Nosocomial pneumonia in the intensive care unit acquired by mechanically ventilated versus nonventilated patients.

RATIONALE: Most current information on hospital-acquired pneumonia (HAP) is extrapolated from patients with ventilator-associated pneumonia (VAP). No studies have evaluated HAP in the intensive care unit (ICU) in nonventilated patients. OBJECTIVES: To compare pneumonia acquired in the ICU by mechanically ventilated versus nonventilated patients. METHODS: We prospectively collected 315 episodes of ICU-acquired pneumonia. We compared clinical and microbiologic characteristics of patients with VAP (n = 164; 52%) and nonventilator ICU-acquired pneumonia (NV-ICUAP; n = 151; 48%). Among NV-ICUAP patients, 79 (52%) needed subsequent intubation. MEASUREMENTS AND MAIN RESULTS: Compared with NV-ICUAP, patients with VAP were more severe (APACHE-II 17 ± 6 vs. 15 ± 5; P < 0.001) and pneumonia occurred later in the ICU (8 ± 8 vs. 5 ± 6 d; P < 0.001). Etiologic diagnosis (117, 71% vs. 64, 42%; P < 0.001), nonfermenting (28% vs. 15%; P = 0.009) and enteric gram-negative bacilli (26% vs. 13%; P = 0.006), and methicillin-sensitive Staphylococcus aureus (14% vs. 6%; P = 0.031) were more frequent in VAP, likely caused by more patients with lower respiratory tract samples cultured (100% vs. 84%; P < 0.001). However, in patients with defined etiology only, the proportion of pathogens was similar between groups, except for a higher proportion of Streptococcus pneumoniae in NV-ICUAP (P = 0.045). The hospital mortality also was similar. CONCLUSIONS: Despite a lower proportion of pathogens in NV-ICUAP compared with VAP, the type of isolates and outcomes are similar regardless of whether pneumonia is acquired or not during ventilation, indicating they may depend on patients' underlying severity rather than previous intubation. With the diagnostic techniques currently recommended by guidelines, both types of patients might receive similar empiric antibiotic treatment.

Validation of the American Thoracic Society-Infectious Diseases Society of America guidelines for hospital-acquired pneumonia in the intensive care unit.

BACKGROUND: The 2005 guidelines of the American Thoracic Society-Infectious Diseases Society of America Guidelines for Hospital for managing hospital-acquired pneumonia classified patients according to time of onset and risk factors for potentially drug-resistant microorganisms to select the empirical antimicrobial treatment. We assessed the microbial prediction and validated the adequacy of these guidelines for antibiotic strategy. METHODS: We prospectively observed 276 patients with intensive care unit-acquired pneumonia. We classified patients into group 1 (early onset without risk factors for potentially drug-resistant microorganisms; 38 patients) and group 2 (late onset or risk factors for potentially drug-resistant microorganisms; 238 patients). We determined the accuracy of guidelines to predict causative microorganisms and the influence of guidelines adherence in patients' outcome. RESULTS: Microbial prediction was lower in group 1 than in group 2 (12 [50%] of 24 vs 119 [92%] of 129; P < .001) mainly because of potentially drug-resistant microorganisms in 10 patients (26%) from group 1. Guideline adherence was higher in group 2 (153 [64%] vs 7 [18%]; P < .001). Guideline adherence resulted in more treatment adequacy than did nonadherence (69 [83%] vs 45 [64%]; P = .013) and a trend toward better response to empirical treatment in group 2 only but did not influence mortality. Reclassifying patients according to the risk factors for potentially drug-resistant microorganisms of the former 1996 American Thoracic Society guidelines increased microbial prediction in group 1 to 21 (88%; P = .014); all except 1 patient with potentially drug-resistant microorganisms were correctly identified by these guidelines. CONCLUSIONS: The 2005 guidelines predict potentially drug-resistant microorganisms worse than the 1996 guidelines. Adherence to guidelines resulted in more adequate treatment and a trend to a better clinical response in group 2, but it did not influence mortality.