Results of bronchoscopically obtained lower airway cultures from adult sickle cell disease patients with the acute chest syndrome.

Purpose: The purpose of this study was to determine the frequency of bacterial pneumonia as a cause of the acute chest syndrome in adult patients with sickle cell disease based on bronchoscopically obtained lower airway cultures and to describe the clinical, laboratory, and roentgenographic features of the acute chest syndrome in a series composed entirely of adult patients with sickle cell disease.
Patients and Methods: We reviewed the hospital records from 19 episodes (18 patients) of acute chest syndrome in adult patients with sickle cell disease (greater than or equal to 19 years of age) who had undergone flexible bronchoscopy to obtain lower airway cultures between January 1979 and July 1987. We also recorded patients' clinical, laboratory, and roentgenographic characteristics.
Results: Pneumonia was diagnosed in four of 19 episodes (21%) of acute chest syndrome based on quantitative cultures obtained at bronchoscopy. The pneumonia was caused by Streptococcus pneumoniae in two patients and mixed aerobic and anaerobic organisms in the other two patients. Forty-four of 45 blood cultures were negative, and one grew Staphylococcus epidermidis, which was considered a contaminant. Chest roentgenograms revealed lower lobe involvement in 17 episodes (90%) and bilateral infiltrates in six (32%). Pleural effusions occurred in seven episodes (37%), and pleural fluid samples obtained from five of these revealed sterile exudates.
Conclusion: The results of this retrospective study suggest that bacterial pneumonia is an uncommon cause of acute chest syndrome in adult patients with sickle cell disease. These results are consistent with previous retrospective studies using noninvasive techniques to diagnose pneumonia. Nevertheless, there appeared to be no reliable noninvasive variables that could accurately differentiate between patients with and without pneumonia and, consequently, we recommend empiric antibiotic therapy in addition to usual supportive care of these patients.