RESUMO
OBJECTIVE: Pediatric cardiac surgery is associated with a temporary rise in cardiac troponin T (cTnT) during the postoperative period. We examined whether dexamethasone given before cardiopulmonary bypass has myocardial protective effects as assessed by the postoperative production of cTnT. DESIGN AND SETTING: Prospective randomized interventional study in the pediatric intensive care unit in a university hospital. INTERVENTIONS: Patients were randomly allocated to act as controls or receive a single dose of dexamethasone (1 mg/kg) during induction of anesthesia. MEASUREMENTS AND RESULTS: cTnT was measured four times postoperatively: immediately after admission to the pediatric intensive care unit (PICU) and 8, 15, and 24 h thereafter. The two groups had similar mean cTnT concentrations on PICU admission: those receiving dexamethasone 1.85 ng/ml (1.55-2.15) and those not receiving it 2 ng/ml (95% confidence interval 1.56-2.51). Concentrations of cTnT 8 h after admission to the PICU differed significantly after 8 h: 1.99 ng/ml (1.53-2.45) in those receiving dexamethasone and 3.08 ng/ml (2.46-3.69) in those not receiving it. After subgroup statistical analysis differences between the two groups remained significant only at 8 h, not those after 15 or 24 h. CONCLUSIONS: The use of dexamethasone (1 mg/kg) before cardiopulmonary bypass is associated with a brief but significant reduction in postoperative cTnT production. The clinical significance of this effect is unclear.