Methaemalbumin: a diagnostic surrogate for methaemoglobinaemia and treatment with red cell exchange in a patient with thalassaemia.

A man in his 30s with alpha thalassaemia (four-alpha globin gene deletion) presented with 1 week of shortness of breath and 1 month of general malaise. Pulse oximetry monitoring revealed low peripheral oxygen saturation of approximately 80% despite maximal high-flow nasal cannula oxygen (fractional inspired oxygen 1.0-60 L/min flow).