Preeclampsia: pathophysiology, old and new strategies for management

Preeclampsia continues to be a leading cause of maternal and foetal mortality and morbidity worldwide. It is defined as hypertension and proteinuria after 20 weeks' gestation, which resolves after delivery. It is complicated by intracerebral haemorrhage, pulmonary oedema and respiratory and hepatic failure, which form the commonest causes of death. There is a genetic and immunological element to the pathophysiology of the disease, which is still not completely understood, but the underlying cause is an abnormality of placentation and placental hypoxia. This is thought to result in an imbalance of angiogenic and antiangiogenic proteins that leads to systemic endothelial disruption and multiorgan involvement. Successful treatment requires delivery of the placenta and management should be undertaken by a multidisciplinary team, aiming primarily to stabilise the condition of the mother before delivery is contemplated. Guidelines and protocols all have common management goals which are to treat hypertension, prevent seizures, control fluid intake and optimise the timing of delivery. Hypertension can be treated with a range of antihypertensive drugs, but labetalol is regarded as first-line therapy. Magnesium sulphate is the treatment of choice for eclampsia because it reduces the risk of seizures by more than 50%. A fluid restriction policy should be used to prevent iatrogenic pulmonary oedema. Effective anaesthetic management relies on neuraxial techniques. Epidural, combined spinal-epidural and single-shot spinal anaesthetic techniques are all perfectly acceptable and should be actively promoted to the mother unless contraindications such as thrombocytopaenia exist.