HELLP syndrome

CHICAGO -- Intravenous dexamethasone provides more rapid recovery of liver function, arterial blood pressure, and urinary output in patients with prepartum HELLP syndrome, compared with betamethasone, Dr. Christy M. Isler said at the annual meeting of the Central Association of Obstetricians and Gynecologists.

About 1 in 10 patients with preeclampsia develop HELLP syndrome, characterized by hemolysis, elevated liver enzymes, and low platelet counts.

While still largely controversial, intravenous dexamethasone has been the standard treatment of HELLP syndrome at the University of Mississippi Medical Center, Jackson, while intramuscular betamethasone has been a standard therapy given to hasten fetal lung maturation. The investigators' hope in conducting the study was that if betamethasone were shown to be as effective as dexamethasone for treating HELLP, the number of agents to which patients were exposed would be decreased because they wouldn't need the dexamethasone, Dr. Isler explained in an interview.

In the study, 40 patients with class I or II HELLP syndrome were randomly assigned to receive dexamethasone, 10 mg IV every 12 hours, or betamethasone, 12 mg IM every 24 hours, until they achieved symptom resolution, stabilization of a blood pressure less than 160 / 110 mm Hg, and a urinary output of at least 50 cc/hr. Both groups were treated for a mean of 20 hours.

The 19 patients in the dexamethasone group had significantly more rapid improvement in aspartate aminotransferase levels, indicating better liver function, compared with the 21 patients in the betamethasone group.

And compared with baseline values, dexamethasone was associated with a significantly quicker time-averaged drop in arterial pressure (-15.6 mm Hg), compared with betamethasone (-8.1 mm Hg).

The time-averaged change in urinary output, compared with baseline, was also significantly better in the dexamethasone group (13 cc/hr) than in the betamethasone group (-12 cc/hr). Additionally patients in the betamethasone group were more likely to require antihypertensive therapy (71% vs. 21%) and an intravenous fluid bolus for oliguria (43% vs. 0%).

The time-averaged change in platelet counts and lactate dehydrogenase levels was also better in the dexamethasone group, but not significantly so.

"There were no immediate adverse neonatal outcomes," Dr. Isler said. But given recent concerns about exposure to multiple courses of prenatal steroids, she and her associates are conducting a follow-up trial to investigate the effects of high-dose dexamethasone therapy on neonatal adrenal suppression.

Further investigation also is needed to determine whether betamethasone at a higher dose would work as well as high-dose dexamethasone. However, betamethasone is not available for intravascular use.

The stage is set for a large, multicenter, three-arm heterogenous study comparing dexamethasone, betamethasone, and a control group, Dr. Washington Hill of Sarasota (Fla.) Memorial Hospital noted in a formal critique of the paper. Until then, "let's be cautious about who is given [dexamethasone] therapy and closely monitor those who receive it," he added.

"Keep in mind that a larger, more heterogeneous study population may have found ... some or no benefit." It's not unusual for therapies that initially look promising on the basis of small studies to fizzle in larger investigations, said Dr. Hill, citing the failure of thyroid-releasing hormone to further accelerate fetal lung maturity and of home uterine activity monitoring to prevent preterm birth in larger studies.

"There are still many unanswered questions," not the least of which is the safety of prolonged and repeated use of corticosteroids in the developing fetus, Dr. Hill warned.

The study did not address a number of clinically important variables, including cesarean section rates, development of pulmonary edema, the need for a blood transfusion or other replacement therapies, or clinically significant liver failure.

COPYRIGHT 2001 International Medical News Group
COPYRIGHT 2001 Gale Group