Procalcitonin guided antibiotic therapy for LRTIs

Serum procalcitonin is associated with infection severity and is more specific for bacterial rather than viral infections. Huang et al. (NEJM 2018;379:236) investigated whether procalcitonin-guided use of antibiotics in lower respiratory tract infections (LRTI) reduces the number of total antibiotic days over a 30 day period. This randomised control multi-centred clinical trial focused on patients admitted to emergency departments from 14 U.S hospitals with suspected LRTI and divided them into two groups: the usual care group (n=834) and the procalcitonin group (n=830). Prior to study initiation the trial sites had educational updates on best practice for LRTI management. Clinicians in the procalcitonin group were provided with initial and/or serial procalcitonin results alongside a procalcitonin-guided antibiotic guideline. There was no significant difference between the two groups in mean number of antibiotic days (4.2 days for the procalcitonin group vs 4.3 days for the usual care group; difference −0.05 days, 95% CI −0.6 to 0.5 days, P=0.87). Patients with lower levels of procalcitonin had fewer infective symptoms and therefore the impact of measuring procalcitonin on treatment decisions was negligible. The study …