Increased mortality of ventilated patients with endotracheal Pseudomonas aeruginosa without clinical signs of infection
The patients who have Pseudomonas aeruginosa colonization do worse compared to patients who have ventilator associated pneumonia, according to this prospective study in Journal of CCM 1.
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. It was a prospective, single-center, observational, cohort study in a medical-surgical intensive care units in a tertiary care university hospital.
Patients: All adult patients requiring more than/ =48 hrs of mechanical ventilation and identified as having newly acquired P. aeruginosa in their lower respiratory tracts.
Results:
- Of 45 patients with high P. aeruginosa burdens ( more than/=1,000,000 cfu/mL in endotracheal aspirates; more than/=10,000 cfu/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 (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 (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.
Trivia: Do you know that P. aeruginosa is capable of growth in Diesel and Jet fuel where it is known as a hydrocarbon utilizing microorganism ("HUM bug") and also has the ability to grow at 42 degree Celsius?
References: Please click to get abstract
1. Increased mortality of ventilated patients with endotracheal Pseudomonas aeruginosa without clinical signs of infection - Critical Care Medicine. 36(9):2495-2503, September 2008
