Pneumonia in the surgical intensive care unit: factors determining successful outcome.

A review of 85 consecutive patients who acquired pneumonia in a surgical intensive care unit revealed several parameters associated with successful treatment. Fifty-five patients (65%) recovered after a single course of antimicrobial therapy. Statistical analysis demonstrated significant differences between those treated successfully and those whose therapy failed during the duration of intubation (7.2 +/- 1.5 days versus 29.3 +/- 4.3 days), duration of ventilation (6.7 +/- 1.4 days versus 14.8 +/- 3.2 days), and the alveolar-arterial oxygen gradient on the day of diagnosis (215 +/- 23 mm Hg versus 343 +/- 33 mm Hg, all p < 0.01). Multiple antimicrobial resistance was uncommon in bacteria isolated on initial culture but occurred in two thirds of patients with treatment failures. Pneumonia due to Pseudomonas aeruginosa and Staphylococcus aureus were associated with the highest rate of treatment failure, which were 56% and 45%, respectively.