Use of piperacillin/tazobactam and meropenem in a Danish intensive care unit

INTRODUCTION. Intensive care unit (ICU) patients often have infections, and early empirical treatment with broad-spectrum antibiotics is recommended. As the choice between different agents is not supported by high-certainty evidence and as a part of a larger research programme, we aimed to describe the use of piperacillin/tazobactam (PTZ) and meropenem (MER) in patients in a university hospital ICU in Denmark and the patient outcomes of each of these treatments. METHODS. We prospectively screened all patients admitted to the general 24-bed ICU at Rigshospitalet for 12 consecutive weeks as from 1 November 2022. Patients were included if they received PTZ or MER during their ICU stay. The primary outcome was 90-day mortality. RESULTS. Among 286 patients, 184 (64%) received PTZ and/or MER; 112 (61%) were men, and 161 (88%) received life support. Among these, 80 (43%) received PTZ, 76 (41%) received MER and 28 (15%) received both agents, mainly as empirical treatment. At 90 days, 22 (28%) had died among patients receiving PTZ, 19 (26%) among those receiving MER and eight (29%) among those receiving both agents. At 90 days, 19 cases of a bacterium with new acquired resistance were identified in 17 of the 184 patients (9%) (eight cases among those receiving PTZ, five among those receiving MER, and six among those treated with both agents); vancomycin-resistant enterococci (VRE) accounted for 16 of the 19 cases. CONCLUSIONS. Most patients in the ICU of a Danish university hospital received antibiotic treatment with PTZ and/or MER, mainly as empirical treatment. Mortality and the occurrence of bacteria with new acquired resistance, mainly VRE, appeared to the same extent in the groups.