Currently, no reliable non-invasive methods of monitoring the severity of in vivo cyanide toxicity and resulting physiological responses. We developed a Broadband Diffuse Optical Spectroscopy (DOS) prototype system that combines multi-frequency domain photon migration with near infrared spectroscopy to measure bulk tissue absorption and scattering between 600 and 1000nm wavelengths. This system was used to optically monitor CN toxicity and treatment using Hydroxocobalamin (OHCO) by simultaneously quantifying oxy- and deoxy- hemoglobins, tissue saturation (StO2), and redox states of cytochrome C oxidase.
A cyanide toxicity and treatment model using New Zealand White (NZW) rabbits we developed was used. A DOS probe was placed on the shaved inner thigh over the muscle of the right hind leg. A sodium cyanide solution of 6mg in 60cc saline was infused over thirty minutes at a rate of 1.4cc per minute (4.2 mg total). Resultant CN toxicity was then reversed by infusing Hydroxocobalamin at a rate of 0.5cc per minute (700 mg total). DOS measurements and concurrent physiological measurements including arterial and venous blood gases, CO, and oxygen saturation, were obtained throughout the experiment. The non-invasive DOS methods were compared to traditional invasive methods.
Broadband DOS measurements were able to monitor the progression of cyanide toxicity and subsequent treatment with OHCO noninvasively. By monitoring the tissue oxygen profile (OxyHb and DeOxyHb concentrations and STO2) and the concentration changes of cytochrome c oxidase redox states, we successfully monitored the severity of in vivo cyanide toxicity and therapeutic effects of OHCO.
DOS enables non-invasive detection of CN toxicity and reversal using OHCO. DOS provides an opportunity for quantitative non-invasive monitoring for a range of clinical conditions where specific solute concentration measurements may be important.
DOS can be a effective method for in vivo non-invasive monitoring of diseases associated with hemoglobin saturation, or cytochrome oxidase dysfunction such as cyanide toxicity, and could be also be used to monitor a wide range of chromophores that absorb in the near infrared region.
K Kreuter, Product/procedure/technique that is considered research and is NOT yet approved for any purpose. Unapproved procedure-use of hydroxocobalamin for treatment of cyanide poisoning.