Over the last decade, bacterial resistance has increased alarmingly among nosocomial gram-negative bacilli (GNB) in intensive care units (ICUs). In Pseudomonas aeruginosa imipenem-resistance (R) was 18%, quinolone-R 27%, cephalosporin-R 26%, extended spectrum β-lactamase (ESBL)–producing Klebsiella pneumoniae >10%, and third-generation cephalosporin-resistant Enterobacter spp 35% (National Nosocomial Infection Surveillance data 2000). In addition, ICU outbreaks caused by multiresistant Acinetobacter baumannii have increasingly been reported worldwide. The role of cephalosporin overuse has been noted in numerous nosocomial outbreaks due to ESBL-producing K. pneumoniaes. Most ICUs face the challenge of managing patients with endemic P. aeruginosa infections, in whom antibiotic therapy seems to play a decisive role selecting bacterial flora. P. aeruginosa pneumonia should always be considered in late ventilator-associated pneumonia (VAP) and in early VAP with previous antibiotic therapy. Nowadays, many strains of A. baumannii are highly resistant to modern β-lactams, aminoglycosides, and fluoroquinolones; of great concern, resistance to carbapenems has already emerged worldwide. Reinforcement of cleaning procedures, handwashing, and isolation methods remain the cornerstone of control programs in A. baumannii outbreaks. Attributed mortality of these infections is a controversial issue but probably low. Because of that, acute clinical judgment in selecting the patients who really need antibiotics is essential. Overall, multiresistant GNB infections in ICUs make their correct therapeutic antimicrobial management a real challenge for physicians. The risk of mortality in patients with life-threatening infections is substantially increased if initial antibiotic therapy is inadequate. However, excessive antibiotic use has been linked with the development of resistance. There is a general consensus that an early broad-spectrum empirical antibiotic therapy with a high probability of covering the likely pathogens should be used for serious VAP or other life-threatening infections. Appropriate general guidelines may be useful to establish a rational antibiotic policy, but their application should take into account the local organism ecology and resistance patterns.
Over the last decade, bacterial resistance has increased alarmingly among nosocomial gram-negative bacilli in intensive care unit patients, including multiresistant Pseudomonas aeruginosa and Acinetobacter baumannii, extended spectrum β-lactamase–producing Klebsiella pneumoniae and derepressed Enterobacter spp. These infections make their correct therapeutic antimicrobial management a real challenge for physicians. Appropriate general guidelines may be useful to establish a rational antibiotic policy, but their application should take into account the local organism ecology and resistance patterns.
From the Infectious Diseases Service, Department of Medicine, Hospital de Bellvitge, University of Barcelona, Spain.
Address correspondence to: Javier Ariza, Infectious Diseases Service, Hospital de Bellvitge, C/ Feixa Llarga s/n 08907, L'Hospitalet de Llobregat, Barcelona, Spain. Email: firstname.lastname@example.org.