Maternal and Fetal Haemodynamic Effects of Spinal and Extradural Anaesthesia for Elective Caesarean Section

Abstract

Serial haemodynamic investigations were performed in 32 women who were allocated randomly to receive either spinal or extradural anaesthesia for elective Caesarean section. Cardiac output was measured by Doppler and cross-sectional echocardiography at the aortic valve. Doppler flow velocity waveforms were recorded also from the umbilical artery. Preloading with Ringer lactate solution 1 litre increased cardiac output in both groups. After injection of bupivacaine, cardiac output remained increased in the extradural group, but decreased in the spinal group. This was associated with an increase in umbilical artery pulsatility index in the spinal group. Umbilical artery pH was less in the spinal group (7.22 vs 7.27), although no neonate was depressed at birth. The maximum percentage change in cardiac output and umbilical artery pulsatility index correlated with umbilical artery pH (r = 0.54, r = 0.72, respectively). There was no significant correlation with change in arterial pressure.

Maternal cardiovascular consequences of positioning after spinal anaesthesia for Caesarean section: left 15° table tilt vs. left lateral

“…Decreases in cardiac output are more frequent than systemic hypotension during spinal anaesthesia [8]. Clinically, anaesthetists use surrogate indicators such as nausea, vomiting and sudden bradycardia to warn of low cardiac output.…”

Randomised trial of intravenous infusion of ephedrine or mephentermine for management of hypotension during spinal anaesthesia for Caesarean section

“…Several studies have reported a surprisingly high incidence of fetal acidosis that is not accompanied by neonatal depression after spinal anaesthesia for Caesarean section [2,3,10]. Mercier et al [33] reported a 63% incidence of foetal acidosis with a prophylactic intravenous infusion of ephedrine in parturients receiving spinal anaesthesia during Caesarean section.…”

“…Regional anaesthesia for Caesarean delivery is associated with a high incidence of maternal hypotension [1] and may result in fetal acidaemia due to decreased uteroplacental blood flow [2][3][4]. Commonly used methods to prevent or treat such hypotension include preloading with fluids [5], avoidance of aortocaval compression [6] and the administration of vasopressor drugs [7][8][9][10].…”

Exposé clinique: l’anesthésie pour une césarienne chez une parturiente qui présente une grosse tumeur intrathoracique

“…The resurgence in popularity of spinal anesthesia for elective Cesarean section notwithstanding, some anesthesiologists would still choose an epidural when it is desirable to avoid hypotension. 22 Elevation of the legs does not reliably protect against a drop in blood pressure following spinal anesthesia for Cesarean section. 2 3 Careful titration of incremental doses of epidural local anesthetic, along with a slower onset of anesthesia, permits better maternal cardiovascular compensation for sympathetic blockade.…”