A patient who has been receiving mechanical ventilation for a week has just developed VAP. How does this epidemiologic variable (time of onset) affect patient treatment and outcome?

A. no different than if the patient developed VAP after 2 days of mechanical ventilation
B. involvement of multidrug resistant pathogens and increased mortality
C. associated with antibiotic-sensitive bacteria, but increased mortality
D. connected with variably sensitive bacteria and better prognosis

?ANS: B
A. Incorrect response: See explanation B.
B. Correct response: The time of onset is an important epidemiologic variable and risk factor for specific pathogens in patients with VAP. Early-onset VAP, onset within the first 4 days of hospitalization, usually carries a better prognosis and is more likely to be caused by antibiotic-sensitive bacteria. Late-onset VAP, after 4 days of hospitalization, is more likely to be caused by multidrug resistant pathogens, and is associated with increased mortality and morbidity.
C. Incorrect response: See explanation B.
D. Incorrect response: See explanation B