Infection and transfusion therapy in acute leukaemia

Granulocytopenia is the single most important risk factor for infection in patients with acute leukaemia. There are limitations to the effective prophylaxis of infection in granulocytopenic patients, but practical measures include the management of the patient in a private hospital room, the requirement of all medical personnel and visitors to wash their hands carefully and to wear masks, restricting the patient to a low-bacteria diet devoid of fresh fruit, vegetables and salads, and the administration of oral antimicrobial agents for gastrointestinal decontamination. When fever develops, empirical therapy with a combination of an aminoglycoside plus an antipseudomonal beta-lactam should be started promptly. A double beta-lactam combination of cefoperazone or ceftazidime plus piperacillin can be substituted if nephrotoxicity is a concern. The addition of empirical intravenous amphotericin may be useful in patients who remain febrile and granulocytopenic on broad-spectrum antibiotics, especially if surveillance cultures indicate fungal colonization. Amphotericin is also the most reliable agent for the treatment of established fungal infections. Acyclovir is not recommended for prophylaxis in acute leukaemia patients but should be reserved for the treatment of well-documented and clinically significant herpes simplex viral infections. During periods of remission, most patients with AML remain free of infection except when they become granulocytopenic again during intensification or consolidation chemotherapy. On the other hand, children with ALL in remission may experience frequent infections unrelated to granulocytopenia as a consequence of their maintenance chemotherapy. Pneumocystis carinii, varicella zoster, and other viruses are common pathogens. Trimethoprim-sulphamethoxazole is effective prophylaxis against Pneumocystis carinii pneumonia in patients with ALL, while intravenous acyclovir is the drug of choice for treatment of varicella zoster infection. Transfusion therapy in the acute leukaemia patient is guided by the patient's peripheral blood counts and degree of sensitization to blood products. Generally, packed red blood cells are given in order to maintain the haematocrit at greater than 30%, while random-donor platelets are administered to keep the platelet count at greater than 20 X 10(9)/l. If refractoriness to platelet transfusions develops, HLA-matched platelets from family members or selected unrelated donors can be used. Similarly, washed or filtered red blood cells may be given to patients with previous and recurrent non-haemolytic febrile reactions to red blood cell transfusions.(ABSTRACT TRUNCATED AT 400 WORDS)