Tiêu đề 20. TOTAL PARENTERAL NUTRITION.pdf ✅

PHARMD GURU Page 1 DEFINITION:  Total parenteral nutrition (TPN) is intravenous administration of calories & other nutrients in sufficient quantities to achieve tissue synthesis & anabolism. Long ago this was described as hyper alimentation, but now a days it is referred to as TPN.  The administration of a nutritionally adequate hypertonic solution (consisting of glucose, minerals, vitamins etc.) through an indwelling catheter into the superior vena cava or other main vein. TYPES OF PARENTERAL NUTRITION: 1) CENTRAL PARENTERAL NUTRITION:  It is often called as total parenteral nutrition (TPN); delivered into central vein. It includes lipids, vitamins, minerals, amino acids (>5%), dextrose (>20%), & trace elements. Volume restriction, Osmolality (>700 mOsm/kg water). 2) PERIPHERAL PARENTERAL NUTRITION:  PPN is delivered into a smaller or peripheral vein. Total kcal limited by concentration & ratio to volume being administered (usually delivers b/w 1000 to 1500 kcal/day). No volume restriction, Osmolality (<700 mOsm/kg). REQUIREMENTS OF TPN:  TPN solutions are composed of a variety of constituents such as carbohydrate (Ex: dextrose), protein (Ex: crystalline amino acids), fat, electrolytes, trace elements, vitamins & water. Other additives that are sometimes added to TPN solutions are insulin, heparin, & albumin. WATER:  Water function as solvent for biological systems. Water is distributed in the intracellular space & extracellular space. TOTAL PARENTERAL NUTRITION
PHARMD GURU Page 2  In general an adult patient requires fluids up to 20 to 40 ml/kg/day. CARBOHYDRATES: Ex: DEXTROSE provides 3.4 kcal of energy. Carbohydrates are the main source of energy provided during TPN. The monohydrate form of glucose is the primary source of carbohydrates used in TPN. Others carbohydrates source such as fructose, galactose & sorbitol should not be used as energy sources in TPN. LIPIDS (FAT):  This is the primary source of essential fatty acid (linoleic acid) in TPN. Linoleic acid is useful as precursors of prostaglandins & in the synthesis of other fatty acids which are essential for cell membrane integrity.  Earlier soya bean oil was used in TPN formulations, now-a-days olive oil, fish oil & medium chain triglycerides are used.  Fat is obtained from lipid emulsions which are available as 10 % & 20 % W/V solutions. Fat supplies 9 Kcal/g. However, intravenous lipid emulsions supply 1.1 Kcal/ml & 2 Kcal/ml from 10% & 20 % lipid emulsions respectively. AMINO ACIDS (PROTEIN):  Protein is provided by crystalline amino acids (CAA). They are used to prevent nitrogen loss or in the treatment of negative nitrogen balance. 20 Amino acids are required for protein synthesis & metabolism.  1gm of nitrogen is produced by 6.25 gm of protein. They are many commercial preparations of amino acids, most of which are regarded as standard solutions. ELECTROLYTES: Electrolytes form an essential part of TPN regimen. They are used to maintain normal body metabolism. These include:  Sodium(Na) – 100 to 200 mEq;  Potassium(K) – 80 to 120 mEq;  Magnesium(mg) – 8 to 16 mEq;  Calcium(Ca) – 5 to 10 mEq;
PHARMD GURU Page 3  Chloride(Cl) – 100 to 200 mEq;  Phosphate(Po) – 40 to 60 mEq;  Phosphorous (P) – 20 to 40 mEq. VITAMINS: The daily requirement of both water soluble & fat soluble vitamins should be added to TPN formulation. These vitamins are required for the metabolism of carbohydrates, proteins, fats. Fat soluble vitamins are A, D, E & K. Water soluble vitamins are B1, B2, B3, B5, B6, B7, B9, B12, & C. Also included in this group are pantothenic acid, niacin, & biotin. TRACE ELEMENTS:  There are 10 trace elements required for the body. They are iron, copper, zinc, fluorine, manganese, iodine, cobalt, selenium, molybdenum & chromium. MANUFACTURE / PREPARTION OF TPN: PREPARATION AREA:  Laminar flow hoods provide an area for aseptic handling of IV admixture. In laminar flow hoods, the air is filtered through High Efficiency Particulate Air (HEPA) filter. HEPA filters remove 99.9% of all particles larger than 0.3μm.  It must be placed in an air – conditional room, free from any movement in front of it & its inside work bench should be wiped with a suitable disinfectant, 30 minutes before the process. It must be remembered that laminar flow hood is not a means of sterilization, but only maintain an area for IV admixture, if prepared, maintained & used properly by operator with proper aseptic techniques.
PHARMD GURU Page 4 ROOM & EQUIPMENT:  The TPN Room is a separate, sterilized, and well ventilated room. It is equipped with two safety cabinets for the preparation of sterile parenteral solutions, an apparatus for mixing solutions, a refrigerator, a desk, I.V. solutions, and other disposable items needed for work. A reference book on stability / compatibility is available, (Handbook on injectable drugs).  The TPN section of the pharmacy department has an effective and consistent policy for TPN according to the rules and regulations of the MOH (MINISTRY OF HEALTH) Standards.  Provision of specialized formulas of parenteral nutrition to patients with unique medical conditions that require a specified calculated amount of calories, proteins, and other medicinal based on specific criteria, will be compounded only in the pharmacy department under strict aseptic techniques and by a well-trained and certified TPN pharmacy staff.  The TPN unit implements a double check policy at each stage of compounding and visual inspection of the final parenteral nutrition product. LABELLING OF SOLUTIONS: The prepared solution’s label should contain the following:  Name of the drug.  Strength.  Instructions for use.  Expiration date.  The prepared solution is good for 24 hours (stability) and it is to be kept in the refrigerator until the time of use.  TPN solutions should not be mixed with other intravenous solutions (separate lines should be used), unless it is discussed with the pharmacist to determine compatibility.