MedWire News: Using procalcitonin as a marker of severe bacterial infection to guide treatment decisions reduces intensive care unit (ICU) patients’ exposure to antibiotics, shows a randomized trial.
“A procalcitonin-guided strategy could reduce antibiotic selective pressure with potential benefits in the era of multiresistance,” say the researchers in The Lancet.
In the open-label study, 311 patients were assigned to the procalcitonin group, while the other 319 patients were treated according to current guidelines. Antibiotic use for patients in the procalcitonin group was encouraged when serum procalcitonin concentrations reached 0.5 µg/L, and cessation of antibiotics was recommended when procalcitonin levels fell to less than 80% of peak concentration or to less than 0.5 µg/L.
The average length of ICU stay was 15.9 days for the procalcitonin group and 14.4 days for the control group. During this time, patients in the procalcitonin and control groups had an average of 14.3 versus 11.6 days without exposure to antibiotics – a highly significant absolute difference of 2.7 days, and a relative difference of 23%.
The average length of the first episode of antibiotic treatment was 6.6 days for patients in the procalcitonin group, compared with 9.9 days for those in the control group.
This did not appear to affect outcomes, say Michel Wolff (Hôpital Bichat–Claude-Bernard, Paris, France) and colleagues. Mortality rates among patients assigned to the procalcitonin and control groups were 21.2% and 20.4%, respectively, at day 28, and 30.0% and 26.1%, respectively, at day 60.
The absolute differences in mortality – 0.8% at 28 days and 3.8% at 60 days – fell within the investigators’ noninferiority margin of 10%. No death was attributed to an infection relapse.
The reduction in antibiotic exposure was achieved mainly by shortening the treatment duration rather than by delaying its start.
“Because crude procalcitonin concentrations in the ICU could have poor diagnostic benefit, intensivists are understandably reluctant to rely exclusively on biologic markers when severe infection is suspected,” say Wolff et al.
“Thus, procalcitonin might be more useful for stopping antibiotics than for use as a marker to exclude infection.”
