Monitoring plasma antibiotic concentrations in Spanish hospitals

BACKGROUND. Monitoring of plasma aminoglycoside and vancomycin concentrations is a measure of good clinical practice in critically ill patients. However, the frequency and application of this practice in Spanish hospitals is unknown. METHODS. Observational, multicenter study based on a survey designed by the Study Group for Infection in the Critically Ill Patient of the Sociedad Espanola de Enfermedades; Infecciosas y Microbiologia Clinica (SEIMC, Spanish Society of Infectious Diseases and Clinical Microbiology). The survey was sent to the 221 general hospitals with a more than 150-bed capacity included in the hospital directory. Questions regarding the antibiotics monitored, hospital services involved, systems used to report the results, and levels of intervention were included. RESULTS. Information was recorded from 56 (25.3%) hospitals with a total of 36,886 beds, among which 933 (2.5%) corresponded to critically ill patients. In 47 (83.9%) hospitals, plasma concentrations of one or two antibiotics were determined: vancomycin in 47 (83.9% of the total), amikacin in 41 (73.2%), and gentamicin in 40 (71.2%). Analyses were performed by the following services: Biochemistry in 34%, Pharmacy in 25.5% and Pharmacology in 8.5%. Only 57.4% of services recommended dose adjustments according to the results obtained, using eight different dose adjustment models. CONCLUSIONS. In 16% of the hospitals surveyed, monitoring of antibiotic concentrations was not performed in daily practice. There was considerable variation in all phases of the process, especially with regard to adjustment of plasma antibiotic concentrations. Consensus recommendations established by all the Services implicated are required to standardize monitoring of plasma antibiotic concentrations.