Review
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Crit Care Med. May 4, 2016; 5(2): 111-120
Published online May 4, 2016. doi: 10.5492/wjccm.v5.i2.111
Association between infections caused by multidrug-resistant gram-negative bacteria and mortality in critically ill patients
Elisabeth Paramythiotou, Christina Routsi
Elisabeth Paramythiotou, Second Department of Critical Care, Medical School, University of Athens, Attikon University Hospital, 12462 Athens, Greece
Christina Routsi, First Department of Critical Care, Medical School, University of Athens, Evangelismos Hospital, 10676 Athens, Greece
Author contributions: Both authors designed the review, conducted the literature review, wrote the article, prepared the table and made critical revisions related to the intellectual content.
Conflict-of-interest statement: Authors have no conflict of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Elisabeth Paramythiotou, MD, PhD, Second Department of Critical Care, Medical School, University of Athens, Attikon University Hospital, Rimini Stree, 12462 Athens, Greece. lparamyth61@hotmail.com
Telephone: +30-210-6003766 Fax: +30-210-5326414
Received: October 3, 2015
Peer-review started: October 15, 2015
First decision: November 30, 2015
Revised: December 30, 2015
Accepted: March 7, 2016
Article in press: March 9, 2016
Published online: May 4, 2016
Processing time: 205 Days and 21.5 Hours
Abstract

The incidence of gram-negative multidrug-resistant (MDR) bacterial pathogens is increasing in hospitals and particularly in the intensive care unit (ICU) setting. The clinical consequences of infections caused by MDR pathogens remain controversial. The purpose of this review is to summarize the available data concerning the impact of these infections on mortality in ICU patients. Twenty-four studies, conducted exclusively in ICU patients, were identified through PubMed search over the years 2000-2015. Bloodstream infection was the only infection examined in eight studies, respiratory infections in four and variable infections in others. Comparative data on the appropriateness of empirical antibiotic treatment were provided by only seven studies. In ten studies the presence of antimicrobial resistance was not associated with increased mortality; on the contrary, in other studies a significant impact of antibiotic resistance on mortality was found, though, sometimes, mediated by inappropriate antimicrobial treatment. Therefore, a direct association between infections due to gram-negative MDR bacteria and mortality in ICU patients cannot be confirmed. Sample size, presence of multiple confounders and other methodological issues may influence the results. These data support the need for further studies to elucidate the real impact of infections caused by resistant bacteria in ICU patients.

Keywords: Critically ill patients; Infections; Multidrug resistance; Gram-negative pathogens; Mortality

Core tip: The incidence of gram-negative multidrug-resistant (MDR) bacterial pathogens is increasing in hospitals and particularly in the intensive care unit (ICU) setting. The clinical consequences of infections caused by MDR pathogens remain controversial. Until the present time a direct association between infections due to gram-negative MDR bacteria and mortality in ICU patients cannot be confirmed by the studies available. Further studies are needed to elucidate the real impact of infections caused by resistant bacteria in ICU patients.