If not previously given for maintenance, inhaled corticosteroids are commenced. A nebulized anticholinergic drug may be added if the response at this point is unsatisfactory (Barnes, 2015). Also, for severe exacerbations, IV magnesium sulfate or theophylline may prove eicacious. Corticosteroids are given early to all patients with severe acute asthma. Unless the response to bronchodilator and inhaled corticosteroid therapy is prompt, oral or parenteral corticosteroids are given (Lazarus, 2010). One regimen is oral prednisone or prednisolone or IV methylprednisolone in a dose of 30 to 45 mg daily for 5 to 10 days without tapering (Barnes, 2015). Because their onset of action is several hours, corticosteroids are given initially along with 3-agonists for severe acute asthma.
At this juncture, further management depends on the severity and response to therapy. If initial therapy with 3-agonists is associated with improvement of FEV, or PEFR to above 70 percent of baseline, then discharge can be considered. Some women may beneit from longer observation. Alternatively, for the woman with obvious respiratory distress, or if the FEV) or PEFR is <70 percent of predicted after three doses of 3-agonist, admission is usually advisable (Lazarus, 2010). Intensive therapy is continued with inhaled 3-agonists, IV corticosteroids, and close observation for worsening respiratory distress or fatigue in breathing (Racusin, 2013). The woman is cared for in the delivery unit or an intermediate or intensive care unit (ICU) (Dombrowski, 2006; Zeeman, 2003).
Severe asthma of any type not responding after 30 to 60 minutes of intensive therapy is termed status asthmaticus. This has been termed by some as critical asthma symptoms (Kenyon, 2015). Generally, management of nonpregnant patients with status asthmaticus in an intensive care setting results in a good outcome. Consideration should be given to early intubation when maternal respiratory status worsens despite aggressive treatment (see Fig. 51-1). Fatigue, CO2 retention, and hypoxemia are indications for mechanical ventilation (Chan, 2015). Although Lo and colleagues (2013) described a woman with status asthmaticus in whom cesarean delivery was necessary to efect ventilation, Andrews (2013) cautioned that such clinical situations are uncommon.
For the laboring asthmatic, maintenance medications are continued through delivery. Stress-dose corticosteroids are administered to any woman given systemic corticosteroid therapy within the preceding 4 weeks. The usual dose is 100 mg of hydrocortisone given IV every 8 hours during labor and for 24 hours ater delivery. The PEFR or FEV) is determined on admission, and serial measurements are taken if symptoms develop.
Oxytocin or prostaglandins E) or E2 are used for cervical ripening and induction. A nonhistamine-releasing narcotic such as fentanyl may be preferable to meperidine for labor, and epidural analgesia is ideal. For surgical delivery, conduction analgesia is preferred because tracheal intubation can trigger severe bronchospasm. Postpartum hemorrhage is treated with oxytocin or prostaglandin E) or E2. Prostaglandin F2: or ergotamine derivatives are contraindicated because they may cause signiicant bronchospasm.