Neuber Martins Fonseca

Efeito da clonidina associada à bupivacaína a 0,5% hiperbárica na anestesia subaracnóidea

BACKGROUND AND OBJECTIVES: Clonidine is an imidazolynic compound which exhibits partial alpha2-receptor agonist action, with anxiolytic and hypnotic properties. When spinally administered, it produces selective effects in pain modulation and may prolong surgical anesthesia and motor block. This study aimed at evaluating the effects of combined clonidine and 0.5% hyperbaric bupivacaine on spinal anesthesia. METHODS: Thirth ASA I or II patients off both genders, aged between 16 and 57 years and scheduled to undergo surgical inguinal hernia repair were randomly divided into three groups in this prospective double blind study. After monitoring, patients were sedated with 2 mg venous midazolam 10 minutes before surgery, followed by paramedian spinal puncture (L3-L4) in the left lateral position with a 25G Quincke needle. After CSF confirmation, 1 ml of one of the proposed solutions were injected with 15 mg hyperbaric bupivacaine: Group I - 150 µg clonidine; Group II - 75 µg clonidine + 0.5 ml bi-distilled water; and Group III - 1 ml bi-distilled water. The following parameters were evaluated: sensory block level at 5, 20 and 30 minutes, time for two metamers regression, sedation scores through a 0 to 3 scale, motor block by a modified Bromage’s scale, postoperative pain and analgesics requirement. RESULTS: Demographics and maximum sensory level (mode) were similar for all groups. Anesthesia regression and muscle relaxation were longer for Group I. There were no difference in sedation and hemodynamic parameters between groups. Group I had a prolonged analgesia as compared to other groups, what was confirmed by the less need for analgesics as a function of time. CONCLUSIONS: Clonidine has not changed cephalad spread and hemodynamic effects of spinal anesthesia with 0.5% hyperbaric bupivacaine. However, it has promoted better analgesia during the four hours observed after blockade and a prolonged anesthesia.JUSTIFICATIVA Y OBJETIVOS: La clonidina es un compuesto imidazolinico agonista parcial de los receptores a2-adrenergicos con propiedades ansioliticas e hipnoticas. Administrada en el espacio subaracnoideo produce efectos selectivos en la modulacion del dolor, pudiendo aumentar la duracion de la anestesia quirurgica y del bloqueo motor. El objetivo del estudio fue evaluar el efecto de la clonidina asociada a la bupivacaina 0,5% hiperbarica en la anestesia subaracnoidea. METODO: Fueron estudiados 30 pacientes de ambos sexos, escalados para herniorrafia inguinal, estado fisico ASA I o II, con edades entre 16 e 57 anos, distribuidos aleatoriamente en tres grupos. Despues de monitorizacion, los pacientes fueron sedados con midazolam (2 mg), por via venosa, 10 minutos antes del procedimiento anestesico, seguido de puncion subaracnoidea, L3-L4, paramediana, con aguja Quincke 25G, en decubito lateral izquierdo. Despues de la salida del LCR se inyecto 1 ml de una de las soluciones propuestas de acuerdo con el grupo estudiado juntamente con 15 mg de bupivacaina hiperbarica: Grupo I - 150 µg de clonidina, Grupo II - 75 µg de clonidina + 0,5 ml de agua bidestilada y Grupo III - 1 ml de agua bidestilada. Fueron evaluados el nivel del bloqueo con 5, 20 e 30 minutos, tiempo para regresion de dos metameros, sedacion por la escala de 0 a 3, bloqueo motor por la escala modificada de Bromage, dolor pos-operatorio y necesidad de analgesico. RESULTADOS: Hubo uniformidad de los datos antropometricos en los grupos. El nivel del bloqueo anestesico (moda) en los pacientes estudiados fue uniforme en los grupos. La regresion de la anestesia fue retardada en el grupo I, asi como el relajamiento muscular, en relacion a los otros grupos. No hubo diferencia en relacion a la sedacion y a los parametros hemodinamicos entre los grupos. El grupo I presento analgesia prolongada en relacion a los demas grupos, confirmado por la menor necesidad de analgesicos en funcion del tiempo. CONCLUSIONES: La clonidina no altero la dispersion cefalica y los efectos hemodinamicos del bloqueo subaracnoideo con bupivacaina a 0,5% hiperbarica; sin embargo, fue efectiva en una mejor analgesia observada con cuatro horas despues del bloqueo, bien como prolongo el tiempo de anestesia.

Analgesia pós-operatória em cirurgia ortopédica: estudo comparativo entre o bloqueio do plexo lombar por via perivascular inguinal (3 em 1) com ropivacaína e a analgesia subaracnóidea com morfina

JUSTIFICATIVA E OBJETIVOS: O bloqueio do plexo lombar pelo acesso perivascular inguinal, chamado de bloqueio 3 em 1, tem sido utilizado para analgesia pos-operatoria. O objetivo deste estudo foi comparar a analgesia pos-operatoria do bloqueio 3 em 1 a da morfina subaracnoidea em pacientes submetidos a cirurgias ortopedicas em membro inferior (MI). METODO: Foram estudados 40 pacientes escalados para cirurgia ortopedica de MI, de ambos os sexos, estado fisico ASA I e II, com idades entre 15 e 75 anos, distribuidos em 2 grupos (M e BPL). Foi realizada anestesia subaracnoidea em todos os pacientes, em L3-L4 ou L4-L5, com 20 mg de bupivacaina isobarica a 0,5%. No grupo M (n = 20) foi associado 50 µg de morfina ao anestesico local. No grupo BPL (n = 20) foi realizado o bloqueio 3 em 1 ao termino da cirurgia, utilizando 200 mg de ropivacaina a 0,5%. Avaliou-se a analgesia e a intensidade da dor as 4, 8, 12, 14, 16, 20 e 24 horas apos o termino da cirurgia, o nivel do bloqueio subaracnoideo, o tempo cirurgico e as complicacoes. RESULTADOS: A duracao da analgesia no grupo BPL foi de 13,1 ± 2,47, enquanto no grupo M todos os pacientes referiam dor e ausencia de bloqueio motor no primeiro instante avaliado (4 horas). Houve falha do bloqueio de um dos 3 nervos em 3 pacientes. A incidencia de nausea e prurido foi significativamente maior no grupo M. Quanto a retencao urinaria, nao houve diferenca significante entre os grupos. Nao houve depressao respiratoria, hipotensao arterial ou bradicardia. A analgesia pos-operatoria foi mais efetiva no grupo BPL, comparada ao grupo M as 4, 8, 12,14 e 16 horas. As 20 e 24 horas nao houve diferenca significante entre os grupos. CONCLUSOES: A analgesia pos-operatoria proporcionada pelo bloqueio 3 em 1 apresentou efeitos colaterais inferiores a morfina subaracnoidea com tempo de analgesia semelhante.

Recomendações da Sociedade Brasileira de Anestesiologia para segurança em anestesia regional

Foram realizadas buscas em múltiplas bases de dados (Medline de 1965 a 2011, Cochrane Library, e LILACS) e em referências cruzadas com o material levantado para identificação de artigos com melhor desenho metodológico. Após estas buscas, seguiu-se avaliação crítica de seu conteúdo e classificação de acordo com a força da evidência. As buscas foram realizadas entre dezembro de 2010 e abril de 2011. Para buscas no PubMed, foram utilizadas as seguintes estratégias de pesquisa:

Analgesia pós-toracotomia com associação de morfina por via peridural e venosa

JUSTIFICATIVA E OBJETIVOS: Analgesia apos cirurgia de torax e feita por diferentes metodos. O objetivo do estudo foi avaliar a analgesia pos-operatoria com associacao de morfina por via venosa e peridural, comparada ao uso por via isolada. METODO: Foram estudados 20 pacientes submetidos a cirurgia de torax, ambos os sexos, estado fisico ASA I a III. Foi feita medicacao pre-anestesica com midazolam por via venosa (3 a 3,5 mg) na SO. A monitorizacao constou de ECG continuo, pressao arterial invasiva, oximetria de pulso, capnografia, PVC, diurese e temperatura. Primeiramente foi realizada anestesia peridural continua, T7-T8 com 10 ml de bupivacaina a 0,25% e, em seguida, inducao com fentanil (5 µg.kg-1), etomidato (0,2 a 0,3 mg.kg-1) e succinilcolina (1 mg.kg-1). Foi feita IOT com tubo de duplo lume, complementacao com pancuronio (0,08 a 0,1 mg.kg-1) e ventilacao controlada mecânica. Os pacientes foram entao distribuidos aleatoriamente em tres grupos. Ao Grupo I, administrou-se pelo cateter peridural, 2 mg de morfina 0,1% na inducao da anestesia (M1), apos 12 horas (M2) e 24 horas (M3) do final da cirurgia, ao Grupo II, morfina por via venosa em bomba de infusao (15 µg.kg.h-1) precedida de bolus de 50 µg.kg-1, durante 30 horas e ao Grupo III, morfina por via peridural na dose de 0,5 mg em M1, M2 e M3, associada com morfina venosa em bomba de infusao (8 µg.kg.h-1) precedida de bolus de 25 µg.kg-1, por 30 horas. Analise de gases arteriais, frequencias cardiaca e respiratoria, presenca de prurido, nauseas, vomitos e analgesia pos-operatoria foram avaliados a cada 6 horas, ate um total de 30 horas do pos-operatorio. A analgesia foi avaliada por escala de graduacao numerica (EGN) de 0 a 10. RESULTADOS: A EGN apresentou reducao no grupo I apenas no momento M2 nao ocorrendo nos demais intervalos. Nos grupos II e III ocorreu reducao da dor a partir de 18 horas em relacao aos valores iniciais e em relacao ao grupo I. Houve maior necessidade de analgesia complementar no grupo I do que nos outros grupos. CONCLUSOES: Observou-se melhor efeito analgesico com morfina venosa ou com a associacao de vias venosa e peridural utilizando-se menores doses de morfina. Esta diferenca foi expressiva quando menores quantidades de analgesicos complementares foram utilizados nestes grupos, oferecendo um efetivo metodo de analgesia para o pos-operatorio de cirurgia de torax com menores efeitos depressores respiratorios e emetogenicos.

Brazilian Society of Anesthesiology Recommendations for safety in regional anesthesia

1. MD, PhD, Anesthesiologist; Professor at the Medical School of Universidade de Fortaleza (UNIFOR); Responsible for the Centro de Ensino e Treinamento (CET/MEC/SBA) at Hospital Universitario Walter Cantidio, Universidade Federal do Ceara (UFC); President of the Perioperatative Medicine Committee of SBA 2. MD, PhD, Anesthesiologist; Professor at the Anesthesiology Department of Faculdade de Medicina da Universidade Federal de Uberlândia (FMUFU); Responsible for the CET/SBA at FMUFU 3. MD, Anesthesiologist at Instituto Nacional do Câncer (INCA); Co-responsible for the CET/SBA at Hospital Universitario Pedro Ernesto (HUPE), Universidade do Estado do Rio de Janeiro (UERJ); Instructor at the Curso Suporte Avancado de Vida em Anestesia – SAVA/SBA 4. MD, Anesthesiologist; Coordinator of the Anesthesiology Service at Instituto do Câncer de Sao Paulo (ICESP); Member of the SBA Malignant Hyperthermia Committee 5. MD, Anesthesiologist at Hospital Universitario Oswaldo Cruz, Universidade Estadual de Pernambuco (UPE); Co-responsible for the CET/SBA of Hospital da Restauracao, Hospital Getulio Vargas and Hospital Oswaldo Cruz, UPE; President of the Brazilian Society of Anesthesiology, 2011

Anesthesia in a patient with Marshall-Smith syndrome: case report

BACKGROUND AND OBJECTIVES The Marshall-Smith Syndrome is a rare disease characterized by facial dysmorphism, accelerated osseous maturation, retarded neuropsychomotor development, and abnormalities of the airways. Patients with this syndrome have a high risk of developing anesthetic complications, especially concerning the maintenance of the airways. There are very few data in the anesthetic literature regarding this syndrome. The objective of this report was to show the difficulties and anesthetic management in a 28-day old child with this syndrome, who underwent surgery for correction of choanal atresia under general anesthesia. CASE REPORT A male child, 28 days old, weighing 2.8 kg, undergoing general anesthesia for surgical correction of choanal atresia. The child presented the typical manifestations of the Marshall-Smith syndrome, with a narrow thorax, pectus excavatum, large hands and feet, long neck, facial dysmorphism, high and arched palate, and accelerated osseous maturation. Anesthetic induction was done with a mask with 100% O2 associated with sevoflurane. Due to the possibility of a difficult intubation, tracheal intubation with a fibrobronchoscope was scheduled. After tracheal intubation and assisted manual ventilation, 1.5 mg of rocuronium were administered and, after ten minutes, the patient developed bradycardia (80 bpm), severe hypoxemia (O2 saturation of 30%), and manual ventilation through the tracheal tube became impossible. An urgent tracheostomy was done and the surgical procedure was cancelled. CONCLUSION In cases of anesthetic-surgical emergencies, in which the child does not ventilate and tracheal intubation is not possible, there is desaturation and bradycardia, requiring fast and appropriate decision making to guarantee adequate pulmonary ventilation. These patients need careful evaluation of the airways to identify upper and lower airways obstruction. During anesthesia, spontaneous ventilation should be maintained during induction until control of the airways is possible, avoiding the use of neuromuscular blockers.

Abordagem simplificada do nervo ciático por via posterior, no ponto médio do sulco glúteo-femoral, com uso de neuroestimulador

BACKGROUND AND OBJECTIVES The sciatic nerve may be blocked by several routes, all of them with advantages and disadvantages. It is the largest human nerve in diameter and length, being the prolongation of the upper sacral plexus fascicle (L4, L5, S2 and S3). It leaves the pelvis through the foramen ischiadicum majus, passing below the piriform muscle and going down between the greater trochanter and the ischial tuberosity, continuing along the femoral dorsum, anterior to biceps femoris and semitendinous muscles, to the lower femoral third, where it is divided in two major branches called tibial and common fibular nerves. It becomes superficial at the lower border of the gluteus maximus muscle. Based on this anatomic description, we developed a posterior approach with the following advantages: easy identification of the surface anatomy, superficial level of the nerve at this location; and less discomfort to patients since a 5 cm needle may be used. METHODS Seventeen ASA I - III patients aged 21 to 79 years, weighing 55 to 90 kg, undergoing leg or foot surgery were studied. After monitoring, patients were placed in the prone position and blockade was performed at the middle point of the sulcus gluteus (skin fold between nates and posterior thigh), with the aid of a neurostimulator, using 1% plain lidocaine (300 mg). Onset time, blockade performing time, and tibial, common fibular and cutaneous femoris posterior nerves anesthesia were evaluated. Saphenous nerve was also blocked with 5 ml of 1% lidocaine whenever needed. RESULTS Adequate anesthesia was obtained in all cases. There was no patient with cutaneous femoris posterior nerve anesthesia. Blockade performing time was 8.58 +/- 5.71 min. Onset time was 5.88 +/- 1.6 min. Sensory and motor block duration was 4.05 +/- 1.1 and 2.9 +/- 0.8 hours, respectively. CONCLUSIONS This new approach is effective and easy. However, it is not indicated when the cutaneous femoris posterior nerve anesthesia is necessary.BACKGROUND AND OBJECTIVES: The sciatic nerve may be blocked by several routes, all of them with advantages and disadvantages. It is the largest human nerve in diameter and length, being the prolongation of the upper sacral plexus fascicle (L4, L5, S2 and S3). It leaves the pelvis through the foramen ischiadicum majus, passing below the piriform muscle and going down between the greater trochanter and the ischial tuberosity, continuing along the femoral dorsum, anterior to biceps femoris and semitendinous muscles, to the lower femoral third, where it is divided in two major branches called tibial and common fibular nerves. It becomes superficial at the lower border of the gluteus maximus muscle. Based on this anatomic description, we developed a posterior approach with the following advantages: easy identification of the surface anatomy, superficial level of the nerve at this location; and less discomfort to patients since a 5 cm needle may be used. METHODS: Seventeen ASA I - III patients aged 21 to 79 years, weighing 55 to 90 kg, undergoing leg or foot surgery were studied. After monitoring, patients were placed in the prone position and blockade was performed at the middle point of the sulcus gluteus (skin fold between nates and posterior thigh), with the aid of a neurostimulator, using 1% plain lidocaine (300 mg). Onset time, blockade performing time, and tibial, common fibular and cutaneous femoris posterior nerves anesthesia were evaluated. Saphenous nerve was also blocked with 5 ml of 1% lidocaine whenever needed. RESULTS: Adequate anesthesia was obtained in all cases. There was no patient with cutaneous femoris posterior nerve anesthesia. Blockade performing time was 8.58 ± 5.71 min. Onset time was 5.88 ± 1.6 min. Sensory and motor block duration was 4.05 ± 1.1 and 2.9 ± 0.8 hours, respectively. CONCLUSIONS: This new approach is effective and easy. However, it is not indicated when the cutaneous femoris posterior nerve anesthesia is necessary.

Effects of combined clonidine and 0.5% hyperbaric bupivacaine on spinal anesthesia

BACKGROUND AND OBJECTIVES: Clonidine is an imidazolynic compound which exhibits partial alpha2-receptor agonist action, with anxiolytic and hypnotic properties. When spinally administered, it produces selective effects in pain modulation and may prolong surgical anesthesia and motor block. This study aimed at evaluating the effects of combined clonidine and 0.5% hyperbaric bupivacaine on spinal anesthesia. METHODS: Thirth ASA I or II patients off both genders, aged between 16 and 57 years and scheduled to undergo surgical inguinal hernia repair were randomly divided into three groups in this prospective double blind study. After monitoring, patients were sedated with 2 mg venous midazolam 10 minutes before surgery, followed by paramedian spinal puncture (L3-L4) in the left lateral position with a 25G Quincke needle. After CSF confirmation, 1 ml of one of the proposed solutions were injected with 15 mg hyperbaric bupivacaine: Group I - 150 µg clonidine; Group II - 75 µg clonidine + 0.5 ml bi-distilled water; and Group III - 1 ml bi-distilled water. The following parameters were evaluated: sensory block level at 5, 20 and 30 minutes, time for two metamers regression, sedation scores through a 0 to 3 scale, motor block by a modified Bromage’s scale, postoperative pain and analgesics requirement. RESULTS: Demographics and maximum sensory level (mode) were similar for all groups. Anesthesia regression and muscle relaxation were longer for Group I. There were no difference in sedation and hemodynamic parameters between groups. Group I had a prolonged analgesia as compared to other groups, what was confirmed by the less need for analgesics as a function of time. CONCLUSIONS: Clonidine has not changed cephalad spread and hemodynamic effects of spinal anesthesia with 0.5% hyperbaric bupivacaine. However, it has promoted better analgesia during the four hours observed after blockade and a prolonged anesthesia.JUSTIFICATIVA Y OBJETIVOS: La clonidina es un compuesto imidazolinico agonista parcial de los receptores a2-adrenergicos con propiedades ansioliticas e hipnoticas. Administrada en el espacio subaracnoideo produce efectos selectivos en la modulacion del dolor, pudiendo aumentar la duracion de la anestesia quirurgica y del bloqueo motor. El objetivo del estudio fue evaluar el efecto de la clonidina asociada a la bupivacaina 0,5% hiperbarica en la anestesia subaracnoidea. METODO: Fueron estudiados 30 pacientes de ambos sexos, escalados para herniorrafia inguinal, estado fisico ASA I o II, con edades entre 16 e 57 anos, distribuidos aleatoriamente en tres grupos. Despues de monitorizacion, los pacientes fueron sedados con midazolam (2 mg), por via venosa, 10 minutos antes del procedimiento anestesico, seguido de puncion subaracnoidea, L3-L4, paramediana, con aguja Quincke 25G, en decubito lateral izquierdo. Despues de la salida del LCR se inyecto 1 ml de una de las soluciones propuestas de acuerdo con el grupo estudiado juntamente con 15 mg de bupivacaina hiperbarica: Grupo I - 150 µg de clonidina, Grupo II - 75 µg de clonidina + 0,5 ml de agua bidestilada y Grupo III - 1 ml de agua bidestilada. Fueron evaluados el nivel del bloqueo con 5, 20 e 30 minutos, tiempo para regresion de dos metameros, sedacion por la escala de 0 a 3, bloqueo motor por la escala modificada de Bromage, dolor pos-operatorio y necesidad de analgesico. RESULTADOS: Hubo uniformidad de los datos antropometricos en los grupos. El nivel del bloqueo anestesico (moda) en los pacientes estudiados fue uniforme en los grupos. La regresion de la anestesia fue retardada en el grupo I, asi como el relajamiento muscular, en relacion a los otros grupos. No hubo diferencia en relacion a la sedacion y a los parametros hemodinamicos entre los grupos. El grupo I presento analgesia prolongada en relacion a los demas grupos, confirmado por la menor necesidad de analgesicos en funcion del tiempo. CONCLUSIONES: La clonidina no altero la dispersion cefalica y los efectos hemodinamicos del bloqueo subaracnoideo con bupivacaina a 0,5% hiperbarica; sin embargo, fue efectiva en una mejor analgesia observada con cuatro horas despues del bloqueo, bien como prolongo el tiempo de anestesia.

Tibial and Common Fibular Nerve Block in the Popliteal Fossa with Single Puncture Using Percutaneous Nerve Stimulator: Anatomical Considerations and Ultrasound Description

BACKGROUND AND OBJECTIVES Techniques of peripheral nerve block have gained popularity over the last two decades becoming a growing anesthetic option for limb surgeries. This study proposes a technical approach of the tibial and common fibular nerves in the popliteal fossa with single puncture using percutaneous nerve stimulator, considering the correlation with an anatomical and ultrasound study. METHODS This prospective, observational, randomized study was performed with 28 patients scheduled for foot surgeries. After localizing the tibial and common fibular nerves through percutaneous stimulation, the puncture was performed at the point of tibial nerve stimulation with a 5-cm needle (B.Braun, Stimuplex 50), and 10 mL of levobupivacaine were injected. The needle was pulled back and redirected to the point of common fibular nerve stimulation looking for the corresponding motor response, and 10 mL of the local anesthetic were injected. Imaging study of the popliteal region was performed by ultrasound to correlate the anatomy with the technique used. RESULTS Adequate anesthesia was obtained in all cases. The mean time to localize the tibial and common fibular nerves suing the percutaneous stimulator was 57.1 and 32.8 seconds, respectively, and with the nerve stimulator it was 2.22 and 1.79 minutes, respectively. The mean depth of the needle into the tibial nerve was 10.7 mm. CONCLUSIONS The approach for tibial and common fibular nerves with single puncture in the popliteal fossa using peripheral nerve stimulator is a good option for anesthesia and analgesia for foot surgeries.

An evaluation of new circle system of anesthesia. Quantitative anesthesia with isoflurane in new zealand rabbits

A small circuit system of anesthesia was developed by Fonseca and Goldenberg in 1993. The authors used in this study New Zealand White (NZW) rabbits under closed system anesthetic regiment by insoflurane. Twenty male adult New Zealand rabbits were distributed in two groups of ten animals. No premedicant drugs were given. Endotraqueal intubation was made after intravenous administration of propofol (10mg/kg). Insoflurane was used to anesthesia management, administred by lowflow closed system technique with cooper kettle vaporizer, fixed by pre-calculated vaporizing flow in double times intervals. The group II underwent surgical periostal scratching in the medial tibial surface at the proximal shaft. Rabbits breathed spontaneously. Hypotensio, hypercapnia and respiratory acidosis were characteristic of the cardiopulmonary effects of the anesthesia. The corneal reflex and pinch reflex was useful as reliable indicators of anesthesic depth. Manual or mechanical ventilation should be considered as a way of improving alveolar ventilation and normalize blood-gas values. The system developed by Fonseca and Goldenberg was considered suitable for anesthesic management in rabbits.