Elimination of S100B and renal function after cardiac surgery.

OBJECTIVES

To determine the biologic half-life of the S100B protein and to investigate if the elimination of S100B depends on glomerular filtration rate (GFR).

DESIGN

Prospective human study.

SETTING

University hospital.

PARTICIPANTS

Sixteen patients who underwent cardiac surgery with cardiopulmonary bypass.

INTERVENTIONS

Shed mediastinal blood (autotransfusion) was returned to the patients postoperatively and used to study the kinetics of S100B. Iohexol was infused simultaneously to estimate GFR. S100B was measured at 0, 20, 40, 60, and 180 minutes after infusion. Iohexol was measured at 180 and 240 minutes after infusion.

MEASUREMENTS AND MAIN RESULTS

S100B followed first-order kinetics, and the biologic half-life for S100B was determined to be 25.3 +/- 5.1 minutes. GFR was determined to be 63.8 +/- 34.4 mL/min. No correlation was found between GFR and S100B half-life.

CONCLUSIONS

The elimination of S100B after cardiac surgery is faster than reported earlier and not affected by a moderate decrease in GFR. This finding is important when evaluating S100B levels after cardiac surgery.