When evaluating the lab work of a client in hepatic coma, which of the following lab tests is most important?

When a client is in hepatic coma due to liver failure, the liver cannot metabolize amino acids completely, leading to elevated ammonia levels. Increased ammonia can cause brain-tissue irritation, worsening the coma. Therefore, monitoring serum ammonia levels is crucial in assessing the severity of hepatic coma. Choices A, B, and D are less relevant in the context of hepatic coma. Blood urea nitrogen primarily assesses kidney function, serum calcium levels are not directly related to hepatic coma, and serum creatinine is more indicative of kidney function rather than liver function in this scenario.