Initial therapy for hospitalized asthmatic patients most often includes intravenous aminophylline, intravenous corticosteroids, inhaled and oral beta agonist therapy, and supplemental oxygen. Pulmonary function status is monitored by repeated measurements of peak expiratory flow rate. Though the initial therapy may be identical, patients hospitalized for treatment of acute asthma respond to therapy at different rates. Patients with a rapid response achieve their maximum pulmonary function values within three days, whereas those with a slow response often require more than seven days. At present there is no clear description of the recovery rates for a hospitalized asthma patient and only a few attempts have been made to predict the rate of response. As a result, the importance of understanding the individual patients response to therapy and the need for predicting that response early in the course of hospitalization have been understated. The ability to identify the patient with a slow response and insight regarding the pattern of response to therapy help predict the length of hospitalization, an important consideration in this age of DRGs.
The criteria established by Benfield and Smith to provide a useful means for predicting who will be a slow responder: (1) age greater than 40 years; (2) lack of atopy; (3) duration of attack greater than seven days; (4) three admissions in the previous 12 months; (5) maintenance oral corticosteroids; and (6) pulsus paradoxus greater than 25 mm Hg. Furthermore, our previous data suggest a consistent recovery pattern for individuals as reflected by simple pulmonary function measurements. Recovery approaches baseline pulmonary function status in a nearly asymptotic manner.
However, it is important to note that, even in a “stable” patient, peak flow measurements vary considerably and it could take successive measurements over a three- to four-day period to establish a good estimate of baseline pulmonary function status. A patient with a rapid response to asthma therapy may manifest a complete recovery within this time period. Problems arise in the management of slow responders who may not be identified as such. A single simple measurement such as peak expiratory flow rate done on a twice daily basis during hospitalization and then on a weekly follow-up basis to document continued improvement are more helpful in the management of a slow responder than a full set of pulmonary function tests done less frequently.
With the current pressures for cost containment, there may be a tendency to discharge a patient prematurely from the hospital or emergency room before the patient has attained an acceptable peak expiratory flow rate. Caution needs to be exercised with the slowly responding patient. Such a patient may require a lengthy hospitalization or at least frequent outpatient monitoring to document an acceptable recovery. Furthermore, premature discharge can result in reexacerbation necessitating additional hospitalization. Hospital admissions that are characterized by a slow response in an adult asthmatic patient may require greater than two weeks of hospitalization to attain an acceptable level of recovery. The current DRG guidelines regarding hospitalization for acute asthma may be too restrictive for the slowly responding patient.