Asthma Guidelines: Management of Chronic Asthma
James W. Stout, MD, MPH, FAAP
•Once the diagnosis of asthma is established, the foundations of chronic asthma care are an initial assessment of asthma severity, followed by planned preventive visits to assess symptom control and adjust therapy over time. (See also Chapter 30, Asthma Guidelines: Overview.)
•In primary care, a main objective is determining which patients with asthma should use a bronchodilator only when needed for symptoms and which patients should also take a daily controller medication, typically an inhaled corticosteroid. This is achieved with a structured approach to severity and symptom control.
Assessing Asthma Severity and Control
•Severity and control are assessed by using a structure of impairment and risk with the following metrics.
▪Symptom frequency (daytime and nighttime), short-acting bronchodilator use for symptoms
▪Lung function (forced expiratory volume in 1 second [FEV1] percentage predicted and ratio of FEV1 to forced vital capacity [FVC])
•Exacerbations that require a “burst” of oral corticosteroids increase risk.
▪Abnormal lung function may also be considered a predictor of future risk.
•At an initial visit, assess asthma severity. Although this may change over time, it is meant to represent the intrinsic severity of disease.
•The asthma guidelines provide 4 levels of asthma severity: intermittent, mild persistent, moderate persistent, and severe persistent (severity and control tables can be found at www.nhlbi.nih.gov/files/docs/guidelines/asthgdln.pdf, on pages 71–77)
•Control assessment involves essentially the same metrics as severity, but they are applied over time.
•If the patient is using controller therapy, assess whether he or she is adhering to the treatment plan and confirm that the inhaler delivery technique is correct before adjusting medication dose.
Metrics for Assessment
•A Venn diagram (Figure 32-1) shows the main markers of asthma impairment and risk, which reflect the decision-making structure for assessment of asthma severity and control presented in the National Heart, Lung, and Blood Institute Third Expert Panel Report tables.
•Only one of these criteria needs to be positive for asthma to be classified as persistent in severity or not well controlled (both classifications warrant daily controller medication), although 2 or 3 criteria may often overlap.
•For children <5 years of age, a careful history of impairment and risk is used to assess severity and control, and lung function information is typically unavailable.
Figure 32-1. Venn diagram of the drivers of asthma severity and control. FEV1 = forced expiratory volume in 1 second, FVC = forced vital capacity, SABA = short-acting β2-adrenergic agonist.
•Spirometry has several indications in primary care pediatrics. These include
—Diagnosis and severity assessment of asthma in patients ≥5 years of age
—Follow-up of asthma control (especially when changing medications)
—Evaluation of chronic cough
—Evaluation of shortness of breath and other chronic respiratory complaints
—Evaluation of baseline lung function in a patient with exercise-induced bronchospasm
The goal is for the patient to have normal or near-normal lung function during periods of wellness.
•First and most importantly, assess whether the FEV1 percentage predicted and/or the FEV1/FVC ratio represents obstruction for the patient. (See Table 32-1; see also Figure 4-4 in Chapter 4, Office Pulmonary Function Testing.)
aUse actual ratios (not percentage of predicted values).
•A careful, structured history of symptom frequency is critical for assessing severity and control.
•Chronic cough, wheeze, or trouble breathing (daytime and nighttime) or bronchodilator use for symptoms that persist for at least half of a typical week represents asthma that is persistent in severity and not well controlled.
—Two such tools are the Asthma Control Test (ACT) and the Childhood ACT (C-ACT) (Box 32-1). Scores from these tools can be used to assess this domain of asthma control.
Asthma Control Test (ACT): 5 items, 12 years of age through adulthood
20 and higher: Well controlled
16–19: Not well controlled
15 or lower: Very poorly controlled
Childhood Asthma Control Test (C-ACT): 7 items, 4–11 years of age
20 and higher: Well controlled
13–19: Not well controlled
12 or lower: Very poorly controlled
•The ACT and C-ACT have good reliability, validity, and responsiveness to changing clinical conditions . They are also easy to administer and interpret .
•Other examples of available and validated scoring tools include the Asthma Therapy Assessment Questionnaire (available at evidencebasedpractice.osumc.edu/Documents/Guidelines/ATAQChecklist.pdf) and the Asthma Control
Questionnaire (available at www.qoltech.co.uk/acq.html).