Professor and Chief of Medicine; Institut Jules Bordet, Dpt of Medicine, 1 rue Héger--Bordet, 1000 BRUSSELS, BELGIUM
Results from clinical trials conducted over the past 15 years suggest the following:
- Early empiric therapy with broad-spectrum antibiotics directed against Gramnegative bacillary bacteremia is necessary in febrile granulocytopenic cancer patients.
- The level and dynamics of the granulocyte count are both extremely important in determining the clinical outcome.
- Most empiric antimicrobial regimens will require therapeutic modifications; these alterations are necessary and they contribute to a high overall success rate.
- Only microbiologically documented infections and especially bacteremias are useful for the investigation of initial response to antimicrobial regimens.
- The response rate of Gram-negative bacillary bacteremia is clearly influenced by the susceptibility of the causative pathogen to the b-lactam component of the empiric regimen; emergence or resistance to some b-lactam antibiotics is quite common and necessitated successive modifications of empiric regimens with time.
- The combination of anti-pseudomonal /S-lactam with an aminoglycoside is recommended as the standard for empiric therapy in febrile granulocytopenic cancer patients, especially in those with severe and persisent granulocytopenia who are suspected of having Gram-negative bacillary bacteremia; moderately neutropenic and/or asymptomatic patients may do well with monotherapy.
- Gram-positive pathogens have become a common cause of bacteremia in granulocytopenic cancer patients; the response rate to the usual empiric regimens is suboptimal and some of these patients may require early or empiric administration of vancomycin.
- Patients with severe granulocytopenia and protacted fever whose blood cultures remain negative have a high probability of presenting occult fungal infections especially if a possible clinical site appears; in these patients, empiric antifungal agents, namely amphotericin B, are probably indicated.
- In patients who have, in addition to neutropenia, a severe immunodepression, like those receiving allogenic bone marrow transplants, therapy directed against CMV might be helpful, especially in the case of pneumonitis.
