sábado, 1 de octubre de 2011

Efedrina en cesárea



Anestesia subaracnoidea en la paciente obstétrica: profilaxis y tratamiento de la hipotensión arterial
Dra. Mayelín Conyedo Martínez, Dr. Rubén Rodríguez Rodríguez, Dra. María Elena Ruiz Esponda, Dr. Fernando Cabreales Lugones, Dr. Sixto F. González Pérez, Dra. Letty M. Lorenzo Barrios
Hospital General Docente "Ricardo Santana Martínez".
Gaceta Médica Espirituana 2009; 11(3)
Resumen
Introducción: La anestesia subaracnoidea es la técnica regional más utilizada en la paciente obstétrica cuando se le realiza cesárea segmentaria. Sin embargo, se asocia con una mayor incidencia y más acentuadas disminuciones de la presión arterial en comparación con otras técnicas. Objetivo: Actualizar a través de una revisión la prevención y tratamiento la hipotensión arterial en la paciente obstétrica después de la anestesia subaracnoidea, centrada fundamentalmente en metaanálisis, ensayos clínicos controlados, artículos de expertos y revisiones sistemáticas. Conclusión: El presente de la anestesia obstétrica apunta a un cambio en la conducta terapéutica y profiláctica de la hipotensión materna durante la anestesia subaracnoidea.

http://bvs.sld.cu/revistas/gme/pub/vol.11.(3)_11/vol.11.3.11.pdf  
Relación entre la medición de la altura sínfisis-fondo uterino y la dosis de efedrina en anestesia espinal para cesárea electiva
The relationship between symphysis-fundal height and intravenous ephedrine dose in spinal anesthesia for elective cesarean section.
Chung SH, Yang HJ, Lee JY, Chung KH, Chun DH, Kim BK.
Department of Anesthesiology and Pain Medicine, College of Medicine, CHA University, Seongnam, Korea.
Korean J Anesthesiol. 2010 Sep;59(3):173-8. Epub 2010 Sep 20.
Abstract
BACKGROUND: A decreased lumbosacral subarachnoidal space volume is a major factor in the cephalad intrathecal spread of local anesthetics in term parturients and their subarachnoidal space is decreased due to the compressive effect of huge uteri. Therefore, they show a higher level of sensory block and hypotensive episodes. The purpose of this study is to investigate whether the symphysis-fundal height (SFH) correlates with the highest sensory level and the amount of ephedrine administered under spinal anesthesia. METHODS: Fifty-two uncomplicated parturients who consented to spinal anesthesia for elective cesarean section were studied. The SFH of all parturients had been measured just before the spinal anesthesia administered by one person. Hyperbaric bupivacaine with fentanyl 20 µg, was administered for spinal anesthesia. The amount of 0.5% bupivacaine was adjusted according to the patient's height and weight. The level of sensory block and the amounts of ephedrine to treat hypotension, nausea and vomiting were assessed. Linear regression and correlation analysis were applied to analyze the data. RESULTS:
According to the results of correlation analysis, there was no significant correlation between the level of sensory block and SFH. There were statistically significant positive correlations between the amount of ephedrine administered due to hypotension and SFH. CONCLUSIONS: In term parturients choosing elective cesarean section, the SFH is not correlated with the sensory level of spinal anesthesia, but is correlated with the amount of ephedrine administered during spinal anesthesia

http://ekja.org/Synapse/Data/PDFData/0011KJAE/kjae-59-173.pdf 
Paso placentario y efectos fetales metabólicos de la fenilefrina y la efedrina durante anestesia espinal para cesárea 
Placental transfer and fetal metabolic effects of phenylephrine and ephedrine during spinal anesthesia for cesarean delivery.
Ngan Kee WD, Khaw KS, Tan PE, Ng FF, Karmakar MK.
Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, China.warwick@cuhk.edu.hk
Anesthesiology. 2009 Sep;111(3):506-12.
Abstract
BACKGROUND: Use of ephedrine in obstetric patients is associated with depression of fetal acid-base status. The authors hypothesized that the mechanism underlying this is transfer of ephedrine across the placenta and stimulation of metabolism in the fetus. METHODS: A total of 104 women having elective Cesarean delivery under spinal anesthesia randomly received infusion of phenylephrine (100 microg/ml) or ephedrine (8 mg/ml) titrated to maintain systolic blood pressure near baseline. At delivery, maternal arterial, umbilical arterial, and umbilical venous blood samples were taken for measurement of blood gases and plasma concentrations of phenylephrine, ephedrine, lactate, glucose, epinephrine, and norepinephrine. RESULTS: In the ephedrine group, umbilical arterial and umbilical venous pH and base excess were lower, whereas umbilical arterial and umbilical venous plasma concentrations of lactate, glucose, epinephrine, and norepinephrine were greater. Umbilical arterial Pco2 and umbilical venous Po2 were greater in the ephedrine group. Placental transfer was greater for ephedrine (median umbilical venous/maternal arterial plasma concentration ratio 1.13 vs. 0.17). The umbilical arterial/umbilical venous plasma concentration ratio was greater for ephedrine (median 0.83 vs. 0.71). CONCLUSIONS: Ephedrine crosses the placenta to a greater extent and undergoes less early metabolism and/or redistribution in the fetus compared with phenylephrine. The associated increased fetal concentrations of lactate, glucose, and catecholamines support the hypothesis that depression of fetal pH and base excess with ephedrine is related to metabolic effects secondary to stimulation of fetal beta-adrenergic receptors. Despite historical evidence suggesting uteroplacental blood flow may be better maintained with ephedrine, the overall effect of the vasopressors on fetal oxygen supply and demand balance may favor phenylephrine

http://journals.lww.com/anesthesiology/pages/articleviewer.aspx?year=2009&issue=09000&article=00015&type=abstract 
Atentamente
Dr. Benito Cortes-Blanco
Anestesiología y Medicina del Dolor

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