The crude mortality rate for HAP may be as high as 30 to70%, but many of these critically ill patients with HAP die oftheir underlying disease rather than pneumonia. The mortalityrelated to the HAP or “attributable mortality” has been estimatedto be between 33 and 50% in several case-matching studies ofVAP. Increased mortality rates were associated with bacteremia,especially withPseudomonas aeruginosaorAcinetobacterspecies,medical rather than surgical illness, and treatment with ineffectiveantibiotic therapy