Pulmonary exacerbations in cystic fibrosis: young children with characteristic signs and symptoms.

BACKGROUND: A standard definition of pulmonary exacerbation based on signs and symptoms would be useful for categorizing cystic fibrosis (CF) patients and as an outcome measure of therapy. The frequently used definition of treatment with intravenous antibiotics varies with practice patterns. One approach to this problem is to use large data sets which include a patient's signs and symptoms along with their clinician's decision to treat with antibiotics for the diagnosis of pulmonary exacerbation. Previous analysis of such a data set, the Epidemiologic Study of Cystic Fibrosis (ESCF), found that new crackles, increased cough, increased sputum, and weight decline were the four clinical characteristics most strongly influencing providers to treat young CF patients for a pulmonary exacerbation. The objectives of this study were to confirm that these four characteristics influence the decision to treat with antibiotics for a pulmonary exacerbation in young CF patients; to evaluate their implications for future nutritional status and lung function; and to assess the effect of antibiotic treatment on these characteristic signs and symptoms.
METHODS: This was an observational, longitudinal cohort study of clinical care in children <6 years old cared for at sites participating in ESCF.
RESULTS: Using data from children not included in the previous ESCF study, we confirmed that these four characteristics were significantly associated with the likelihood of physicians prescribing antibiotics to treat a pulmonary exacerbation. The number of these characteristics present at a single clinic visit before age 6 predicted hospitalization rate over the next year, the weight-for-age z-score, and the forced expiratory volume in 1 sec (FEV1) percent predicted at age 7. Treatment with antibiotics was associated with a greater decrease in the proportion of children with crackles, cough, and Pseudomonas aeruginosa at a follow-up visit within 6 months.
CONCLUSIONS: New crackles, increased cough, increased sputum, and decline in weight percentile at a single clinic visit increase the risk of future malnutrition, hospitalization, and airflow obstruction in young children with CF. Treatment with antibiotics mitigates some of these signs and symptoms by the first follow-up visit. The presence of these four characteristic signs and symptoms is useful to define pulmonary exacerbations in young children with CF that respond to antibiotic treatment in the short-term and influence long-term prognosis.