American Association of Critical-Care Nurses (AACN) Certification Practice Test

What is the abnormal range for AST and ALT that could signal liver dysfunction?

1. 1-30 IU/L

2. 30-150 IU/L

3. 60-120 IU/L

4. 120-300 IU/L

The correct answer is: 30-150 IU/L

In evaluating liver function, the enzymes aspartate aminotransferase (AST) and alanine aminotransferase (ALT) are critical biomarkers. Typically, normal ranges for AST and ALT can vary slightly depending on the laboratory but are generally accepted to be between 10-40 IU/L for adults. Elevated levels of these enzymes indicate potential liver dysfunction or damage. The selected answer indicates a range of 30-150 IU/L, which encompasses levels that are significantly elevated compared to the normal range. This range suggests mild to moderate liver dysfunction, as AST and ALT levels in this pane could indicate hepatic injury, inflammation, or other liver-related pathology. Levels rising above these thresholds would be a clear indication for further investigation and often correlate with liver disease conditions such as hepatitis, fatty liver disease, or alcohol-related liver injury. In this context, the other ranges provided either fall below the threshold where liver dysfunction is typically suspected or extend into areas that would indicate even more severe dysfunction that may not be assessed in the same manner. Hence, the selection aligns appropriately with clinical expectations for abnormal liver function markers.