TOTAL PARENTRAL NUTRITIONPRESENTED BY: IRFAN AHMEDPHARM.D 4TH PROF.AKHTAR SAEED COLLEGE OF PHARMACEUTICAL SCIENCES

components

History Definition Indications Components of TPN calculation TPN interventions Ordering and administration Infusion pumps Special considerations during preparations Monitoring Incompatibilities

History

In 1960s Drs. Wilmore and Dudrick researched on central venous for growth in infant, elderly patients with catabolic medical conditions Originally termed hyperalimentation

Replaced with TPN, which is more descriptive of the technique

TPN

IV administration of calories, nitrogen and all other nutrients in sufficient quantities to achieve tissue synthesis and anabolism.

Peripheral Parenteral NutritionNutrients are supplied via a peripheral vein, usually a vein in the arm. Another term for PPN is peripheral venous nutrition (PVN).

PVN is used when a patient is unable to ingest adequate calories enterally or when central venous nutrition is not feasible.

Concentration

4.25% amino acid+ 10% dextrose

IV fat emulsion should be run simultaneously with the PVN to minimize thrombophlebitis

THE GOLDEN RULE OF NUTRITION

The gut should always be the preferred route for nutrient administration. Therefore, parenteral nutrition is indicated generally when there is severe gastro-intestinal dysfunction (patients who cannot take sufficient food or feeding formulas by the enteral route) .

Indications

Indicated when adequate nutrition cannot be maintained via GIT. Carcinoma extensive burnsGeriatric refuse to eat Young anorexic patientsSurgical patients who should not be fed orally [NPO]GIT motility disorder Severe vomiting, when enteral feeding cannot be tolerated

Components of TPN and their calculations

Fluids Carbohydrate as dextrose (3.4 kcal/g) Protein as amino acids (4 kcal/g) lipids (10-11 kcal/g) Electrolytes Vitamins Trace minerals

Components of TPN

Dextrose and lipids to provide energy. 70%-85% of calories from dextrose Protein for tissue synthesis and repair. 15%-30% from lipids Determine the appropriate amount of calories needed for the patient by

assessing height, weight, ideal body weight and % of weight loss

CALCULATIONS

Calculation of patient requirements calculated using Harris-Benedict Harris-Benedict equation

FOR MEN

For Men: = 66.67+ (13.75 x weight in kg) + (5 x height in cm) - (6.76x age) DESIGNING THE TPN FORMULA

Estimate Basal Energy Expenditure (BEE).

For women

For women the formula is: = 655.1 + (9.56 * weight in kg) + (1.86 * height in cm) - (4.68 x age)

Total Daily Expenditure(TDE) TDE= BEE* Activity*Stress

Activity BED=1.2 Ambulatory=1.3

Stress: Surgery: 1.2 Infection: 1.4-1.6 Trauma: 1.3-1.5 Burns: 1.5-2.1

Total Daily Expenditure(TDE) TDE= BEE*Activity*Stress non-stressed (ambulatory)- 30 kcal/kg body weight

mild stress (malnourished)- 35-40kcal/kg body weight

severe injury or sepsis- 45-60kcal/kg body weight

severe burns- up to 80kcal/kg body weight infants up to 200kcal/kg body weight

Carbohydrates in TPN

Hydrous Dextrose (glucose) Provides 3.4 kcalg-1 1 L D5W =170 kcal, 1 L D25W = 850 kcal Final dextrose concentrations 5-10% (peripheral) 35% (central) D5W=252 mOsmL-1, D25%=1263 mOsmL-1

Protein requirments

INSOLUBLE AND UNDIGESTED IN BLOOD. Protein- requirements usually estimated empirically. non-stressed 0.5-1g/kg mild stress 1.2-1.4 g/kg moderate stress 1.5-2.0g/kg severe stress 2.0-2.5g/kg

Protein Solutions

Standard formulas EAA (40%) and NEAA (60%) available as 3-15% solutions Protein is provided as a crystalline amino acid solution. 500 ml bottles

are standard. Solutions vary in amino acid concentration and amino acid composition

Intra venous lipids

FAT emulsions Only O/W emulsions can be given by IV. After 2 weeks of TPN Dry scaly skin, hair loss, impaired wound healing Fat provides 9 kcal/g Components soybean (50% linoleic) safflower (72%) glycerol water egg yolk phospholipid

Actions Indications Dosage Drug Incompatibilites

Fatty acids in emulsion form used as a source of calories and to provide essential fatty acids

To prevent fatty acid deficiency for patients requiring parenteral nutrition, and to reverse a known deficency state characterized by scaly skin

ADULTS: 100 mg/min for the first 15-30 min then increase to 2-3 ml/min if no reaction. Give only 500 ml (50 gm) first 24 hrs, in no reaction increase following day. Do not exceed 2.5gm/kg/day

Do not add any other medication to the infusion.

INTRAVENOUS LIPIDS

Intravenous lipids have the highest caloric density of any components of parental nutrition

Intralipid is composed of soybean oil, egg yolk phospholipids, and glycerol. The major fatty acids are linoleic 54%, oleic 26%, palmitic 9% and linolenic 8%

If a patient has been on TPN for 2 weeks Dry Scaly Skin, Hair loss, Impaired Wound healing. Soybean-oil emulsion (Intralipid) Safflower-oil emulsion (Liposyn)

Electrolytes: Guidelines for Electrolyte Requirements

Electrolyte Amount/1000 Calories

Sodium 40-50 mEqPotassium 30-40 mEqChloride 40-50 mEqMagnesium 8-12 mEqCalcium 2-5 mEqPhosphorus 15-25 mEq

Recommended Daily Adult Doses of Parenteral Trace Elements

Trace Element DoseZinc 2.5-4.0 mgCopper 0.5-1.5 mgChromium 10-15 ugManganese 150-800 ugSelenium 40-80 ug

MVI

A 8000 U D 800 U E 4 U Niacin 80 mg B1[Thiamine] 40 mg B2[Riboflavin] 8 mg C 400 mg Folic acid 2 mg

MVI

Vitamin K & . Vitamin B12 separately I.M. Vitamin K 10 mg week-1 Vitamin B12 100 g week-1

TPN interventions

Warm to room temp 1 hr prior to use Hang TPN alone Dextrose concentration > 10% given through a central line Change TPN bag and filter every 24 hours

Ordering and Mixing PN Solutions

The physician writes the Rx TPN prescription. The pharmacist mixes the TPN solution using aseptic technique.

Prescriptions are compounded by mixing the solutions at a 1:1 dextrose-to-amino acid ratio and placing in 1-L bags. Alternatively, lipids can be mixed with the dextrose/amino acid solution, referred to as the 3-in-1 total nutrient admixture (TNA).

ADMINISTRATION

TPN should always be given via an infusion pump. The pharmacist may be consulted regarding drug compatibility for

simultaneous administration of two or more drugs through a single lumen of the catheter.

Avoid the administration of blood products into the lumen designated for parenteral nutrition.

Heparin Flush When parenteral nutrition infusion is being cycled, a heparin flush is

needed to maintain patency of central venous catheter when solution is not infusing.

Initial Considerations

TPN infusion should start slowly so that the body has time to adapt to both the glucose load and the hyperosmolarity of the solution, and to avoid fluid overload.

A pump controls the infusion rate of the TPN solution. There are specific steps in the inititiation procedure to follow regarding the initiation of

TPN infusion.

Infusion Pumps: Electronic ambulatory infusion pumps are commonly used in the home setting. These pumps are lightweight and portable and can be programmed to deliver continuous

infusions, intermittent infusions or single dose medications. Many pumps have the capacity to taper the rate of an infusion. Multichannel pumps allow for the administration of several different infusions at one time

General PN Initiation Procedures

Start with 1 L of TPN solution during the first 24 hours (42 mL/hr as a start rate) Increase volume by 1 liter each day until the desired volume is reached Monitor blood glucose and electrolytes closely Pump administer TPN at a steady rate Don't attempt to catch up if administration gets behind

Continuous vs. Cyclic TPN the patient is fed at night.Cyclic TPN helps prevent hepatotoxicity that can develop with long-term TPN and the fasting period allows essential fatty acids to be released from fat stores.

SPECAIL CONSIDERATIONS DURING PREPARATIONS

Mechanics of Administering Titrate up slowly to allow pancreas to adapt to hypertonic dextrose load Give 1/3 of max rate on day 1, 2/3 on day 2 and full infusion on day 3 Taper to allow pancreas to adapt to withdrawal of hypertonic dextrose Infuse D10 if TPN abruptly discontinued Use filters (0.22 m). Fat can’t run through filters CLEAN ROOM The clean room is a limited-access area, which is separated from the other

pharmacy operations to minimize the potential for contamination. All products are prepared using

the Class 100 laminar flow cabinets

IV Admixture Environment

To provide sterility and pyrogen-free, proper environment is a must Prepare admixture under laminar-flow filter Air filter through High Efficiency Particulate Air (HEPA) flowing at 90fpm

and remove 99.97% particles of 3 m. Air flow either horizontal or vertical HEPA filter must be replace every 6 months Technician or operators must wash hands, gloved and require gowning

Temperature and pH: Temperatures below freezing or above room temperature may result in destabilization of the

lipid emulsion. pH below 5.3 or the addition of additives with a pH of 5.0 may also destabilize the emulsion. Temperature & calcium-phosphorus stability. As the temperature increases, there is an increase in the rate of dissociation of calcium and

phosphorus from their salts. This allows more free calcium and phosphorus to be precipitated

Labeling: The American Society of Enteral and Parenteral Nutrition (ASPEN) addressed the issue of

standard labeling for PN solutions in its recent guidelines. Labels for PN admixtures should include amount per day of base formula, electrolyte additives, micronutrients and medications, quantity per liter for those who admix in 1L volumes, and dosing weight. Auxiliary labels may be helpful when PN orders are written in a different format than the standard label.

Storage and PackagingTPN solutions should always be transported and stored under controlled-temperature refrigeration. TPN solutions are delivered from the pharmacy to the patient’s home, a cooler with cooler

blocks should be used. Refrigerators should be checked to make sure the temperature is constant and that adequate

space is available for storing PN solutions and supplies.

Filtering: Use of a filter during the administration of PN solutions may prevent complications arising

from any particulate matter, microprecipitates or microorganisms potentially present. A 0.2 -1.2-m filter should be used for TPN solutions with amino acids and dextrose. Filters should be replaced every 24 hours. A clogged filter, indicates some type of problem with the TPN solution, such as contamination

of the solution, precipitation, cracking or incompatibilities

Monitoring

Blood work must be drawn to establish baseline lab values, which include: electrolytes, creatinine, triglycerides, BUN, phosphorous, glucose, albumin, magnesium, CBC + differential, carbon dioxide, and total protein Thereafter, monitoring can be performed 2-3 times per week. other include body weight and temperature.

Monitoring of the TPN Patient

Acute condition, unstable patient, early nutrition support

Electrolytes, BUN, SCr: 3-7 times per week Calcium, magnesium, phosphate: 1-3 times per week LFT’s, TP, ALB: once weekly or every other week Triglycerides: weekely or as appropriate for IV fat emulsion use.

Stable hospitalized patient, prolonged parenteral nutrition support Electrolytes, BUN, SCr: 1-3 times per week Calcium, magnesium, phosphate: once weekly or every other week LFT’s TP, ALB: every 2-4 weeks CBC/ differential, PLC RBC indices: every 2-4 weeks

TPN incompatibilities

Drug incompatibilities, drug-nutrient interactions and destabilization of lipids can all adversely affect the stability of parenteral nutrition solutions.

Medications that are incompatible with Parenteral nutrition solutions: 1. Acyclovir

2. Amphotericin B 3. Diazepam 4. Phenytoin 5. Bactrim 6. Metronidazole

Therapeutic IncompatibilityAntagonistic and synergistic effect

Penicillin and cortisone antagonize heparin leading to anticoagulant An increase in amino acid concentration will decrease Theophylline level Anticoagulants drugs are used in TPN in order to reduce or prevent any

tendency toward intravascular or in cardiac clotting

Physical Complications Haze detected Particles detected Color changes, Changes from clear to cloudy, Emitting of gas

Chemical Incompatibilities

Change in pH can change solubility Antibiotics can remain active in 24 hours at the pH of 6.5, but at pH 3.5 it will be destroy. Potassium Penicillin G buffered at pH 6.0-6.5, when added to dextrose, water or NaCl injection it

must also be at buffer 6.0-6.5 to assure activity of antibiotic

MINIMIZATION OF INCOMPATIBILITIES FRESHLY PREPARED FEW ADDITIVES KNOWLEDGEABLE MAKE THEM AWARE ASEPTIC TECHNIQUE KEEP FILE

Refernces

Hospital pharmacy by nadeem irfan bukhari www.pharmj.com www.nyschp.org/the_pharmacist/0998/09 Wikipedia Pharma.knwldgebank.com

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