Characteristics of Nonbacteremic Pseudomonas Pneumonia

The distinguishing clinical course, laboratory findings, and morbid anatomy of nonbacteremic pseudomonas pneumonia is described. These infections occurred in ten patients (eight of whom ultimately died) who were admitted to the Detroit General (Receiving) Hospital during a 30-month surveillance from 1963 through 1965. Chronic lung or heart disease was a cardinal predisposing condition that apparently increased their susceptibility to infection with Bacillus pyocyaneus. In a few, prior administration of antibiotics may have contributed to colonization of upper respiratory passages by Pseudomonas.

Apprehension, confusion, cyanosis, relative bradycardia, reversal of the usual diurnal temperature curve, and abnormal liver and kidney function were striking. At X ray a diffuse nodular lower lobe bronchopneumonia with microabscesses was seen. Pathologically, microabscesses and focal hemorrhage were noted. There was no necrotizing bacillary vasculitis nor thrombosis of pulmonary vessels as has been described when the lungs are involved by pseudomonas bacteremia. The severe toxicity and the pathogenesis of the pulmonary lesions in these patients are probably induced by local production and subsequent circulation of elastase, hemolysin, lecithinase, and lipase elaborated by these bacilli.