Procalcitonin test can reduce antibiotic use in COPD

Journal of Family Practice, April, 2007

* Clinical question

Can procalcitonin level be used to safely guide the use of antibiotics for patients with a chronic obstructive pulmonary disease (COPD) exacerbation?

* Bottom line

Yes, procalcitonin can be used to guide the use of antibiotics for patients with exacerbation of COPD. Antibiotics are optional for those with a procalcitonin level between 0.1 mcg/L and 0.25 mcg/L and are recommended if the procalcitonin level is >0.25 mcg/L.

Level of evidence

1b: Individual randomized controlled trials (with narrow confidence interval)

Study design

Randomized controlled trial (double-blinded)

Funding

Industry

Allocation

Uncertain

Setting

Emergency department

Synopsis

Procalcitonin is a biomarker that is elevated among patients with bacterial infection, but not in those with viral infection or other types of inflammation. A previous study (Lancet 2004; 363:600-607) showed that a new, more accurate assay can identify patients with lower respiratory tract infection who are unlikely to benefit from antibiotics.

In this study, the researchers identified 226 adults who were over 40 years of age and met standard criteria for an exacerbation of COPD. All patients had a procalcitonin level drawn, and were then randomized into a usual-care group or a group that also gave the treating physicians access to the procalcitonin level. A level >0.1 mcg/L was reported as an absence of bacterial infection with no antibiotic recommended; a level between 0.1 and 0.25 mcg/L was reported as possible bacterial infection with antibiotic use optional; and a level >0.25 mcg/L was interpreted as bacterial infection with antibiotic use recommended.

Clinical success or failure was assessed between 2 and 3 weeks after discharge by clinicians blinded to group assignment. Patients were also contacted 6 months after discharge for a clinical assessment. Of the 226 patients initially randomized, 11 in the procalcitonin group and 7 in the standard treatment group were removed from the study because they did not meet criteria for COPD on the basis of inpatient spirometry. For the remainder of the patients, follow-up was excellent.

Having access to the procalcitonin test result significantly reduced antibiotic prescriptions during the index hospitalization (40% vs 72%; P<.001) without any difference in the number of days to the next exacerbation (76 days for each group) or the number of exacerbations or hospitalizations in the next 6 months. Interestingly, no association was found between procalcitonin levels and the presence of purulent sputum or abnormal sputum cultures. Only 10 patients developed pneumonia, too small a number to draw any conclusions about the effect of procalcitonin guidance on the likelihood of pneumonia. There was no significant difference between groups regarding lung function, symptoms, functional status, or hospital length of stay.

FAST TRACK

Antibiotics are recommended when a patient with a COPD exacerbation has a procalcitonin level of >0.25 mcg/L

Stolz D, Christ-Crain M, Bingisser R, et al. Antibiotic treatment of exacerbations of COPD: a randomized, controlled trial comparing procalcitonin-guidance with standard therapy. Chest 2007; 131:9-19.