Medicine of the Future in America

Legionella pneumophila (8)

Fifteen patients with Legionnaires’ disease (50 percent) had respiratory failure, whereas only 19 of84 (22 percent) patients with pneumococcal pneumonia (p<0.01) had it. Some clinical, laboratory, radiographic and evolutive features of patients with Legionnaires’ disease are reflected on Table 3 depending on whether they did or did not have respiratory failure. Development of respiratory failure was associated with involvement of several lobes on the chest roentgenogram and isolation of L pneumophila in any clinical specimen (p<0.05).
The overall mortality of community-acquired pneumonia due to L pneumophila was 10 percent, but in those cases that were not treated with erythromycin initially it was 27 percent. The mortality for patients with pneumococcal pneumonia was 5 percent. The three patients who died suffered from heart disease, had multiple lobes involved, developed respiratory failure, did not receive erythromycin initially, and in all cases, L pneumophila was isolated.
Discussion
The precise etiology of community-acquired pneu monia is unknown in as many as 50 percent of cases,* but recently Levy and colleagues observed that the prognosis was identical whether a bacteriologic diagnosis was made or not.

Table 3—Community-Acquired Pneumonia Caused by L pneumophila: Comparison between Patients with and without Respiratory Failure

Salient Features Group A (with Respiratory Failure) (%) Group B (without Respiratory Failure) (%) PValue
No. of Patients 15 15
Underlying disease 80 73
Hyponatremia 73 40
Elevation of transaminase 46 40
values 20
Elevation of creatinine 33
level 13
Multiple lobes affected 53 46 <0.05
Positive culture 93 <0.05
No. of deaths 3 (20)
This entry was posted in Pulmonary function and tagged erythromycin, etiology, legionnaires disease, Pneumonia, respiratory failure.
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