PROGNOSTIC FACTORS IN LEGIONELLA PNEUMONIA

To the Editor:

We read with interest the study done by El-Ebiary and colleagues (1) that helped define those factors that might predict poor outcome and death in patients hospitalized with severe Legionella pneumophila pneumonia. Logistic regression analysis of their data suggested that an initial APACHE II score greater than 15 and/or a serum sodium level less than 136 mEg/L were the only independent factors related to death. Univariate analysis of the data also identified additional comorbid diseases and acute biochemical abnormalities, including renal failure, as significant contributors to mortality. Not surprisingly, the univariate analysis also found that the lack of appropriate specific treatment for L. pneumophila was related to poor outcome. Other studies support these observations (2).

The mortality rate of their patients with L. pneumophila pneumonia who required admission to the intensive care unit (ICU) was 30% (1). This mortality rate is higher than that reported in other series but may be related to the severity of illness that required intensive care. We share the authors' interest in prognostic factors associated with L. pneumophila infections and have found that the triad of L. pneumophila pneumonia, rhabdomyolysis, and renal failure is associated with a 40% mortality (5). We have observed that the patients who most frequently develop rhabdomyolysis with this infection are young males (mean age 49.3 years). Renal failure developed in 80% of patients with L. pneumophila pneumonia-associated rhabdomyolysis. The triad of L. pneumophila pneumonia, rhabdomyolysis, and rental failure, therefore, appears to have important prognostic implication.

We cannot determine from the narrative if the study cohort of El-Ebiary and colleagues was screened for rhabdomyolysis, but in light of the authors' observation that an elevated BUN and/or renal failure are associated with a worse outcome, we would encourage physicians who suspect L. pneumophila pneumonia to assess their patients for rhabdomyolysis. Early recognition and aggressive treatment with fluids and electrolytes may improve outcomes in these patients.

RYLAND P. BYRD, JR.

CHERYL LYNN FIELDS

THOMAS M. ROY

Department of Internal Medicine

James H. Quillen College of Medicine

East Tennessee College of Medicine

Johnson City, Tennessee

	References

1. El-Ebiary, M., X. Sarmiento, A. Torres, S. Nogue, E. Mesalles, M. Bodi, and J. Almirall. 1997. Prognostic factors of severe Legionella pneumonia requiring admission to ICU. Am. J. Respir. Crit. Care Med. 156: 1467-1472 [Abstract/Free Full Text].

2. Torres, A., J. Serra, Batles, A. Ferrer, P. Jimenez, R. Celis, E. Cobo, and R. Rodriguez-Roisin. 1991. Severe community-acquired pneumonia: epidemiology and prognostic factors. Am. Rev. Respir. Dis. 144: 311-318 .

3. Ortqvist, A., G. Sterner, and J. A. Nilsson. 1985. Severe community-acquired pneumonia requiring hospitalization: factors influencing need of intensive care treatment and prognosis. Scand. J. Infect. Dis. 17: 377-386 [Medline].

4. Torres, A., R. Aznar, J. M. Gatell, P. Jimenez, J. Gonzalez, A. Ferrer, R. Celis, and R. Rodriguez-Roisin. 1990. Incidence, risk, and prognosis factors of nosocomial pneumonia in mechanically ventilated patients. Am. Rev. Respir. Dis. 142: 523-528 [Medline].

5. Byrd, R. P. Jr., and T. M. Roy. 1998. Rhabdomyolsis and bacterial pneumonia. Respir. Med. 92: 358-364 [Medline].

From the Authors:

Thank you for your letter regarding our manuscript on prognosis factors of hospitalized Legionella pneumophila pneumonia (1). We have also observed rhabdomyolysis and renal failure in our patients with L. pneumophila. Since this variable occurred clearly only in 3 patients and all of them survived we did not include this factor in the analysis of prognosis.

We support the comment from Dr. Byrd and colleagues in regards to searching for rhabdomyolysis in patients with legionelosis. Nevertheless, the measurement of CPK blood levels is a routine practice in our respiratory intensive care unit for all admitted patients.

ANTONI TORRES

Hospital Clínic i Provincial de Barcelona

Barcelona, Spain

	References

1. El-Ebiary, M., X. Sarmiento, A. Torres, S. Nogue, E. Mesalles, M. Bodi, and J. Almirall. 1997. Prognostic factors of severe Legionella pneumonia requiring admission to ICU. Am. J. Respir. Crit. Care Med. 156: 1467-1472 .