Acute Asthma During Pregnancy
Rita K. Cydulka, MD, MS
MetroHealth Emergency Medicine, 2500 MetroHealth Drive, Cleveland, OH 44109-1998, USA
The prevalence of asthma in pregnant women will increase as the prevalence of asthma in the general population increases . Many of these patients will suffer acute asthma during pregnancy. A prospectivestudy from Finland suggested that 9.3% of 504 pregnant women who had asthma and who were followed in a pulmonary clinic required emergency treatment for asthma during pregnancy . A more recent and larger prospective study from this country included 1739 pregnant asthmatic women who were followed in obstetric clinics; 5.1% of patients were hospitalized and 15.8% required an unscheduled visitfor an asthma exacerbation during pregnancy . These exacerbations were more common in patients who had persistent asthma and were especially common in patients who had severe persistent asthma, 26.9% of whom required a hospitalization and 36.5% had an unscheduled visit for acute asthma during pregnancy. Data indicate that the course of asthma during pregnancy improves in one third, worsens in onethird, and remains unchanged in one third [4–9]. Asthma symptoms and exacerbations tend to peak during the second trimester [3,4,7–9]. In the study from Finland, exacerbations occurred most frequently between 17 and 24 weeks of pregnancy . Exacerbation during labor and delivery is uncommon, usually is treated easily, and is more likely to occur in patients in whom asthma is controlledinadequately or in those who acquire an infection . Limited data suggest that pregnant asthmatic African American women experience more morbidity than do white women. They are 1.35 times more likely to receive a course of rescue corticosteroids, 1.89 times more likely to visit an emergency department, and 1.73 times more likely to be hospitalized during pregnancy . Asthma exacerbations can harm thefetus in several ways. Poor control of asthma during pregnancy is associated with several poor outcomes for mother
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and baby, including perinatal mortality, preeclampsia, preterm birth, and low birthweight [9,11–15]. Maternal hypoxia may cause fetal hypoxia directly [16,17]. In addition, other consequences of poorly controlled asthma, such as hypocapnia and alkalosis, may cause fetal hypoxia indirectly by reducing uretoplacental blood flow [16,17]. Therefore, acute asthma exacerbations during pregnancy should be managed aggressively in the home, emergency department, and hospital.
Treatmentgoals Home management of asthma exacerbations Pregnant asthmatics must be admonished to be diligent in monitoring their asthma symptoms and vigilant in recognizing early signs and symptoms of acute asthma exacerbation. An increase in cough, the appearance of chest tightness, dyspnea, wheezing, decrease in fetal movement, or a 20% decrease in peak expiratory flow rate (PEFR) may signal theworsening of asthma and should warrant immediate attention. All patients should have a personal action plan for initiating home therapy and for seeking medical attention . The goal of treatment is prevention of maternal and fetal hypoxia and quick reversal of airway obstruction. An algorithm for home therapy is presented in Fig. 1. Home treatment should begin with inhaled b-2 agonist treatment (eg,albuterol, two to four puffs or single nebulizer treatments every 20 minutes for up to 1 hour). Quick resolution of symptoms, ability to resume normal activity, and return of PEFR to greater than 80% of personal best indicate a good response. Prompt further medical attention, such as a visit to the doctor or emergency department, is indicated if there is an incomplete response to initial therapy...