Which Mechanism is Effective on the Hyperamylasaemia After Coronary Artery Bypass Surgery?

BACKGROUND AND AIM: Acute pancreatitis is one of the less frequently diagnosed lethal abdominal complications of cardiac surgery. The incidence of early postoperative period hyperamylasaemia was reported to be 30-70% of patients who underwent coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). The mechanism of pancreatic enzyme elevation after cardiac surgery is not clear. Our aim was to determine the relationship between ischaemia associated temporary renal dysfunction and elevation of pancreatic enzymes after CABG.

METHODS: Forty-one consecutive patients undergoing CABG under CPB were prospectively studied to determine serum total amylase, phospholipase A2, macroamylase, Cystatin C and urine NAG levels.

RESULTS: Hyperamylasaemia was observed in 88% of the cases, with a distribution of 6% at the beginning of cardioplegic arrest, 5% at the 20th minute after cardioplegic arrest, 7% at the 40th minute after cardioplegic arrest, 14% when the heart was re-started, 26% at the 6th hour of intensive care and 30% at the 24th hour of intensive care. All of these patients had asymptomatic isolated hyperamylasaemia, and none of them presented with clinical pancreatitis. As indicators of renal damage; Cystatin C and NAG levels were higher compared to baseline values.

CONCLUSION: Amylase began to rise during initial extracorporeal circulation and reached a maximum level postoperatively at 6 and 24hours. Decreased amylase excretion is the main reason for post CABG hyperamylasaemia.