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Initial use of one or two antibiotics for critically ill patients with community-acquired pneumonia: impact on survival and bacterial resistance

Christophe Adrie12*, Carole Schwebel3, Maïté Garrouste-Orgeas45, Lucile Vignoud5, Benjamin Planquette6, Elie Azoulay7, Hatem Kallel8, Michael Darmon9, Bertrand Souweine10, Anh-Tuan Dinh-Xuan11, Samir Jamali12, Jean-Ralph Zahar13, Jean-François Timsit35 and This article was written on behalf of the Outcomerea Study Group

Author Affiliations

1 Physiology Department, Paris University, Cochin Hospital 27, rue du Faubourg Saint-Jacques, Paris, France

2 Polyvalent ICU, Delafontaine Hospital, Saint Denis, France

3 Polyvalent ICU, University Grenoble 1, Albert Michallon Hospital, Grenoble, France

4 ICU, Saint Joseph Hospital, Paris, France

5 University Grenoble 1, Integrated Research Center U823, Grenoble, France

6 Medical Surgical ICU, André Mignot Hospital, Versailles-Le Chesnay, France

7 Medical ICU, Saint Louis Hospital, Paris, France

8 ICU, Cayenne General Hospital, Cayenne, France

9 Medical ICU, Saint-Etienne University Hospital, Saint-Etienne, France

10 ICU, Gabriel Montpied Hospital, Clermont-Ferrand, France

11 Physiology Department, Cochin Hospital, Paris, France

12 ICU, Dourdan Hospital, Dourdan, France

13 Microbiology Department, Necker Hospital, Paris, France

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Critical Care 2013, 17:R265  doi:10.1186/cc13095

Published: 7 November 2013



Several guidelines recommend initial empirical treatment with two antibiotics instead of one to decrease mortality in community-acquired pneumonia (CAP) requiring intensive-care-unit (ICU) admission. We compared the impact on 60-day mortality of using one or two antibiotics. We also compared the rates of nosocomial pneumonia and multidrug-resistant bacteria.


This is an observational cohort study of 956 immunocompetent patients with CAP admitted to ICUs in France and entered into a prospective database between 1997 and 2010.

Patients with chronic obstructive pulmonary disease were excluded. Multivariate analysis adjusted for disease severity, gender, and co-morbidities was used to compare the impact on 60-day mortality of receiving adequate initial antibiotics and of receiving one versus two initial antibiotics.


Initial adequate antibiotic therapy was significantly associated with better survival (subdistribution hazard ratio (sHR), 0.63; 95% confidence interval (95% CI), 0.42 to 0.94; P = 0.02); this effect was strongest in patients with Streptococcus pneumonia CAP (sHR, 0.05; 95% CI, 0.005 to 0.46; p = 0.001) or septic shock (sHR: 0.62; 95% CI 0.38 to 1.00; p = 0.05). Dual therapy was associated with a higher frequency of initial adequate antibiotic therapy. However, no difference in 60-day mortality was found between monotherapy (β-lactam) and either of the two dual-therapy groups (β-lactam plus macrolide or fluoroquinolone). The rates of nosocomial pneumonia and multidrug-resistant bacteria were not significantly different across these three groups.


Initial adequate antibiotic therapy markedly decreased 60-day mortality. Dual therapy improved the likelihood of initial adequate therapy but did not predict decreased 60-day mortality. Dual therapy did not increase the risk of nosocomial pneumonia or multidrug-resistant bacteria.