[The elevation of serum creatine kinase-MB level in trauma patients: misleading impression of myocardial damage].

OBJECTIVE

To determine the frequency of increase of serum values, not of cardiac origin, of creatine kinase-MB (CK-MB) in trauma patients.

DESIGN

Prospective.

SETTING

University Hospital, Groningen, the Netherlands.

METHODS

51 trauma patients without chest injury (without myocardial contusion) but with (among others) soft tissue injuries, were included. At admission (time point t1) an ECG and chest X-ray were made and blood was collected for measurement of CK total, CK-MB activity and CK-MB mass. If the CK-MB activity/CK total fraction exceeded 3%, CK electrophoresis was performed. Blood analysis was repeated after 24 hours (t2).

RESULTS

CK-MB activity was elevated in 27 patients (53%) at t1 and in 3 (6%) at t2. The fraction CK-MB activity/CK total exceeded 3% in 96% and 33% of these patients at t1 and t2, respectively. In all these cases a CK-BB band was detected by electrophoresis (CK-BB interferes with the CK-MB activity measurement). CK-MB mass was elevated in 11 patients (22%) at t1 and in 19 (37%) at t2.

CONCLUSION

CK-MB was frequently elevated in trauma patients owing to skeletal muscle damage and to interference with CK-MB activity measurements. For the detection of myocardial damage in trauma patients, CK-MB measurements are of little use.