[en] OBJECTIVE: To investigate the frequency and outcomes of ventilated patients with newly acquired large burdens of Pseudomonas aeruginosa and to test the hypothesis that large quantities of bacteria are associated with adverse patient outcomes. DESIGN: A prospective, single-center, observational, cohort study. SETTING: Medical-surgical intensive care units in a tertiary care university hospital. PATIENTS: All adult patients requiring > or = 48 hrs of mechanical ventilation and identified as having newly acquired P. aeruginosa in their lower respiratory tracts between October 2002 and April 2006. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Daily surveillance cultures of endotracheal aspirates were performed on patients intubated > or = 48 hrs; 69 patients with newly acquired P. aeruginosa were enrolled. Daily P. aeruginosa quantification of endotracheal aspirates was performed; clinical signs of infection were noted. Of 45 patients with high P. aeruginosa burdens (> or = 1,000,000 colony-forming units/mL in endotracheal aspirates; > or = 10,000 colony-forming units/mL in bronchoalveolar-lavage), 17 (37.8%) patients did not meet clinical criteria for ventilator-associated pneumonia and had a statistically significant higher risk of death (adjusted hazard ratio, 37.53; 95% confidence interval, 3.79-371.96; p = 0.002) when compared with the patients who had P. aeruginosa ventilator-associated pneumonia. When excluding the ten patients who had ventilator-associated pneumonia attributed to bacteria other than P. aeruginosa or attributed to multiple bacteria including P. aeruginosa, the risk of death remained statistically significant (adjusted hazard ratio, 23.98; 95% confidence interval: 2.49-230.53; p = 0.006). Furthermore, more patients with high P. aeruginosa burdens secreted the type III secretion facilitator protein, PcrV (p = 0.01). CONCLUSIONS: A group of patients with large burdens of P. aeruginosa who did not meet clinical criteria for ventilator-associated pneumonia had an increased risk of death when compared with patients who had high P. aeruginosa burdens and met ventilator-associated pneumonia criteria. Patients with high P. aeruginosa burden seemed to possess more virulent strains.
Disciplines :
Anesthesia & intensive care
Author, co-author :
Zhuo, Hanjing
Yang, Katherine
Lynch, Susan V.
Dotson, Rachel H.
Glidden, David V.
Singh, Gaurav
Webb, W. Richard
Elicker, Brett M.
Garcia, Oscar
Brown, Ronald
Sawa, Yoriko
Misset, Benoît ; Centre Hospitalier Universitaire de Liège - CHU > Service de Soins Intensifs
American Thoracic Society, Infectious Disease Society of America: 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
Garnacho-Montero J, Sa-Borges M, Sole-Violan J, et al: Optimal management therapy for Pseudomonas aeruginosa ventilatorassociated pneumonia: An observational, multicenter study comparing monotherapy with combination antibiotic therapy. Crit Care Med 2007; 35:1888-1895
Fagon JY, Chastre J, Wolff M, et al: Invasive and noninvasive strategies for management of suspected ventilator-associated pneumonia. A randomized trial. Ann Intern Med 2000; 132:621-630
Song Y, Lynch SV, Flanagan J, et al: Increased plasminogen activator inhibitor-1 concentrations in bronchoalveolar lavage fluids are associated with increased mortality in a cohort of patients with Pseudomonas aeruginosa. Anesthesiology 2007; 106: 252-261
Roy-Burman A, Savel RH, Racine S, et al: Type III protein secretion is associated with death in lower respiratory and systemic Pseudomonas aeruginosa infections. J Infect Dis 2001; 183:1767-1774
Hauser AR, Cobb E, Bodi M, et al: Type III protein secretion is associated with poor clinical outcomes in patients with ventilator-associated pneumonia caused by Pseudomonas aeruginosa. Crit Care Med 2002; 30: 521-528
Sawa T, Yahr TL, Ohara M, et al: Active and passive immunization with the Pseudomonas V antigen protects against type III intoxication and lung injury. Nat Med 1999; 5:392-398
Kurahashi K, Kajikawa O, Sawa T, et al: Pathogenesis of septic shock in Pseudomonas aeruginosa pneumonia. J Clin Invest 1999; 104:743-750
National Nosocomial Infections Surveillance (NNIS) System report, data summary from January 1990-May 1999, issued June 1999. Am J Infect Control 1999; 27:520-532
Chastre J, Fagon JY: Ventilator-associated pneumonia. Am J Respir Crit Care Med 2002; 165:867-903
Crouch Brewer S, Wunderink RG, Jones CB, et al: Ventilator-associated pneumonia due to Pseudomonas aeruginosa. Chest 1996; 109: 1019-1029
Heyland D, Dodek P, Muscedere J, et al: A randomized trial of diagnostic techniques for ventilator-associated pneumonia. N Engl J Med 2006; 355:2619-2630
Marquette CH, Copin MC, Wallet F, et al: Diagnostic tests for pneumonia in ventilated patients: Prospective evaluation of diagnostic accuracy using histology as a diagnostic gold standard. Am J Respir Crit Care Med 1995; 151:1878-1888
Tsiotou AG, Sakorafas GH, Anagnostopoulos G, et al: Septic shock: Current pathogenetic concepts from a clinical perspective. Med Sci Monit 2005; 11:RA76-RA85
Augustin DK, Song Y, Baek MS, et al: Presence or absence of lipopolysaccharide O antigens affects type III secretion by Pseudomonas aeruginosa. J Bacteriol 2007; 189: 2203-2209
Sutterwala FS, Mijares LA, Li L, et al: Immune recognition of Pseudomonas aeruginosa mediated by the IPAF/NLRC4 inflammasome. J Exp Med 2007; 204:3235-3245
Schultz MJ, Millo J, Levi M, et al: Local activation of coagulation and inhibition of fibrinolysis in the lung during ventilator associated pneumonia. Thorax 2004; 59: 130-135
Flanagan JL, Brodie EL, Weng L, et al: Loss of bacterial diversity during antibiotic treatment of intubated patients colonized with Pseudomonas aeruginosa. J Clin Microbiol 2007; 45:1954-1962
Fabregas N, Ewig S, Torres A, et al: Clinical diagnosis of ventilator associated pneumonia revisited: Comparative validation using immediate post-mortem lung biopsies. Thorax 1999; 54:867-873
Torres A, el-Ebiary M, Padro L, et al: Validation of different techniques for the diagnosis of ventilator-associated pneumonia. Comparison with immediate postmortem pulmonary biopsy. Am J Respir Crit Care Med 1994; 149:324-331
Delclaux C, Roupie E, Blot F, et al: Lower respiratory tract colonization and infection during severe acute respiratory distress syndrome: Incidence and diagnosis. Am J Respir Crit Care Med 1997; 156:1092- 1098
Luyt CE, Chastre J, Fagon JY: Value of the clinical pulmonary infection score for the identification and management of ventilator-associated pneumonia. Intensive Care Med 2004; 30:844-852
Fagon JY, Chastre J, Hance AJ, et al: Evaluation of clinical judgment in the identification and treatment of nosocomial pneumonia in ventilated patients. Chest 1993; 103: 547-553
Wu CL, Yang D, Wang NY, et al: Quantitative culture of endotracheal aspirates in the diagnosis of ventilator-associated pneumonia in patients with treatment failure. Chest 2002; 122:662-668
Graat ME, Choi G, Wolthuis EK, et al: The clinical value of daily routine chest radiographs in a mixed medical-surgical intensive care unit is low. Crit Care 2006; 10:R11