List 2 causes (apart from cardiovascular or respiratory) of cyanosis.

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College Answer

List 2 causes (apart from cardiovascular or respiratory) of cyanosis.

•     Severe methemoglobinemia
•      Sulfhemoglobinemia
•     Hemoglobin mutation
•      Polycythaemia
•     Hypothermia / cold
•     High altitude

Discussion

The college presents us with a long and inventive list.

To this list, one can still add a few (obscure) differentials.

Here we go:

  • Methylene blue or indocyanine gree dye injection
  • Hemosiderosis
  • Excess consumption of colloidal silver
  • Chronic massive doses of amiodarone
  • Chlorpromazine

And, the causes suggested by the college:

  • Severe methemoglobinemia (though the blood in these cases is supposed to be chocolate brown)
  • Sulfhemoglobinemia
  • Hemoglobin mutation (eg. Haemoglobin Beth Israel, etc)
  • Polycythaemia
  • Hypothermia
  • High altitude

References

References

 

Nagel, Ronald L., et al. "Hemoglobin Beth Israel: A mutant causing clinically apparent cyanosis." New England Journal of Medicine 295.3 (1976): 125-130.

Walker, H. Kenneth, et al. "Cyanosis." in Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition (1990).