Background
The optimal duration of antibiotic therapy for hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) is not clear. A multicentre randomised controlled trial indicated similar clinical efficacy for 8 versus 15 days of antibiotic therapy for VAP, with less emergence of multiresistant organisms following the shorter course [1]. Pseudomonas aeruginosa is difficult to eradicate, however, and American Thoracic Society guidelines for treatment of HAP due to P. aeruginosa recommend 14 days of therapy [2]. Our aim was to study the rate of recurrence following treatment of Gram-negative HAP in a critically ill population with short-course (typically 5 days) antibiotic therapy.
Materials and methods
We retrospectively reviewed 50 patients treated consecutively with short-course (typically 5 days) antibiotic therapy for Gram-negative HAP in a UK teaching hospital critical care unit from 2004 to 2007. Pneumonia was defined as semi-quantitative respiratory culture (≥2+) of a single Gram-negative isolate, clinical pulmonary infection score ≥6 and initiation of antibiotic therapy. Recurrence of HAP was defined either as relapse (pure growth of the organism causing the initial infection) or reinfection (due to a different organism). Patients were studied until hospital discharge or death.
Results
Demographic and outcome data are summarised in Table 1. The commonest causative organisms were P. aeruginosa (42%), Enterobacter species (14%) and Klebsiella species (14%). Two patients died before completing the initial course of antibiotics.
Table 1.
Demographic and outcome data
| Demographic data at initial diagnosis | |
| Median age (range) (years) | 69.5 (19–84) |
| Sex (% male) | 78 |
| Mechanical respiratory support (%) | 78 |
| Median APACHE II score | 19 |
| Outcome of patients surviving initial course of antibiotics | |
| Nonresolution (%) | 2.1 |
| Recurrence (%) | 10.4 (all relapse) |
| Intensive care unit mortality (%) | 41.7 |
| Hospital mortality (%) | 60.4 |
Conclusion
Treatment of Gram-negative HAP in the critically ill patient with short-course antibiotic therapy is associated with a low rate of recurrence (10.4%). This compares favourably with reported recurrence rates of 18–26% following ≥2 weeks of antibiotic therapy for VAP [1,3,4].
References
- Chastre J, Wolff M, Fagon JY. et al. Comparison of 8 vs 15 days of antibiotic therapy for ventilator-associated pneumonia in adults: a randomized trial. JAMA. 2003;290:2588–2598. doi: 10.1001/jama.290.19.2588. [DOI] [PubMed] [Google Scholar]
- American Thoracic Society. Guidelines for the management of adults with hospital-acquired, ventilator-associated, and healthcare-associated pneumonia. Am J Respir Crit Care Med. 2005;171:388–416. doi: 10.1164/rccm.200405-644ST. [DOI] [PubMed] [Google Scholar]
- Combes A, Figliolini C, Trouillet JL. et al. Recurrent Pseudomonas aeruginosa pneumonia in ventilated patients: relapse or reinfection? Crit Care Med. 2003;31:1102–1107. doi: 10.1097/01.CCM.0000059313.31477.2C. [DOI] [PubMed] [Google Scholar]
- Rello J, Mariscal D, March F. et al. Factors predicting ventilator-associated pneumonia recurrence. Am J Respir Crit Care Med. 1998;157:912–916. doi: 10.1164/ajrccm.157.3.9703014. [DOI] [PubMed] [Google Scholar]