The effect of colloid co-hydration on the use of phenylephrine and hemodynamics during low-dose combined spinal-epidural anesthesia for cesarean delivery

Abstract

Background: Ephedrine has been recommended as the best vasopressor in obstetrics. But, recent clinical evidences show the possibility that phenylephrine has become more pertinent as a primary vasopressor. We think a phenylephrine infusion with colloid co-hydration will be more useful in maintaining baseline blood pressure in combined spinal-epidural anesthesia (CSEA) for cesarean section. Methods: CSEA was performed using 6 mg bupivacaine and 20 μg fentanyl as a spinal and 10 ml of 0.25% levobupivacaine as an epidural in randomized, colloid co-hydration (hydroxyethl starch, HES 500 ml) (group C, n = 34) or no colloid co-hydration (group N, n=34) parturients scheduled to undergo cesarean delivery. After an infusion of 100 μg phenylephrine following the spinal injection, phenylephrine was intermittently infused using a PCA-pump to maintain the baseline blood pressure (BP). Systolic BP and heart rate (HR) were checked and total phenylephrine amount was measured. Nausea and vomiting and fetal umbilical pH/base excess (BE) were also investigated. Results: There was a lower incidence of bradycardia in the C group compared with the N group (5.9% vs. 32.4%, p = 0.014), and total phenylephrine consumption was less in the C group (400 μg vs. 500 μg, p = 0.019). The incidence of reactive hypertension (11.8% vs. 55.9%, p ＜ 0.001), and the hypotension (0% vs. 11.8%, p = 0.114) were lower in the C group, too. The others were comparable in both groups. Conclusions: Colloid co-hydration was effective in reducing the phenylephrine use and the incidences of abnormal hemodynamics such as hypotension, bradycardia and hypertension in low-dose CSEA for cesarean delivery. (Korean J Anesthesiol 2008; 55: 685~90)