Patterns of antimicrobial therapy in severe nosocomial infections: empiric choices, proportion of appropriate therapy, and adaptation rates—a multicentre, observational survey in critically ill patients

• Published in: International journal of antimicrobial agents Vol. 35; no. 4; pp. 375 - 381
• Main Authors: Vogelaers, Dirk, De Bels, David, Forêt, Frédéric, Cran, Sophie, Gilbert, Eric, Schoonheydt, Karen, Blot, Stijn
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2010; Elsevier
• Subjects: Aged; Anti-Bacterial Agents - therapeutic use; Antibiotic resistance; Antibiotics. Antiinfectious agents. Antiparasitic agents; Appropriate therapy; Bacteremia - drug therapy; Biological and medical sciences; Critical Illness; Cross Infection - drug therapy; Drug Resistance, Multiple, Bacterial; Female; General aspects; Gram-Negative Bacteria - drug effects; Gram-Negative Bacteria - isolation & purification; Gram-Negative Bacterial Infections - drug therapy; Gram-Positive Bacteria - drug effects; Gram-Positive Bacteria - isolation & purification; Gram-Positive Bacterial Infections - drug therapy; Human infectious diseases. Experimental studies and models; Humans; Infection; Infectious Disease; Infectious diseases; Intensive care; Male; Medical sciences; Middle Aged; Multidrug resistance; Peritonitis - drug therapy; Pharmacology. Drug treatments; Pneumonia, Bacterial - drug therapy; Prospective Studies; Treatment Outcome; Infection; Intensive care; Appropriate therapy; Multidrug resistance; Antibiotic resistance; Human; Nosocomial infection; Treatment resistance; Choice; Critically ill; Antimicrobial agent; Antibiotic; Survey; Treatment; Proportion; Multiple resistance; Antibacterial agent; Adaptation
• ISSN: 0924-8579; 1872-7913
• DOI: 10.1016/j.ijantimicag.2009.11.015

Abstract This prospective, observational multicentre ( n = 24) study investigated relationships between antimicrobial choices and rates of empiric appropriate or adequate therapy, and subsequent adaptation of therapy in 171 ICU patients with severe nosocomial infections. Appropriate antibiotic therapy was defined as in vitro susceptibility of the causative pathogen and clinical response to the agent administered. In non-microbiologically documented infections, therapy was considered adequate in the case of favourable clinical response <5 days. Patients had pneumonia ( n = 127; 66 ventilator-associated), intra-abdominal infection ( n = 23), and bloodstream infection ( n = 21). Predominant pathogens were Pseudomonas aeruginosa ( n = 29) Escherichia coli ( n = 26), Staphylococcus aureus ( n = 22), and Enterobacter aerogenes ( n = 21). In 49.6% of infections multidrug-resistant (MDR) bacteria were involved, mostly extended-spectrum β-lactamase (EBSL)-producing Enterobacteriaceae and MDR non-fermenting Gram-negative bacteria. Prior antibiotic exposure and hospitalisation in a general ward prior to ICU admission were risk factors for MDR. Empiric therapy was appropriate/adequate in 63.7% of cases. Empiric schemes were classified according to coverage of (i) ESBL-producing Enterobacteriaceae and non-fermenting Gram-negative bacteria (“meropenem-based”), (ii) non-fermenting Gram-negative bacteria (schemes with an antipseudomonal agent), and (iii) first-line agents not covering ESBL-Enterobacteriaceae nor non-fermenting Gram-negative bacteria. Meropenem-based schemes allowed for significantly higher rates of appropriate/adequate therapy ( p < 0.001). This benefit remained when only patients without risk factors for MDR were considered ( p = 0.021). In 106 patients (61%) empiric therapy was modified: in 60 cases following initial inappropriate/inadequate therapy, in 46 patients in order to refine empiric therapy. In this study reflecting real-life practice, first-line use of meropenem provided significantly higher rates of the appropriate/adequate therapy, irrespective of presence of risk factors for MDR.