Immune function and nutrition. The clinical role of the intravenous nurse.

Protein-calorie malnutrition is considered to be one of the most frequent causes of immunosuppression in the world today. Malnutrition can affect the functioning of T cells, B cells, and macrophages, the principle players involved in cell-mediated and humoral immunity. Immune function is measured by the total lymphocyte count and delayed cutaneous hypersensitivity reaction. Nutritional markers include serum albumin and transferrin levels. Immune function is affected by protein (especially arginine intake); the balance between omega-6 and omega-3 fatty acid intake; and adequate amounts of vitamins A, E, and C, and the minerals zinc and iron. A deficiency of these nutrients puts the patient at increased risk of infection. Non-nutritional factors can influence immune functioning as well. The intravenous nurse must review the patients history, physical examination, and laboratory values to achieve a global view of the patient's immune function and nutrition status in order to be able to develop an appropriate care plan based on this nursing diagnosis: potential for infection secondary to alteration in immune function.