Pulmonary edema associated with the use of betamimetic agents in preterm labor.

A case report of pulmonary edema associated with the use of a betamimetic agent in preterm labor is reported. A 31-year-old, black multigravida woman, 28 weeks pregnant, was admitted to the hospital with dysuria, vaginal bleeding, and uterine contractions. She had experienced premature labor in her previous pregnancies, and she had a history of kidney stones, confirmed by pyelography, and repeated urinary tract infections. Eighteen hours after admission, the contractions were occurring every five minutes. Terbutaline sulfate constant infusion (10-20 micrograms/min) was started. By hospital day 2, the uterine contractions were occurring every 1-2 minutes and lasting 50 seconds. The terbutaline therapy was discontinued, and isoxsuprine hydrochloride infusion was started at 240 micrograms/min and gradually increased to 800 micrograms/min. The patient complained of smothering and became tachypneic after one hour and 40 minutes of therapy. The shortness of breath and tachypnea continued in spite of the administration of oxygen and positional changes. The isoxsuprine was discontinued. The diagnosis of pulmonary edema was confirmed by abnormal findings in the chest roentgenogram, bilateral rales, and a decrease in arterial blood oxygen pressure. A literature review of pulmonary edema associated with the administration of beta sympathomimetic drugs is presented, which suggests this adverse effect is multifactorial in origin. Precipitating factors may include corticosteroids, fluid overload, low levels of serum potassium, twin gestations, a sustained tachycardia greater than 140 beats per minute, undiagnosed cardiopulmonary disease, or catecholamine-induced cardiac injury. Patients requiring betamimetics for the delay of premature labor should be monitored closely to obviate this complication.