Acute lung injury and acute respiratory distress syndrome in malaria

Malaria is an important treatable cause of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) in the tropics and in the returning traveller in the non-endemic areas. ARDS is an important complication in severe, complicated falciparum malaria and has been described in P. vivax and P. ovale malaria also. Malarial ALI/ARDS is more common in adults than in children. Pregnant women and non-immune individuals are more prone to develop this condition. Increased alveolar capillary permeability resulting in intravascular fluid loss into the lungs appears to be the key pathophysiologic mechanism. In malaria, ARDS can develop either at initial presentation or after initiation of treatment when the parasitaemia is falling and the patient is improving. Patients present with acute onset dysnoea that can rapidly progress to respiratory failure. The diagnosis of malaria is confirmed by slide microscopy supported by the use of rapid antigen tests. Patients with malarial ARDS should be managed in an intensive care unit. Careful attention must be paid to haemodynamic stabilisation and optimising fluid balance. Currently, specific treatment choices for malaria include parenteral artemisinins or intravenous quinine along with doxycycline. Respiratory failure requires endotracheal intubation and assisted mechanical ventilation. Co-existent bacterial sepsis is frequently present in patients with malarial ARDS eventhough an obvious focus may not be evident. Appropriate broad spectrum antibiotic therapy must be started when there is a clinical suspicion after procuring the microbiological specimens. ARDS in malaria is a disease with a high mortality. Early diagnosis, institution of specific antimalarial treatment and assisted ventilation can be life-saving.