Objective: To analyze the incidence of hyperamylasemia after cardiac surgery in children, the pathogenic mechanisms and the relationship with morbidity and mortality.
Patients and methods: A prospective open study was made in the Intensive Care Unit of a tertiary care pediatric hospital. One hundred thirty-one patients (75 boys and 56 girls), between 7 days and 16 years of age, were studied after cardiac surgery between 1992 and 1994. We determined serum amylase on their admission, at 24 hours, between the 2nd and 5th days, and thereafter according to the clinical evolution. We considered a serum amylase higher than 250 UI/L as hyperamylasemia. We also determined liver enzyme levels (AST, ALT, Gamma-glutamyl transpeptidase, alkaline phosphatase, and direct and total bilirubin) and renal function (urea and creatinine). We studied the relationship between hyperamylasemia and the type of surgery, shock, renal insufficiency, hepatic alterations and mortality.
Results: Fourteen patients (10%) showed hyperamylasemia. Mean serum amylase in these patients was 534 +/- 332.6 UI/L (range 252-1426 UI/L). Of the patients were cardiopulmonary bypass was performed, 11.4% presented hyperamylasemia, and 8.5% of the patients without a cardiopulmonary bypass surgery (non-significant difference). Of the children with hyperamylasemia, 42.8% suffered shock during the postoperative period after cardiac surgery and only 15.2% of the rest of the patients (p < 0.05). There were no differences in the incidence of renal insufficiency and liver alterations between children with hyperamylasemia and the rest of the patients. There was no significant difference between the mortality of children with hyperamylasemia (7.1%) and the rest of the children (4.7%; p > 0.05).
Conclusions: Hyperamylasemia is frequent after cardiac surgery in children. Hyperamylasemia is related to shock and the ischemia is probably the most pathogenic factor.