Abstract and Introduction
Abstract
Introduction Patients with severe acute exacerbations of asthma often receive inappropriate antibiotic treatment. We aimed to determine whether serum procalcitonin (PCT) levels can effectively and safely reduce antibiotic exposure in patients experiencing exacerbations of asthma.
Methods In this randomized controlled trial, a total of 216 patients requiring hospitalization for severe acute exacerbations of asthma were screened for eligibility to participate and 169 completed the 12-month follow-up visit. Patients were randomized to either PCT-guided (PCT group) or standard (control group) antimicrobial therapy. In the control group, patients received antibiotics according to the attending physician's discretion; in the PCT group, patients received antibiotics according to an algorithm based on serum PCT levels. The primary end point was antibiotic exposure; secondary end points were clinical recovery, length of hospital stay, clinical and laboratory parameters, spirometry, number of asthma exacerbations, emergency room visits, hospitalizations and need for corticosteroid use due to asthma.
Results PCT guidance reduced antibiotic prescription (48.9% versus 87.8%, respectively; P < 0.001) and antibiotic exposure (relative risk, 0.56; 95% confidence interval, 0.44 to 0.70; P < 0.001) compared to standard therapy. There were no significant differences in clinical recovery, length of hospital stay or clinical, laboratory and spirometry outcomes in both groups. Number of asthma exacerbations, emergency room visits, hospitalizations and need for corticosteroid use due to asthma were similar during the 12-month follow-up period.
Conclusion A PCT-guided strategy allows antibiotic exposure to be reduced in patients with severe acute exacerbation of asthma without apparent harm.
Introduction
Asthma is a problem worldwide, with an estimated incidence of 300 million affected individuals and 250,000 annual deaths from asthma. Acute exacerbations of asthma account for nearly 2 million emergency department (ED) visits and 500,000 admissions each year in the United States, frequently ranking as a major cause of absence from work and decreased productivity and incurring the greatest health-care costs. Severe exacerbations of asthma are potentially life-threatening and often put patients at increased risk of ED admission and hospitalization.
Because most exacerbations of asthma are associated with viral respiratory tract infection (RTI) and bacterial infection seems to play only a minor role, global asthma management guidelines do not recommend routine use of antibiotics. However, in countries with high prescription rates for antibiotics, many asthma patients with exacerbations are treated with antibiotics, leading to antibiotic overuse and bacterial resistance. In the United States, approximately 22% of acute asthma patients in the ED receive an antibiotic unnecessarily. In England, a high antibiotic prescription rate (57%) was observed in asthma patients. In our previous study in China, about 70% of patients with mild to moderate acute exacerbation of asthma received antibiotics.
As many as 75% of all antibiotic doses are prescribed for RTIs, such as acute bronchitis, community-acquired pneumonia (CAP), acute exacerbations of asthma or chronic obstructive pulmonary disease (COPD), despite their mainly viral cause. This inappropriate use of antibiotics is believed to be a main cause of the spread of bacterial resistance. There is a need to reduce unnecessary antibiotic use during treatment of RTI, and much effort has been put into the search for sensitive and specific tools to guide antibiotic therapy in RTI patients. Clinical trials that have used procalcitonin (PCT) to guide antibiotic therapy for patients with RTI have shown that a biomarker-driven algorithm can cut antibiotic prescribing significantly and that this can be achieved without any increase in adverse events or treatment failures. PCT-guided antibiotic stewardship reduced initial antibiotic prescription rates by 40% to 50% in patients with LRTI (lower respiratory tract infection) presenting to the ED and by 70% to 80% in ambulatory patients presenting to their general physicians and reduced total antibiotic exposure in CAP by 40% to 50%.
In our previous study, we demonstrated that PCT can be used accurately and effectively to determine whether acute asthma patients have bacterial infections and to guide the use of antibiotics in the treatment of acute exacerbation of mild to moderate asthma. However, we included few severe asthma patients in the study, and the study had only a 6-week follow-up period. We therefore undertook a randomized controlled study to assess the usefulness of PCT guidance for antibiotic use in hospitalized patients with severe acute exacerbation of asthma, and this time included a 12-month follow-up period.