Severe anaemia in childhood cerebral malaria is associated with profound coma.

BACKGROUND: Severe anaemia in children with cerebral malaria has been associated with respiratory distress secondary to lactic acidosis and/or hypoxia. The ensuing metabolic derangement may further depress the level of consciousness culminating in presentation with profound coma. This association has poorly been studied.
OBJECTIVE: To determine the relationship between profound coma at presentation and the presence of severe anaemia in children with cerebral malaria.
METHODS: This cross-sectional study involved 100 children with cerebral malaria who were consecutively recruited at admission in the Paediatric emergency unit of Mulago hospital in Uganda from July to December 2000. Clinical and laboratory evaluation was done using the hospital's guidelines for the management of severe malaria. The exposure factor of interest was severe anaemia (Hb < 5.0 g/dl) and occurrence of profound coma (Blantyre coma Scale 0) was the outcome measure.
RESULTS: Severe anaemia and profound coma were seen in 20% and 9% of the children respectively. Severe anaemia was independently associated with profound coma, adjusted OR 1.34 (CI 1.17 - 1.95), p = 0. 002 and age < 3 years, adjusted OR 1.42 (CI 1.13 - 1.54), p = 0.001). Thirty percent of those with severe anaemia had deep sighing (acidotic) breathing compared to only 15% of those with haemoglobin (Hb) > 5 g/dl, OR 1.21 (CI 0.90 - 1.64), p = 0.118. There was no association between the malaria parasite density and severe anaemia. A similar proportion of those with severe anaemia regained consciousness within 24 hours compared to those with Hb > 5 g/dl (30 vs 42.5%), OR 1.56 (0.65 - 3.71), p = 0.307.
CONCLUSIONS: The findings suggest that profound coma in cerebral malaria may not only result from primary malaria encephalitis but possibly also from a metabolic dysfunction due to severe anaemia.