Giovani Alves Monteiro

Phenylephrine for blood pressure control in elective cesarean section: therapeutic versus prophylactic doses

BACKGROUND AND OBJECTIVES Spinal block is commonly used in cesarean sections and, if some prophylactic measures are not taken, the incidence of hypotension is higher than 80%. The objective of this study was to compare the efficacy of the administration of therapeutic or prophylactic doses of phenylephrine to maintain blood pressure in patients undergoing spinal block for elective cesarean section. METHODS One hundred and twenty gravidas undergoing elective cesarean sections under spinal block, randomly divided in three equal groups according to the regimen of phenylephrine administered, were included in this study. In Group 1, continuous infusion of phenylephrine, using an infusion pump at 0.15 microg.kg(-1).min(-1) was administered after the spinal block. In Group 2, a single dose of prophylactic phenylephrine 50 microg was administered after the spinal block, and Group 3 received a single dose of phenylephrine 50 microg in case of hypotension, which was defined as a drop in SBP and/or DBP of up to 20% of baseline levels. The incidence of hypotension, nausea, and vomiting as well as the Apgar score were evaluated. RESULTS The incidence of hypotension was significantly greater in Group 3, affecting 85% of the gravidas. In Groups 1 and 2 hypotension was seen in 17.5% and 32.5% of the cases respectively (p < 0.001). The incidence of nausea was much higher in Group 3 affecting 40% of the patients while in Groups 1 and 2 it was 10% and 15% respectively which was statistically significant. CONCLUSIONS According to the methodology used, this study showed that prophylactic continuous infusion of phenylephrine initiated immediately after the spinal block for cesarean section is more effective in reducing the incidence of hypotension and maternal and fetal side effects.

Analgesia pós-operatória para cesariana: a adição de clonidina à morfina subaracnóidea melhora a qualidade da analgesia?

JUSTIFICATIVA E OBJETIVOS: O mecanismo de acao analgesica a2-adrenergico tem sido explorado ha mais de 100 anos. A clonidina aumenta de maneira dose-dependente a duracao dos bloqueios sensitivo e motor e tem propriedades antinociceptivas. O objetivo desse estudo foi avaliar se a adicao de clonidina na dose de 15 e 30 µg a raquianestesia, para cesariana, com bupivacaina hiperbarica a 0,5% (12,5 mg) e morfina (100 µg), melhora a qualidade da analgesia pos-operatoria. METODO: Foi realizado um estudo prospectivo e aleatorio com 60 pacientes divididas em tres grupos: BM - bupivacaina hiperbarica a 0,5% (12,5 mg) e morfina (100 µg), BM15 - bupivacaina hiperbarica a 0,5% (12,5 mg), morfina (100 µg) e clonidina (15 µg) e BM30 - bupivacaina hiperbarica a 0,5% (12,5 mg), morfina (100 µg) e clonidina (30 µg), administradas separadamente. No peri-operatorio, foram anotados o consumo de efedrina e a avaliacao do recem-nascido pelo indice de Apgar. No pos-operatorio, a dor foi avaliada na 12a h pela Escala Analogica Visual, o tempo para solicitacao de analgesicos e efeitos colaterais pos-operatorios, como prurido, nauseas, vomitos, bradicardia, hipotensao arterial e sedacao. Os valores foram considerados significativos quando p < 0,05. RESULTADOS: Os grupos foram homogeneos. O consumo de efedrina e a avaliacao pelo indice de Apgar nao exibiram diferenca estatistica significativa entre os grupos. Os escores de dor e o tempo medio de analgesia mostraram diferenca entre os grupos BM e BM15/BM30 e nao houve diferenca com relacao a incidencia de efeitos colaterais pos-operatorios. CONCLUSOES: A adicao de clonidina na raquianestesia com bupivacaina hiperbarica a 0,5% (12,5 mg) e morfina (100 µg) para cesariana, melhorou a qualidade da analgesia pos-operatoria, sem aumentar a incidencia de efeitos colaterais, sendo 15 µg de clonidina a dose sugerida.BACKGROUND AND OBJECTIVES The mechanism of action of alpha2-adrenergic analgesia has been explored for more than one hundred years. The increased duration of the sensitive and motor blockades caused by clonidine is dose-dependent and has antinociceptive properties. The objective of this study was to evaluate whether the addition of 15 to 30 microg of clonidine to spinal anesthesia for cesarean sections with 0.5% hyperbaric bupivacaine (12.5 mg) and morphine (100 microg) improves the quality of postoperative analgesia. METHODS We realized a prospective, randomized study that included 60 patients divided in 3 groups: BM - 0.5% hyperbaric bupivacaine (12.5 mg) and morphine (100 microg), BM15 - 0.5% hyperbaric bupivacaine (12.5 mg), morphine (100 microg), and clonidine (15 mg), and BM30 - 0.5% hyperbaric bupivacaine (12.5 mg), morphine (100 microg), and clonidine (30 microg), administered separately. In the perioperative period the use of ephedrine and the newborns Apgar score were recorded. In the postoperative period, the pain was evaluated in the 12th h by the VAS, the length of time it took the patient to ask for analgesics, and the postoperative side effects, such as pruritus, nausea, vomiting, bradycardia, hypotension, and sedation. The values were considered significant when p < 0.05. RESULTS The groups were homogenous. The use of ephedrine and the evaluation by the Apgar score did not show statistically significant differences among the different groups. The pain scores and the average time to start analgesia showed differences among the groups BM and BM15/BM30, and there were no differences regarding the incidence of postoperative side effects. CONCLUSIONS The addition of clonidine to spinal anesthesia with 0.5% hyperbaric bupivacaine (12.5 mg) and morphine (100 microg) for cesarean section improved the quality of the postoperative analgesia without increasing the incidence of side effects. We suggest that the dose of 15 microg of clonidine should be used.

Utilização da fenilefrina para controle da pressão arterial em cesarianas eletivas: dose terapêutica versus profilática

JUSTIFICATIVA Y OBJETIVOS: La raquianestesia se usa a menudo en casos de cesarea y si algunas medidas profilacticas no se adoptan, la incidencia de hipotension arterial es superior al 80%. El objetivo de este estudio fue comparar la eficacia de la fenilefrina cuando se administra terapeutica o profilacticamente para el mantenimiento de la presion arterial en pacientes sometidas a la raquianestesia para cesareas electivas. METODO: Se estudiaron 120 gestantes sometidas a cesareas electivas bajo raquianestesia, ubicadas aleatoriamente en tres grupos iguales, conforme al regimen de administracion de fenilefrina. En el Grupo 1, se administro fenilefrina en infusion continua, con bomba de infusion en dosis de 0,15 µg.Kg-1.min-1 despues de la raquianestesia. En el Grupo 2, fue administrada fenilefrina en dosis unica, de forma profilactica, en dosis de 50 µg despues de la raquianestesia, y en el Grupo 3, fenilefrina en dosis unica de 50 µg en el caso de hipotension arterial definida como una caida de la PAS y/o PAD en hasta un 20% con relacion al promedio de los valores basales. Se evaluo la incidencia de hipotension arterial, nauseas, vomitos y el indice de Apgar. RESULTADOS: La incidencia de hipotension arterial fue significativamente mas elevada en el Grupo 3, acaeciendo en un 85% de las embarazadas. En los Grupos 1 y 2, ocurrio en un 17,5% y 32,5% de los casos respectivamente (p < 0,001). La incidencia de nauseas fue bastante superior en el Grupo 3 en un 40% de las pacientes, mientras que en los Grupos 1 y 2 la incidencia fue de un 10% y un 15% respectivamente, presentando significancia estadistica. CONCLUSIONES: A tono con la metodologia utilizada, el estudio muestra que la infusion continua profilactica de fenilefrina iniciada inmediatamente despues de la realizacion de la raquianestesia para cesarea, es mas efectiva en la reduccion de la incidencia de hipotension arterial y los efectos colaterales maternos y fetales.

Postoperative analgesia for cesarean section: does the addiction of clonidine to subarachnoid morphine improve the quality of the analgesia?

JUSTIFICATIVA E OBJETIVOS: O mecanismo de acao analgesica a2-adrenergico tem sido explorado ha mais de 100 anos. A clonidina aumenta de maneira dose-dependente a duracao dos bloqueios sensitivo e motor e tem propriedades antinociceptivas. O objetivo desse estudo foi avaliar se a adicao de clonidina na dose de 15 e 30 µg a raquianestesia, para cesariana, com bupivacaina hiperbarica a 0,5% (12,5 mg) e morfina (100 µg), melhora a qualidade da analgesia pos-operatoria. METODO: Foi realizado um estudo prospectivo e aleatorio com 60 pacientes divididas em tres grupos: BM - bupivacaina hiperbarica a 0,5% (12,5 mg) e morfina (100 µg), BM15 - bupivacaina hiperbarica a 0,5% (12,5 mg), morfina (100 µg) e clonidina (15 µg) e BM30 - bupivacaina hiperbarica a 0,5% (12,5 mg), morfina (100 µg) e clonidina (30 µg), administradas separadamente. No peri-operatorio, foram anotados o consumo de efedrina e a avaliacao do recem-nascido pelo indice de Apgar. No pos-operatorio, a dor foi avaliada na 12a h pela Escala Analogica Visual, o tempo para solicitacao de analgesicos e efeitos colaterais pos-operatorios, como prurido, nauseas, vomitos, bradicardia, hipotensao arterial e sedacao. Os valores foram considerados significativos quando p < 0,05. RESULTADOS: Os grupos foram homogeneos. O consumo de efedrina e a avaliacao pelo indice de Apgar nao exibiram diferenca estatistica significativa entre os grupos. Os escores de dor e o tempo medio de analgesia mostraram diferenca entre os grupos BM e BM15/BM30 e nao houve diferenca com relacao a incidencia de efeitos colaterais pos-operatorios. CONCLUSOES: A adicao de clonidina na raquianestesia com bupivacaina hiperbarica a 0,5% (12,5 mg) e morfina (100 µg) para cesariana, melhorou a qualidade da analgesia pos-operatoria, sem aumentar a incidencia de efeitos colaterais, sendo 15 µg de clonidina a dose sugerida.BACKGROUND AND OBJECTIVES The mechanism of action of alpha2-adrenergic analgesia has been explored for more than one hundred years. The increased duration of the sensitive and motor blockades caused by clonidine is dose-dependent and has antinociceptive properties. The objective of this study was to evaluate whether the addition of 15 to 30 microg of clonidine to spinal anesthesia for cesarean sections with 0.5% hyperbaric bupivacaine (12.5 mg) and morphine (100 microg) improves the quality of postoperative analgesia. METHODS We realized a prospective, randomized study that included 60 patients divided in 3 groups: BM - 0.5% hyperbaric bupivacaine (12.5 mg) and morphine (100 microg), BM15 - 0.5% hyperbaric bupivacaine (12.5 mg), morphine (100 microg), and clonidine (15 mg), and BM30 - 0.5% hyperbaric bupivacaine (12.5 mg), morphine (100 microg), and clonidine (30 microg), administered separately. In the perioperative period the use of ephedrine and the newborns Apgar score were recorded. In the postoperative period, the pain was evaluated in the 12th h by the VAS, the length of time it took the patient to ask for analgesics, and the postoperative side effects, such as pruritus, nausea, vomiting, bradycardia, hypotension, and sedation. The values were considered significant when p < 0.05. RESULTS The groups were homogenous. The use of ephedrine and the evaluation by the Apgar score did not show statistically significant differences among the different groups. The pain scores and the average time to start analgesia showed differences among the groups BM and BM15/BM30, and there were no differences regarding the incidence of postoperative side effects. CONCLUSIONS The addition of clonidine to spinal anesthesia with 0.5% hyperbaric bupivacaine (12.5 mg) and morphine (100 microg) for cesarean section improved the quality of the postoperative analgesia without increasing the incidence of side effects. We suggest that the dose of 15 microg of clonidine should be used.

Raquianestesia com agulha de Quincke 27G, 29G e Whitacre 27G: análise da dificuldade técnica, incidência de falhas e cefaléia

BACKGROUND AND OBJECTIVES: Technology has allowed for the production of fine needles which decrease headache incidence, but increase technical difficulties and failure rates. This study aimed at prospectively evaluating technical difficulties and incidence of failures and headaches in patients submitted to spinal anesthesia with 27G, 29G Quincke and 27G Whitacre needles. METHODS: Participated in this study 300 patients, aged below 50 years, submitted to spinal anesthesia with the aid of an introducer (20G 1¼), who were divided into three groups, according to needle type and gauge: GI (27G Quincke), GII (29G Quincke) and Glll (27G Whitacre). Technical difficulties and failure rates were evaluated in the operating room. Postoperative headache was evaluated until hospital discharge. Headache patients were treated with analgesics, hydration and, if needed, epidural blood patch. RESULTS: There were no significant differences in technical difficulties, failure rate and headache. Total headache incidence was 1.6%, always mild and of short duration, without the need for epidural blood patch. CONCLUSIONS: In the conditions of this study, 27G, 29G Quincke and 27G Whitacre needles have neither influenced the incidence of headache or spinal block failure nor puncture difficulties.Justificativa e Objetivos A tecnologia tem possibilitado a produção de agulhas de fino calibre, que reduzem a incidência de cefaléia, mas promovem aumento na dificuldade técnica e possibilidades de falhas. O objetivo deste estudo foi avaliar prospectivamente a dificuldade técnica, a incidência de falhas e de cefaléia, em pacientes submetidos a raquianestesia com agulhas de Quincke 27G, 29G e Whitacre 27G. Método Participaram do estudo 300 pacientes, com idades abaixo de 50 anos, submetidos à raquianestesia com auxilio de introdutor (20G 11⁄4) e divididos em três grupos, conforme o tipo e calibre da agulha utilizada: GI (Quincke 27G), GII (Quincke 29G) e GIII (Whitacre 27G). Na sala de operação foram analisadas a dificuldade técnica e a incidência de falhas. No período pós-operatório foi avaliada a incidência de cefaléia até a alta hospitalar. Os pacientes que apresentaram cefaléia seriam tratados com analgésicos, hidratação e, se necessário, tampão sangüíneo peridural. Resultados Não houve diferença significativa entre os grupos em relação a dificuldade técnica, a incidência de falhas e de cefaléia. A incidência global de cefaléia foi 1,6% de intensidade leve e de curta duração, não sendo necessário o uso do tampão sangüíneo peridural. Conclusões Nas condições desse estudo as agulhas Quincke 27G, 29G e Whitacre 27G não influenciaram a incidência de cefaléia ou falhas de bloqueio subaracnóideo e nem a dificuldade da punção.

Spinal anesthesia with 27G and 29G Quincke and 27G Whitacre needles: technical difficulties, failures and headache

BACKGROUND AND OBJECTIVES: Technology has allowed for the production of fine needles which decrease headache incidence, but increase technical difficulties and failure rates. This study aimed at prospectively evaluating technical difficulties and incidence of failures and headaches in patients submitted to spinal anesthesia with 27G, 29G Quincke and 27G Whitacre needles. METHODS: Participated in this study 300 patients, aged below 50 years, submitted to spinal anesthesia with the aid of an introducer (20G 1¼), who were divided into three groups, according to needle type and gauge: GI (27G Quincke), GII (29G Quincke) and Glll (27G Whitacre). Technical difficulties and failure rates were evaluated in the operating room. Postoperative headache was evaluated until hospital discharge. Headache patients were treated with analgesics, hydration and, if needed, epidural blood patch. RESULTS: There were no significant differences in technical difficulties, failure rate and headache. Total headache incidence was 1.6%, always mild and of short duration, without the need for epidural blood patch. CONCLUSIONS: In the conditions of this study, 27G, 29G Quincke and 27G Whitacre needles have neither influenced the incidence of headache or spinal block failure nor puncture difficulties.Justificativa e Objetivos A tecnologia tem possibilitado a produção de agulhas de fino calibre, que reduzem a incidência de cefaléia, mas promovem aumento na dificuldade técnica e possibilidades de falhas. O objetivo deste estudo foi avaliar prospectivamente a dificuldade técnica, a incidência de falhas e de cefaléia, em pacientes submetidos a raquianestesia com agulhas de Quincke 27G, 29G e Whitacre 27G. Método Participaram do estudo 300 pacientes, com idades abaixo de 50 anos, submetidos à raquianestesia com auxilio de introdutor (20G 11⁄4) e divididos em três grupos, conforme o tipo e calibre da agulha utilizada: GI (Quincke 27G), GII (Quincke 29G) e GIII (Whitacre 27G). Na sala de operação foram analisadas a dificuldade técnica e a incidência de falhas. No período pós-operatório foi avaliada a incidência de cefaléia até a alta hospitalar. Os pacientes que apresentaram cefaléia seriam tratados com analgésicos, hidratação e, se necessário, tampão sangüíneo peridural. Resultados Não houve diferença significativa entre os grupos em relação a dificuldade técnica, a incidência de falhas e de cefaléia. A incidência global de cefaléia foi 1,6% de intensidade leve e de curta duração, não sendo necessário o uso do tampão sangüíneo peridural. Conclusões Nas condições desse estudo as agulhas Quincke 27G, 29G e Whitacre 27G não influenciaram a incidência de cefaléia ou falhas de bloqueio subaracnóideo e nem a dificuldade da punção.

Analgesia postoperatória para cesárea: ¿la adición de clonidina a la morfina subaracnoidea mejora la calidad de la analgesia?

JUSTIFICATIVA E OBJETIVOS: O mecanismo de acao analgesica a2-adrenergico tem sido explorado ha mais de 100 anos. A clonidina aumenta de maneira dose-dependente a duracao dos bloqueios sensitivo e motor e tem propriedades antinociceptivas. O objetivo desse estudo foi avaliar se a adicao de clonidina na dose de 15 e 30 µg a raquianestesia, para cesariana, com bupivacaina hiperbarica a 0,5% (12,5 mg) e morfina (100 µg), melhora a qualidade da analgesia pos-operatoria. METODO: Foi realizado um estudo prospectivo e aleatorio com 60 pacientes divididas em tres grupos: BM - bupivacaina hiperbarica a 0,5% (12,5 mg) e morfina (100 µg), BM15 - bupivacaina hiperbarica a 0,5% (12,5 mg), morfina (100 µg) e clonidina (15 µg) e BM30 - bupivacaina hiperbarica a 0,5% (12,5 mg), morfina (100 µg) e clonidina (30 µg), administradas separadamente. No peri-operatorio, foram anotados o consumo de efedrina e a avaliacao do recem-nascido pelo indice de Apgar. No pos-operatorio, a dor foi avaliada na 12a h pela Escala Analogica Visual, o tempo para solicitacao de analgesicos e efeitos colaterais pos-operatorios, como prurido, nauseas, vomitos, bradicardia, hipotensao arterial e sedacao. Os valores foram considerados significativos quando p < 0,05. RESULTADOS: Os grupos foram homogeneos. O consumo de efedrina e a avaliacao pelo indice de Apgar nao exibiram diferenca estatistica significativa entre os grupos. Os escores de dor e o tempo medio de analgesia mostraram diferenca entre os grupos BM e BM15/BM30 e nao houve diferenca com relacao a incidencia de efeitos colaterais pos-operatorios. CONCLUSOES: A adicao de clonidina na raquianestesia com bupivacaina hiperbarica a 0,5% (12,5 mg) e morfina (100 µg) para cesariana, melhorou a qualidade da analgesia pos-operatoria, sem aumentar a incidencia de efeitos colaterais, sendo 15 µg de clonidina a dose sugerida.BACKGROUND AND OBJECTIVES The mechanism of action of alpha2-adrenergic analgesia has been explored for more than one hundred years. The increased duration of the sensitive and motor blockades caused by clonidine is dose-dependent and has antinociceptive properties. The objective of this study was to evaluate whether the addition of 15 to 30 microg of clonidine to spinal anesthesia for cesarean sections with 0.5% hyperbaric bupivacaine (12.5 mg) and morphine (100 microg) improves the quality of postoperative analgesia. METHODS We realized a prospective, randomized study that included 60 patients divided in 3 groups: BM - 0.5% hyperbaric bupivacaine (12.5 mg) and morphine (100 microg), BM15 - 0.5% hyperbaric bupivacaine (12.5 mg), morphine (100 microg), and clonidine (15 mg), and BM30 - 0.5% hyperbaric bupivacaine (12.5 mg), morphine (100 microg), and clonidine (30 microg), administered separately. In the perioperative period the use of ephedrine and the newborns Apgar score were recorded. In the postoperative period, the pain was evaluated in the 12th h by the VAS, the length of time it took the patient to ask for analgesics, and the postoperative side effects, such as pruritus, nausea, vomiting, bradycardia, hypotension, and sedation. The values were considered significant when p < 0.05. RESULTS The groups were homogenous. The use of ephedrine and the evaluation by the Apgar score did not show statistically significant differences among the different groups. The pain scores and the average time to start analgesia showed differences among the groups BM and BM15/BM30, and there were no differences regarding the incidence of postoperative side effects. CONCLUSIONS The addition of clonidine to spinal anesthesia with 0.5% hyperbaric bupivacaine (12.5 mg) and morphine (100 microg) for cesarean section improved the quality of the postoperative analgesia without increasing the incidence of side effects. We suggest that the dose of 15 microg of clonidine should be used.

Association of fentanyl or sufentanil an 0.5% isobaric bupivacaine in spinal anesthesia: a comparative study

BACKGROUND AND OBJECTIVES Since the discovery of opioid receptors and the increase in spinal cord neuropharma- cological knowledge as to transmission and inhibition of nociceptive stimulations, there has been an increased interest in spinal drugs for anesthesiology and pain relief. This study aimed at prospectively evaluating the clinical efficacy of fentanyl (25 microg) and sufentanil (5 microg) with isobaric bupivacaine (10 mg), in patients submitted to spinal anesthesia for varicose vein surgery. METHODS Participated in this study 60 patients, physical status ASA I and II, aged below 60 years, submitted to spinal anesthesia for varicose vein sugery, who were randomly distributed in three groups: B (10 mg isobaric bupivacaine), BF (10 mg isobaric bupivacaine and 25 microg fentanyl) and BS (10 mg isobaric bupivacaine and 5 microg sufentanil). Spinal anesthesia was induced in the left lateral position; lumbar puncture was performed at L3-L4, with 27G Quincke needles. The following parameters were evaluated after spinal anesthesia: onset time, sensory and motor block level. The following parameters were recorded during the procedure: arterial hypotension, bradycardia, respiratory depression, oxygen hemoglobin peripheral saturation decrease, nausea, vomiting, pruritus and shivering. Analgesia duration was evaluated in the post-operative period. RESULTS Groups were homogeneous. There were no significant differences in onset time, motor block and analgesia duration. There were differences in sensory block level between the control group and the opioid groups in all studied moments. Pruritus was the most frequent side-effect in the opioid groups. CONCLUSIONS The addition of fentanyl (25 microg) and sufentanil (5 microg) to isobaric bupivacaine (10 mg) in spinal anesthesia affects sensory block levels.

Raquianestesia con aguja de Quincke 27G, 29G y Whitacre 27G: análisis de la dificultad técnica, incidencia de fallas y cefalea

BACKGROUND AND OBJECTIVES: Technology has allowed for the production of fine needles which decrease headache incidence, but increase technical difficulties and failure rates. This study aimed at prospectively evaluating technical difficulties and incidence of failures and headaches in patients submitted to spinal anesthesia with 27G, 29G Quincke and 27G Whitacre needles. METHODS: Participated in this study 300 patients, aged below 50 years, submitted to spinal anesthesia with the aid of an introducer (20G 1¼), who were divided into three groups, according to needle type and gauge: GI (27G Quincke), GII (29G Quincke) and Glll (27G Whitacre). Technical difficulties and failure rates were evaluated in the operating room. Postoperative headache was evaluated until hospital discharge. Headache patients were treated with analgesics, hydration and, if needed, epidural blood patch. RESULTS: There were no significant differences in technical difficulties, failure rate and headache. Total headache incidence was 1.6%, always mild and of short duration, without the need for epidural blood patch. CONCLUSIONS: In the conditions of this study, 27G, 29G Quincke and 27G Whitacre needles have neither influenced the incidence of headache or spinal block failure nor puncture difficulties.Justificativa e Objetivos A tecnologia tem possibilitado a produção de agulhas de fino calibre, que reduzem a incidência de cefaléia, mas promovem aumento na dificuldade técnica e possibilidades de falhas. O objetivo deste estudo foi avaliar prospectivamente a dificuldade técnica, a incidência de falhas e de cefaléia, em pacientes submetidos a raquianestesia com agulhas de Quincke 27G, 29G e Whitacre 27G. Método Participaram do estudo 300 pacientes, com idades abaixo de 50 anos, submetidos à raquianestesia com auxilio de introdutor (20G 11⁄4) e divididos em três grupos, conforme o tipo e calibre da agulha utilizada: GI (Quincke 27G), GII (Quincke 29G) e GIII (Whitacre 27G). Na sala de operação foram analisadas a dificuldade técnica e a incidência de falhas. No período pós-operatório foi avaliada a incidência de cefaléia até a alta hospitalar. Os pacientes que apresentaram cefaléia seriam tratados com analgésicos, hidratação e, se necessário, tampão sangüíneo peridural. Resultados Não houve diferença significativa entre os grupos em relação a dificuldade técnica, a incidência de falhas e de cefaléia. A incidência global de cefaléia foi 1,6% de intensidade leve e de curta duração, não sendo necessário o uso do tampão sangüíneo peridural. Conclusões Nas condições desse estudo as agulhas Quincke 27G, 29G e Whitacre 27G não influenciaram a incidência de cefaléia ou falhas de bloqueio subaracnóideo e nem a dificuldade da punção.