Antibiotics against Pseudomonas aeruginosa for COPD exacerbation in ICU: a 10-year retrospective study

Abstract

Summary: Chronic obstructive pulmonary disease (COPD) is a frequent source of hospitalization. Antibiotics are largely prescribed during COPD exacerbation. Our hypothesis is that large broad-spectrum antibiotics are more and more frequently prescribed. Our results confirm this trend and highlight that the increase in large broad-spectrum use in COPD exacerbation is largely unexplained.

Background: Acute COPD exacerbation (AECOPD) is frequently due to respiratory tract infection, and the benefit of antipseudomonal antibiotics (APA) is still debated. Health care-associated pneumonia (HCAP) was defined in 2005 and requires broad-spectrum antibiotherapy. The main objectives are to describe the antibiotic use for AECOPD in intensive care unit and to identify factors associated with APA use and AECOPD prognosis.

Methods: We conducted a monocentric, retrospective study on all AECOPDs in the intensive care unit treated by antibiotics for respiratory tract infection. Treatment failure (TF) was defined by death, secondary need for mechanical ventilation, or secondary systemic steroid treatment. A multivariate analysis was used to assess factors associated with APA prescription and TF.

Results: From January 2000 to December 2011, 111 patients were included. Mean age was 69 years (±12), mean forced expiratory volume 38% of theoretic value (±13). Thirty-five (31%) patients were intubated, and 52 (47%) were treated with noninvasive ventilation. From 107 patients, 8 (7%) cases of Pseudomonas aeruginosa were documented. APAs were prescribed in 21% of patients before 2006 versus 57% after (P=0.001). TF prevalence was 31%. Risk factors for P. aeruginosa in COPD and HCAP diagnosis did not influence APA, whereas the post-2006 period was independently associated with APA prescription (odds ratio 6.2; 95% confidence interval 1.9-20.3; P=0.0013). APA did not improve TF (odds ratio 1.09; 95% confidence interval 0.37-3.2).

Conclusion: HCAP guidelines were followed by an increase in APA use in AECOPD, without an improvement in prognosis. HCAP prevalence cannot account for the increasing APA trend. Time effect reveals a drift in practices. The microbiological effect of such a drift must be evaluated.

Keywords: COPD; ICU; Pseudomonas aeurginosa; antibiotics; exacerbation.

Figure 1

Study flow chart. Abbreviations: AECOPD, acute chronic obstructive pulmonary disease exacerbation; AIPA, antibiotics inactive against Pseudomonas aeruginosa; APA, antipseudomonal antibiotics; ICU, intensive care unit.

Figure 2

Antipseudomonal antibiotics (APA) prescription frequency prior to and after January 2006.

Figure 3

Antibiotic prescription depending on the respiratory infection diagnosis (bronchitis, CAP, HCAP, or NP). Notes: *HCAP diagnosis was used as of January 1, 2006. White: antibiotics inactive on Pseudomonas aeruginosa, grey: antibiotics active on Pseudomonas aeruginosa. Before 2006 (thick arrow); after 2006 (thin arrow). Abbreviations: CAP, community-acquired pneumonia; HCAP, health care-associated pneumonia; NP, nosocomial pneumonia.