Serum transaminases as a prognostic factor in children post cardiac surgery

Elevated serum transaminases that are often observed in critically ill children are frequently attributed to liver injury. Indeed, hypoperfused or hypoxemic livers will produce sudden and marked elevations of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). The aim of this study was to determine the frequency and consequences of elevated serum transaminases in children following cardiac surgery.

Charts of all children admitted to the Pediatric Intensive Care Unit following cardiac surgery over a 10-year period were retrospectively analyzed.

Of the 384 children studied, 46 (11.9%) had elevated transaminases. Extreme ALT and AST levels (≥20-fold elevations over the upper limit of normal) were found in 3.4% and 4.7% of the children, respectively. Tetralogy of Fallot and double outlet right ventricle were significantly more common (P < 0.001) among the elevated transaminases group (26% and 13% vs 17% and 2.5%, respectively). A significant difference (P < 0.001) was noted between overall mortality among 384 patients studied: 15.8%, versus a mortality of 43.4% among children who manifested elevated transaminases levels following cardiac surgery. AST, ALT and lactate dehydrogenase peak levels were significantly higher in the group of children who died in comparison to the survivors (P < 0.05). Kaplan-Meier survival analysis demonstrated lower survival among the patients who had extreme ALT elevations (P < 0.05).

Elevation of transaminases following cardiac surgery occurs more frequently than previously reported, particularly in the setting of right-sided heart failure. Extreme elevation of ALT, AST and lactate dehydrogenase correlated with decreased postoperative survival and places these children in a high-risk category, requiring closer, more stringent monitoring.