A clinician’s decision to administer any drug is based on the balance between likely benefit and possible risk to the patient. This is true for magnesium sulphate (MgSO4) in the setting of severe preeclampsia and the prevention and treatment of eclampsia. A few pithy facts are worth a reminder.
While not uncommon in the low resource setting, eclampsia is rare in Australia affecting about 4 per 10,000 pregnancies or about 1 in 200 women with preeclampsia. Predicting which woman is the “1” is the challenge and, despite what individual clinicians might believe, not possible with any confidence. Indeed, 20% of women developing eclampsia have a seizure without any warning, some without any hypertension or other prior signs of preeclampsia. Of the women who do have an eclamptic seizure, most fit only once. The health risks to the woman and her fetus do not even appear to be primarily related to the seizure but more to the severity of the underlying preeclampsia. As the Bard of Avon would say “much ado about nothing”.
Let’s be clear, if a woman has had an eclamptic seizure she should receive anti-convulsant therapy and that therapy should be MgSO4. There is no uncertainty here. However, as an individual clinician working in Australia each of us will only encounter this scenario a few times, at most, in our professional lives. (All the more reason to have an eclampsia box with clear instructions on what do to).
Less clear is when to give MgSO4 as prophylaxis for eclampsia. As Shakespeare’s Rosalind might say: “can one desire too much of a good thing?” The answer is (al)most certainly yes. In this session the risks and benefits of judicious versus liberal MgSO4 seizure prophylaxis will be discussed, perhaps deciding on which approach represents better medicine. While some will inevitably take a rather fatalistic “all’s well that ends well” approach, the evidence is in favour of ………….