NURSING PROCESS: THE PATIENT RECEIVING PARENTERAL NUTRITION
The nurse assists in identifying patients who may be candidates for PN. Indicators include any significant weight loss (10% or more of usual weight), a decrease in oral food intake for more than 1 week, any significant sign of protein loss (serum albumin levels less than 3.2 g/dL [32 g/L], muscle wasting, decreased tis-sue healing, or abnormal urea nitrogen excretion), and persistent vomiting and diarrhea. The nurse carefully monitors the patient’s hydration, electrolyte levels, and calorie intake.
Based on the assessment data, the major nursing diagnoses may include the following:
• Imbalanced nutrition, less than body requirements, related to inadequate oral intake of nutrients
• Risk for infection related to contamination of the central catheter site or infusion line
• Risk for excess or deficient fluid volume related to altered infusion rate
• Risk for immobility related to fear that the catheter will be-come dislodged or occluded
• Risk for ineffective therapeutic regimen management re-lated to knowledge deficit about home PN therapy
The most common complications are pneumothorax, air em-bolism, a clotted or displaced catheter, sepsis, hyperglycemia, rebound hypoglycemia, and fluid overload. These problems and the associated collaborative interventions are described in Table 36-5.
The major goals for the patient may include optimal level of nu-trition, absence of infection, adequate fluid volume, optimal level of activity (within individual limitations), knowledge of and skill in self-care, and prevention of complications.
A continuous, uniform infusion of PN solution over a 24-hour period is desired. In some cases, however (eg, home care patients), cyclic PN may be appropriate. With cyclic PN, there is a set time during a 24-hour period when PN is infused and a set time when it is not. The time periods for infusion are sufficient to meet the patient’s nutritional and pharmacologic needs. Ideally, cyclic PN is infused over an 8- to 10-hour period during the night.
The patient is weighed daily (this may be decreased to two or three times per week), at the same time of the day under the same conditions for accurate comparison. Under the PN regimen (without additional energy expenditure), a satisfactory weight gain is usually achieved. It is important to keep accurate intake and output records and calculations of fluid balance. A calorie count is kept of any oral nutrients. Trace elements (copper, zinc, chromium, manganese, and selenium) are included in PN solu-tions and are individualized for each patient. The PN solutions are prescribed daily by the physician on a standard PN order form based on laboratory values and patient tolerance.
The high glucose content of PN solutions makes these solutions ideal culture media for bacterial and fungal growth, and CVADs provide a port of entry. Candida albicans is the most common in-fectious organism. Other infectious organisms include Staphylo-coccus aureus, Staphylococcus epidermidis, and Klebsiella pneumoniae. Meticulous technique is essential to prevent infection.
The primary sources of microorganisms for catheter-related infections are the skin and the catheter hub. The catheter site is covered with an occlusive gauze dressing that is usually changed every other day. Alternatively, a transparent dressing may be used and changed weekly. The Centers for Disease Control and Prevention recommends changing dressings for CVADs only if they are damp, bloody, loose, or soiled. The dressings are changed using sterile technique. The nurse and patient wear masks dur-ing dressing changes to reduce the possibility of airborne contam-ination. The area is checked for leakage, bloody drainage, a kinked catheter, and skin reactions such as inflammation, redness, swelling, tenderness, or purulent drainage. The nurse puts on sterile gloves and cleanses the area with tincture of 2% iodine or a chlorhexidine solution on a sterile gauze. The site is cleaned thoroughly using circular motion from the site outward approx-imately 3 inches. This is repeated two times. This is followed with the same cleaning procedure using 2 × 2-inch gauze pads moist-ened with sterile water or saline solution (alcohol is used to re-move iodine). Next the catheter lumens are cleaned from the exit site to the distal end with an alcohol wipe. The insertion site is covered with an occlusive gauze pad or transparent dressing cen-tered over the area.
The advantages of using a transparent dressing over the gauze pad are that it allows frequent examination of the catheter site without changing the dressing, it adheres well, and it is more comfortable for the patient. When an extension set is used with a central catheter, it is considered an extension of the catheter it-self. It is not routinely changed with dressing or tubing changes. The connection (hub) between the catheter and extension tubing is secured with adhesive tape to prevent separation and exposure to air. Main-line IV tubing and filters are changed every 72 to 96 hours, and all connections are taped securely to avoid breaks in the integrity of the system. The dressing and tubing are labeled with the date, time of insertion, time of dressing change, and ini-tials of the person who carried out the procedure; this informa-tion is also documented in the medical record.
The catheter is another major source of colonization and in-fection. Antiseptic-impregnated central venous catheters are new devices that reduce catheter colonization by coating of the catheter surfaces with antimicrobial agents. Two types are avail-able, one coated with chlorhexidine/silver sulfadiazine and the other with minocycline/rifampin (Hanna et al., 2001).
An infusion pump is necessary for PN to maintain an accurate rate of administration. A designated rate is set in milliliters per hour, and the rate checked every 30 to 60 minutes. An alarm signals a problem. The infusion rate should not be increased or decreased to compensate for fluids that have infused too quickly or too slowly. If the solution runs out, 10% dextrose and water is infused until the next PN solution is available from the pharmacy.
If the rate is too rapid, hyperosmolar diuresis occurs (excess sugar will be excreted), which, if severe enough, can cause in-tractable seizures, coma, and death. Symptoms of rapid hyper-tonic fluid intake include headache, nausea, fever, chills, and increasing lethargy.
If the flow rate is too slow, the patient does not get the maxi-mal benefit of calories and nitrogen. Intake and output are recorded every 8 hours so that fluid imbalance can be readily de-tected. The patient is weighed two or three times a week; in ideal situations, the patient will show neither weight loss nor signifi-cant weight gain. The nurse assesses for signs of dehydration (eg, thirst, decreased skin turgor, decreased central venous pressure) and reports these findings to the physician immediately. It is essential to monitor blood glucose levels, because hyperglycemia can cause diuresis and excessive fluid loss.
Activities and ambulation are encouraged when the patient is physically capable. With a catheter in the subclavian vein, the pa-tient is free to move the extremities and should be encouraged to maintain good muscle tone. If applicable, the teaching and exer-cise program initiated in the occupational and physical therapy departments should be reinforced.
Successful home PN requires teaching the patient and family spe-cialized skills using an intensive training program and follow-up supervision in the home. This is accomplished through a team ef-fort. The financial costs of such programs, although high, are less than those incurred in a hospital. Initiation of a home program may be the only way the patient can be discharged from the hospital.
Ideal candidates for home PN are those patients who have a reasonable life expectancy after return home, have only a limited number of medical illnesses other than the one that has resulted in the need for PN, and are highly motivated and fairly self-sufficient. In addition, ability to learn, availability of family in-terest and support, adequate finances, and the physical plan of the home are factors that must be assessed when the decision for home PN is made.
Home health care agencies sponsoring home PN programs have developed teaching brochures for every aspect of the treat-ment, including catheter and dressing care, use of an infusion pump, administration of fat emulsions, and instillation of hepa-rin flushes. Teaching begins in the hospital and continues in the home or in an ambulatory infusion center.
The home care nurse should be aware that the average patient needs about 2 weeks of instruction and reinforcement. For more information about home patient education, see Charts 36-4 and 36-5.
Expected patient outcomes may include the following:
1) Attains or maintains nutritional balance
2) Is free of infection at the catheter site
a. Is afebrile
b. Has no purulent drainage from the catheter insertion site
c. Has intact IV line
3) Is hydrated, as evidenced by good skin turgor
4) Achieves an optimal level of activity, within limitations
5) Demonstrates skill in managing PN regimen
6) Prevents complications
a. Maintains proper catheter and equipment function
b. Has no symptoms of sepsis
c. Maintains metabolic balance within normal limits
d. Shows improved and stabilized nutritional status