Procalcitonin (PCT) plasma concentration and clearance kinetics during continuous venovenous hemofiltration (CVVH). (a) PCT ultrafiltrate clearances (± standard deviation, ml/min) at 15 min (T15'), 60 min (T60') and 6 hours (T6h) after setup of CVVH (*P < 0.01). (b) PCT plasma clearances (± standard deviation, ml/min) at T15', T60' and T6h (** not significant). (c) PCT plasma concentration (± standard deviation, ng/ml) at the beginning of CVVH (T0) and every 24 hours during 4 days (J1–J4) (*** not significant). Cluf, ultrafiltrate clearance; Clp, plasma clearance.