Evaluation of the technique of localization of the epidural space with the aid of a peripheral nerve stimulator and epidurographic, comparing two techniques for determining the infused volume, in rabbits (Oryctolagus Cuniculus).

Veterinary care for rabbits has been growing, and, consequently, the anesthetic and analgesic management of this species must be improved. The aim of the present study was to evaluate the technique of localization of the epidural space with the aid of a peripheral nerve stimulator and epidurographic, comparing two techniques for determining the infused volume in rabbits (Oryctolagus Cuniculus). In a prospective, randomized blinded study, six healthy New Zealand rabbits, adults, and weighing from 2.2 kg to 3.8 kg received two treatments, at 1 week intervals: 0.33 mL/kg (treatment I) or 0.05 mL per centimeter of the spine (treatment II) of ioexol epidurally. In both treatments, a peripheral nerve stimulator (2 Hz, 0.25 mA and 0.1 milliseconds) was used to determine the location of the epidural space. Latero-lateral and ventro-dorsal radiographs were taken after five (T5) and twenty-five minutes (T25) of iohexol administration. The epidural space was correctly accessed in 92% of attempts. Treatment I received a smaller volume of contrast than treatment II, 1.0 ± 0.2 mL versus 2.1 ± 0.1 mL (mean ± standard deviation), respectively (p = 0.007). At T5, the cranial progression of the contrast varied between L4 and L5 in treatment I, and L5 and T10 in treatment II. At T25, no contrast was observed in any rabbit. In conclusion, peripheral nerve stimulator aided in accessing the lumbosacral epidural space, and the administration of 0.05 mL per centimeter of the spine resulted in greater cranial progression of contrast.

Real-time ultrasound-guided lumbosacral epidural anaesthesia in obese or appropriate body condition score dogs: A randomized clinical trial.

Correctly identifying the puncture site and needle position in obese dogs can be challenging to achieve epidural anaesthesia. The current study aimed to evaluate a real-time ultrasound-guided technique, to perform epidural anaesthesia in obese or appropriate body condition score dogs, based on visualization of local anaesthetic flow during its injection, compared to the traditional method of palpation of anatomical landmarks. Seventy-two client-owned dogs were evaluated in a prospective, comparative, randomized clinical trial, allocated into four groups of 18 dogs. For the Palpation-guided 1 (PG1) and 2 (PG2) groups, epidural anaesthesia was based on palpating anatomical landmarks. Dogs with a body condition score (BCS) 1-5/9 were included in the PG1 (non-obese), and those with a BCS 6-9/9 in PG2 (obese) groups. In the Ultrasound-guided 1 (USG1 - BCS 1-5/9) and 2 (USG2 - BCS 6-9/9) groups, epidural anaesthesia was guided by ultrasound (US). The flow of anaesthetic through the epidural canal was observed in all dogs by US. There were fewer needle-to-bone contacts in the US-guided groups when performing epidural anaesthesia; this only occurred on the vertebral laminae, never in the vertebral canal. Ultrasound guidance enabled local anaesthetic injection into the epidural space without the need for palpation of anatomical landmarks to guide needle placement. Blood reflux occurred in 11.1% (PG1), 22.2% (PG2), 5.5% (USG1), and 0% (USG2) of the dogs. Ultrasound-guided punctures led to fewer vascular punctures. Epidural anaesthesia was effective in all animals, and no complications were observed.

Empiema epidural espinhal em gato com suspeita de linfoma em canal vertebral / Spinal epidural empyema in a cat with suspect of spinal canal lymphoma

Background: Spinal epidural empyema (SEE) is a rare disease in cats that has been described as a cause of severe compressive myelopathy. It is characterized by accumulation of purulent exudate in the form of an abscess in the epidural space. Neurological signs range from spinal hyperesthesia to rapidly progressive paraplegia and may be associated with systemic signs. Spinal lymphoma is the most common neoplasm affecting the central nervous system of cats and can mimic different neoplasms and non-neoplastic diseases, such as SEE. The aim of this study is to report a case of SEE in a cat and highlight the similarities in neurological, laboratory, and imaging findings between this disease and spinal lymphoma. Case: A 8-month-old male neutered mixed-breed cat was referred to the Veterinary Medical Teaching Hospital (HVU) of the UFSM with acute, non-progressive paraplegia. On neurological examination, the patient was paraplegic with no nociception, normal spinal reflexes, increased muscle tone in the pelvic limbs, absence of cutaneous trunci reflex, and spinal hyperesthesia between T13-L1, demonstrating injury in the T3-L3 spinal cord segment. The differential diagnoses included acute spinal cord trauma, neoplasm (lymphoma), and infectious diseases. Hemogram showed lymphocytosis (8062/µL); the biochemical examinations were unremarkable. Tests for antibodies against feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) antigens were negative. Simple radiography, abdominal ultrasonography, and cerebrospinal fluid findings were also normal. Myelography showed left dorsolateral extradural spinal cord compression from T12 to L1. Based on these findings, the presumptive diagnosis was spinal lymphoma and chemotherapy was initiated. After 2 days, the animal began to show hyporexia, adipsia, vomiting, and diarrhea, in addition to an increase in subcutaneous volume in the thoracolumbar region. Antibiotic therapy was initiated; however, the patient died. Necropsy revealed an abscess in the left dorsolateral extradural space at T12-T13 and T13-L1. Bacterial cultures revealed the presence of Neisseria spp. that was resistant to various antibiotics. On the basis of these findings, the animal was diagnosed with SEE. Discussion: This case report aims to inform veterinarians about the diagnosis of SEE. SEE is a rare condition in cats compared to spinal lymphoma; however, their presentation is similar. Even in imaging examinations, such as magnetic resonance imaging, it is not possible to differentiate between these 2 conditions. The evolution of clinical signs made the diagnosis of the present case difficult since it was acute and not progressive. All cases of SEE reported in the literature were progressive, acute, or chronic. Although testing for FeLV was negative, only 56% of cats with spinal lymphoma test positive for this virus. Clinical signs reported by the owner after the start of chemotherapy may be related to adverse effects, such as immunosuppression, which led to worsening of the condition, culminating in the appearance of a subcutaneous abscess. Subsequently, SEE was suspected; however, surgical decompression was not performed as the animal died soon after. The authors of this report reinforce the need for a definitive and non-presumptive diagnosis of spinal lymphoma to initiate chemotherapy because it mimics different neoplasms and non-neoplastic diseases, such as SEE. Surgical removal of the compressive mass in the spinal cord and histopathological analyses are necessary.

Fibrosis epidural postquirúrgica: presentación de un caso con enfoque médico legal / Postsurgical epidural fibrosis: presentation of a case with a medical-legal approach

Resumen La fibrosis epidural es un hallazgo clínico y radiológico el cual se encuentra relacionado directamente en su génesis con los procedimientos quirúrgicos realizados en la columna vertebral. Esta patología es la causa más frecuente del síndrome de cirugía fallida de columna, manifestada clínicamente como un dolor equiparable en severidad al presentado previo a la intervención quirúrgica realizada. La fibrosis epidural es parte del proceso de cicatrización usual de los tejidos circundantes de la columna vertebral, en otras palabras, es esperable que esta suceda, sin embargo, solo una mínima cantidad de las personas intervenidas desarrollan clínicamente la sintomatología. La importancia del análisis de esta patología radica en que estas valoraciones son ingresadas al Departamento de Medicina Legal por asunto de reagravación de alguna secuela ocasionada por algún evento traumático. Es imprescindible conocer a profundidad los diferentes aspectos etiológicos, fisiopatológicos, clínicos, radiológicos y terapéuticos que involucran esta patología vertebral, así como, el respectivo análisis médico legal en este tipo de casos, tomando en consideración todos los elementos de juicio que permitan relacionar este hallazgo con algún hecho denunciado. En el presente artículo se realizará un análisis médico legal de un caso de reagravación por fibrosis epidural valorado en el Departamento de Medicina Legal de Costa Rica, donde el peritado interpone una denuncia contra el ente asegurador al ser rechazada la posibilidad de reapertura del riesgo laboral presentado.

Abstract The epidural fibrosis is a clinical and radiological finding that is related with the surgical procedures performed on the spine. This pathology is the most frequent cause of failed back syndrome or post laminectomy syndrome, that is clinically manifested by an acute pain comparable in severity with the surgical intervention. Epidural fibrosis is part of the usual healing process of the surrounding tissues of the spine, in other words, it's to be expected as a result of this procedures, nevertheless, only a small number of people who have been intervened, actually develop the symptoms clinically. The importance of this pathology lies in the fact that these assessments are attended in the Legal Medicine Department due to the aggravation issues of any sequel caused by a traumatic event. It is essential to know such things as the etiology, pathophysiology, clinical manifestations, radiological findings, and the therapeutic aspects that involve this vertebral disease, as well as, the respective forensic analysis, in order to use all the elements of judgment that allows to relate what is documented with the denounced findings.

Comparison of three sitting positions for combined spinal - epidural anesthesia: a multicenter randomized controlled trial.

BACKGROUND AND OBJECTIVES: The aim of this prospective, multi-centered and multi-arm parallel randomized trial was to test the hypothesis that modified sitting positions including hamstring stretch position (HSP) and squatting position (SP) would reduce needle - bone contact events and increase the success rate of combined spinal - epidural anesthesia (CSEA) compared to traditional sitting position (TSP) in patients undergoing total knee or hip arthroplasty. PATIENTS AND METHODS: Three hundred and sixty American Society of Anesthesiologists (ASA) I-III patients, aged between 45-85 years were randomly allocated to one of three groups using computer-generated simple randomization: group TSP (n = 120), group HSP (n = 120), and group SP (n = 120). Primary outcome measures were the number of needle-bone contact and success rates. Secondary outcome measure was the ease of interspinous space identification. RESULTS: Seven patients in group SP and four of HSP could not tolerate their position and were excluded. Number of needle-bone contact, success rates, and grade of interspinous space identification were similar between groups (p = 1.000). Independent of positioning, the success rates were higher in patients whose interspinous space was graded as easy compared to difficult or impossible (p < 0.001). Success rates reduced, interspinous space identification became more challenging, and number of needle - bone contact increased as patient's body mass index (BMI) increased (p < 0.001). CONCLUSION: SP and HSP may be used as alternatives to the TSP. BMI and ease of interspinous space identification may be considered important determinants for CSEA success.

Clinical utility of epidural volume extension following reduced intrathecal doses: a randomized controlled trial.

BACKGROUND AND OBJECTIVES: Epidural Volume Extension (EVE) involves instillation of normal saline into the epidural space soon after an intrathecal injection, with the aim to augment the sensory block height. Its clinical relevance lies in the possibility of using reduced intrathecal dose and yet achieving the desired sensory block level. Intrathecal dose is a known determinant of the level of sensory block. Whether EVE is dependent on intrathecal dose is not known. METHODS: We conducted a randomized, controlled, double-blind study to compare the maximum sensory level (Smax) achieved with or without application of EVE to two different reduced intrathecal doses. Eighty four adult male patients of ASA status I or II with body weight between 50-70kg and height in the range of 150-180cm, scheduled for orthopedic lower limb surgery using combined spinal epidural anesthesia were randomized to receive, either intrathecal dose (5 or 8mg) with or without EVE, in accordance to group allocation. RESULTS: Smax was lowered by application of EVE to 5mg intrathecal bupivacaine (T8.9±4.3 vs. T6.4±1.9 with and without EVE respectively; p = 0.030). Smax was similar when EVE was applied to 8mg intrathecal bupivacaine than without it (T5.8±1.8 vs. T6.4±2.2 respectively; p= 0.324). CONCLUSION: EVE should not be applied to 5mg plain bupivacaine during a combined spinal epidural block in patients undergoing lower limb orthopedic surgery as it may result in a decrease in the maximum sensory level.

Concordance between the loss of resistance technique and ultrasound in measuring the distance from the skin to the epidural space in pediatric patients: Observational study / Concordancia entre la técnica de pérdida de resistencia y ecografia en la medición de la distancia entre la piel y el espacio epidural en pacientes pediátricos: Estudio observacional

Abstract Introduction: The use of ultrasound in regional anesthesia has become a standard technique to improve nerve block accuracy and reduce associated complications. The literature reports a good correlation between the distance from the skin to the dura mater or the ligamentum flavum measured on ultrasound and the conventional technique of "loss of resistance". Latin American populations have not been included in the studies conducted so far but, because of differences in physical build, it is important to determine whether this correlation is maintained in the various populations. This paper offers new information about the role of ultrasound in determining the distance to the ligamentum flavum and recognizing the proximity of the dura mater to avoid accidental puncture of this structure in Latin American populations. Objective: To determine correlation and concordance in estimating the distance from the skin to the epidural space between the loss of resistance technique and ultrasound measurement. Methodology: Observational study conducted in 52 pediatric patients who received general anesthesia plus epidural analgesia for acute perioperative pain management between July 2014 and November 2015 to assess correlation and concordance between loss of resistance and ultrasound measurement of distance to the epidural space. Results: There is a correlation between distances measured using the two techniques, which appears to be higher as patient age increases. As for concordance, the study found that 0.43 cm should be added to the ultrasound measurement to achieve agreement with the distance obtained using the loss of resistance technique; however, the interval between the two measurements is 1.15 cm. Conclusions: A correlation was found between the measurement taken from the skin to the epidural space using ultrasound and the measurement obtained with the traditional needle puncture and loss of resistance technique. Although concordance was not as expected and the distance measured with ultrasound may be smaller than the real measurement with the needle, ultrasound offers good guidance regarding proximity to the epidural space.

Resumen Introducción: El uso del ultrasonido en la anestesia regional se ha convertido en una técnica estándar para mejorar la precisión de los bloqueos nerviosos y disminuir las complicaciones relacionadas con dicha anestesia. La literatura informa que hay una buena correlación entre la distancia entre la duramadre o el ligamento amarillo y la piel según el ultrasonido y la técnica convencional de "pérdida de resistencia". Los estudios realizados hasta ahora no han incluido población latinoamericana y, debido a las diferencias en la contextura física, es importante determinar si esta correlación se mantiene en varias poblaciones. Con este trabajo se aporta nueva información sobre la utilidad del ultrasonido para determinar la distancia al ligamento amarillo y advertir la cercanía de la duramadre con el fin de evitar la punción accidental de esta estructura en población latina. Objetivo: Determinar la correlación y concordancia en la estimación de la distancia de la piel al espacio epidural entre la técnica de pérdida de resistencia y la medición por ultrasonido. Metodología: Se llevó a cabo un estudio observacional en 52 pacientes pediátricos, que recibieron anestesia general más analgesia epidural para manejo del dolor agudo perioperatorio entre julio de 2014 y noviembre de 2015. Se evaluó la correlación y la concordancia de la distancia medida al espacio epidural entre la técnica de pérdida de resistencia y la distancia por ultrasonido. Resultados: Existe una correlación entre la distancia obtenida mediante las dos técnicas de medición que parece aumentar a medida que aumenta la edad de los pacientes. En cuanto a la concordancia se encontró que a la medida tomada por ultrasonido se le debería sumar 0,43 cm para que concuerde con la distancia tomada por pérdida de resistencia; no obstante, el intervalo entre ambas medidas es de 1,15 cm. Conclusiones: Encontramos una correlación entre la medida tomada desde la piel hasta el espacio epidural por ultrasonido y la tomada por la técnica tradicional de punción con aguja y pérdida de resistencia. Aunque la concordancia que hallamos no fue la esperada, y la medición del ultrasonido puede ser menor a la medición real encontrada con la aguja, es una buena guía para advertir la cercanía del espacio epidural.

[Correlation of the epidural space measured intraoperatively and estimated by MRI or US: an observational study]. / Correlação entre a profundidade do espaço peridural medida no intraoperatório e a estimada por RM ou US: estudo observacional.

BACKGROUND AND OBJECTIVES: To assess the agreement between the epidural depth measured from the surgical site with the epidural depths estimated with magnetic resonance imaging (MRI) and ultrasound scanning. METHODS: Fifty patients of either sex, scheduled for L4-5 lumbar disc surgery under general anesthesia were enrolled in this prospective observational study, and the results of 49 patients were analyzed. The actual epidural depth was measured from the surgical site with a sterile surgical scale. The MRI-derived epidural depth was measured from the MRI scan. The ultrasound estimated epidural depth was measured from the ultrasound image obtained just before surgery. RESULTS: The mean epidural depth measured from the surgical site was 53.80 ± 7.67mm, the mean MRI-derived epidural depth was 54.06 ± 7.36mm, and the ultrasound-estimated epidural depth was 53.77 ± 7.94mm. The correlation between the epidural depth measured from the surgical site and MRI-derived epidural depth was 0.989 (r2 = 0.979, p < 0.001), and the corresponding correlation with the ultrasound-estimated epidural depth was 0.990 (r2 = 0.980, p < 0.001). CONCLUSIONS: Both ultrasound-estimated epidural depth and MRI-derived epidural depth have a strong correlation with the epidural depth measured from the surgical site. Preprocedural MRI-derived estimates of epidural depth are slightly deeper than the epidural depth measured from the surgical site, and the ultrasound estimated epidural depths are somewhat shallower. Although both radiologic imaging techniques provided reliable preprocedural estimates of the actual epidural depth, the loss of resistance technique cannot be discarded while inserting epidural needles.

3D anatomical model for teaching canine lumbosacral epidural anesthesia.

Purpose To develop a 3D anatomical model for teaching canine epidural anesthesia (3DMEA) and to assess its efficacy for teaching and learning prior to the use of live animals. Methods The creation of 3DMEA was based on 3D optical scanning and 3D printing of canine bone pieces of the fifth to the seventh lumbar vertebrae, sacrum and pelvis. A total of 20 male dogs were scheduled for castration. 20 veterinary students watched a video showing epidural anesthesia in dogs before the clinical attempt and were assigned to control or 3DMEA groups. Students in the 3DMEA group trained in the model after the video. For the clinical trial, the epidural procedure was performed by students under the veterinary supervision. When observed the absence of response to nociceptive stimuli, the epidural was considered successful. Then, all students answered a questionnaire evaluating the main difficulty founded in the technique and its degree of difficulty. Results The 3DMEA group reported a lower degree of difficulty to perform the epidural anesthesia technique when compared with the control group (p=0.0037). The 3DMEA reproduced the anatomical structures, allowing the perception of the distance of needle in relation to the iliac prominences during epidural anesthesia. Its mobility allowed simulation of the animal in standing position and sternal recumbency. Conclusion The use of 3DMEA demonstrated greater efficacy in the execution of the technique, being effective in the teaching and learning process before the epidural anesthesia in live animals.

[Incidence of epidural spread after Chayen's approach to lumbar plexus block: a retrospective study]. / Incidência de dispersão peridural após bloqueio do plexo lumbar com técnica de Chayen: estudo retrospectivo.

BACKGROUND AND OBJECTIVES: The lumbar plexus block (LPB) is a key technique for lower limb surgery. All approaches to the LPB involve a number of complications. We hypothesized that Chayen's approach, which involves a more caudal and more lateral needle entry point than the major techniques described in the literature, would be associated with a lower rate of epidural spread. METHOD: We reviewed the electronic medical records and chart of all adult patients who underwent orthopedic surgery for total hip arthroplasty (THA) and hip hemiarthroplasty due to osteoarthritis and femoral neck fracture with LPB and sciatic nerve block (SNB) between January 1, 2002, and December 31, 2017, in our institute. The LPB was performed according to Chayen's technique using a mixture of mepivacaine and levobupivacaine (total volume, 25 mL) and a SNB by the parasacral approach. The sensory and motor block was evaluated bilaterally during intraoperative and postoperative period. RESULTS: A total number of 700 patients with American Society of Anesthesiologists (ASA) physical status I to IV who underwent LPB met the inclusion criteria. The LPB and SNB was successfully performed in all patients. Epidural spread was reported in a single patient (0.14%; p <0.05), accounting for an 8.30% reduction compared with the other approaches described in the literature. No other complications were recorded. CONCLUSIONS: This retrospective study indicates that more caudal and more lateral approach to the LPB, such as the Chayen's approach, is characterized by a lower epidural spread than the other approach to the LPB.

Incidence of epidural spread after Chayens approach to lumbar plexus block: a retrospective study / Incidência de dispersão peridural após bloqueio do plexo lumbar com técnica de Chayen: estudo retrospectivo

Abstract Background and objectives: The lumbar plexus block (LPB) is a key technique for lower limb surgery. All approaches to the LPB involve a number of complications. We hypothesized that Chayen's approach, which involves a more caudal and more lateral needle entry point than the major techniques described in the literature, would be associated with a lower rate of epidural spread. Method: We reviewed the electronic medical records and chart of all adult patients who underwent orthopedic surgery for Total Hip Arthroplasty (THA) and hip hemiarthroplasty due to osteoarthritis and femoral neck fracture with LPB and Sciatic Nerve Block (SNB) between January 1, 2002, and December 31, 2017, in our institute. The LPB was performed according to Chayen's technique using a mixture of mepivacaine and levobupivacaine (total volume, 25 mL) and a SNB by the parasacral approach. The sensory and motor block was evaluated bilaterally during intraoperative and postoperative period. Results: A total number of 700 patients with American Society of Anesthesiologists (ASA) physical status I to IV who underwent LPB met the inclusion criteria. The LPB and SNB was successfully performed in all patients. Epidural spread was reported in a single patient (0.14%;p < 0.05), accounting for an 8.30% reduction compared with the other approaches described in the literature. No other complications were recorded. Conclusions: This retrospective study indicates that more caudal and more lateral approach to the LPB, such as the Chayen's approach, is characterized by a lower epidural spread than the other approach to the LPB.

Resumo Justificativa e objetivos: O bloqueio do plexo lombar (BPL) é uma técnica fundamental para a cirurgia de membros inferiores. Todas as abordagens do BPL são associadas a uma série de complicações. Nossa hipótese foi de que a abordagem de Chayen, que envolve um ponto de entrada da agulha mais caudal e mais lateral do que as principais técnicas descritas na literatura, estaria associada a menor incidência de dispersão peridural. Método: Revisamos os prontuários médicos eletrônicos e em papel de todos os pacientes adultos submetidos à artroplastia total do quadril (ATQ) e hemiartroplastia do quadril devido a osteoartrite ou fratura do colo do fêmur empregando-se BPL associado ao bloqueio do nervo ciático (BNC), entre 1 de janeiro de 2002 e 31 de dezembro de 2017 em nossa instituição. Realizamos o BPL usando a técnica de Chayen e uma mistura de mepivacaína e levobupivacaína (volume total de 25 mL) e o BNC pela abordagem parassacral. Testes sensorial e motor bilaterais foram realizados no intra e pós-operatório. Resultados: Os critérios de inclusão foram obedecidos pelo total de 700 pacientes classe ASA I a IV submetidos ao BPL. Os BPL e BNC foram realizados com sucesso em todos os pacientes. A dispersão peridural foi relatada em um único paciente (0,14%; p < 0,05), representando uma redução de 8,30% quando comparada às outras abordagens descritas na literatura. Nenhuma outra complicação foi registrada. Conclusões: Este estudo retrospectivo indica que a abordagem mais caudal e mais lateral do BPL, como a técnica de Chayen, é caracterizada por menor dispersão peridural do que outras abordagens do BPL.

Correlation of the epidural space measured intraoperatively and estimated by MRI or US: an observational study / Correlação entre a profundidade do espaço peridural medida no intraoperatório e a estimada por RM ou US: estudo observacional

Abstract Background and objectives: To assess the agreement between the epidural depth measured from the surgical site with the epidural depths estimated with magnetic resonance imaging (MRI) and ultrasound scanning. Methods: Fifty patients of either sex, scheduled for L4‒5 lumbar disc surgery under general anesthesia were enrolled in this prospective observational study, and the results of 49 patients were analyzed. The actual epidural depth was measured from the surgical site with a sterile surgical scale. The MRI-derived epidural depth was measured from the MRI scan. The ultrasound estimated epidural depth was measured from the ultrasound image obtained just before surgery. Results: The mean epidural depth measured from the surgical site was 53.80 ± 7.67 mm, the mean MRI-derived epidural depth was 54.06 ± 7.36 mm, and the ultrasound-estimated epidural depth was 53.77 ± 7.94 mm. The correlation between the epidural depth measured from the surgical site and MRI-derived epidural depth was 0.989 (r2 = 0.979, p < 0.001), and the corresponding correlation with the ultrasound-estimated epidural depth was 0.990 (r2 = 0.980, p < 0.001). Conclusions: Both ultrasound-estimated epidural depth and MRI-derived epidural depth have a strong correlation with the epidural depth measured from the surgical site. Preprocedural MRI-derived estimates of epidural depth are slightly deeper than the epidural depth measured from the surgical site, and the ultrasound estimated epidural depths are somewhat shallower. Although both radiologic imaging techniques provided reliable preprocedural estimates of the actual epidural depth, the loss of resistance technique cannot be discarded while inserting epidural needles.

Resumo Justificativa e objetivos: Avaliar a concordância entre a profundidade peridural medida no campo cirúrgico com a profundidade peridural estimada pela Ressonância Magnética (RM) e ultrassonografia. Métodos: Cinquenta pacientes de ambos os sexos agendados para cirurgia de disco lombar L4-5 sob anestesia geral foram incluídos neste estudo observacional prospectivo, e os resultados de 49 pacientes foram analisados. A profundidade peridural real foi medida no campo cirúrgico com uma régua cirúrgica estéril. A profundidade peridural obtida pela Ressonância Magnética (RM) foi medida a partir das imagens do exame de RM. A profundidade peridural estimada pelo ultrassom foi medida a partir da imagem do ultrassom obtida imediatamente antes da cirurgia. Resultados: A profundidade peridural média medida no campo cirúrgico foi de 53,80 ± 7,67 mm; a profundidade peridural média da RM foi de 54,06 ± 7,36 mm; e a profundidade peridural estimada por ultrassom foi de 53,77 ± 7,94 mm. A correlação entre a profundidade peridural medida no campo cirúrgico e a profundidade peridural derivada da RM foi de 0,989 (r2 = 0,979; p < 0,001); e a correlação correspondente com a profundidade peridural estimada por ultrassom foi de 0,990 (r2 = 0,980; p < 0,001). Conclusões: Tanto a profundidade peridural estimada por ultrassom quanto a profundidade peridural derivada da RM mostram forte correlação com a profundidade peridural medida no campo cirúrgico. As estimativas pré-operatórias da profundidade peridural derivadas da RM são um pouco mais profundas do que a profundidade peridural medida no campo cirúrgico, e as profundidades peridurais estimadas por ultrassom são um pouco mais rasas. Embora ambas as técnicas de imagem radiológica tenham fornecido estimativas pré-operatórias confiáveis da profundidade peridural real, a técnica de perda de resistência não pode ser descartada durante a inserção da agulha peridural.

Effects of caudal block in pediatric surgical patients: a randomized clinical trial / Efeitos do bloqueio peridural caudal em pacientes cirúrgicos pediátricos: estudo randomizado

Abstract Background: Surgery generates a neuroendocrine stress response, resulting in undesirable hemodynamic instability, alterations in metabolic response and malfunctioning of the immune system. Objectives: The aim of this research was to determine the effectiveness of caudal blocks in intra- and postoperative pain management and in reducing the stress response in children during the same periods. Methods: This prospective, randomized clinical trial included 60 patients scheduled for elective herniorrhaphy. One group (n = 30) received general anesthesia and the other (n = 30) received general anesthesia with a caudal block. Hemodynamic parameters, drug consumption and pain intensity were measured. Blood samples for serum glucose and cortisol level were taken before anesthesia induction and after awakening the patient. Results: Children who received a caudal block had significantly lower serum glucose (p < 0.01), cortisol concentrations (p < 0.01) and pain scores 3 h (p = 0.002) and 6 h (p = 0.003) after the operation, greater hemodynamic stability and lower drug consumption. Also, there were no side effects or complications identified in that group. Conclusions: The combination of caudal block with general anesthesia is a safe method that leads to less stress, greater hemodynamic stability, lower pain scores and lower consumption of medication.

Resumo Justificativa: O estresse cirúrgico causa resposta neuroendócrina, resultando em instabilidade hemodinâmica indesejável, modificações na resposta metabólica e disfunção no sistema imune. Objetivos: O objetivo deste estudo foi avaliar, em pacientes pediátricos, a eficácia do bloqueio peridural caudal no controle da dor intra e pós-operatória e na redução da resposta ao estresse nesses períodos. Métodos: Estudo clínico prospectivo randomizado que incluiu 60 pacientes submetidos à herniorrafia eletiva. Um grupo (n = 30) recebeu anestesia geral e o outro (n = 30), anestesia geral combinada a bloqueio caudal. Foram medidos os parâmetros hemodinâmicos, o consumo de medicamentos e a intensidade da dor. Amostras de sangue para medir glicemia e cortisol plasmático foram obtidas antes da indução e após o despertar dos pacientes. Resultados: As crianças que receberam bloqueio peridural caudal apresentaram valores significantemente mais baixos para glicemia (p < 0,01), concentração de cortisol (p < 0,01) e escores de dor de 3 horas (p = 0,002) e 6 horas (p = 0,003) após a cirurgia, maior estabilidade hemodinâmica e menor consumo de medicamentos. Além disso, não foram observados efeitos colaterais ou complicações nesse grupo. Conclusões: O bloqueio peridural caudal combinado à anestesia geral é uma técnica segura e que se associa a menor estresse, maior estabilidade hemodinâmica, redução nos escores de dor e baixo consumo de medicamentos.

[Inadvertent epidural ampicillin administration during labor: case report]. / Administração peridural inadvertida de ampicilina durante trabalho de parto: relato de caso.

BACKGROUND: Inadvertent epidural drug administration is associated with morbidity and mortality. Several drugs have been administered accidentally through the epidural catheter and most of our knowledge is based on case reports. CASE REPORT: A 33 year-old woman presented for delivery. Placement of epidural catheter was requested for labor analgesia and priming dose was administered. Five minutes later, ampicillin 1g was given through the catheter inadvertently without hemodynamic or neurological changes. Ropivacaine administration was repeated, always with symptomatic relief until delivery. At hospital discharge, she remained without neurological or hemodynamic alterations. CONCLUSIONS: The majority of errors are due to syringe and drug exchanges, and inadvertent route administration. Erroneous administration into the epidural space can have immediate and late effects and there is no definitive and effective treatment. There are several preventive measures to reduce the potential complications; some opt for watchful waiting, others opt for administering other drugs as a dilution attempted.

[Effects of caudal block in pediatric surgical patients: a randomized clinical trial]. / Efeitos do bloqueio peridural caudal em pacientes cirúrgicos pediátricos: estudo randomizado.

BACKGROUND: Surgery generates a neuroendocrine stress response, resulting in undesirable hemodynamic instability, alterations in metabolic response and malfunctioning of the immune system. OBJECTIVES: The aim of this research was to determine the effectiveness of caudal blocks in intra- and postoperative pain management and in reducing the stress response in children during the same periods. METHODS: This prospective, randomized clinical trial included 60 patients scheduled for elective herniorrhaphy. One group (n = 30) received general anesthesia and the other (n = 30) received general anesthesia with a caudal block. Hemodynamic parameters, drug consumption and pain intensity were measured. Blood samples for serum glucose and cortisol level were taken before anesthesia induction and after awakening the patient. RESULTS: Children who received a caudal block had significantly lower serum glucose (p < 0.01), cortisol concentrations (p < 0.01) and pain scores 3 hours (p = 0.002) and 6 hours (p = 0.003) after the operation, greater hemodynamic stability and lower drug consumption. Also, there were no side effects or complications identified in that group. CONCLUSIONS: The combination of caudal block with general anesthesia is a safe method that leads to less stress, greater hemodynamic stability, lower pain scores and lower consumption of medication.

Inadvertent epidural ampicillin administration during labor: case report / Administração peridural inadvertida de ampicilina durante trabalho de parto: relato de caso

Abstract Background: Inadvertent epidural drug administration is associated with morbidity and mortality. Several drugs have been administered accidentally through the epidural catheter and most of our knowledge is based on case reports. Case report: A 33 year-old woman presented for delivery. Placement of epidural catheter was requested for labor analgesia and priming dose was administered. Five minutes later, ampicillin 1 g was given through the catheter inadvertently without hemodynamic or neurological changes. Ropivacaine administration was repeated, always with symptomatic relief until delivery. At hospital discharge, she remained without neurological or hemodynamic alterations. Conclusions: The majority of errors are due to syringe and drug exchanges and inadvertent route administration. Erroneous administration into the epidural space can have immediate and late effects and there is no definitive and effective treatment. There are several preventive measures to reduce the potential complications; some opt for watchful waiting, others opt for administering other drugs as a dilution attempted.

Resumo Justificativa: A administração inadvertida peridural de drogas está associada à morbidade e mortalidade. Várias drogas foram administradas acidentalmente pelo cateter peridural e a maior parte do que sabemos se baseia em relatos de caso. Relato de caso: Uma gestante de 33 anos chegou em trabalho de parto. Foi solicitada colocação de cateter peridural para analgesia de parto e a dose inicial foi administrada. Cinco minutos depois, 1 g de ampicilina foi dado através do cateter inadvertidamente, sem alterações hemodinâmicas ou neurológicas. A administração de ropivacaína foi repetida, sempre com alívio dos sintomas até o parto. Na alta hospitalar, a paciente continuava sem alterações neurológicas ou hemodinâmicas. Conclusões: A maioria dos erros é por troca de seringa ou drogas, ou administração de rota inadvertida. A administração errônea no espaço peridural pode apresentar efeitos imediatos e tardios e não há tratamento definitivo ou efetivo. Existem várias medidas preventivas para reduzir complicações potenciais; alguns escolhem observação cuidadosa, outros a administração de outras drogas para tentar a diluição.

3D anatomical model for teaching canine lumbosacral epidural anesthesia

Abstract Purpose To develop a 3D anatomical model for teaching canine epidural anesthesia (3DMEA) and to assess its efficacy for teaching and learning prior to the use of live animals. Methods The creation of 3DMEA was based on 3D optical scanning and 3D printing of canine bone pieces of the fifth to the seventh lumbar vertebrae, sacrum and pelvis. A total of 20 male dogs were scheduled for castration. 20 veterinary students watched a video showing epidural anesthesia in dogs before the clinical attempt and were assigned to control or 3DMEA groups. Students in the 3DMEA group trained in the model after the video. For the clinical trial, the epidural procedure was performed by students under the veterinary supervision. When observed the absence of response to nociceptive stimuli, the epidural was considered successful. Then, all students answered a questionnaire evaluating the main difficulty founded in the technique and its degree of difficulty. Results The 3DMEA group reported a lower degree of difficulty to perform the epidural anesthesia technique when compared with the control group (p=0.0037). The 3DMEA reproduced the anatomical structures, allowing the perception of the distance of needle in relation to the iliac prominences during epidural anesthesia. Its mobility allowed simulation of the animal in standing position and sternal recumbency. Conclusion The use of 3DMEA demonstrated greater efficacy in the execution of the technique, being effective in the teaching and learning process before the epidural anesthesia in live animals.

Hyaluronic acid in tobacco-exposed rats. Inflammatory reaction, and duration of effect1.

PURPOSE: To evaluate the hyaluronic acid (HA) inflammatory reaction, fibroblasts, fibrosis and duration of effect in the dorsal region of tobacco-exposed rats. METHODS: Ten Wistar rats were divided into two groups: tobacco-exposed-group (TEG;n=5) and air-control-group (CG;n=5). The TEG animals were tobacco-exposed twice a day, 30-minutes/session, during 60 days. After this period, all animals received 0.1 mL HA subcutaneous injection in the dorsal area. The volume of HA was measured immediately after HA injection and weekly using a hand-caliper in nine weeks. After this period, all the animals were euthanized, and a specimen of was collected to evaluate inflammatory cells, fibroblasts, and fibrosis by HE. RESULTS: This study showed a higher inflammatory reaction in TEG than CG: inflammatory cell-count (CG: 1.07±0.9; TEG: 8.61±0.36, p<0.001); fibroblast count (CG: 2.92±0.17; TEG: 19.14±0.62, p<0.001), and fibrosis quantification (CG: 2.0; TEG: 3.75, p<0.001). The analysis of the HA volume in nine weeks in the dorsal region did not show a difference between groups (p=0.39). CONCLUSIONS: This study suggested that the HA injection in the TEG caused an increase in inflammatory cell count, fibroblast, and fibrosis quantification when compared to the CG. There was no difference in the duration of effect of HA between the groups.

Hyaluronic acid in tobacco-exposed rats. Inflammatory reaction, and duration of effect

Abstract Purpose: To evaluate the hyaluronic acid (HA) inflammatory reaction, fibroblasts, fibrosis and duration of effect in the dorsal region of tobacco-exposed rats. Methods: Ten Wistar rats were divided into two groups: tobacco-exposed-group (TEG;n=5) and air-control-group (CG;n=5). The TEG animals were tobacco-exposed twice a day, 30-minutes/session, during 60 days. After this period, all animals received 0.1 mL HA subcutaneous injection in the dorsal area. The volume of HA was measured immediately after HA injection and weekly using a hand-caliper in nine weeks. After this period, all the animals were euthanized, and a specimen of was collected to evaluate inflammatory cells, fibroblasts, and fibrosis by HE. Results: This study showed a higher inflammatory reaction in TEG than CG: inflammatory cell-count (CG: 1.07±0.9; TEG: 8.61±0.36, p<0.001); fibroblast count (CG: 2.92±0.17; TEG: 19.14±0.62, p<0.001), and fibrosis quantification (CG: 2.0; TEG: 3.75, p<0.001). The analysis of the HA volume in nine weeks in the dorsal region did not show a difference between groups (p=0.39). Conclusions: This study suggested that the HA injection in the TEG caused an increase in inflammatory cell count, fibroblast, and fibrosis quantification when compared to the CG. There was no difference in the duration of effect of HA between the groups.

Espacio retrodural de okada: comunicación de un caso / Retrodural space of okada: communication of a case

Se describe un caso en el que, al realizar una inyección facetaria lumbar, se observó pasaje del contraste y del corticoide hacia la faceta controlateral. se plantea que el pasaje controlateral del contraste y del corticoide se realizó a través del espacio retrodural de Okada, un espacio potencial dorsal al ligamento amarillo, que puede facilitar la comunicación entre distintos compartimientos del complejo ligamentoso posterior de la columna vertebral, en este caso entre las facetas articulares. se muestran las imágenes y se informa sobre la conducta tomada ante una imagen desconocida. se discuten otras posibles causas de pasaje controlateral del contraste, así como otras imágenes que pueden visualizarse en relación del espacio retrodural de Okada. el conocimiento de este espacio resulta de gran importancia para el anestesiólogo que realiza técnicas regionales, en particular a la hora de interpretar imágenes durante los procedimientos intervencionistas.

The following text describes a case in which during a lumbar facet injection, contrast and corticoid passage to the contralateral side was observed. the contralateral passage through the retrodural space of Okada is proposed. this is a potential dorsal space to the yellow ligament that can facilitate communication between different compartments of the posterior ligamentous complex of the spine, in this case between the articular facets. the images are shown and the behavior on an unknown image is reported. other possible causes of contralateral contrast passage are discussed, as well as other images that can be visualized in relation to the retrodural space of Okada. the knowledge of this space is of great importance for the anesthesiologist who performs regional techniques, in particular when interpreting images during interventionist procedures.