Rapid multicomponent analysis of hemoglobin derivatives for controlled antidotal use of methemoglobin-forming agents in cyanide poisoning.

When cyanide poisoning is treated with a methemoglobin-forming agent, oxidative metabolism is protected at the expense of the oxygen capacity of the blood. The affinity of methemoglobin for CN- is high enough to compete with cytochrome oxidase, which protects the latter from becoming blocked, but all hemoglobin used for this purpose is lost for the transport of oxygen. Therefore, the fractions of the various hemoglobin derivatives present in the blood should be carefully monitored during this kind of treatment. After we had developed a multiwavelength spectrophotometric method for this purpose, we studied the feasibility of using a modified commercial six-wavelength hemoglobin photometer (Radiometer OSM3) for easy and rapid analysis of methemoglobin and methemoglobin cyanide in small samples of blood. All conditions appeared to be fulfilled for the construction of a practical multiwavelength photometer for reliably monitoring methemoglobin therapy in patients with cyanide poisoning, even in the presence of carboxyhemoglobin, as often occurs in fire victims.