Causes of myoglobinemia in surgery with artificial circulation
Korotkina, R.N.; Smirnov, L.S.; Zatsepina, N.E.; Lokshin, L.S.; Sinitsyn, G.S.; Karelin, A.A.
Anesteziologiia i Reanimatologiia 5: 63-65
2000
ISSN/ISBN: 0201-7563 PMID: 11220941 Document Number: 513652
Release of myoglobin (Mg) into the plasma and increase of its concentration during perfusion are a result of muscle cell injury during artificial circulation. High values of oxygen tension and hypothermia during cardiosurgery are sources of active oxygen forms damaging the biomembranes. We investigated release of Mg into the blood and relationship of this parameter with oxygen tension and depth of cooling. 95 patients were tested during open-heart surgery and operations on the main vessels: 25 perfusions at 30-32 degrees C, 41 at 26-29 degrees C, and 20 at 12-14 degrees C. The patients were divided into subgroups depending on arterial blood oxygen pressure. Myoglobin release into the blood was minimum under mild hypothermia and moderate PaO2. The degree of myoglobinemia increased with elevation in PaO2. As body temperature decreased, the concentration of Mg increased and differences between the groups with different PaO2 leveled. Critical myoglobinemia (30-fold vs. the initial value) was observed in the group with the deepest hypothermia (14 degrees C). Since the myocardium contains high amounts of Mg, it is clear that loss of this heme-containing protein impairs the feeding of the myocardium and, hence, decreases its contractility.