Asthma complicates approximately 4 percent of pregnancies. Studies indicate that as many as 42 percent of pregnant asthmatics require hospitalization and that an additional 11 to 18 percent have one or more visits to the ED for exacerbation. 34 In 1993, the NAEPP Expert Panel developed guidelines for the treatment of asthma exacerbation during pregnancy.34 The principles of managing acute asthma exacerbation are similar to those of managing exacerbation in a nonpregnant state. They consist of repetitive lung function measurements, maintenance of oxygen saturation at greater than 95 percent, administration of repetitive inhaled b 2-agonist and early administration of systemic corticosteroids, along with fetal monitoring. Early intervention during acute exacerbation is key to the prevention of impaired maternal and fetal oxygenation. Uncontrolled asthma is associated with a variety of maternal and fetal complications, including hyperemesis, hypertension, toxemia, vaginal hemorrhage, complicated labor, intrauterine growth retardation, preterm birth, increased perinatal mortality, and neonatal hypoxemia. Although no asthma medication labeled to date qualifies for an FDA use-in-pregnancy category A rating (adequate well-controlled studies in pregnant women have failed to demonstrate risk to the fetus), problems as a result of routine treatment of asthma in the ED have not been reported.
Hyperventilation of pregnancy leads to a higher Pa o2 and a diminished Paco2. Thus, a Pao2 of less than 70 mmHg in a pregnant women with acute asthma represents fairly severe hypoxemia, and a Paco2 of greater than 35 mmHg represents respiratory failure.35 During asthma exacerbation, the normal alkalosis of pregnancy is aggravated, leading to a decrease in placental blood flow. Hypoxemia is usually more severe in the fetus than in the mother.
b2 agonists and inhaled corticosteroids are considered safe during pregnancy and are recommended as a routine part of asthma management. As in nonpregnant patients, a short burst of oral steroid (40 to 60 mg prednisone per day) or its equivalent, should be considered for pregnant asthmatics discharged from the ED after treatment for an exacerbation.
Was this article helpful?
If you suffer with asthma, you will no doubt be familiar with the uncomfortable sensations as your bronchial tubes begin to narrow and your muscles around them start to tighten. A sticky mucus known as phlegm begins to produce and increase within your bronchial tubes and you begin to wheeze, cough and struggle to breathe.