Chapter 8. Intravenous Therapy
8.12 Parenteral Nutrition (PN)
Parenteral nutrition (PN) is a form of nutritional support given intravenously. PN includes proteins, carbohydrates, fats, vitamins, and minerals. It aims to prevent and restore nutritional deficits, allowing bowel rest while supplying adequate caloric intake and essential nutrients, and removing antigenic mucosal stimuli (Perry et al., 2018; Triantafillidis & Papalois, 2014 ). PN may be short-term or long-term nutritional therapy, and it may be administered in hospital or even at home following extensive patient education. The caloric requirements of each patient are individualized according to the degree of stress, organ failure, and percentage of ideal body weight. PN may be administered as peripheral parenteral nutrition (PPN) or via a central line, depending on the components and osmolality. Central veins are the veins of choice because there is less risk of thrombophlebitis and vessel damage (Chowdary & Reddy, 2010). According to Chowdary & Reddy (2010), candidates for PN are:
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Patients with paralyzed or nonfunctional GI tract, or conditions that require bowel rest, such as small bowel obstruction, ulcerative colitis, or pancreatitis
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Patients who have had nothing by mouth (NPO) for seven days or longer
- Critically ill patients
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Babies with an immature gastrointestinal system or congenital malformations
- Patients with chronic or extreme malnutrition, or chronic diarrhea or vomiting with a need for surgery or chemotherapy
- Patients in hyperbolic states, such as burns, sepsis, or trauma
PN is made up of two components: amino acid/dextrose solution and a lipid emulsion solution (see Figure 8.33). The ratios are determined by the dietitian in consultation with the physician and vary depending on the patient’s metabolic needs, clinical history, and blood work. Medications can be added depending on compatibility (for example heparin and insulin are common additives). The solutions are available premixed by the manufacturer. Orders are reviewed daily to ensure the patient receives the solution best suited to their changing needs. The specific mixture, strength, volumes, and any additives must be confirmed by the health care provider every time a new bag is hung.
PN is not compatible with other IV solutions, nor is it compatible with many medications. As such, PN should have a dedicated IV line. PN must be administered using an EID (IV pump), and requires special IV filter tubing (see Figure 8.34) for the amino acids and lipid emulsion to reduce the risk of particles entering the patient. Agency policy may allow amino acids and lipid emulsions to be infused together above the filters. PN tubing will not have any access ports and must be changed according to agency policy (usually every 24 hours). Always review agency policy on setup and equipment required to infuse PN.
A prescriber may order a total fluid intake (TFI) for the amount of fluid to be infused per hour to prevent fluid