Serum Creatine Kinase and Lactate Dehydrogenase Changes After Anterior Approaches to the Thoracic and Lumbar Spine

Ten patients undergoing anterior approaches to the thoracic and lumbar spine had prospective determinations of serum creatine kinase, lactate dehydrogenase, and their myocardial-associated isoenzymes (CK-MB and the LD-1/LD-2 ratio). None of these patients experienced postoperative myocardial infarction. Skeletal muscle injury associated with anterior spinal surgery resulted in significant elevations of serum CK-MB on postoperative Day 1; however, the LD-1/LD-2 ratio did not change significantly. Although false-positive elevations of serum CK-MB occurred, no patient had a CK-MB value exceeding 50 IU/liter combined with an LD-1/LD-2 ratio exceeding 1.0 (so-called "flipped LD" pattern). In evaluating suspected postoperative myocardial infarction, the authors recommend determining the isoenzymes of both serum creatine kinase and lactate dehydrogenase. In postoperative patients, elevations of CK-MB exceeding 50 IU/liter combined with an LD-1/LD-2 ratio exceeding 1.0 should not be attributed to skeletal muscle injury alone after anterior approaches to the thoracic and lumbar spine.