Final answer:
An elevated Alanine aminotransferase level of 90 U/L is a laboratory result that requires immediate notification to the health care provider because it suggests potential liver damage or dysfunction, which is critical when managing patients prescribed lovastatin due to the medication's potential hepatotoxic effects.
Step-by-step explanation:
The finding that requires the nurse to notify the health care provider immediately is an Alanine aminotransferase (ALT) level of 90 U/L. The normal range for ALT, an enzyme that indicates liver function, is usually between 5-15 IU/litre. An elevated ALT level can signify acute liver damage, such as viral hepatitis or paracetamol overdose, which could be exacerbated by the prescription of statins like lovastatin due to their potential hepatotoxic effects. Therefore, a result of 90 U/L is significantly higher than the upper limit of normal and could point to liver injury or dysfunction that might require medical intervention or adjustment of the medication regimen.