ABC | Volume 114, Nº5, May 2020

Statement Brazilian Cardiology Society Statement for Management of Pregnancy and Family Planning in Women with Heart Disease – 2020 Arq Bras Cardiol. 2020; 114(5):849-942 4.6. Prophylaxis of Seizure in Preeclampsia - Eclampsia and Magnesium Sulfate Therapy 293,275, 299-303 Since the publication of the results of results of The Collaborative Eclâmpsia Trial – Maggie Trial, 302 o magnesium sulfate (MgSO 4 ) is the drug of choice when eclampsia is imminent, and it is the only drug that is effective against seizures in preeclampsia. 299 Randomized clinical trials have demonstrated that it is superior to hydantoin, diazepam, and placebo for preventing eclampsia and recurrence of seizuresn, in addition its low cost, easy to administer and does not cause sedation. 300-303 Therefore, the use of magnesium sulfate is highly recommended for cases of imminent eclampsia, HELLP syndrome (15% of these patients develop eclampsia) and pre -eclampsia with clinical and/or laboratory deterioration, including difficult-to-control hypertension. 303 The initial dose, properly administered, does not pose a risk of intoxication. However, it is recommended to monitor the patellar reflex, respiratory rate and diuresis. If there is no patellar reflex, respiratory depression (respiratory rate < 16 rpm) and diuresis below 25 ml/h, it is recommended to stoped MgSO4 intravenous and measure serum levels. The therapeutic concentration of the magnesium ion varies from 4 to 7 mEq/L (4.8 to 8.4 mg/dl). The patellar reflex is abolishedwith 8 to 10mEq/L, the risk of respiratory arrest starting at 12 mEq/L and cardiac arrest of 25 mEq/L. Calcium gluconate (1 g intravenously – 10 ml at 10% – administered slowly) should be used in cases of signs of magnesium intoxication. In respiratory arrest, in addition to calcium gluconate, endotracheal intubation andmechanical ventilation should be performed. In patients with renal impairment (creatinine ≥ 1.2 mg/dl), the maintenance dose should be half the recommended dose. Magnesium sulfate infusion should be stopped only if diuresis is less than 25 ml. In view of values within normal limits, treatment should be maintained or restarted. 304 The prevention of convulsive crises in preeclampsia is guided by the following recommendations: • Loading dose: (MgSO4 50% – ampoule with 10ml – contains 5 g de magnésio) – 4 to 6 g of MgSO 4 , intravenous, in a single dose (dilute 8 to 12 ml of 50% solution in 100 ml of 5% glucose solution and administer, with an infusion pump, for 30 minutes); • Maintenance dose: 1 to 2 g per hour, intravenous (dilute 10 ml of MgSO4 50% (1 ampoule) in 490 ml of 0,9% of saline solution. The final concentration will be 1 g/100 ml. Infuse the solution intravenously at a rate of 100 ml per hour in a continuous infusion pump. It is necessary to maintain the MgSO4 for 24 hours after delivery or the last seizure. In cases of recurrence of the seizure, an additional 2 g of magnesium sulfate is administered intravenously (bolus) and the dose of 2 g/h is used as maintenance. If two of these boluses do not control seizures, the drug of choice will be diphenylhydantoin in its classic regimen for treating seizures. In these cases, the investigation of brain complications, especially intracranial hemorrhages, is recommended. After the first 24 hours of observation and evaluation, it is necessary to decide on conservative conduct or termination of pregnancy. Childbirth is the only intervention that leads to the resolution of pre-eclampsia and eclampsia. It is recommended that the expectant conduct is only until 37 weeks of gestation. After this gestational date or if the diagnosis of pre-eclampsia is performed at term, the resolution of the pregnancy should be indicated, thus reducing maternal risks, without altering the perinatal results. 4.6.1 Key Points • In women with gestational hypertension, pre-existing hypertension overlapping with gestational hypertension or with damage or symptoms of hypertension and subclinical organs, initiation of drug treatment is recommendedwhen SBP ≥ 140 mmHg or DBP ≥ 90 mmHg; • A goal treatment for blood pressure in SHG should be 140/80 to 85 mmHg. DBP to ≤ 80 mmHg, antihypertensive drugs shouldbe reducedor discontinued; • Methyldopa, beta-blockers (except atenolol) and calcium channel blockers are recommended as the drugs of choice for the treatment of hypertension in pregnancy; • ACE inhibitors, ARBs or direct renin inhibitors are not recommended during pregnancy; • Diuretic therapy is usually avoided because plasma volume is reduced inwomenwho develop preeclampsia; • Considers SBP ≥ 170 mmHg or DBP ≥ 110 mmHg to be an emergency in a pregnant woman who should be admitted to hospital immediately for treatment; The consensus is to reduce BP to < 160/105 mmHg to avoid acute hypertensive complications in the mother; fetal heart rate monitoring; • Magnesium sulphate should be used to prevent and treat seizures in women with gestational hypertension and preeclampsia with severe or imminent eclampsia; • In a hypertensive emergency, the most effective drugs are nifedipine, hydralazine and labetalol (not available in Brazil); • In preeclampsia associated with pulmonary edema, nitroglycerin administered as i.v. infusion is recommended; • The delivery is a single intervention that leads to resolution of preeclampsia and eclampsia. 4.7. Prognosis and Prevention of Preeclampsia Clinical prediction models based on risk factors have low sensitivity, and they generally do not include a large number of pregnant women who might develop preeclampsia during the course of gestation. The following biochemical markers stand out: placental growth factor (PlGF), which is proangiogenic and, when its levels are low between weeks 11 and 13, and soluble FMS-like tyrosine kinase 1 (sFlt-1), which is antiangiogenic and which, when its levels are high, may predict preeclampsia. As neither of them have sufficient sensitivity, the relationship between both factors (sFlt-1/PIGF) is currently being studied, with more promising results. There is, at the moment, however, no predictive laboratory test available in clinical practice. 304 It is also possible to utilize Doppler ultrasound as an auxiliary tool. By evaluating pulsatility and resistance in uterine arteries, it may classify pregnant women by risk of developing 900