Brazilian Journal of Anesthesiology
https://bjan-sba.org/article/doi/10.1590/S0034-70942010000400006
Brazilian Journal of Anesthesiology
Scientific Article

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

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

José Francisco Nunes Pereira das Neves; Giovani Alves Monteiro; João Rosa de Almeida; Roberto Silva Sant'Anna; Hellen Bedim Bonin; Carlos Furtado Macedo

http://dx.doi.org/10.1590/S0034-70942010000400006 Braz J Anesthesiol, vol.60, n4, p.395-398, 2010
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Resumo

JUSTIFICATIVA E OBJETIVOS: A anestesia raquídea é utilizada com frequência em casos de cesariana e se algumas medidas profiláticas não forem adotadas a incidência de hipotensão arterial é superior a 80%. O objetivo deste estudo foi comparar a eficácia da fenilefrina quando administrada terapêutica ou profilaticamente para a manutenção da pressão arterial em pacientes submetidas à anestesia raquídea para cesarianas eletivas. MÉTODO: Foram estudadas 120 gestantes submetidas a cesarianas eletivas sob anestesia raquídea, alocadas aleatoriamente em três grupos iguais, conforme o regime de administração de fenilefrina. No Grupo 1, administrou-se fenilefrina em infusão contínua, em bomba de infusão, na dose de 0,15 µg.Kg-1.min-1 após a anestesia raquídea. No Grupo 2, foi administrada fenilefrina em dose única, de forma profilática, na dose de 50 µg após a anestesia raquídea e, no Grupo 3, fenilefrina em dose única de 50 µg em caso de hipotensão arterial definida como queda da PAS e/ou PAD de até 20% em relação à média dos valores basais. Avaliou-se a incidência de hipotensão arterial, náuseas, vômitos e do índice de Apgar. RESULTADOS: A incidência de hipotensão arterial foi significativamente maior no Grupo 3, ocorrendo em 85% das gestantes. Nos Grupos 1 e 2, ocorreu em 17,5% e 32,5% dos casos, respectivamente (p < 0,001). A incidência de náuseas foi bem superior no Grupo 3, ocorrendo em 40% das pacientes, enquanto nos Grupos 1 e 2 a incidência foi de 10% e 15%, respectivamente, apresentando significância estatística. CONCLUSÕES: De acordo com a metodologia empregada, o estudo mostra que a infusão contínua profilática de fenilefrina iniciada imediatamente após a realização da anestesia raquídea para cesariana é mais efetiva para reduzir a incidência de hipotensão arterial e os efeitos colaterais maternos e fetais.

Palavras-chave

ANESTESIA, Obstétrica, CIRURGIA, Obstétrica, COMPLICAÇÕES, DROGAS

Abstract

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 µg.kg-1.min-1 was administered after the spinal block. In Group 2, a single dose of prophylactic phenylephrine 50 µg was administered after the spinal block, and Group 3 received a single dose of phenylephrine 50 µg 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.

Keywords

ANESTHESIA, Obstetric, COMPLICATIONS, DRUGS, SURGERY, Obstetric

References

Tanaka M, Balki M, Parkes RK. ED95 of phenylephrine to prevent spinal-induced hypotension and/or nausea at elective cesarean delivery. Int J Obstet Anesth. 2009;18:125-130.

Macarthur A, Riley ET. Obstetric anesthesia controversies: vasopressor choice for postspinal hypotension during cesarean delivery. Int Anesthesiol Clin. 2007;45:115-132.

Saravanan S, Kocarev M, Wilson RC. Equivalent dose of ephedrine and phenylephrine in the prevention of post-spinal hypotension in Caesarean section. Br J Anaesth. 2006;96:95-99.

Hennebry MC, Stocks GM, Belavadi P. Effect of i.v phenylephrine or ephedrine on the ED50 of intrathecal bupivacaine with fentanyl for Caesarean section. Br J Anaesth. 2009;102:806-811.

Ngan Kee WD, Khaw KS. Vasopressors in obstetrics: what should we be using?. Curr Opin Anaesthesiol. 2006;19:238-243.

Prakash S, Pramanik V, Chellani H. Maternal and neonatal effects of bolus administration of ephedrine and phenylephrine during spinal anaesthesia for caesarean delivery: a randomized study. Int J Obstet Anesth. 2010;19:24-30.

Loughrey JPR, Yao N, Datta S. Hemodynamic effects of spinal anesthesia and simultaneous intravenous bolus of combined phenylephrine and ephedrine versus ephedrine for cesarean delivery. Int J Obstet Anesth. 2005;14:43-47.

Magalhães E, Govêia CS, Ladeira LCA. Efedrina versus fenilefrina: prevenção de hipotensão arterial durante anestesia raquídea para cesariana e efeitos sobre o feto. Rev Bras Anestesiol. 2009;59:11-20.

Siddik-Sayyid SM, Nasr VG, Taha SK. A randomized trial comparing colloid preload to coload during spinal anesthesia for elective cesarean delivery. Anesth Analg. 2009;109:1219-1224.

Ngan Kee WD, Khaw KS, Ng FF. Prophylactic phenylephrine infusion for preventing hypotension during spinal anesthesia for cesarean delivery. Anesth Analg. 2004;98:815-821.

Ngan Kee WD, Khaw KS, Tan PE. Placental transfer and fetal metabolic effects of phenylephrine and ephedrine during spinal anesthesia for cesarean delivery. Anesthesiology. 2009;111:506-512.

Langesaeter E, Rosseland LA, Stubhaug A. Continuous invasive blood pressure and cardiac output monitoring during cesarean delivery: a randomized, double-blind comparison of low-dose versus highdose spinal anesthesia with intravenous phenylephrine or placebo infusion. Anesthesiology. 2008;109:856-863.

Ngan Kee WD, Tam YH, Khaw KS. Closed-loop feedback computer-controlled infusion of phenylephrine for maintaining blood pressure during spinal anaesthesia for caesarean section: a preliminary descriptive study. Anaesthesia. 2007;62:1251-1256.

Dyer RA, Reed AR, van Dyk D. Hemodynamic effects of ephedrine, phenylephrine, and the coadministration of phenylephrine with oxytocin during spinal anesthesia for elective cesarean delivery. Anesthesiology. 2009;111:753-765.

Slullitel A. Vasopressores. Tratado de Anestesiologia SAESP. 2006:655-666.

Erkinaro T, Kavasmaa T, Pakkila M. Ephedrine and phenylephrine for the treatment of maternal hypotension in a chronic sheep model of increased placental vascular resistance. Br J Anaesth. 2006;96:231-237.

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