Methaemoglobinaemia occurring in dental practice

For the medical management of methaemoglobinaemia, see Methaemoglobinaemia.

Methaemoglobinaemia occurs when haemoglobin oxidises to methaemoglobin, resulting in a reduced oxygen-carrying capacity of blood cells, functional anaemia and impaired delivery of oxygen to the tissues. Methaemoglobinaemia can occur after exposure to oxidants, and is a rare adverse effect of local anaesthetics. Onset can occur within minutes or be delayed. Slate-grey skin discolouration and cyanosis are the most distinct features; other signs and symptoms include headache, light-headedness, shortness of breath, fatigue and tachycardia. Blood may appear to be dark red or brown in colour, and can remain so even after administering oxygen.

Methaemoglobinaemia can be life threatening and requires emergency referral to hospital. In dental practice, follow the advice in Management of methaemoglobinaemia in dental practice for first-aid management of patients with methaemoglobinaemia.