Nosocomial pneumonia in the intensive care unit acquired by mechanically ventilated versus nonventilated patients.
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.
Esperatti
Mariano
M
Institut Clínic del Tòrax, Hospital Clinic, IDIBAPS, Universitat de Barcelona, Spain.
Ferrer
Miquel
M
Theessen
Anna
A
Liapikou
Adamantia
A
Valencia
Mauricio
M
Saucedo
Lina Maria
LM
Zavala
Elisabeth
E
Welte
Tobias
T
Torres
Antoni
A
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