Effect of a clinical procalcitonin algorithm to guide antibiotic therapy in patients with lower respiratory tract infections outside study conditions: a post-study survey

Abstract

Introduction: A procalcitonin (PCT) algorithm was demonstrated to reduce antibiotic exposure in patients with lower respiratory tract infections (LRTI) in several randomised controlled trials. Data on the efficacy of PCT-guided antibiotic stewardship in real life and outside study conditions are lacking. Methods: We prospectively monitored antibiotic therapy and adherence to the published PCT algorithm in consecutive hospitalized patients with LRTI admitted to the Kantonsspital Aarau (Switzerland), a former ProHOSP study hospital [1], between April and November 2008. Results: Median age of the 130 included patients (36% females) was 70 (IQR 57 to 82) years. Community-acquired pneumonia was diagnosed in 78%, while 17% had acute and 5% had exacerbation of chronic bronchitis. Mortality rate was 11.5% and 6.9% of patients needed ICU admission. In 70% of patients (n = 91), antibiotics were administered or withheld according to the PCT algorithm. In the 39 patients (30%) where the PCT algorithm was overruled, the main reasons were severe immunosuppression (30%), high-risk LRTI (13%), other infections (8%) and clinical judgement of the treating physician (33%). Overall, the median duration of antibiotic therapy was 6 days (IQR 1 to 10), 4 days (IQR 0 to 7) when the PCT algorithm was followed and 10 days (IQR 8 to 14) when it was overruled, respectively. In patients with community-acquired pneumonia, median days on antibiotic therapy was 7 days (IQR 4 to 10), which was similar to the PCT group in a trial in the same institution (P = 0.44) [1]. Conclusions: The present study mirrors the use of PCT-guided antibiotic therapy in clinical practice and outside trial conditions. Antibiotic exposure, however, strongly depends on the adherence to a clinical PCT algorithm