Marildo A Gouveia

Continuous spinal anesthesia versus combined spinal epidural block for major orthopedic surgery: prospective randomized study

CONTEXT AND OBJECTIVES In major orthopedic surgery of the lower limbs, continuous spinal anesthesia (CSA) and combined spinal epidural anesthesia (CSE) are safe and reliable anesthesia methods. In this prospective randomized clinical study, the blockading properties and side effects of CSA were compared with single interspace CSE, among patients scheduled for major hip or knee surgery. DESIGN AND SETTING Prospective clinical study conducted at the Institute for Regional Anesthesia, Hospital de Base, São José do Rio Preto. METHODS 240 patients scheduled for hip arthroplasty, knee arthroplasty or femoral fracture treatment were randomly assigned to receive either CSA or CSE. Blockades were performed in the lateral position at the L3-L4 interspace. Puncture success, technical difficulties, paresthesia, highest level of sensory and motor blockade, need for complementary doses of local anesthetic, degree of technical difficulties, cardiocirculatory changes and postdural puncture headache (PDPH) were recorded. At the end of the surgery, the catheter was removed and cerebrospinal fluid leakage was evaluated. RESULTS Seven patients were excluded (three CSA and four CSE). There was significantly lower incidence of paresthesia in the CSE group. The resultant sensory blockade level was significantly higher with CSE. Complete motor blockade occurred in 110 CSA patients and in 109 CSE patients. Arterial hypotension was observed significantly more often in the CSE group. PDPH was observed in two patients of each group. CONCLUSION Our results suggest that both CSA and CSE provided good surgical conditions with low incidence of complications. The sensory blockade level and hemodynamic changes were lower with CSA.

Assessment of the densities of local anesthetics and their combination with adjuvants: an experimental study

BACKGROUND AND OBJECTIVES The relative density of a local anesthetic in relation to that of the cerebrospinal fluid (CSF) at 37 degrees C is one of the most important physical properties that affect the level of analgesia obtained after the subarachnoid administration of the drug. The objective of this study was to determine the density of local anesthetic solutions, with and without glucose, and the combination of the local anesthetic with adjuvants at 20 degrees C, 25 degrees C, and 37 degrees C. METHODS The density (g.mL(-1)) was determined by using a DMA 450 densimeter with a sensitivity of +/- 0.00001 g.mL(-1). The densities, and variations, according to the temperature were obtained for all local anesthetics and their combination with opioids at 20 degrees C, 25 degrees C, and 37 degrees C. The solution is hyperbaric if its density exceeds 1.00099, hypobaric when its density is lower than 1.00019, and isobaric when its density is greater than 1.00019 and lower than 1.00099. RESULTS The densities of both local anesthetics and adjuvants decrease with the increase in temperature. At 37 degrees C, all glucose-containing solutions are hyperbaric. In the absence of glucose, all solutions are hypobaric. At 37 degrees C, morphine, fentanyl, sufentanil, and clonidine are hypobaric. CONCLUSIONS The densities of local anesthetics and adjuvants decrease with the increase in temperature and increase when glucose is added. The knowledge of the relative density helps select the most adequate local anesthetic to be administered in the subarachnoid space.JUSTIFICATIVA E OBJETIVOS: Uma das mais importantes propriedades fisicas que afetam o nivel da analgesia obtida apos a injecao subaracnoidea de um anestesico local e sua densidade relativa a densidade do liquido cefalorraquidiano (LCR) a 37°C. O objetivo deste trabalho foi determinar a densidade das solucoes de anestesicos locais com e sem glicose e a combinacao de anestesico local com adjuvantes a 20°C, 25°C e 37°C em avaliacao laboratorial. METODO: A densidade (g.mL-1) foi medida como auxilio de um densimetro DMA 450, sensivel a ± 0,00001 g.mL-1. A densidade e suas variacoes com a temperatura foram obtidas de todos os anestesicos locais e suas combinacoes com opioides a 20°C, 25°C e 37°C. A solucao e hiperbarica se sua densidade excede a 1,00099, a solucao e hipobarica quando a densidade esta abaixo de 1,00019 e e isobarica quando a densidade e maior que 1,00019 e menor que 1,00099. RESULTADOS: Ambos, anestesicos locais e adjuvantes, exibem diminuicao da densidade quando se aumenta a temperatura. A 37°C, todas as solucoes que contem glicose sao hiperbaricas. Na ausencia de glicose, todas as solucoes sao hipobaricas. A 37°C, morfina, fentanil, sufentanil e clonidina sao hipobaricas. CONCLUSOES: A densidade dos anestesicos locais e adjuvantes diminui com o aumento da temperatura e aumenta com a adicao de glicose. O conhecimento da baricidade, densidade relativa, ajuda na selecao do anestesico local mais adequado e dos adjuvantes para uso subaracnoideo.

Unilateral spinal anesthesia with hypobaric bupivacaine

BACKGROUND AND OBJECTIVES Restricted sympathetic block during spinal anesthesia may minimize hemodynamic changes. In theory, the use of non-isobaric local anesthetics may induce unilateral anesthesia and limit sympathetic blockade to one side of the body. The local anesthetic dose and the time patients need to remain in the lateral position for achieving unilateral spinal anesthesia are not known. This prospective study investigated the incidence of unilateral spinal anesthesia following injection through a 27G Quincke needle of 0.15% hypobaric bupivacaine, prepared with 1.5 ml standard isobaric bupivacaine plus fentanyl (25 microg), in patients in the lateral position with the limb to be operated upwards. METHODS Spinal anesthesia with 0.15% bupivacaine + fentanyl (25 microg) was induced through a 27G Quincke needle in 22 ASA I and II patients undergoing orthopedic surgery. Dural puncture was performed with the patient in the lateral position with the side to be operated upwards. After removal of 3 to 5 ml of CSF, 5 ml of the hypobaric bupivacaine-fentanyl mixture were injected at a speed of 1 ml.15 s-1. Sensory and motor block (pinprick/scale 0 to 3) were compared between operated and contralateral sides. RESULTS Motor and sensory blocks in operated and contralateral sides were significantly different in all moments for both groups. Unilateral spinal anesthesia was obtained in 71% of the patients. No hemodynamic changes were observed in any patient. No patient developed post-dural puncture headache. CONCLUSIONS Hypobaric 0.15% bupivacaine (7.5 mg) associated to fentanyl provided a predominantly unilateral block after twenty minutes in the lateral position. Major advantages of unilateral spinal anesthesia were hemodynamic stability, patient satisfaction and the absence of post-dural puncture headache.

Avaliação da Densidade dos anestésicos locais e da combinação com adjuvantes: estudo em laboratório

BACKGROUND AND OBJECTIVES The relative density of a local anesthetic in relation to that of the cerebrospinal fluid (CSF) at 37 degrees C is one of the most important physical properties that affect the level of analgesia obtained after the subarachnoid administration of the drug. The objective of this study was to determine the density of local anesthetic solutions, with and without glucose, and the combination of the local anesthetic with adjuvants at 20 degrees C, 25 degrees C, and 37 degrees C. METHODS The density (g.mL(-1)) was determined by using a DMA 450 densimeter with a sensitivity of +/- 0.00001 g.mL(-1). The densities, and variations, according to the temperature were obtained for all local anesthetics and their combination with opioids at 20 degrees C, 25 degrees C, and 37 degrees C. The solution is hyperbaric if its density exceeds 1.00099, hypobaric when its density is lower than 1.00019, and isobaric when its density is greater than 1.00019 and lower than 1.00099. RESULTS The densities of both local anesthetics and adjuvants decrease with the increase in temperature. At 37 degrees C, all glucose-containing solutions are hyperbaric. In the absence of glucose, all solutions are hypobaric. At 37 degrees C, morphine, fentanyl, sufentanil, and clonidine are hypobaric. CONCLUSIONS The densities of local anesthetics and adjuvants decrease with the increase in temperature and increase when glucose is added. The knowledge of the relative density helps select the most adequate local anesthetic to be administered in the subarachnoid space.JUSTIFICATIVA E OBJETIVOS: Uma das mais importantes propriedades fisicas que afetam o nivel da analgesia obtida apos a injecao subaracnoidea de um anestesico local e sua densidade relativa a densidade do liquido cefalorraquidiano (LCR) a 37°C. O objetivo deste trabalho foi determinar a densidade das solucoes de anestesicos locais com e sem glicose e a combinacao de anestesico local com adjuvantes a 20°C, 25°C e 37°C em avaliacao laboratorial. METODO: A densidade (g.mL-1) foi medida como auxilio de um densimetro DMA 450, sensivel a ± 0,00001 g.mL-1. A densidade e suas variacoes com a temperatura foram obtidas de todos os anestesicos locais e suas combinacoes com opioides a 20°C, 25°C e 37°C. A solucao e hiperbarica se sua densidade excede a 1,00099, a solucao e hipobarica quando a densidade esta abaixo de 1,00019 e e isobarica quando a densidade e maior que 1,00019 e menor que 1,00099. RESULTADOS: Ambos, anestesicos locais e adjuvantes, exibem diminuicao da densidade quando se aumenta a temperatura. A 37°C, todas as solucoes que contem glicose sao hiperbaricas. Na ausencia de glicose, todas as solucoes sao hipobaricas. A 37°C, morfina, fentanil, sufentanil e clonidina sao hipobaricas. CONCLUSOES: A densidade dos anestesicos locais e adjuvantes diminui com o aumento da temperatura e aumenta com a adicao de glicose. O conhecimento da baricidade, densidade relativa, ajuda na selecao do anestesico local mais adequado e dos adjuvantes para uso subaracnoideo.

Raquianestesia posterior para cirurgias anorretais em regime ambulatorial: estudo piloto

JUSTIFICATIVA Y OBJETIVOS: El aumento del numero de cirugias ambulatoriales exige el empleo de metodos anestesicos que permitan la liberacion del paciente despues de la cirugia. Frecuentemente, las cirugias anorrectales son realizadas con los pacientes hospitalizados. Este estudio examina la posibilidad de que esos procedimientos puedan ser realizados en regimen ambulatorial con bajas dosis de bupivacaina hipobarica. METODO: Treinta pacientes, estado fisico ASA I y II, fueron sometidos a la raquianestesia con solucion hipobarica de bupivacaina a 0,15% a traves de aguja 27G Quincke para cirugias anorrectales. La puncion subaracnoidea fue realizada con el paciente en decubito ventral con auxilio de un cojin en su abdomen para corregir la lordosis lumbar y el espacio intervertebral. RESULTADOS: El bloqueo sensitivo fue logrado en todos los pacientes. Su dispersion vario de T10 a L2 con moda en T12. Apenas tres pacientes presentaron algun grado de bloqueo motor. La duracion del bloqueo fue de 122,17 ± 15,35 minutos. Estabilidad hemodinamica fue observada en todos los pacientes. Ningun paciente desarrollo cefalea despues de puncion de la dura-mater. CONCLUSIONES: Seis miligramos de bupivacaina a 0,15% en solucion hipobarica proporcionaron un bloqueo predominantemente sensitivo, cuando inyectados en decubito ventral. Las principales ventajas son la rapida recuperacion, estabilidad hemodinamica y satisfaccion del paciente, siendo una buena indicacion para anestesia ambulatorial.

Low dose of lidocaine: comparison of 15 with 20 mg/ml with dextrose for spinal anesthesia in lithotomy position and ambulatory surgery.

Background: Spinal anesthesia with the local anesthetic lidocaine has come under scrutiny because it is associated with transient neurologic symptoms (TNS). Although TNS is not associated with either lidocaine concentration or dose, its incidence has never been examined with very small doses of hyperbaric spinal lidocaine in patients in the lithotomy position. We designed this study prospectively to compare the efficacy of low‐dose 15 mg/ml with low‐dose 20 mg/ml hyperbaric lidocaine in patients undergoing elective outpatient surgery in the lithotomy position.

Low hypobaric bupivacaine doses for unilateral spinal anesthesia

JUSTIFICATIVA Y OBJETIVOS: Para evitar alteraciones hemodinamicas, obtener recuperacion mas rapida y limitar la dispersion cefalica de la raquianestesia apenas en el miembro operado fue realizado este estudio con bupivacaina a 0,15%, con objetivo de obtenerse raquianestesia unilateral. METODO: Raquianestesia con 3,3 ml de bupivacaina hipobarica a 0,15% (5 mg) fue realizada a traves de aguja 27G Quincke en 20 pacientes estado fisico ASA I y II sometidos a cirugias ortopedicas. La puncion subaracnoidea fue realizada por via lateral con el paciente en decubito lateral, con el miembro a ser operado vuelto para arriba, y 3,3 ml de bupivacaina hipobarica fueron inyectados en la velocidad de 1 ml a cada 15 segundos. Bloqueo sensitivo y motor (picada de aguja y escala de 0 a 3) fueron comparados entre los lados que serian operados y el contralateral. RESULTADOS: Los bloqueos motor y sensitivo entre el lado operado y el contralateral fueron significativamente diferentes en todos los tiempos evaluados. Raquianestesia unilateral fue obtenida en 75% de los pacientes. Estabilidad hemodinamica fue observada en todos los pacientes. Ningun paciente desarrollo cefalea pos-raquianestesia. CONCLUSIONES: La bupivacaina hipobarica a 0,15% en dosis de 5 mg proporciona un predominante bloqueo unilateral. Veinte minutos son suficientes para su instalacion. La principal ventaja de la raquianestesia unilateral es la estabilidad hemodinamica.BACKGROUND AND OBJECTIVES The possibility to achieve unilateral spinal anesthesia with 0.15% bupivacaine was studied with the purpose of minimizing hemodynamic changes, limiting the cephalad dispersion of the anesthetic and promoting a faster recovery. METHODS Twenty ASA I - II patients undergoing orthopedic surgeries were given spinal 0.15% hypobaric bupivacaine through a 27G Quincke needle. Dural puncture was performed with patients in the lateral position, with the limb to be operated upwards, and 3.3 ml (5 mg) hypobaric bupivacaine were injected at the rate of 1 ml.15 s(-). Sensory and motor block (pinprick and 0 to 3 scale) were compared between operated and contralateral sides. RESULTS Motor and sensory block in operated and contralateral sides were significantly different in all evaluated times. Unilateral spinal anesthesia was achieved in 75% of patients. All patients remained hemodynamically stable, and no one developed post-dural puncture headache. CONCLUSIONS Hypobaric bupivacaine (5 mg) is able to provide a predominant unilateral block with the patient being kept twenty minutes in the lateral position. Major unilateral spinal anesthesia advantage is hemodynamic stability.

Reducing the concentration to 0.4% enantiomeric excess hyperbaric levobupivacaine (s75: r25) provides unilateral spinal anesthesia. Study with different volumes.

BACKGROUND AND OBJECTIVES Unilateral spinal anesthesia may be obtained with hypobaric or hyperbaric solution. The objective of this study was to compare different doses of enantiomeric excess hyperbaric levobupivacaine to achieve unilateral spinal anesthesia. METHOD One hundred and twenty patients were randomized to receive 4 mg, 6 mg or 8 mg of 0.4% enantiomeric excess levobupivacaine. The solutions were administered at the L3-L4, with the patient in a lateral position and kept at this position according to dose administration for 5, 10 or 15 minutes. Sensory block (pinprick) and motor block (scale 0-3) were compared between the operated and contralateral sides. RESULTS The onset of analgesia was rapid and comparable between groups. Sensory block was significantly higher in the operated than in nonoperated limb at all times of evaluation. Increasing the dose by 1 mL (2mg) corresponded to an increase of two segments in the mode for the operated side. In the operated side, motor block (MB = 3) of patients occurred in 31 (77.5%) with 4 mg, 38 (95%) with 6 mg, and 40 (100%) with 8 mg. There was a positive correlation between increased dose, blockade duration, and hypotension. All patients were satisfied with the technique used. CONCLUSIONS Spinal anesthesia with different volumes of enantiomeric excess hyperbaric bupivacaine (S75: R25) provided a 78% incidence of unilateral spinal block, with the smallest dose used (4 mg) the most efficient.

Selective sensory spinal anaesthesia with hypobaric lidocaine for anorectal surgery

Background: Lidocaine has been used for spinal anaesthesia since 1948, seemingly without causing concern until recently. This study aimed at evaluating the feasibility of performing anorectal surgery in outpatient settings with low hypobaric lidocaine doses.

Baixas doses de bupivacaína hipobárica para raquianestesia unilateral

JUSTIFICATIVA Y OBJETIVOS: Para evitar alteraciones hemodinamicas, obtener recuperacion mas rapida y limitar la dispersion cefalica de la raquianestesia apenas en el miembro operado fue realizado este estudio con bupivacaina a 0,15%, con objetivo de obtenerse raquianestesia unilateral. METODO: Raquianestesia con 3,3 ml de bupivacaina hipobarica a 0,15% (5 mg) fue realizada a traves de aguja 27G Quincke en 20 pacientes estado fisico ASA I y II sometidos a cirugias ortopedicas. La puncion subaracnoidea fue realizada por via lateral con el paciente en decubito lateral, con el miembro a ser operado vuelto para arriba, y 3,3 ml de bupivacaina hipobarica fueron inyectados en la velocidad de 1 ml a cada 15 segundos. Bloqueo sensitivo y motor (picada de aguja y escala de 0 a 3) fueron comparados entre los lados que serian operados y el contralateral. RESULTADOS: Los bloqueos motor y sensitivo entre el lado operado y el contralateral fueron significativamente diferentes en todos los tiempos evaluados. Raquianestesia unilateral fue obtenida en 75% de los pacientes. Estabilidad hemodinamica fue observada en todos los pacientes. Ningun paciente desarrollo cefalea pos-raquianestesia. CONCLUSIONES: La bupivacaina hipobarica a 0,15% en dosis de 5 mg proporciona un predominante bloqueo unilateral. Veinte minutos son suficientes para su instalacion. La principal ventaja de la raquianestesia unilateral es la estabilidad hemodinamica.BACKGROUND AND OBJECTIVES The possibility to achieve unilateral spinal anesthesia with 0.15% bupivacaine was studied with the purpose of minimizing hemodynamic changes, limiting the cephalad dispersion of the anesthetic and promoting a faster recovery. METHODS Twenty ASA I - II patients undergoing orthopedic surgeries were given spinal 0.15% hypobaric bupivacaine through a 27G Quincke needle. Dural puncture was performed with patients in the lateral position, with the limb to be operated upwards, and 3.3 ml (5 mg) hypobaric bupivacaine were injected at the rate of 1 ml.15 s(-). Sensory and motor block (pinprick and 0 to 3 scale) were compared between operated and contralateral sides. RESULTS Motor and sensory block in operated and contralateral sides were significantly different in all evaluated times. Unilateral spinal anesthesia was achieved in 75% of patients. All patients remained hemodynamically stable, and no one developed post-dural puncture headache. CONCLUSIONS Hypobaric bupivacaine (5 mg) is able to provide a predominant unilateral block with the patient being kept twenty minutes in the lateral position. Major unilateral spinal anesthesia advantage is hemodynamic stability.