Chapter 18 Nutrition Support Intravenous Access

Intravenous access is determined by expected length of therapy and by the individual who will be responsible for managing the access device—the older adult, clini- cian, or family member. There are a variety of IV access devices that can be used to administer PN. IV access devices are generally categorized as either peripheral or central and either temporary or perma- nent. Peripheral catheters can be used to administer peripheral parenteral nutrition; however, this is short- term therapy and provides little nutrition support (13). It should be used in the rare occasions when enteral or parenteral nutrition is delayed or not available for a short period of time (less than two weeks). Central catheters used to administer PN include temporary central catheters, which do not require surgery, may be inserted at the bedside by a physician, and are generally used in the hospital only; tunneled catheters (ie, Hickman, Broviac, Groshong), which are inserted surgically or radiologically, are tunneled sub- cutaneously, and have an exit site on the chest wall; and implantable devices (eg, Mediport, PORT-A- CATH), which are inserted surgically, are completely under the skin, and are accessed using a special needle. A peripherally inserted central catheter (PICC) is another type of IV access device. A PICC can be inserted radiologically or at the bedside by a specially trained nurse and is typically used to administer IV antibiotics but can also be used for PN. Permanent catheters (ie, tunneled catheters, implanted devices, or PICCs) are usually required for administration of PN in nursing facilities or at home (30).

Regular and meticulous care of central catheters is imperative to prevent catheter-related problems such as infection or sepsis. Catheter sepsis is the most common therapy-related reason for readmission of clients receiving home parenteral nutrition. Catheter care pro- tocols must be in place in any institution or home par- enteral therapy program where catheters are used for nutrition support.

Components of Parenteral Nutrition Solutions

Macronutrients

The macronutrients used in parenteral nutrition solu- tions are dextrose, amino acids, and lipids (25). Requirements are based on the clinical and nutritional status of the individual (13). Dextrose is the primary source of calories and provides 3.4 kcal/g and is avail- able in concentrations ranging from 5% to 70%. Amino acids provide 4 kcal/g and are available in concentra- tions ranging from 3% to 15%. Lipids as fat emulsions provide essential fatty acids in addition to being a

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source of energy. Lipid emulsions, usually provided in a 20% concentration (although 10% is available), may be provided daily in the PN solution or once or twice weekly as a separate solution. A 20% fat emulsion con- tains 2 kcal/mL. The macronutrient composition of parenteral nutrition solutions administered to older adults may need to be adjusted to compensate for age-related changes in body composition, nutrient metabolism, and organ function (13,21). Protein needs should always be met first to ensure adequate protein intake.

Fluid

Parenteral nutrition solutions must meet fluid require- ments for individuals who are unable to maintain hydration enterally (13,21). Fluid intake must be ade- quate to replace normal losses via urine, feces, sweat, and respiration, along with abnormal losses such as output from ostomies, fistulas, wounds, or a chest tube. Maintaining fluid homeostasis is more difficult in older adults because of age-related alterations in thirst per- ception and decreases in cardiovascular and renal func- tion. Careful monitoring and documentation of fluid input/output, weight, labs, and vital signs is necessary for managing fluid status in clients receiving parenteral nutrition.

Micronutrients

Electrolytes, minerals, vitamins, and trace elements are essential for normal cellular function and need to be added daily to the PN solution (13). Requirements vary among individuals based on clinical status, nutritional status, renal function, and medications. There are no different standards for IV requirements for micronutri- ents for older adults. Electrolytes are commercially available as single or multiple additives and can be added as needed to the PN solution. Most IV multivita- min preparations now contain vitamin K. While vitamin K administration may interfere with anticoagu- lation therapy, current recommendations suggest man- aging this with a consistent vitamin K intake and not avoidance of it, either in the oral diet or in the IV mul- tivitamin. Multiple trace element preparations contain anywhere from four to six components. Some vitamins and trace elements can be ordered as single additives if needed.

Medications

The use of PN as a method for administering medica- tions is generally not recommended because of poten- tial incompatibility between the drug and other components of the solution, the inability to adjust or discontinue the dosage without discontinuing the solu- tion, and the necessity to infuse medications continu- ously rather than intermittently (31). Medications