Management of chemical cyanosis by oxygen saturation readings

Chemical cyanosis is an oxygen transport deficiency produced by exposure to aromatic nitro- or animo-compounds. Evaluation of its severity by methemoglobin determinations defines the problem incompletely and is time consuming. Twenty-nine patients were studied over a five-year period by both methemoglobin level using classical laboratory methods and oxygen saturation level, using a reflection oximeter. The two results were found to bear an inverse linear relationship. Oxygen saturation may be determined easily and rapidly by the reflection oximeter method, and may be used safely as a guide to treatment of chemical cyanosis. No changes would have been made in medical management of any of the patients if the decisions had been made on the basis of the oxygen saturation level of less than 90% rather than the methemoglobin percentage of 10% or more.