Minimally invasive cardiac output monitoring during spinal anaesthesia for Caesarean section

Abstract

Heart rate and blood pressure are appropriately used as surrogate markers of maternal cardiac output (CO) during spinal anaesthesia (SA) for Caesarean section (CS). Maintenance of baseline maternal blood pressure, using phenylephrine, has been shown to produce the closest to zero umbilical arterial base deficit, despite the fact that phenylephrine may depress maternal cardiac output. However, the maximum change in cardiac output has been shown to correlate better with uteroplacental blood flow than upper arm blood pressure. The maintenance of blood pressure and maternal cardiac output are therefore both important for maternal safety and comfort, and fetal wellbeing. Two studies of cardiac output changes during SA for CS are presented, employing pulse wave form analysis (LiDCOplus, LiDCO Ltd, Cambridge, UK).