Key Learning Points

1. 1. Anaemia in critical illness is often multifactorial. Careful assessment of history and trend of haemoglobin and full blood count parameters can help direct further investigations.

2. 2. Restrictive red cell transfusion strategies are associated with lower mortality in the intensive care unit. The default transfusion threshold is 70 g/l unless there are specific conditions, e.g. cardiac disease.

3. 3. Thrombocytopenia in critical illness is common and often reflects abnormal physiology; therefore, the mainstay of management is to treat the underlying cause.

4. 4. Patients with sickle cell disease (SCD) have highly variable clinical presentations due to different sickle genotypes and clinical heterogeneity within each genotype. Therefore, the severity of previous sickle cell crises is the best indicator of severity of their condition. Management should be led by haematologists with experience in SCD.

5. 5. Therapeutic plasma exchange removes harmful large molecules from the circulation. Protocols vary according to indication; therefore, management should be directed by the clinical team with expertise in the underlying condition.