title: Nosocomial pneumonia in the intensive care unit acquired by mechanically ventilated versus nonventilated patients.
abstract: BACKGROUND
  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.
  
  
  OBJECTIVE
  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.
  
  
  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.
authors.affiliation: Institut Clínic del Tòrax, Hospital Clinic, IDIBAPS, Universitat de Barcelona, Spain.
authors.forename: Mariano
authors.initials: M
authors.lastname: Esperatti
authors.forename: Miquel
authors.initials: M
authors.lastname: Ferrer
authors.forename: Anna
authors.initials: A
authors.lastname: Theessen
authors.forename: Adamantia
authors.initials: A
authors.lastname: Liapikou
authors.forename: Mauricio
authors.initials: M
authors.lastname: Valencia
authors.forename: Lina Maria
authors.initials: LM
authors.lastname: Saucedo
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Zavala
authors.forename: Tobias
authors.initials: T
authors.lastname: Welte
authors.forename: Antoni
authors.initials: A
authors.lastname: Torres
mesh_terms: D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D005858:Germany / Q000453:epidemiology; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D015994:Incidence; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000453:epidemiology* / Q000382:microbiology; D053717:Pneumonia, Ventilator-Associated / Q000453:epidemiology / Q000209:etiology*; D011446:Prospective Studies; D012307:Risk Factors; D012122:Ventilators, Mechanical / Q000382:microbiology