The crude mortality rate for HAP may be as high as 30-70%, but many critically ill patients with HAP die because of their underlying disease rather than pneumonia. The mortality related to HAP or “attributable mortality” has been estimated to be 33-50% in several case-matching studies of VAP. Increased mortality rates were associated with bacteremia, especially with Pseudomonas aeruginosa or Acinetobacter species, medical rather than surgical illness, and treatment with ineffective antibiotic therapy (46,47). Other studies using similar methodology failed to identify any attributable mortality due to VAP, suggesting a variable outcome impact according to the severity of underlying medical conditions (48-50).