Obstetrics and Gynecology/Hypertensive Disorders including Pre-Eclampsia
- Diastolic blood pressure greater than 90mmHg on two recordings on the same arm greater than five minutes apart.
- Gestational hypertension must be new onset after the 20th week of gestation.
- Affects 5% of pregnancies.
- Along with bleeding, the leading cause of maternal mortality in Canada.
- 35% risk of developing preeclampsia
- Hypertension in pregnant women diangosed prior to the 20th wee of gestation.
- 25% risk of developing preeclampsia, with a 25% recurrence.
- Gestational hypertension with proteinuria or end organ dysfunction.
- Preexisting hypertension with resistant hypertension with new or worsening proteinuria or one or more adverse conditions.
- Resistant hypertension requires 3 or more drugs for control after 20 weeks of gestation.
- Proteinuria is suspected at a urine dipstick result >2. If this result is positive, a 24h protein collection should be done and the result will be >300mg/day. The latter test is performed to account for orthostatic proteinuria which may confound the dipstick test.
- Adverse conditions are defined as
- BP >160/110
- HELLP syndrome: Hemolysis, Elevated Liver enzymes, Low Platelets. Leads to placental abruption, hepatic and or renal dysfunction, preterm delivery, and death.
- Proteinuria >5g per day
- CNS symptoms
- Pulmonary edema
- Fetal growth restriction
- Severe preeclampsia is pre-eclampsia beginning before 34 weeks with 5g proteinuria per day. 20% of these women develop HELLP
- Etiology unknown, but may involve vascular endothelial damage and widespread coagulation.
- Risk factors include nulliparity, >35 or <18 years of age in the mother, past history of preeclampsia or hypertension, connective tissue disease, diabetes, black, thrombophilia, antiphospholipid antibody syndrome, and mulitfetal gestation.
- The primary factor is vasospasm to separate end organs.
- Hematologic abnormalities include hemolysis, thrombocytopenia, and coaglulopathy secondary to hepatic dysfunction.
- Decreased renal blood flow leads to increased blood urea nitrate concentration.
- Neurological sequelae ensue: headache, visual changes, seizures from intracranial bleeding.
- Decreased blood flow to the fetus creates hypoxia, growth restriction, and oligohydramnios.
- The primary treatment for gestational hypertension and pre-eclampsia is delivery.
- If term gestation (>37 weeks), deliver the baby.
- If preterm (<34 weeks), only deliver if membranes have ruptured, if the fetal status is questionable, intrauterine growth retardation, and the fetal lungs appear mature.
- Patients should be sent to a tertiary center with high-level neonatal care.
- If adverse conditions are present
- Antihypertensive medications should be administered (target less than 160/110, but with the diastolic pressure no lower than 90 acutely)
- MgSO4 IV bolus and infusion for eclampsia, antihypertensives, and delivery. The mother is the first priority in this circumstance.
- Delivery independent of gestational age for HELLP syndrome.
- Prevention: baby aspirin once every day; calcium 1g per day, every day.
|Magnesium Sulfate Toxicity|
|May lead to cardiac arrest|
|Decreased urine output|
|Loss of deep tendon reflexes|
|Must be treated with 10cc of 10% Calcium Gluconate STAT|