Skip to main content

Aetiology of pneumonia in the ICU: the need for early Gram-negative cover

Introduction

Pneumonia remains one of the commonest infectious causes of intensive care unit (ITU) admissions. Despite recent advances, mortality in the ITU from this diagnosis remains around 50% [1]. Early targeted antibiotic therapy to minimise the development of ventilator-associated pneumonia is recommended [2]. This requires an updated knowledge of aetiology of this common diagnosis in ITU settings.

Methods

We conducted a retrospective cohort study into 200 consecutive admissions to our ITU with coded diagnosis of pneumonia. Baseline patient characteristics microbiological diagnosis, disease severity and mortality outcomes were studied.

Results

The average patient age in this cohort was 58 years (range 11 to 90 years). The male to female ratio was 1.35:1. All of the patients were admitted to ITU within 48 hours of their hospital admission, mainly due to worsening respiratory failure. Out of the total of 200 cases, microbiological isolates were identified in 110 (55%). Eighty-five isolates were deemed likely to be pathogenic (42.5%) while 25 (12.5%) were likely to be the result of antibiotic use (candida and coliforms species in sputum). Gram-negative bacteria were responsible for 50.9% isolates. Streptococcus pneumoniae remained the single most common isolate (28/110; 25.4%). Pseudomonas species (23/110; 20.9%) and Haemophilus influenzae (11/110; 10%) were the second and third most common isolates. Pseudomonas infection was more often associated with advanced age and existing lung pathology. Staphylococcus aureus was isolated in 8.1% (9/110) with one confirmed as methicillin resistant (MRSA). Atypical organisms (Legionella 2.7%, mycoplasma spp. 0.9%) and fastidious organisms (Stenotrophomonas maltophilia 2.7%) were also isolated. Other organisms isolated included enterobacter cloacae, Citrobacter koseri, Streptococcus Group A, Haemophilus parainfluenzae, Moraxella catarrhalis and Kleibsella species. Mortality amongst our patients was 28.5% (57/200). This was comparable with previously published findings.

Conclusions

Whilst the aetiology of pneumonia in our cohort is similar to that previously reported [3], the incidence of Gram-negative organisms is much higher. This, if reconfirmed, may have important implications in designing targeted antibiotic therapy for pneumonia in ITU settings.

References

  1. 1.

    Lim WS, et al.: Thorax. 2009,64(Suppl III):iii1-iii55.

    PubMed  Google Scholar 

  2. 2.

    Craven DE, et al.: Clin Infect Dis. 2010,51(Suppl 1):S59-S66.

    Article  PubMed  Google Scholar 

  3. 3.

    Emmi V, et al.: Infez Med. 2005, (Suppl):7-17.

    Google Scholar 

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to A Khanna.

Rights and permissions

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and Permissions

About this article

Cite this article

Khanna, A., Al-shather, H., Chawla, M. et al. Aetiology of pneumonia in the ICU: the need for early Gram-negative cover. Crit Care 15, P221 (2011). https://doi.org/10.1186/cc9641

Download citation

Keywords

  • Pneumonia
  • Streptococcus Pneumoniae
  • Haemophilus Influenzae
  • Methicillin
  • Enterobacter Cloaca