Variables that contribute to the hemodynamic changes observed in parturients undergoing CD with neuraxial anesthesia include hydration; maternal positioning during and after the block; the block type, height and density; the presence of hypertensive disorders of pregnancy; gestational age; the number of gestations; the presence of labor; and the prophylactic or therapeutic use of vasoactive substances. The most effective strategies for prevention of neuraxial-induced hypotension include prehydration with a sufficient amount of colloid or co-loading with sufficient crystalloid or colloid, positioning the parturient for surgery in the left uterine displacement position, using a lower dose of intrathecal bupivacaine, and most notably, administering a prophylactic vasoactive agent such as phenylephrine. An understanding of how each contributing variable contributes to the overall hemodynamic picture will assist the anesthesiologist in predicting, preventing or treating hemodynamic changes that occur during cesarean delivery with neuraxial anesthesia. Mitigating these hemodynamic alterations may ultimately improve the safety and side-effect profile for the mother undergoing cesarean delivery and her baby.
Expert Rev of Obstet Gynecol. 2012;7(1):59-75. © 2012 Expert Reviews Ltd.