In this research proposal, the primary objective is to describe PK parameters (area under the curve (AUC), clearance (Cl), distribution volume (Vd) and half life (T1/2)) for the antibiotics of interest (amoxicillin(-(clavulanic acid), flucloxacillin, piperacillin-tazobactam, meropenem and clindamycin) for this adult non critically ill surgery population.