Abstract
Lactate level is an important index for predicting cardiac events. There are some debates about time and type of sampling for defining of its prognostic values. To assess the prognostic importance of arterial lactate level in patients after cardiac surgery with regarding to operation factors serial arterial lactate levels during and after surgery was measured up to 24 hours, these data were processed by T-independent test and chi-square, P less than 0.01 was significant. 31 patients entered to study, high persistent arterial lactate level (1.5-4 mmol/L) can be seen in most patients (80%) during operation which returned to normal level (<1.5 mmol/L) up to12(th) hours post operation in 75% of cases. Persistent high level (>4 mmol/L) will occur unusually at 24(th) hour but can be associated with poor prognosis. Serial measurement of serum lactate level can be helpful for our management quality and very highly persistent arterial lactate level (>4 mmol/lit) up to 24 hours after operation will increase mortality rate in operated patients for congenital heart disease.