Parenteral nutrition refers to nutritional support provided by an intravenous route. Access may be a peripheral vein or central vein. Peripheral venous access is usually used for short term support and limits the volume of fluids and nutrients that can be delivered. Whenever possible, enteral nutrition is preferred in order to provide nutrients to the gut and maintain the intestinal barrier.
Indications for Parenteral Nutrition
Parenteral nutrition is used in cases of gut failure or severe gastrointestinal disease. Catheter-related sepsis is a significant risk in immunocompromised patients. In HIV/AIDS, TPN will induce weight gain, the composition of which depends on the underlying etiology of the malnutrition. Septic patients tend to gain primarily fat whereas those with malabsorption or inadequate dietary intake gain more body cell mass. It is possible that this modality may not be widely available throughout the Region. However, it is an option that should be pursued when necessary.
Components of Parenteral Nutrition
The solution for parenteral nutrition consists of nutrients in their simple form,namely dextrose, amino acids, lipids and micronutrients. Dextrose is the monosaccharide that provides the major source of non-protein energy. Each gram of dextrose in parenteral solution provides 3. 4 kilocalories or 14. 2 kilojoules. Carbohydrate should be provided in adequate amounts to spare protein, but not in excess as this may cause hyperglycemia, fatty liver or other complications. The recommended rate of dextrose infusion should not exceed 4 to 5 mg/kg/minute. Amino acids provide protein to maintain nitrogen balance and prevent degradation of somatic proteins. Protein requirements are calculated based on clinical condition and goals of treatment. Amino acid solutions provide 4 kilocalories per gram or 18. 1 kilojoules per gram. Parenteral lipid emulsions provide a concentrated source of energy and essential fatty acids. They may be used in conjunction with carbohydrate and amino acid solutions or alone for caloric enhancement. The energy content of lipid emulsions depends on the formulation. ten percent yields 1. 1 kilocalorie per mL; 20% yields 2. 0 kilocalories per mL; 30% yields 3. 0 kilocalories per mL. There is some evidence that parenteral lipids may have a negative effect on immunity. In patients with HIV infection lipids should not exceed 30% of total energy intake or 1 g/kg/day. Hyperlipidemia may also develop if lipids are not cleared. Thus serum lipids should be monitored at baseline and regular intervals thereafter. Micronutrients and electrolytes are provided as standardized components of parenteral solutions. These may be modified according to the needs of the patient.
Anabolic Therapy
Nutrition support will usually result in weight gain, but for some PLWHA, classified as non-responders, there is evidence of an anabolic block, whereby the regained weight is composed of a disproportionately high amount of body fat with limited accretion of lean tissue. This phenomenon can be identified with body composition analysis. Thus,although re-feeding is always necessary, it is not always sufficient for some individuals. In cases where lean tissue gains are insufficient, an anabolic agent may be required such as testosterone replacement. Other anabolic therapies that have shown favorable results include Oxandrin, Decadurabolan, and Recombinant Growth Hormone.
Palliative Care
When AIDS patients become terminally ill and medical care becomes mainly palliative,not curative, the nutrition care plan should reflect the overall goals of care. Nutritional therapy is directed to alleviating symptoms and providing comfort. Nutrition support should be considered to improve quality of life if the patient, caregivers and medical team agree to this intervention.
Common Dietary Problems
During the course of treatment and care, many dietary problems can arise. Strategies to help alleviate common problems are addressed in
Pregnancy, Lactation and HIV
Pregnancy, lactation, and HIV disease engender physiologic stress, with increased nutritional needs for energy, protein and micronutrients. It is well recognized that the nutritional health of a pregnant woman influences pregnancy outcome. Nutritional
status has even greater implications for the HIV-infected woman who is at higher risk of premature delivery and having a low birth weight infant.
Low birth weight infants have an increased incidence of infant mortality as well as medical and developmental complications. Other risk factors, such as pregnancy during adolescence, substance use, opportunistic infection, low pre-pregnancy weight and inadequate gestational weight gain impose further risks of a poor pregnancy outcome. Moreover, vitamin A deficiency has been associated with poor pregnancy outcome and increased risk of perinatal HIV transmission. Pregnant HIV-positive women should be referred early in pregnancy to a dietitian or other suitable health care professional for counselling to optimize nutritional status and improve pregnancy outcome. It is essential to assess complementary therapy use, as mega-doses of vitamins and some herbal preparations are contraindicated in pregnancy.
Weight Gain in Pregnancy
Recommended weight gain based on pre-pregnancy weight:
Underweight (BMI 25):
Nutritional Requirements
12. 5-18. 0 kg
11. 5-16. 0 kg
7. 0-11. 5 kg
According to the Recommended Dietary Allowances for use in the Caribbean, the following requirements for pregnancy/lactation are in addition to the requirements for HIV+ women:
4? Additional 285 kilocalories per day to support fetal growth and development
Additional 6 grams protein per day
Prenatal multivitamin-mineral daily (to include at least 0. 4 mg folic acid)
Other micronutrient supplements as needed (e. g. iron, calcium)
Lactation: additional 500 kcal per day and 11 grams of protein Vitamin A:
Maternal vitamin A deficiency is associated with increased risk of vertical HIV transmission to the infant. However, there is little evidence that vitamin A supplementation of the pregnant woman reduces the risk of HIV infection to the infant. Moreover, high doses of vitamin A can be teratogenic. Should supplementation be necessary, the following WHO guidelines can be used.
Iron deficiency anemia is highly prevalent in pregnant women throughout the world. Anemia is associated with increased risk of maternal and fetal morbidity and mortality, as well as intrauterine growth failure. Iron status should be assessed and deficiency should be treated. WHO recommend that women receive 60 mg iron during 6 months of pregnancy and 120 mg per day to treat severe anaemia.
Folate deficiency:
Folate deficiency causes megaloblastic anemia and is associated with risk of neural tube defects in the infant (e. g. spina bifida). WHO recommends 0. 4 mg folate supplement daily.