Page 60 - 80 guidelines for the treatment of malaria_opt
P. 60

nd
              Guidelines for the treatment of malaria – 2  edition


            anaemia where there has been adaptation and a compensatory right shift in the oxygen
            dissociation curve.

            8.10.4 Exchange blood transfusion

            There have been many anecdotal reports and several series claiming benefit for exchange
            blood transfusion (EBT) in severe malaria but no comparative trials, and there is no
            consensus on whether it reduces mortality or how it might work. The rationale for EBT
            has been variously proposed as:
            •  removing infected red blood cells from the circulation and, therefore, lowering the
               parasite burden (although only the circulating relatively non-pathogenic stages are
               removed; this is also achieved rapidly with artemisinin derivatives);
            •  reducing rapidly both the antigen load and the burden of parasite-derived toxins,
               metabolites and toxic mediators produced by the host; and
            •  replacing the rigid unparasitized red cells by more deformable cells and, therefore,
               alleviating microcirculatory obstruction.

            Exchange blood transfusion requires intensive nursing care and a relatively large volume
            of blood, and it carries significant risks. There is no consensus on the indications, benefits
            and dangers involved, or on practical details such as the volume of blood that should
            be exchanged. It is, therefore, not possible to make any recommendation regarding the
            use of EBT.

            8.10.5   Use of anticonvulsants
            The treatment of convulsions in cerebral malaria with intravenous (or, if this is not
            possible, rectal) benzodiazepines or intramuscular paraldehyde is similar to that for
            repeated seizures from any cause. In a large double-blind placebo-controlled evaluation
            of a single prophylactic intramuscular injection of 20 mg/kg body weight of phenobarbital
            (phenobarbitone) in children with cerebral malaria there was a reduction in seizures,
            but a significant increase in mortality in phenobarbital recipients. This resulted from
            respiratory arrest, and it was associated with additional benzodiazepine use. A 20 mg/kg
            dose of phenobarbital should not be given without respiratory support, but whether
            a lower dose would be effective and safer, or whether if ventilation is given, mortality
            would not be increased is not known. In the absence of further information, prophylactic
            anticonvulsants are not recommended.

            8.10.6   Concomitant use of antibiotics
            The threshold for administering antibiotic treatment should be low in severe malaria.
            Septicaemia and severe malaria are associated and there is a diagnostic overlap, particularly
            in children. Unexplained deterioration may result from a supervening bacterial infection.
            Although enteric bacteria (notably Salmonella) have predominated in most trial series,
            a variety of bacteria have been cultured from the blood of patients diagnosed as having
    46
   55   56   57   58   59   60   61   62   63   64   65