Free fatty acids (FFA) travel through the blood combined with albumin and in this form are called nonesterified fatty acids (NEFA). Normally, approximately three fatty acid molecules are combined with each molecule of albumin. If, however, the need for fatty acid transport is great (e.g., when needed carbohydrates are not available or cannot be used for energy), as many as 30 fatty acids can combine with one albumin molecule. Thus, although blood levels of FFA are never very high, they rise impressively after stimuli to release fat. The same stimuli that elevate FFA will, in most cases, also elevate serum triglycerides and may produce alterations in lipoprotein levels. Specific causes of both elevated and decreased FFA, including drugs, are listed in Table 5-11.

• Ingestion of alcohol within 24 hours before the test may result in falsely elevated values.
• Failure to follow dietary restrictions before the test may alter values.
• Drugs known to alter FFA levels should not be ingested unless the test is being performed to evaluate such effects (see Table 5-11).

• Support for diagnosing uncontrolled or untreated diabetes mellitus, as indicated by elevated levels
• Evaluation of response to treatment for diabetes, as indicated by declining levels
• Suspected malnutrition, as indicated by elevated levels
• Known or suspected disorder associated with excessive hormone production (see Table 5-11), as indicated by elevated levels
• Evaluation of response to therapy with drugs known to alter FFA levels (see Table 5-11)

Nursing Care Before the Procedure

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

• The client should abstain from alcohol for 24 hours and from food for at least 8 hours before the test.
• Water is not restricted.
• Drugs known to affect FFA levels (see Table 5-11) may be withheld before the test, although this may not always be done if the therapeutic effect on FFA levels is being evaluated.

A venipuncture is performed and the sample collected in a red-topped tube. The sample should be sent immediately 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 foods and any drugs withheld before the test.
• Abnormal values: Note and report any increased level. Assess in relation to glucose and ketone and to lipid and lipoprotein electrophoresis levels. Assess for recent weight gain or loss. Instruct in appropriate fat and carbohydrate intake in the diet.