Prognostic factors previously shown to be associated with a poor outcome in HIV patients admitted to ICU are low CD4 count and advanced HIV disease stage, acute illness severity (SAPS I: simplified acute Table 1 Laboratory investigations on admission to Royal Free Hospital Haematology unit physiology score I; or APACHE II: acute physiology & chronic health evaluation II), and the need for, and duration of, mechanical ventilation whilst on the ICU [4] . In addition, a haematological malignancy also independently further confers a poor prognosis. Such patients typically have severely impaired host defences and the undertaking of invasive procedures, such as endotracheal intubation and central venous cannulation, carries a major risk of infection.