Maternal haemodynamic changes during spinal anaesthesia for caesarean section

The most frequent response to spinal anaesthesia for elective caesarean section is a marked decrease in systemic vascular resistance and partial compensation from increased stroke volume and heart rate. Early administration of phenylephrine by bolus or continuous infusion is indicated in most cases. Recent work has expanded our knowledge of the therapeutic range of phenylephrine and indicates that the heart rate response to vasopressors is a good surrogate marker for cardiac output. Further research should examine haemodynamic changes during spinal anaesthesia in high-risk pregnant women with early onset preeclampsia or cardiac disease.