The nurse is caring for a client diagnosed with chronic hepatitis who is receiving the medication lactulose. Which of these laboratory results would indicate the medication is achieving the desired therapeutic effect?

Choice A Reason: Increased Serum Albumin

Increased serum albumin is not a direct indicator of the therapeutic effect of lactulose in patients with chronic hepatitis. Albumin is a protein made by the liver, and its levels can be affected by liver function. However, lactulose primarily works by reducing ammonia levels in the blood, not by increasing albumin levels. Normal serum albumin levels range from 3.5 to 5.5 grams per deciliter (g/dL). While improved liver function might eventually lead to increased albumin levels, this is not the primary therapeutic effect of lactulose.

Choice B Reason: Decreased Serum Bilirubin

Decreased serum bilirubin is also not a direct indicator of lactulose’s therapeutic effect. Bilirubin is a byproduct of the normal breakdown of red blood cells and is processed by the liver. Elevated bilirubin levels can indicate liver dysfunction, but lactulose’s main role is to reduce ammonia levels, not bilirubin. Normal serum bilirubin levels are typically between 0.1 to 1.2 milligrams per deciliter (mg/dL). While improved liver function might reduce bilirubin levels, this is not the primary goal of lactulose therapy.

Choice C Reason: Decreased Serum Ammonia

Decreased serum ammonia is the correct indicator of the therapeutic effect of lactulose in patients with chronic hepatitis. Lactulose is used to treat hepatic encephalopathy, a condition caused by high levels of ammonia in the blood due to liver dysfunction. Lactulose works by converting ammonia into ammonium, which is then excreted from the body. Normal serum ammonia levels are less than 50 micromoles per liter (µmol/L) in adults56. A decrease in serum ammonia levels indicates that lactulose is effectively reducing the toxic levels of ammonia in the blood, thereby achieving its desired therapeutic effect.

Choice D Reason: Decreased Serum Alanine Aminotransferase (ALT)

Decreased serum alanine aminotransferase (ALT) is not a direct indicator of lactulose’s therapeutic effect. ALT is an enzyme found in the liver that helps convert proteins into energy for liver cells. Elevated ALT levels can indicate liver damage. Normal ALT levels range from 7 to 56 units per liter (U/L). While improved liver function might reduce ALT levels, lactulose’s primary role is to reduce ammonia levels, not directly affect ALT.