Total Parenteral Nutrition Definition
Nutrition is very vital in the wellness of an individual. It is an important factor to aid patient to full recovery. Problem lies when a patient is unable to sustain daily nutritional requirements due to the present health condition a patient is suffering. There are conditions in which feeding is impossible through normal digestive process.
Total parenteral nutrition is a method of supplying nutrients to the body by an intravenous route. It is indicated to patients with impaired or non functional gastrointestinal tract due to an interruption in its continuity or absorptive capacity is impaired. Total parenteral nutrition is also indicated in pediatric cases of gastrointestinal disorders such as congenital anomalies. The goals of administering TPN are to improve the nutritional status of the patient, to attain weight gain and to enhance the healing process.
Administering total parenteral solution can be initiated in three methods in which health practitioner can determine which method best suit the patient. The three methods are:
- Peripheral – TPN solution used is less hypertonic and infused through the peripheral vein.
- Atrial – surgically inserting external right atrial catheters using single or double lumen; infusion can also be done through subcutaneous port.
- Central – is indicated for moderate to long-term intravenous therapy and catheter is inserted mostly at the subclavian vein owing to its area and stability in insertion site.
Total Parenteral Nutrition Guidelines
It is important to assess the patient carefully to determine the nutritional needs and anticipate any metabolic changes that may occur due to the underlying condition of the patient including the medications and therapies in the treatment regimen of the patient prior to total parenteral nutrition initiation. Certain criteria have to be evaluated prior to administration of TPN such as the degree of weight loss, nitrogen balance, amount of muscle loss, total lean mass and the tolerance of the patient in ingesting food through GI tract.
There are guidelines to follow when administering TPN solution.
- Verify or double check doctor’s order of TPN which should be a written order. Instruction, formula and calculations must be detailed.
- Verify patients demographic and the solution to be infused ensuring that the TPN solution goes to the right patient in right dosage.
- Observe strict aseptic precaution prior to administering the solution.
- Check placement of central line via chest after insertion and prior to beginning infusion.
- Check vital signs to determine if patient is febrile.
- Check line for purulent drainage from the catheter insertion site.
- Ensure catheter and equipment are functioning properly.
- Do not draw blood sample from TPN line or IV pushed medications directly through the line.
- Monitor blood glucose every 6 hours and monitor other lab values.
- Weigh the patient two to three times a week at the same time of the day under the same conditions to achieve accurate comparison.
- Prevent infection by changing the dressing aseptically usually two to three times a week.
- Check for line leakage, kinked catheter and skin reactions.
- Check flow rate every half to one hour and do not increase or decrease infusion rate to compensate for infusion too slowly or too quickly.
- Gradually discontinue TPN at the end of therapy to avoid hypoglycemia.
Total Parenteral Nutrition Components
Total parenteral nutrition can be commercially prepared or can be prepared by a pharmacist in prescribed nutritional intravenous solution using strict aseptic precautions. It is usually prepared in liter batches according to standard formula.
TPN Solutions contains:
- Amino acids
- Fat emulsion
Total Parenteral Nutrition Calculations
Designing TPN solution needs consideration such as:
- Energy needed by the patient
- Protein or nitrogen a patient need per day
- Fluid required and tolerance of patient
- Fat emulsion the patient needed and can tolerate
- Dextrose needed and its concentration
- Type of electrolyte a patient needs and its quantity
Calculation starts with determining the energy needs of the patient which can be derived using the formula:
Weight of patient in kg x kcal/day required
Determining protein needs:
Use the non protein (Kcal) to (N) nitrogen ratio
Calculating for the fluid needs:
Body weight x minimum fluid need for hydration
Ex. 70kg x 50 cc/kg = 3500cc/day
Total Parenteral Nutrition Complications and Side Effects
Total parenteral nutrition supplies the nutrient requirement of a patient but it can also cause side effects such as:
- Development of mouth sores
- Poor night vision
- Skin quality changes
Immediate medical attention if there is a presence of side effects such as:
- Rapid weight loss
- Occurrence of fever and chills
- Experience stomach pain or upset stomach
- Difficulty in breathing
- Muscle weakness, twitching and cramps
- Convulsions or seizures
Significant complications may also occur such as:
- Blood clots
- Glucose abnormality
- Hepatic complication
- Serum electrolytes and minerals abnormality
- Gallbladder complications
Total Parenteral Nutrition Vs Peripheral Parenteral Nutrition
Peripheral parenteral nutrition has the same component as with total parenteral nutrition only in peripheral parenteral nutrient the concentration is much lower than TPN. PPN is also administered via peripheral vein and is typically used for short term usually for 2 weeks or less due to limited tolerance of the patient.