The aim of this study was to determine the risk factors for nosocomial infections of imipenem-resistant Pseudomonas aeruginosa (IRPA). A prospective case-control study was performed at a tertiary care hospital in Ankara from January to December 2004. The patients with nosocomial P. aeruginosa infection were included in the study. The features of the patients with IRPA infections were compared to those with imipenem-sensitive P. aeruginosa (ISPA) infections. Only the first isolation of P. aeruginosa was considered. Nosocomial infections were defined according to Center for Disease Control (CDC) criteria. IRPA was isolated from 75 (44.1%) patients, and ISPA was isolated from 95 (55.9%) patients during the study period. IRPA were most frequently isolated from endotracheal aspirate (19%) cultures (p= 0.048), whereas ISPA were most frequently isolated from urine (28%) cultures (p= 0.023). In multivariate analysis, a longer duration of hospital stay until P. aeruginosa isolation (odds ratio [OR], 1.027; 95% confidence interval [CI], 1.002-1.054, p=0.034), arterial catheter administration (OR, 2.508; 95% CI, 1.062-5.920, p=0.036), vancomycin (OR, 2.882; 95% CI, 1.130-7.349, p=0.027), piperacillin-tazobactam (OR, 6.425; 95% CI, 2.187-18.875, p=0.001), and imipenem (OR, 3.580; 95% CI, 1.252- 10.245, p=0.017) treatment within the 14 days before isolation of IRPA were independently associated with imipenem resistance. It was concluded that treatment with imipenem, vancomycin and piperacillin-tazobactam were major risk factors for IRPA infections in hospitalized patients. The nosocomial occurrence of IRPA was also strongly related to the duration of hospital stay, arterial catheter administration.
Adult ; Aged ; Anti-Bacterial Agents/*pharmacology/therapeutic use ; Case-Control Studies ; Cross Infection/drug therapy/epidemiology/*microbiology ; Drug Resistance, Multiple, Bacterial ; Female ; Humans ; Imipenem/*pharmacology/therapeutic use ; Length of Stay ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Multivariate Analysis ; Penicillanic Acid/analogs & derivatives/pharmacology/therapeutic use ; Piperacillin/pharmacology/therapeutic use ; Prospective Studies ; Pseudomonas Infections/drug therapy/epidemiology/*microbiology ; Pseudomonas aeruginosa/drug effects/*isolation & purification ; Risk Factors ; Vancomycin/pharmacology/therapeutic use

No abstract available.
Adult ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Bone Marrow Transplantation ; Capnocytophaga/drug effects/genetics/*isolation & purification ; Gram-Negative Bacterial Infections/complications/*diagnosis/drug therapy ; Humans ; Leukemia, Lymphocytic, Chronic, B-Cell/complications/*diagnosis ; Male ; Microbial Sensitivity Tests ; Penicillanic Acid/analogs & derivatives/pharmacology/therapeutic use ; Piperacillin/pharmacology/therapeutic use ; RNA, Ribosomal, 16S/chemistry/metabolism ; Sequence Analysis, RNA ; Sequence Homology, Nucleic Acid ; Transplantation, Homologous ; Treatment Outcome

INTRODUCTIONInstitutional febrile neutropenia (FN) management protocols were changed following the finding of a high prevalence of ceftazidime-resistant Gram-negative bacteraemia (CR-GNB) among haematology patients with FN. Piperacillin/tazobactam replaced ceftazidime as the initial empirical antibiotic of choice, whereas carbapenems were prescribed empirically for patients with recent extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae colonisation/infection. An audit was conducted to determine the impact of these changes.

METHODSData from all FN episodes between October 2008 and December 2010 were collected prospectively, with mid-November 2009 demarking the transition between pre-intervention and intervention periods. Outcomes measured included 30-day mortality post-development of FN and the presence of CR-GNB.

RESULTSThere were 427 FN episodes (200 in the pre-intervention period) from 225 patients. The prevalence of CRGNB was 10.3%, while the 30-day mortality was 4.7%, with no difference between pre-intervention and intervention periods. Independent risk factors for 30-day mortality included the presence of active haematological disease, vancomycin prescription and older age. Independent factors associated with initial CR-GNB were profound neutropenia, the presence of severe sepsis and active haematological disease. Recent ESBL-producing Enterobacteriaceae colonisation/infection was not predictive of subsequent CR-GNB (positive predictive value 17.3%), whereas a model based on independent risk factors had better negative predictive value (95.4%) but similarly poor positive predictive value (21.4%), despite higher sensitivity.

CONCLUSIONA change in the FN protocol did not result in improved outcomes. Nonetheless, the audit highlighted that empirical carbapenem prescription may be unnecessary in FN episodes without evidence of severe sepsis or septic shock, regardless of previous microbiology results.

Academic Medical Centers ; Adult ; Bacteremia ; complications ; drug therapy ; Carbapenems ; therapeutic use ; Ceftazidime ; pharmacology ; Drug Resistance, Multiple ; Febrile Neutropenia ; complications ; drug therapy ; Female ; Gram-Negative Bacteria ; Humans ; Male ; Middle Aged ; Penicillanic Acid ; administration & dosage ; analogs & derivatives ; Piperacillin ; administration & dosage ; Prevalence ; Prospective Studies ; Risk Factors ; Sepsis ; Singapore ; Treatment Outcome ; Universities