TPN Prescription Adel Hasanin TPN PRESCRIPTION

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1 TPN PRESCRIPTION 1) Calculate the IBW (ideal body weight in kg) Males: IBW = 50 kg kg for each inch over 5 feet. Females: IBW = 45.5 kg kg for each inch over 5 feet. New formula: IBW = 22 x H 2 (where H: height in meter) 2) Is the actual body weight is > 130% of the calculated IBW? Then use the adjusted body weight (ABW): adjusted body weight (kg) = IBW + 0.4(actual weight - IBW) 3) Calculate the Total Energy Requirements: 40 Kcal/kg/day (malnutrition with mild stress and normal weight) 4) Calculate the Kcals needed from lipid: 30% of Total Energy Requirements (= 0.3 x TER) 5) Calculate the lipid volume (ml of 20% lipid): Kcals needed from lipids / 2 (or divide by 1.1 for 10% lipid) 6) Calculate the lipid rate of infusion: lipid volume divided by 12 hours (run over 6-12 hours) 7) Calculate the total fluid requirements (including lipid): 1 ml/kcal/day 8) Calculate the TPN volume (excluding lipid): total fluid requirements lipid volume 9) Calculate the rate of TPN (AA/dex) infusion: TPN volume (excluding lipid) / 24 hours (run over 24 hours) 10) Calculate the grams needed of dextrose: 70% of total energy requirements / ) Calculate the dextrose concentration (%): grams needed of dextrose / TPN volume (excluding lipid) x ) Calculate the protein requirements: 1.5 g/kg/day for moderately stressed (fracture, surgery...) 13) Calculate the protein (AA) concentration (%): protein requirement (in grams) / TPN volume (excluding lipid) x ) Electrolytes, trace elements, and others: Na (2 /kg/day) Cl (2 /kg/d) K (1 /kg/d) Ca (0.3 /kg/d) Mg (0.4 /kg/d) Trace elements: Tracutil 10 ml ampoule once daily: Balanced mixture of the 9 trace elements Iron, Zinc, Manganese, Copper, Chromium, Molybdenum, Selenium, Fluoride and Iodide; meets the daily requirements of essential trace elements Albumin: Can be added if serum albumin levels are very low. Heparin: An anticoagulant used to prevent blood clots from forming on the IV catheter. Insulin: Used if needed to regulate blood glucose levels. The amount of regular insulin given (added directly to the TPN solution) depends on the blood glucose level; if the level is normal and the final solution contains the usual 25% dextrose concentration, the usual starting dose is 5 to 10 units of regular insulin /L of TPN fluid. 15) Labs (baseline & then biweekly): CBC, creatinine, urea, Na, K, Cl, Ca, Mg, phosphate, total protein & albumin, AST, ALT, alkaline phosphatase, bilirubin (T&D), LDH, cholesterol & triglyceride, PT, PTT, Fe, TIBC, Zn, Cu, RBS (Q 6 hours). 1

2 1) Charts of Protein Needs (g/kg) Adults APPENDIX Pediatrics Health States Requirement* Age (y) Requirement* Normal Stressed Normal Moderately stressed (infarction, fracture, surgery) Severely Stressed (burns, multiple fractures) Renal Disease Predialysis Hemodialysis Peritoneal dialysis ) Charts of Energy Needs by Kcal/kg Non-Stressed Patients: Stressed Patients: Weight Status Activity Level* Health Status kcal/kg Basal energy needs Overweight Ambulatory (st. maintenance) Normal weight Malnutrition with mild stress 40 Underweight Severe injuries / sepsis Extensive burns 80 *Activity Levels Defined: 1. Sedentary: confined to chair or bedrest 2. Light: Mostly seated or standing, with arm movements 3. Moderate: Frequent movements involving arms and legs, walking briskly 4. Marked: Walking uphill, activities requiring intermittent but frequent spurts of energy. 3) Kcals derived from lipid, dextrose, and protein: 1 g Lipids = 9 kcal energy: The 10% lipid emulsion contains 1.1 kcal/ml; the 20% emulsion contains 2 kcal/ml. Dextrose in solution has 3.4 kcal/g rather than 4 Kcal/g as in dietary carbohydrates 1 g Protein = 4 kcal Energy 2

3 4) Mineral supp. based on health: Amount per Kg Body Weight Mineral Potassium Sodium Calcium Normal State of Catabolism Mild- Mod m Eq Phosphorous Severe m Eq Comments Give 5-6 /g of N infused TPN Prescription 0.25 m Eq/kg needed for calcium equilibrium. Dependent on simultaneous administration of PO and Na, not N retention Needs related to nitrogen retention which is related to kcal intake. Give PO per 1000 dex kcals. Give 2 per gram of N infused. 5) Mineral supp. based on lab values Mineral Lab Value Daily need Potassium Sodium Calcium Phosphorous Chloride Above Below 3.5 Above Below 136 Above Above Below 2.5 Above Below Eq m Eq 15 mm mm

4 6) Trace Element Supplementation Zinc Copper Iron Chromium Manganese Iodine Selenium Element Dose mg mg 1.0 mg mcg mg 1-2 mcg mcg 7) Vitamin Supplementation Recommendations Vitamin Adults Children Under 11 years A (IU) D(IU) E(IU) Thiamin (mg) Riboflavin (mg) Pantothenic Acid (mg) Folate (mcg) B-12 (mcg) Biotin (mg) C (mg) ) General PN Initiation Procedures Start with 1 liter of TPN solution during the first 24 hours (or use 42 cc/hr as a typical start rate). Alternatively, the solution is started slowly at 50% of the calculated requirements, using 5% dextrose to make up the balance of fluid. 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. 4

5 9) Guidelines for Monitoring PN Patients Parameter Initial Period Stable Body temperature Every Shift Every Shift Fluid intake/output Daily Daily Glycosuria Every 8 hours Every 6 hours Electrolytes (Na/K) First 3 days Biweekly Calcuim, Phosphate, Baseline Weekly BUN/creatinine Baseline Biweekly Alb/total protein, Chol. Baseline Weekly Triglycerides Baseline As indicated Liver enzymes: SGPT, SGOT Baseline Weekly LDH, alk phos, dir/indir bilirubin Baseline Weekly PT/PTT Baseline Weekly Platelet count* Baseline As indicated Fe/TIBC, Zn/Cu Baseline As indicated N-Balance (24 hr UUN) hours after full rate achieved As indicated *Needed initially for catheter insertion purposes BUN = blood urea nitrogen; SGPT = serum glutamic-pyruvic transaminase; SGOT serum glutamic-oxaloacetic transaminase; LDH = lactate dehydrogenase; PT = prothrombin time; PTT = partial thrommboplastin time; TIBC = total iron-binding caacity, UUN=urinary urea nitrogen 10) Terminating the infusion: The procedure for terminating the TPN infusion is controversial. Some patients can tolerate an abrupt stop, and others tolerate a gradual termination, over a two hour period, better Gradual termination prevents rebound hypoglycemia, especially for diabetic, septic, and stressed patients. The endocrine system adjusts to a continuous infusion of dextrose by secreting a certain level of insulin. If the dextrose supply is withdrawn suddenly, the insulin level will not adjust right away, resulting in a relative insulin excess and hypoglycemia. 5