Study: Defining Characteristics of Pulmonary Edema in Severe Preeclampsia

A study of patients with severe preeclampsia shows that those who experience pulmonary edema have a higher risk for severe maternal morbidity, extended postpartum hospital stays and admission to intensive care.

Researchers also learned that nulliparity and autoimmune disease are risk factors for pulmonary edema among those with preeclampsia. Earlier diagnosis of severe preeclampsia also increases the risk.

The study, published in the American Journal of Perinatology, makes a case for increased awareness of pulmonary edema as a manifestation of severe preeclampsia.

“We were trying to identify any specific clinical factors that characterize preeclampsia complicated by pulmonary edema,” says Adina Kern-Goldberger, MD, one of the study’s authors and a maternal-fetal medicine specialist at Cleveland Clinic. “Pulmonary edema is a known manifestation of severe preeclampsia. It tends to be less common, but it can be very severe.”

Changes in blood vessels in the setting of preeclampsia are linked to vascular permeability, which in turn may lead to pulmonary edema. The study shows that pulmonary edema is associated with a more severe phenotype of severe preeclampsia.

“That sounds obvious, but it sometimes can be helpful to see it in actual patient cases,” says Dr. Kern-Goldberger. “Preeclampsia is characterized by blood pressure elevations. With severe preeclampsia, we tend to think mostly about severe hypertension or hypertensive urgency, and about the neurologic complications like seizures and strokes. We're not always thinking about the cardiac and respiratory manifestations.”

Among a cohort of 340 patients with severe preeclampsia who delivered babies in 2019, seven (2.1%) had pulmonary edema. Those individuals had been diagnosed with preeclampsia earlier in pregnancy, had longer postpartum stays and were more likely to have been admitted to the ICU.

“None of those findings are surprising, but they hadn't been demonstrated before,” says Dr. Kern-Goldberger.

Clinical takeaways

Among the clinical implications is that fluid balance in patients with preeclampsia should be carefully monitored.

“We have to be vigilant for signs and symptoms of pulmonary edema in patients with severe preeclampsia,” says Dr. Kern-Goldberger. “We need to take oxygen-saturation monitoring and reports of any respiratory complaints very seriously. Pulmonary edema is treatable with diuretic medication. If you're able to identify and treat it quickly, you can potentially help avoid a longer hospital admission and ICU admission and respiratory support. So this should always be on the consciousness of physicians taking care of patients with preeclampsia.”

Improved monitoring abilities also would be welcome, says Dr. Kern-Goldberger.

“Right now, monitoring in the obstetric patient population in general, and specifically patients with preeclampsia, relies on blood a pressure cuff that goes off every 15 minutes and a pulse oximeter that generates continuous data. We don't have built-in capacities to look at trends in oxygen saturation,” she says. “I think changing that is where the improved value will be. Once a patient is symptomatic with shortness of breath, they already have pulmonary edema. And it’s treatable. But it would be great to get ahead of that with better detection.”