Abstract: |
Introduction: Since positive blood cultures are uncommon in patients with nosocomial pneumonia (NP), the responsible pathogens are usually isolated from respiratory samples. Studies on bacteremia associated with hospital-acquired pneumonia (HAP) have reported fatality rates of up to 50%. The purpose of the study is to compare risk factors, pathogens and outcomes between bacteremic nosocomial pneumonia (B-NP) and nonbacteremic nosocomial pneumonia (NB-NP) episodes. Methods: This is a prospective, observational and multicenter study (27 intensive care units in nine European countries). Consecutive patients requiring invasive mechanical ventilation for an admission diagnosis of pneumonia or on mechanical ventilation for > 48 hours irrespective of admission diagnosis were recruited. Results: A total of 2,436 patients were evaluated; 689 intubated patients presented with NP, 224 of them developed HAP and 465 developed ventilation-acquired pneumonia. Blood samples were extracted in 479 (69. 5%) patients, 70 (14. 6%) being positive. B-NP patients had higher Simplified Acute Physiology Score (SAPS) II score (51. 5 ± 19. 8 vs. 46. 6 ± 17. 5, P = 0. 03) and were more frequently medical patients (77. 1% vs. 60. 4%, P = 0. 01). Mortality in the intensive care unit was higher in B-NP patients compared with NB-NP patients (57. 1% vs. 33%, P < 0. 001). B-NP patients had a more prolonged mean intensive care unit length of stay after pneumonia onset than NB-NP patients (28. 5 ± 30. 6 vs. 20. 5 ± 17. 1 days, P = 0. 03). Logistic regression analysis confirmed that medical patients (odds ratio (OR) = 5. 72, 95% confidence interval (CI) = 1. 93 to 16. 99, P = 0. 002), methicillin-resistant Staphylococcus aureus (MRSA) etiology (OR = 3. 42, 95% CI = 1. 57 to 5. 81, P = 0. 01), Acinetobacter baumannii etiology (OR = 4. 78, 95% CI = 2. 46 to 9. 29, P < 0. 001) and days of mechanical ventilation (OR = 1. 02, 95% CI = 1. 01 to 1. 03, P < 0. 001) were independently associated with B-NP episodes. Bacteremia (OR = 2. 01, 95% CI = 1. 22 to 3. 55, P = 0. 008), diagnostic category (medical patients (OR = 3. 71, 95% CI = 2. 01 to 6. 95, P = 0. 02) and surgical patients (OR = 2. 32, 95% CI = 1. 10 to 4. 97, P = 0. 03)) and higher SAPS II score (OR = 1. 02, 95% CI = 1. 01 to 1. 03, P = 0. 008) were independent risk factors for mortality. Conclusions: B-NP episodes are more frequent in patients with medical admission, MRSA and A. baumannii etiology and prolonged mechanical ventilation, and are independently associated with higher mortality rates. |