Hemolysis is not uncommon during cardiovascular surgery, resulting in elevated circulating levels of cell-free oxyhemoglobin (FHb). The effect of hemolysis on intestinal microcirculation and gut wall integrity is unclear.
A research article to be published on January 14, 2011 in the World Journal of Gastroenterology addresses this question. An animal model was developed with FHb plasma levels similar to those found during cardiovascular surgery. The influence of circulating FHb on intestinal microcirculation was studied using fluorescent microspheres and intestinal injury was evaluated both biochemically and histopathologically.
This is the first study to show a decreased intestinal microcirculatory blood flow during elevated levels of circulating FHb, resulting in intestinal damage. Moreover, a strong correlation between elevated circulating FHb and intestinal injury is revealed.
Therefore, circulating FHb levels should be closely monitored in clinical practice when treating these patients, who are at risk of developing gastrointestinal complications.