case of this sarcoma in the literature.

A comparative study between single injection (corner pocket approach) and double injection costoclavicular block: A randomized parallel arm, non-inferiority trial.

BACKGROUND: Previous studies have shown that ultrasound guided costoclavicular block may require a double shot to provide adequate, rapid sensory and motor blockade. In this trial, we hypothesized that if the corner pocket approach (between axillary artery and median cord) is used instead of the central approach (at the midpoint of the 3 cords) when performing single-shot costoclavicular block, the onset of blockade would be non-inferior to the double-shot technique. METHOD: Ninety patients undergoing upper limb surgery were randomized to 2 groups for ultrasound-guided costoclavicular block (CCB) at a tertiary hospital. One group received ultrasound guided single-shot CCB using the corner pocket approach and other received ultrasound guided double-shot - the first shot at the centre of the 3 cords and the second between the axillary artery and the median cord. An observer blinded to group assignment recorded blockade onset time (defined as the time required to achieve a minimal sensorimotor composite score of 14 out of 16 points). RESULTS: Of the 101 patients assessed for eligibility, 90 were recruited over period of 1 year (February 2022 to January 2023), with 45 in each group. Onset time was 22.1 ±â€¯3.1 min in the single-shot group and 22.4 ±â€¯2.9 min in the double-shot group. This difference was insignificant (P = .3). CONCLUSION: Time to onset of blockade and full anaesthesia are similar in single-shot corner pocket CCB vs double-shot CCB. Further studies are required to determine the minimum effective volume of local anaesthetic required for the described technique.

Costoclavicular brachial plexus block: A review of current evidence.

The brachial plexus block can be performed through several approaches. The recently described ultrasound-guided costoclavicular block at the costoclavicular space has gained popularity, presenting promising results for upper limb anaesthesia and postoperative analgesia. This block comes as an alternative to the traditional infraclavicular approach, with results suggesting improved block quality and reduced risk of complications. This article presents a narrative review of the literature and the current evidence available. A bibliographic search was conducted in the database PubMed and relevant articles published between 2015 and December 2020 to this topic were selected.

Anesthetic management using costoclavicular brachial plexus block with patient-controlled analgesia in Pediatrics: A case report.

The costoclavicular brachial plexus block (CBPB) has been receiving increasing attention as an effective technique for upper arm surgery conducted without phrenic paralysis. However, studies in children are lacking. CBPB was applied to a 10 year-old girl undergoing scheduled radial and ulnar osteotomy due to multiple cartilaginous exostoses and ulnar lengthening. CBPB was performed with a bolus administration of 10 mL of 0.25% levobupivacaine, and the catheter was sequentially replaced in the right costoclavicular space. After surgery, a continuous infusion of 0.17% levobupivacaine through a catheter was initiated at 2 mL/h, along with patient-controlled analgesia (PCA) of 3 mL 0.17% levobupivacaine with a 60-min lock out. The patient complained of 5/10 pain on the numerical rating scale (NRS) 2 h after surgery, which improved immediately after bolus administration. The analgesia induced by CBPB was otherwise effective (NRS ≤ 2). CBPB with PCA may provide adequate analgesia in paediatric cases.

Unilateral thoracic outlet syndrome in a case with bilateral cervical ribs, does it always produce compression?

BACKGROUND: The cervical rib can be a rare finding in asymptomatic subjects. When it produces compression, it affects variably the vasculo-nervous structures of the brachial plexus; the clinical history is progressive. The imaging studies indicate the site of osteo-neuro-vascular conflict and electrophysiological studies indicate the degree of neural involvement. CASE REPORT: We present a patient with an eight-month history of paresis and right dysesthesias, with an image of bilateral cervical ribs with different anatomical characteristics. This case discusses how a variant of the anatomy produces pathology and when it is not related to compression.

ANTECEDENTES: La costilla cervical puede ser un raro hallazgo en sujetos asintomáticos. Cuando produce compresión, afecta variablemente a las estructuras vasculonerviosas del plexo braquial. El cuadro clínico es progresivo. Los estudios de imagen indican el sitio de conflicto osteoneurovascular, y los electrofisiológicos, el grado de afección neural. CASO CLÍNICO: Presentamos un paciente con historia de 8 meses de paresia y disestesias derechas, con imagen de costillas cervicales bilaterales con diferentes características anatómicas. Con este caso se discute cómo una variante de la anatomía produce patología y cuando no está relacionada a compresión.

Complications associated with three brachial plexus blocking techniques: Systematic review and meta-analysis.

BACKGROUND: Brachial plexus block has become one of the most widely-used anaesthetic techniques in the world for upper limb anaesthesia. There are three different brachial blocks techniques: supraclavicular, infraclavicular and axillary block. However, its execution is not exempt from possible clinical complications, and it is not clear which of these is associated with a lower complication rate and greater anaesthetic success. MATERIALS AND METHODS: Systematic review and meta-analysis following the Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines to identify controlled clinical trials reporting the three techniques. The main outcome was the incidence of anaesthetic complications, and the secondary ones were an anaesthetic success, time of performance and anaesthetic latency. RESULTS: 25 controlled clinical trials, with 2012 patient, were included. The methodological quality of the included studies is moderate to high. For the main outcome, the main complication reported was a vascular puncture, followed by transient neurological injury, symptomatic diaphragmatic paralysis and pneumothorax. No differences were found in complications associated with the three anaesthetic techniques. Additionally, no differences were found regarding anaesthetic success. CONCLUSIONS: Anesthetic complications associated with the three brachial block techniques are low, with no medium and long-term sequelae; however, none of the three techniques seems to be superior among them to reduce these complications. All three techniques are highly successful when performed using ultrasound imaging.

Anesthetic management using costoclavicular brachial plexus block with patient-controlled analgesia in Pediatrics: A case report. / Tratamiento anestésico mediante bloqueo del plexo braquial costoclavicular con analgesia controlada por el paciente en Pediatría: caso clínico.

Anesthetic management using costoclavicular brachial plexus block with patient-controlled analgesia in pediatrics: a case report Abstract The costoclavicular brachial plexus block (CBPB) has been receiving increasing attention as an effective technique for upper arm surgery conducted without phrenic paralysis. However, studies in children are lacking. CBPB was applied to a 10 year-old girl undergoing scheduled radial and ulnar osteotomy due to multiple cartilaginous exostoses and ulnar lengthening. CBPB was performed with a bolo administration of 10 mL of 0.25% levobupivacaine, and the catheter was sequentially replaced in the right costoclavicular space. After surgery, a continuous infusion of 0.17% levobupivacaine through a catheter was initiated at 2 mL/h, along with patient-controlled analgesia (PCA) of 3 mL 0.17% levobupivacaine with a 60-minute lock out. The patient complained of 5/10 pain on the numerical rating scale (NRS) 2 hours after surgery, which improved immediately after bolus administration. The analgesia induced by CBPB was otherwise effective (NRS ≤ 2). CBPB with PCA may provide adequate analgesia in pediatric cases.

Perioperative diaphragm point-of-care ultrasound as a prediction tool of postoperative respiratory failure in high-risk patients: A feasibility study and case series. / Ecografía diafragmática perioperatoria en el punto de atención como herramienta de predicción de fallo respiratorio postoperatorio en pacientes de alto riesgo: estudio de viabilidad y serie de casos.

INTRODUCTION: Respiratory muscle function in the postoperative period is a key to whether a patient develops Postoperative Respiratory Failure (PRF) or not. PRF occurs when the gas exchange does not meet metabolic needs. Ipsilateral paralysis of the hemidiaphragm after interscalenic brachial plexus block (ISB) causes an acute reduction of respiratory muscle function. This reduction does not cause PRF when the contralateral hemidiaphragm generates enough gas exchange to meet metabolic demands. OBJECTIVES: To study the evolution of hemidiaphragmatic muscle function during the perioperative period with diaphragmatic ultrasound (D-POCUS), and use it as an innovative tool to predict PRF, assessing the contralateral hemidiaphragm in the event of acute hemidiaphragm paralysis. METHODS: Patients considered high risk, scheduled for shoulder surgery with ISB are studied. Both hemidiaphragms were evaluated by ultrasound, before and after the procedure, measuring Thickening Fraction (TF) and Diaphragmatic Excursion (DE). PACU patients with PRF were registered. RESULTS: There was a significant reduction in the TF and DE of the ipsilateral hemidiaphragm in the six patients studied. Only 1/6 patients showed signs of PRF. The evaluation of the contralateral hemidiaphragm during the postoperative period showed that in the five patients without signs of PRF, there were no significant changes in the function of the contralateral hemidiaphragm. The patient, who showed a reduction in contralateral hemidiaphragm function, was the only one who suffered PRF. CONCLUSIONS: In this case series, D-POCUS allows to know the perioperative function of the diaphragm in high-risk patients. All patients suffered an acute reduction of hemidiaphragm function after ISB; however, these patients did not develop PRF when the contralateral hemidiaphragm function was preserved.

DREZotomy in the treatment of deafferentation pain: review of results and analysis of predictive factors for success. / Drezotomía en el tratamiento del dolor por desaferentización: revisión de resultados y análisis de factores predictores de éxito.

BACKGROUND AND OBJECTIVES: The treatment of deafferentation pain by spinal DREZotomy is a proven therapeutic option in the literature. In recent years, use of DREZotomy has been relegated to second place due to the emergence of neuromodulation therapies. The objectives of this study are to demonstrate that DREZotomy continues to be an effective and safe treatment and to analyse predictive factors for success. PATIENTS AND METHODS: A retrospective study was conducted of all patients treated in our department with spinal DREZotomy from 1998 to 2018. Bulbar DREZotomy procedures were excluded. A visual analogue scale (VAS) and the reduction of routine medication were used as outcome variables. Demographic, clinical and operative variables were analysed as predictive factors for success. RESULTS: A total of 27 patients (51.9% female) with a mean age of 53.7 years underwent DREZotomy. The main cause of pain was brachial plexus injury (BPI) (55.6%) followed by neoplasms (18.5%). The mean time of pain evolution was 8.4 years with a mean intensity of 8.7 according to the VAS, even though 63% of the patients had previously received neurostimulation therapy. Favourable outcome (≥50% pain reduction in the VAS) was observed in 77.8% of patients during the postoperative period and remained in 59.3% of patients after 22 months average follow-up (mean reduction of 4.9 points). This allowed for a reduction in routine analgesic treatment in 70.4% of them. DREZotomy in BPI-related pain presented a significantly higher success rate (93%) than the other pathologies (41.7%) (p=.001). No association was observed between outcome and age, gender, DREZ technique, duration of pain or previous neurostimulation therapies. There were six neurological complications, four post-operative transient neurological deficits and two permanent deficits. CONCLUSION: Dorsal root entry zone surgery is effective and safe for treating patients with deafferentation pain, especially after brachial plexus injury. It can be considered an alternative treatment after failed neurostimulation techniques for pain control. However, its indication should be considered as the first therapeutic option after medical therapy failure due to its good long-term results.

[Perineural dexamethasone in ultrasound-guided interscalene brachial plexus block with levobupivacaine for shoulder arthroscopic surgery in the outpatient setting: randomized controlled trial]. / Dexametasona perineural em bloqueio de plexo braquial interescalênico com levobupivacaína guiado por ultrassonografia para artroscopia de ombro em regime ambulatorial: ensaio clínico controlado e randomizado.

BACKGROUND AND OBJECTIVES: In shoulder arthroscopy, on an outpatient basis, the patient needs a good control of the postoperative pain that can be achieved through regional blocks. Perineural dexamethasone may prolong the effect of these blocks. The aim of this study was to evaluate the effect of perineural dexamethasone on the prolongation of the sensory block in the postoperative period for arthroscopic shoulder surgery in outpatient setting. METHODS: After approval by the Research Ethics Committee and informed consent, patients undergoing arthroscopic shoulder surgery under general anesthesia and ultrasound-guided interscalene brachial plexus block were randomized into Group D - blockade performed with 30 mL of 0.5% levobupivacaine with vasoconstrictor and 6 mg (1.5 mL) of dexamethasone and Group C - 30 mL of 0.5% levobupivacaine with vasoconstrictor and 1.5 mL of 0.9% saline. The duration of the sensory block was evaluated in 4 postoperative moments (0, 4, 12 and 24 hours) as well as the need for rescue analgesia, nausea and vomiting incidence, and Visual Analog Pain Scale (VAS). RESULTS: Seventy-four patients were recruited and 71 completed the study (Group C, n=37; Group D, n=34). Our findings showed a prolongation of the mean time of the sensitive blockade in Group D (1440±0 min vs. 1267±164 min, p<0.001). It was observed that Group C had a higher mean pain score according to VAS (2.08±1.72 vs. 0.02±0.17, p <0.001) and a greater number of patients (68.4% vs. 0%, p <0.001) required rescue analgesia in the first 24 hours. The incidence of postoperative nausea and vomiting was not statistically significant. CONCLUSION: Perineural dexamethasone significantly prolonged the sensory blockade promoted by levobupivacaine in interscalene brachial plexus block, reduced pain intensity and rescue analgesia needs in the postoperative period.

[The need for supplemental blocks in single versus triple injections in infraclavicular brachial plexus blocks with a medial approach: a clinical and anatomic study]. / Bloqueio complementar de nervos no bloqueio de plexo braquial infraclavicular com técnica medial de injeção única versus tripla: estudo anátomo­clínico.

BACKGROUND AND OBJECTIVES: To evaluate the single-injection and triple-injection techniques in infraclavicular blocks with an ultrasound-guided medial approach in terms of block success and the need for supplementary blocks. METHODS: This study comprised 139 patients who were scheduled for elective or emergency upper-limb surgery. Patients who received an infraclavicular blocks with a triple-injection technique were included in Group T (n=68). Patients who received an infraclavicular blocks with a single-injection technique were included in Group S (n=71). The number of patients who required supplementary blocks or had complete failure, the recovery time of sensory blocks and early and late complications were noted. RESULTS: The block success rate was 84.5% in Group S, and 94.1% in Group T without any need for supplementary nerve blocks. The blocks were supplemented with distal peripheral nerve blocks in 8 patients in Group S and in 3 patients in Group T. Following supplementation, the block success rate was 95.8% in Group S and 98.5% in Group T. These results were not statistically significant. A septum preventing the proper distribution of local anesthetic was clearly visualized in 4 patients. The discomfort rate during the block was significantly higher in Group T (p <0.05). CONCLUSION: In ultrasound-guided medial-approach infraclavicular blocks, single-injection and triple-injection techniques did not differ in terms of block success rates. The need for supplementary blocks was higher in single injections than with triple injections. The presence of a fascial layer could be the reason for improper distribution of local anesthetics around the cords.

[YouTube as an informational source for brachial plexus blocks: evaluation of content and educational value]. / YouTube como fonte informativa sobre bloqueios do plexo braquial: avaliação de conteúdo e valor educativo.

BACKGROUND AND OBJECTIVES: YouTube, the most popular video-sharing website, contains a significant number of medical videos including brachial plexus nerve blocks. Despite the widespread use of this platform as a medical information source, there is no regulation for the quality or content of the videos. The goals of this study are to evaluate the content of material on YouTube relevant to performance of brachial plexus nerve blocks and its quality as a visual digital information source. METHODS: The YouTube search was performed using keywords associated with brachial plexus nerve blocks and the final 86 videos out of 374 were included in the watch list. The assessors scored the videos separately according to the Questionnaires. Questionnaire-1 (Q1) was prepared according to the ASRA guidelines/Miller's Anesthesia as a reference text book, and Questionnaire-2 (Q2) was formulated using a modification of the criteria in Evaluation of Video Media Guidelines. RESULTS: 72 ultrasound-guided and 14 nerve-stimulator guided block videos were evaluated. In Q1, for ultrasound-guided videos, the least scores were for Q1-5 (1.38) regarding the complications, and the greatest scores were for Q1-13 (3.30) regarding the sono-anatomic image. In videos with nerve stimulator, the lowest and the highest scores were given for Q1-7 (1.64) regarding the equipment and Q1-12 (3.60) regarding the explanation of muscle twitches respectively. In Q2, 65.3% of ultrasound-guided and 42.8% of blocks with nerve-stimulator had worse than satisfactory scores. CONCLUSIONS: The majority of the videos examined for this study lack the comprehensive approach necessary to safely guide someone seeking information about brachial plexus nerve blocks.

[Ultrasound-guided costoclavicular block as an alternative for upper limb anesthesia in obese patients]. / Bloqueio costoclavicular guiado por ultrassonografia como alternativa para anestesia de membro superior em paciente obeso.

BACKGROUND AND OBJECTIVES: Costoclavicular brachial plexus block is an anesthesia performed through the infraclavicular route described in the literature as a safe and effective route for upper limb anesthesia distal to the elbow. The following report describes the case of a patient whose traditional plexus blocking techniques presented ultrasound visualization difficulty, but the costoclavicular approach was easy to visualize for anesthetic blockade. CASE REPORT: A grade 3 obese patient scheduled for repair of left elbow fracture and dislocation. Ultrasound examination revealed a distorted anatomy of the supraclavicular region and the axillary region with skin lesions, which made it impossible to perform the blockade in these regions. It was decided to perform an infraclavicular plexus block at the costoclavicular space, where the brachial plexus structures are more superficial and closer together, supported by a muscular structure, lateral to all adjacent vascular structures and with full view of the pleura. The anesthetic block was effective to perform the procedure with a single injection and uneventfully. CONCLUSION: Costoclavicular brachial plexus block is a good alternative for upper limb anesthesia distal to the elbow, being a safe and effective option for patients who are obese or have other limitations to the use of other upper limb blocking techniques.

Utility of ultrasound-guided injection of botulinum toxin type A for muscle imbalance in children with obstetric brachial plexus palsy: Description of the procedure and action protocol. / Utilidad del tratamiento con infiltraciones ecoguiadas de toxina botulínica A en el desequilibrio muscular de niños con parálisis obstétrica del plexo braquial. Descripción del procedimiento y protocolo de actuación.

INTRODUCTION: Obstetric brachial plexus palsy (OBPP) usually has a favourable prognosis. However, nearly one third of all severe cases have permanent sequelae causing a high level of disability. In this study, we explore the effectiveness of ultrasound-guided injection of botulinum toxin A (BoNT-A) and describe the procedure. PATIENTS AND METHODS: We designed a prospective, descriptive study including patients with moderate to severe OBPP who were treated between January 2010 and December 2014. We gathered demographic data, type of OBPP, and progression. Treatment effectiveness was assessed with the Active Movement Scale (AMS), the Mallet classification, and video recordings. RESULTS: We gathered a total of 14 133 newborns, 15 of whom had OBPP (1.6 per 1000 live births). Forty percent of the cases had severe OBPP (0.4/1000), a dystocic delivery, and APGAR scores < 5; mean weight was 4038g. Mean age at treatment onset was 11.5 months. The muscles most frequently receiving BoNT-A injections were the pronator teres, subscapularis, teres major, latissimus dorsi, and pectoralis major. All the patients who completed the follow-up period (83%) experienced progressive improvements: up to 3 points on the AMS and a mean score of 19.5 points out of 25 on the Mallet classification at 2 years. Treatment improved muscle function and abnormal posture in all cases. Surgery was avoided in 3 patients and delayed in one. Adverse events were mild and self-limited. CONCLUSIONS: Due to its safety and effectiveness, BoNT-A may be used off-label as an adjuvant to physical therapy and/or surgery in moderate to severe OBPP. Ultrasound may increase effectiveness and reduce adverse effects.

Analysis of previous training with simulated models on the success rate of ultrasound-guided supraclavicular block. Prospective cohort study. / Análisis del entrenamiento previo con modelos simulados en el porcentaje de éxito del bloqueo supraclavicular guiado por ultrasonido. Estudio de cohorte prospectivo.

INTRODUCTION: The teaching based on simulation and acquisition of skills is changing the paradigm of education and restructuring the clinical residences, with the aim of acquiring better skills, increasing procedural success, reducing complications, as well as providing safe, effective, and efficient and focused care of the patient. Peripheral nerve blocks have advanced as techniques for anatomical repairs, use of neurostimulator, and ultrasound. The posgraduate anaesthesiology program implemented a teaching program that included phases of theoretical teaching, training with simulated models, and application in real scenarios. OBJECTIVE: To analyse the success, the management of the ultrasound equipment and the incidence of complications of ultrasound-guided supraclavicular blocks (BSE) in the clinical scenario, performed by residents of anaesthesiology previously trained with a theoretical and simulated model. METHODS: Prospective cohort study among residents of anaesthesiology (R1, R2, R3, R4), who received previous theoretical-practical training on simulated models. The evaluation was performed by expert anaesthesiologists, with video analysis of the ultrasound screen performed at the time of BSE initiation. RESULTS: The evaluation included 16 residents, who performed 156 BSE. None had previous experience in ultrasound-guided blocks. The success of the block was 96.15%. The team management was excellent (from 86% to 95%), with no significant differences among the residents. (P=.61) The incidence of complications was 0.64%, corresponding to arterial puncture. CONCLUSIONS: In BSE, previous training with a theoretical and simulated model could increase the probability of success and reduce complications. With adequate training, first year residents managed to successfully carry out the procedure.