Mortality/Morbidity: Most patients with primary lung abscess improve with antibiotics, with cure rates documented at 90-95% (Bartlett, 1992). The mortality rate for patients with underlying immunocompromised status or bronchial obstruction who develop lung abscess may be as high as 75% (Pohlson, 1985). A retrospective study (Hirshberg, 1995) reported the overall mortality rate of lung abscesses caused by mixed gram-positive bacteria and gram-negative bacteria at approximately 20%.