Total Parenteral Nutrition 7 Total Parenteral Nutrition

Conditions Requiring TPN Cancer AIDS Crohn’s disease Surgical removal of intestines Severe diarrhea Hyperemesis gravidarum (uncontrollable vomiting during pregnancy)

Conditions Requiring TPN (cont’d) Premature neonate Coma

Ingredients TPNs are extremely complex sterile compounds May have up to 15 to 20 additives Greater incidence of error or incompatibility TPN bag volume: 500 ml to 4 L Average patient receives 3 to 4 L/day

Ingredients (cont’d) TPNs prone to growth of microorganisms Maintaining aseptic technique is essential

Ingredients (cont’d) Base solution Dextrose: carbohydrates/sugar; provides calories Amino acids: protein; build/maintain body tissue Lipids: fat; energy storage Sterile water: used to adjust TPN volume

Ingredients (cont’d) Additives Electrolytes: sodium, potassium, chloride, phosphate, calcium, magnesium Trace elements: zinc, copper, manganese, chromium Vitamins

Fluid Maintenance Physician decides total TPN volume & chooses base solutions Fluid requirements based on weight or BSA Factors affecting fluid amounts needed Dehydration Overhydration Related conditions

Fluid Maintenance (cont’d) Patients are monitored for Fluid balance variations Nutritional needs

Fluid Requirement Formula Based on Body Weight

Calories and Carbohydrates Dextrose Wide range of concentrations: 2.5 to 70% 50% & 70% are most common strengths for TPN Each gram provides 3.45 kcal

Calories and Carbohydrates (cont’d) Lipids Prevent essential fatty acid deficiency Contribute to total caloric content Available in concentrations of 10%, 20%, 30% 10% & 20% may be infused directly into vein 30% must be mixed into TPN bag

Calories and Carbohydrates (cont’d) Ideal caloric mix 50–80% dextrose 20–50% fat Each gram of fat provides 9 kcal

Amino Acids Molecular units that make up proteins Build, maintain, & repair body tissues 8 of 22 amino acids are essential Essential: not produced by body Nonessential: body can synthesize Provide nitrogen, which aids in protein metabolism

Electrolytes and Minerals Sodium: 80–100 mEq/day Determines total body water Potassium: 80–100 mEq/day Aids nerve & muscle function (heart) Regulates water balance of cells Balances electrolytes

Electrolytes and Minerals (cont’d) Chloride: 80–100 mEq/day Regulates water balance of cells Maintains blood volume & pressure, pH

Electrolytes and Minerals (cont’d) Calcium: 15–20 mEq (0.2–0.3 mEq/kg/day) Bone formation/maintenance Nerve function Muscle contraction Blood clotting Heart function

Electrolytes and Minerals (cont’d) Magnesium: 15–25 mEq (0.25–0.35 mEq/kg/day) Muscles & nerves Phosphate: 20–30 mM (7–9 mM/1000 kcal) Bone growth Energy Fighting infection Proper muscle function

The Order Physician writes order & sends to pharmacy Pharmacy follows protocols in compounding TPN Types of order Standard: basic, nonspecialized for average patient Specialized

The Order (cont’d) Administration route Central line: dextrose concentration >10% Peripheral line: dextrose concentration ≤10%

Factors to Consider in Choosing Peripheral vs. Central Line Type of medication being administered Osmolarity & pH of solution Duration of therapy Diagnosis or medical condition of patient Patient preferences Current availability & status of veins Patient history Secondary risk factors

Infusion Rate Must be steady Large changes can cause significant Hypoglycemia Hyperglycemia At beginning, rate is tapered up for several hours When complete, rate is tapered down

Infusion Rate (cont’d) During interruption, a bag of low-concentration dextrose (10%) can be infused

Compounding the TPN Pharmacist Compares patient’s lab values to TPN order Suggests clinical changes, if needed Checks calcium gluconate & potassium phosphate levels to ensure no precipitation Performs calculations

Compounding the TPN (cont’d) Pharmacy Technician Chooses correct size bags, syringes, & needles Compounds base solutions (manually or auto) Draws up additives in separate syringes Injects additives into TPN bag (after pharmacist checks)

Compounding the TPN (cont’d) Pharmacy Technician (cont’d) Mixes the bag between each addition Inspects solution for particulates

Automated Devices Automix 3+3 Automated compounder linked to a computer Order is entered into computer Computer calculates amount of each ingredient Computer displays warnings if levels are off

Automated Devices (cont’d) Automix 3+3 (cont’d) Label is printed out Tech enters patient info, hangs correct size bag Compounder pumps fluid into IV bag

Automated Devices (cont’d) Micromix Compounds TPN additives Can add up to 10 different additives to bag Reduces amount of syringes to be drawn Reduces error rate Adds additives to TPN bag using specific gravity

Automated Devices (cont’d) Micromix (cont’d) Can pump as little as 2 mL into TPN bag Can measure to tenths (0.1 mL)