Maternal cardiac output response to colloid preload and vasopressor therapy during spinal anaesthesia for caesarean section in patients with severe pre‐eclampsia: a randomised, controlled trial

Abstract

SummaryWe examined the haemodynamic effects of colloid preload, and phenylephrine and ephedrine administered for spinal hypotension, during caesarean section in 42 women with severe early onset pre-eclampsia. Twenty patients with predelivery spinal hypotension were randomly allocated to receive an initial dose of either 50 lg phenylephrine or 7.5 mg ephedrine; the primary outcome was percentage change in cardiac index. After a 300-ml colloid preload, mean (SD) cardiac index increased from 4.9 (1.1) to 5.6 (1.2) l.min À1 .m À2 (p < 0.01), resulting from an increase in both heart rate, from 81.3 (17.2) to 86.3 (16.5) beats.min À1 (p = 0.2), and stroke volume, from 111.8 (19.0) to 119.8 (17.9) ml (p = 0.049).Fourteen (33%) and 23 (54.8%) patients exhibited a stroke volume response > 10% and > 5%, respectively; a significant negative correlation was found between heart rate and stroke volume changes. Spinal hypotension in 20 patients was associated with an increase from baseline in cardiac index of 0.6 l.min À1 .m À2 (mean difference 11.5%; p < 0.0001). After a median [range] dose of 50 lg phenylephrine or 15 [7.5-37.5] mg ephedrine, the percentage change in cardiac index during the measurement period of 150 s was greater, and negative, in patients receiving phenylephrine vs. ephedrine, at À12.0 (7.3)% vs. 2.6 (6.0)%, respectively (p = 0.0001). The percentage change in heart rate after vasopressor was higher in patients receiving phenylephrine, at À9.1 (3.4)% vs. 5.3 (12.6)% (p = 0.0027), as was the change in systemic vascular resistance, at 22.3 (7.5) vs. À1.9 (10.5)% (p < 0.0001). Phenylephrine effectively reverses spinal anaesthesiainduced haemodynamic changes in severe pre-eclampsia, if left ventricular systolic function is preserved.

International consensus statement on the management of hypotension with vasopressors during caesarean section under spinal anaesthesia

“…In a subsequent randomised trial investigating spinal anaesthesia for caesarean section in early onset severe pre‐eclampsia, the maternal haemodynamic effects of ephedrine and phenylephrine were formally compared. After a 300‐ml colloid pre‐load, a median bolus dose of 50 μg phenylephrine returned the spinal anaesthesia‐induced changes in systemic vascular resistance, heart rate and cardiac output towards baseline more effectively than 15 mg ephedrine boluses .…”

Ephedrine versus phenylephrine as a vasopressor for spinal anaesthesia-induced hypotension in parturients undergoing high-risk caesarean section: meta-analysis, meta-regression and trial sequential analysis

“…1) of which finally eight studies, including 712 parturients, were analysed. [18][19][20][21][22][23][24][25] Five studies reported on caesarean section for preeclamptic women and three studies on other high-risk cases. Details of the studies are shown in Table 1.…”

The Efficiency Of Preventing Hypotension By Passive Leg Raise Application In Pregnant Women Planned For Cesarean Section Under Spinal Anesthesia

“…Spinal anestezi sonrası oluşan hipotansiyonu önlemek için preload veya koload, sol tilt manevrası, profilaktik efedrin ya da diğer vazopresörlerin uygulandığı geleneksel yöntemlerin kendi aralarında karşılaştırılması ile ilgili çeşitli çalışmalar yapılmıştır (11)(12)(13)(14)(15)(16)(17) . Ancak PBK 'ya bağlı oluşan fizyolojik değişiklikleri ortaya koyan çok az çalışma vardır.…”