The pregnant patient can be an intimidating encounter for many emergency physicians. Rarely do we find ourselves alone in managing the pregnant critically ill patient. Emergency physicians, however, are expected to handle these emergencies competently.
Explore This IssueACEP News: Vol 28 – No 04 – April 2009
Preeclampsia is defined as hypertension and proteinuria that occur after 20 weeks gestation. The spectrum of illness ranges from gestational hypertension to severe preeclampsia to eclampsia. Preeclampsia and eclampsia can occur up to 6 weeks postpartum.
Occurring in approximately 5% of pregnancies in the United States, preeclampsia occurs in as many as 14% of pregnancies worldwide. Maternal mortality is estimated at 790 per 100,000 live births, and fetal complications arising from premature birth are common.
Management should focus on blood pressure control, seizure prophylaxis and treatment, fluid management, and delivery when necessary. Although obstetric consultation is warranted in every case of preeclampsia, emergency physicians should be comfortable with the initial management.
Theoretical causes of preeclampsia include an imbalance of thromboxane and prostacyclin, immunologic abnormalities, increased vascular reactivity to vasoactive agents, hyperdynamic increase in cardiac output, abnormal development of the placenta, and genetic variations of the angiotensinogen gene.
One theory is that abnormal placental vasculature causes underperfusion, which in turn leads to activation of these factors.
Risk factors include first pregnancy, preeclampsia in previous pregnancy, age, race, family history of preeclampsia, diabetes, obesity, chronic hypertension, renal disease, and periodontal disease. Pregnancy-associated risk factors include chromosomal abnormalities, hydatidiform mole, multifetal pregnancy, oocyte donation or donor insemination, and urinary tract infection.
Women with preexisting hypertension have a 10%-25% increased risk of superimposed preeclampsia and should be closely monitored for proteinuria and edema. Preeclamptic patients are at risk for seizures, placental abruption, thrombocytopenia, cerebral hemorrhage, pulmonary edema, liver hemorrhage, and renal failure. These risks are present until delivery. Hypertension caused by preeclampsia resolves spontaneously by 12 weeks postpartum.
Diagnostic criteria for preeclampsia include a systolic blood pressure greater than 140 mm Hg or a diastolic blood pressure greater than 90 mm Hg in a woman who was normotensive prior to 20 weeks gestation.
If hypertension precedes pregnancy, is present before 20 weeks of gestation, or persists longer than 12 weeks postpartum, it is defined as preexisting hypertension. The elevation must be present in two successive measurements 4-6 hours apart.1