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Bacteremia, Streptococcus mitis, Neutropenia, Adult respiratory distress syndrome
During the last decades, gram-positive bacteremia has increased dramatically. Gram-positive cocci are the most frequent cause of nosocomial bloodstream infections. Among Gram-positive cocci, Viridans streptococci are a common cause of bacteremia in cancer patients with neutropenia, causing serious complications such as pneumonia, septic shock, and ARDS [1-6]. We present a series of cases of VGS bacteremia complicated with ARDS; early initiation of corticosteroids resulted in complete recovery.
Materials and Methods
A retrospective chart review of patients with hematologic malignancy diagnosed with VGS bacteremia admitted to the Moffitt Cancer Center in Tampa, Florida between 1/1/2001 and 4/1/2012 was completed. Data was collected about respiratory symptoms, diagnosis of adult respiratory syndrome, results of blood cultures, medications received and outcome.
In this study, 70 cases of VGS bacteremia in neutropenic patients were reviewed. The most common adverse event of VGS bacteremia in this group of patients is the development of serious pulmonary complications such as ARDS. In our study, 7 patients developed ARDS. The most common identifies streptococcal species was Streptococcus mitis, isolated in 4 of 7 patients. All 7 patients received corticosteroids early with the onset of respiratory failure. The most commonly prescribed regimen was methylprednisolone 60 mg intravenously every 12 hour for an average of 3 days. All patients received comparable supportive care, appropriate antibiotics, ventilation and hemodynamic support. All patients (100 %) recovered from respiratory failure after receiving corticosteroids. There were no significant adverse events attributable to steroids use.
Streptococcus mitis is the species most frequently isolated from the patients who have developed ARDS from Streptococcus viridans bacteremia. Our data suggest that the early administration of corticosteroids to neutropenic patients who develop early signs of respiratory failure with VGS bacteremia can prevent the progression of ARDS and improve mortality. Moderate doses of steroids with short duration of administration were not associated with significant adverse events in our case series. While the use of corticosteroids in this setting has been described in the literature since the early 1990s, there remains a scarcity of data and our study help shed some light on this area. Moreover there is little recognition among clinicians of the association between ARDS and VGS bacteremia (particularly mitis species in neutropenic cancer patients) and thus this treatment modality is used late in the course of illness which may reduce benefit. Further studies are warranted to validate these findings and to further examine the utility of preemptive use of corticosteroids in cancer patients who develop VGS bacteremia, in regards to ARDS incidence reduction.