In October 2005, surgeons operating on a 42-year-old Canadian man at Vancouver’s St. Paul’s Hospital got a shock when they discovered dark-green blood coursing through his arteries, like Star Trek’s Mr Spock.
Stunned, the medical team immediately sent his blood for analysis. The test revealed the blood discolouration was caused by sulfhaemoglobinaemia, which occurs when a sulphur atom gets incorporated into the oxygen-carrying haemoglobin protein in blood.
Doctors suspected that the patient’s arguably excessive intake of migraine medication sumatriptan, which contains a sulfonamide group, caused his sulfhaemoglobinaemia.
The patient was already a bit of a medical departure. He had fellen asleep in a kneeling position, which caused compartment syndrome and a buildup of pressure in his legs.
Compartment syndrome is a condition in which increased pressure within one of the body’s anatomical compartments results in insufficient blood supply to tissue within that space. There are two main types: acute and chronic. Compartments of the leg or arm are most commonly involved.
Treatment is by surgery to open the compartment, completed in a timely manner. If not treated within six hours, permanent muscle or nerve damage can result.
The patient recovered uneventfully, and stopped taking sumatriptan after discharge. When seen five weeks after his last dose, he was found to have no sulfhaemoglobin in his blood.
The Canadian doctors explained that sulfhaemoglobinaemia usually goes away as red blood cells regenerate. While, in very extreme cases a transfusion might be necessary.
They further explained that sulfhaemoglobinaemia is so rare that we don’t have a perfect understanding how it happens, but some drug donates a sulphur group that binds to the hemoglobin molecule and prevents it from binding to oxygen, and that gives it the green colour.
Green blood can be found in some forms of lifesuch as some marine worms. But it is a condition normally associated with science fiction and not medical texts. As Mr Spock’s green Vulcan blood was supposed to have been caused by copper replacing the iron in haemoglobin.
Apart from the “green blood syndrome”, there are various others rare medical conditions like methemoglobinemia and etc. which turn human’s blood into blue. Your can read about these strange cases here.