Isocitrate dehydrogenase (ICD) catalyzes the decarboxylation of isocitrate in the Krebs cycle. This enzyme is important in controlling the rate of the cycle, which must be precisely adjusted to meet the energy needs of cells. ICD is found in the liver, heart, skeletal muscle, placenta, platelets, and erythrocytes.

• Numerous drugs, including those that are hepatotoxic, may cause elevated levels.

• Elevated serum aspartate aminotransferase (ALT, SGOT) or ALP of uncertain etiology, or both:
  • Elevated ICD levels are seen in early viral hepatitis, cancer of the liver, intrahepatic and extrahepatic obstruction, biliary atresia, cirrhosis, and preeclampsia.
• Therapy with potentially hepatotoxic drugs that may lead to elevated ICD levels early in the course of treatment

Nursing Care Before the Procedure

Client preparation is the same as that for any study involving collection of a peripheral blood sample (see Appendix I).

• Because many drugs may alter ICD levels, a medication history should be obtained. It is recommended that any drugs that may alter test results be withheld for 24 hours before the test, although this practice should be confirmed with the person ordering the study.

A venipuncture is performed and the sample collected in a red-topped tube. The sample should be handled gently to avoid hemolysis and transported promptly to the laboratory.

Nursing Care After the Procedure

Care and assessment after the procedure are the same as for any study involving the collection of a peripheral blood sample.

• Resume any drugs withheld before the test, pending test results.