Things to note: Prevention - Advise adequate dietary calcium (at least 1 000 mg daily).
- Bed rest, preferably in hospital.
- Lifestyle adjustment and diet.
- Monitor BP, urine output, renal and liver function tests, platelet count, proteinuria and fetal condition.
- Consider delivery when risks to mother outweigh risks of prematurity to baby.
Medical Treatment: Prevention For women at high risk of pre-eclampsia, e.g. pre-eclampsia in a previous pregnancy, chronic hypertension, diabetes, antiphospholipid syndrome or SLE, from 16 weeks gestation onwards:
- Aspirin, oral, 75-150 mg daily with food.
- Calcium, oral.
- For high-risk patients: Calcium carbonate, oral, 500 mg 12 hourly (equivalent to 1 g elemental calcium daily).
- Although the benefit is greatest in high-risk women, consider use of this agent in all pregnant women.
- When using iron together with calcium supplementation, ensure that iron and calcium are taken at least 4 hours apart from one another.
Treatment Antihypertensives- Drug treatment will be dictated by blood pressure response.
- Monitor progress until a stable result is achieved.
- In general, diuretics are contra-indicated for hypertension in pregnant women.
- When needed, combine drugs using lower doses of the three agents before increasing the doses to a maximum.
- Methyldopa, oral, 250 mg 8 hourly as a starting dose.
- Increase to 500 mg 6 hourly, according to response.
- Maximum dose: 2 g/day.
AND/OR- Amlodipine, oral, 5 mg daily.
AND/OR - Hydralazine, oral, 25 mg 8 hourly.
- Titrate up to 50 mg 6 hourly
Hypertensive emergency - SBP equal to or greater than160 mmHg or DBP equal to or greater than 110 mmHg. Admit to a high-care setting for close monitoring.
Preload with:
- Sodium chloride 0.9%, IV infusion, 200 mL.
- Nifedipine, oral, 10 mg
- Repeat after an hour if needed until systolic blood pressure <160 mmHg and diastolic blood pressure < 110 mmHg
- Swallow whole. Do not chew, bite or give sublingually.
OR - Hydralazine, oral, 25 mg
- Repeat after an hour if needed until systolic blood pressure < 160 mmHg and diastolic blood pressure < 110 mmHg.
If unable to take oral or inadequate response:
- Lasslol, IV infusion, 2 mg/minute to a total of 1-2 mg/kg.
- Reconstitute solution as follows:
Discard 40mL of sodium chloride 0.9% from a 200mL container. Add 2 vials (2 x 100 mg) of Lasslol (5 mg/mL) to the remaining 160 mL of sodium chloride 0.9% to create a solution of 1 mg/mL. Start at 40mL/hour to a maximum of 160 mL/hour. Titrate against BP - aim for BP of 140/100 mmHg.
Delivery - Oxytocin, IV/IM, 10 units as a single bolus after delivery of the baby.
- Ergot-containing drugs are contraindicated in hypertensive women, including pre-eclampsia, following delivery of the baby.
- Pre-eclamptic and eclamptic women are hypovolaemic, particularly when the haematocrit exceeds 40%, but are also susceptible to pulmonary oedema. Consequently, hypotension is a risk during anaesthesia. Careful infusion of IV fluids is important. Limit blood-loss at Caesarean section.
- Both epidural and spinal anaesthesia may be used for operative delivery in hypertensive women, including pre-eclampsia. This should be administered by an experienced person, with meticulous attention to IV fluid management and haemodynamic monitoring.
- Epidural analgesia is ideal for labour and delivery, but should only be undertaken by experienced practitioners in a unit properly equipped for resuscitation and with facilities available for urgent operative delivery. Avoid excessive IV fluids as there is no need for IV fluid loading in labour.