Preeclampsia and anaesthesia

The most recent findings on preeclampsia with a focus on maternal mortality, haemodynamic changes, clotting disorders and anaesthesia are reviewed.

Preeclampsia is a major cause of maternal morbidity and mortality. Cerebral haemorrhage is the single most common cause of maternal death in preeclampsia and currently far outnumbers pulmonary oedema. Although there was a focus on diastolic pressure in the past, the present recommendations of the National Enquiries into Maternal Death advocate treatment of systolic blood pressures above 160 mmHg in order to avoid intracranial bleeding. Noninvasive monitoring techniques such as pulse wave analysis and echocardiography have provided new insights into the haemodynamic changes of preeclampsia and corroborated previous findings. In early-onset preeclampsia, the most common haemodynamic features include vasoconstriction, low cardiac output and low filling pressures. Neuraxial anaesthesia aids in providing stable haemodynamics, the incidence of hypotension and the need for vasopressors are reduced compared with healthy parturients, and cardiac output is unchanged. With cautious fluid administration, the risk of pulmonary oedema seems negligible. In order to avoid spinal epidural haematoma in the presence of thrombocytopenia, spinal anaesthesia may afford the best risk-benefit analysis. It remains open to question whether thromboelastography will aid in guiding treatment in the future.

Cerebral haemorrhage is the major cause of maternal mortality in preeclampsia and any increases in maternal blood pressure above 160 mmHg or at induction of general anaesthesia should be treated. Traditional rapid sequence induction is, therefore, best avoided; neuraxial anaesthesia is the technique of choice.