Preeclampsia Update

Clayton Wilde, M.D.
Member, UMIA Board of Directors

In recent years there has been an increased frequency of misdiagnosis or poorly managed gestational hypertension with subsequent adverse outcomes. For many years, Williams Obstetrics utilized its own classification and management plan. Williams was recently revised to reflect the World Health Organization consensus. Gestational hypertension (previously PIH or pregnancy induced hypertension) is a blood pressure of 140/90 after the 20th week of gestation in a previously normotensive pregnant woman. The diagnosis of preeclampsia is based on the presence of gestational hypertension with evidence of end organ damage. The usual end organ damage noted is proteinuria of 1+ or > at dipstick or > 300 mg/24 hours on 24 hour urine. Because proteinuria may be erratic throughout the day or absent completely, careful search for other criteria such as HELLP syndrome should be undertaken. HELLP syndrome frequently presents without proteinuria. The diagnosis of preeclampsia may be made by noting findings such as elevated liver function tests, thrombocytopenia, severe symptoms such as persistent severe headache, new right upper abdominal pain or new persistent nausea and vomiting, elevated creatinine or pulmonary edema. The key to safe management is to respond to the hypertension promptly and look for end organ damage. Classification as to degree of severity is inappropriate and potentially dangerous. If the diagnosis of preeclampsia is made, the patient should be delivered and not temporized. Perinatal consultation for infants remote from term may be in order. Antihypertensives should not be used to temporize a patient. They should only be used to control life threatening hypertension. The cerebral vasculature cannot autoregulate when the mean arterial pressure is > 120 mm Hg. If such a blood pressure occurs, it should be rapidly controlled with IV or PO Labetolol or Nifedipine (if the patient is not on magnesium). Failure to do so has resulted in a number of intracranial bleeds with poor outcomes. Hypertension should be monitored after delivery and appropriate medications provided to maintain control.

One of the frequently seen diagnosis failures results from the belief that preeclampsia cannot occur days to weeks postpartum. Frequently the most severe preeclamptics are seen during the postpartum period. The patient may present to the ER with shortness of breath and severe headache associated with hypertension. It is not uncommon for the patient’s urine to be negative for protein but HELLP labs are abnormal. Often the patient receives a CT angiogram to rule out pulmonary embolus, but the only finding is mild-to-moderate pulmonary edema and small pleural effusions. Every radiologist should be aware that such a radiographic finding in a post partum patient may be severe preeclampsia until proven otherwise. ER personnel should aggressively treat hypertension and perform HELLP labs. If necessary, admission for control of hypertension or management of preeclampsia is in order. Failure to recognize preeclampsia in the post partum state has resulted in catastrophic outcomes.