Study examines correlation between point-of-care monitors, lactate flux during CEA procedure

Aug 25 2010

CAS Medical Systems, Inc. (Nasdaq:CASM) today announced a new study to be published in the Canadian Journal of Anesthesia. The study from researchers in the Departments of Anesthesia and Surgery, at the University of Manitoba, Winnipeg, MB, Canada examined the correlation between a variety of point-of-care monitors and lactate flux, an indicator of metabolic stress during carotid endarterectomy (CEA).

There are approximately 140,000 CEA procedures performed in the U.S. every year. The ability to assess the brain-at-risk during CEA under general anesthesia remains a major clinical challenge. A monitor that quickly alerts anesthesiologists in real-time of the potential for cerebral injury during CEA would be of considerable value to enhance the safety of this procedure. The authors note that "the ideal point-of-care monitor specific to anesthesia can accurately predict when an organ is at risk during an operative procedure so that a therapeutic intervention can be initiated to prevent further or permanent damage to that organ."

The authors theorize that the body introduces lactate into the brain to serve as a critically important fuel for cerebral metabolism when the brain is faced with diminished oxygen supply, such as occurs during cross clamp in the CEA procedure. Results from this observational study suggest that large changes in cerebral tissue saturation (SctO2) as measured by the FORE-SIGHT^® Absolute Oximeter may provide a surrogate for measuring lactate changes during the CEA procedure.

When assessing point-of-care monitors for correlation and identification of lactate changes, the authors suggest that the non-invasive FORE-SIGHT monitor may aid in the management of patients undergoing CEA during general anesthesia. Authors found that FORE-SIGHT Absolute Cerebral Oximetry "…correlated well with lactate flux – indicating the brain under stress."  While FORE-SIGHT responded "within seconds" to lactate flux, the other tested point-of-care monitoring techniques (i.e., BIS, DSA and EEG) either failed to correlate or were very slow. The study concluded that alternative point-of-care monitors, such as processed EEG, either by EEGo or BIS, were "not quantitative enough or sensitive enough to indicate patients at risk."