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Learning Objectives. Evaluate baseline knowledge on aspects of TPN assessment, calculations, and management List Total Parenteral Nutrition (TPN) goals and evidence for use Determine nutritional assessment, formula considerations and calculations, and timeline to initiation
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Learning Objectives • Evaluate baseline knowledge on aspects of TPN assessment, calculations, and management • List Total Parenteral Nutrition (TPN) goals and evidence for use • Determine nutritional assessment, formula considerations and calculations, and timeline to initiation • Identify TPN initiation and management strategies including macronutrient and micronutrient delivery, cycling, and weaning • Identify special considerations for TPN formulation as well as complications associated with TPN therapy • Apply knowledge to answer case-based questions
ZC is a 30 year old male who was admitted in July for bowel obstruction. ZC’s nutritional status was evaluated by the clinical dietician. The evaluation determined the following:- ZC has not dieted or routinely exercised in a year- Height 82 inches; IBW ~ 100 kg- January 2008: 100 kg- July 2008: 91 kg - August 2008: 85 kg- Is ZC malnourished? • Yes, based on July weight (lost 9 kg) • No, his amount of weight loss is within normal limits • Yes, based on August weight (lost 6 kg) • Yes, based on IBW
ZC’s PCP would like to start the following TPN. Dex 100 g/L, AA 25 g/L, NaCl 75 mEq/L, KAcetate 75 mEq/L @ 42 mL/hr (1 L/day) - What is the osmolarity of the TPN? Can it be given thru a peripheral line? • 900 mOsm; Central only • 900 mOsm; Peripheral • 1050 mOsm; Central only • 1050 mOsm; Peripheral
The clinical pharmacist would like to adjust ZC’s TPN formula and add lipids. The new TPN formula contains the following:Dex 100 g/L, AA 50 g/L, Lipids (20%) 50 g/L @ 42 mL/hr (1L/day) - How many kcals will the new TPN provide? • 1000 kcals • 1040 kcals • 1070 kcals • 1110 kcals
ZC has been on TPN for 2 days. His chemistry shows the following serum electrolytes.Na 140 Cl 105 BUN 22 Gluc 145 Phos 2.1K 4.1 CO2 35 Cr 1.1 Ca 8.1 Mg 2.1The PCP would like to maintain the TPNpotassium but switch potassium acetate 75 mEq to potassium phosphate (KPhos). - How much KPhos should the R.Ph. add? • KPhos 50 mmol • KPhos 56 mmol • KPhos 75 mmol • KPhos 112.5 mmol
The MD writes an order to change the formula and add calcium gluconate 5 mEq to the Central TPN. The TPN now contains:AA 45 g/L (FreAmine III 10%) Dextrose 200 g/L Lipids 20 g/LCalcium gluconate 5 mEq/LPotassium phosphate 30 mmol/LTotal Volume 1 L- Based on the current Calcium Phosphatecompatibility chart (handout),the calcium and phosphate doses are: • Compatible • Incompatible
On day 4, the TPN is at goal. However, on rounds the medical resident notices that ZC’s BUN has risen from 20 mg/dL to 40 mg/dL, but he has good urine output. The patient is currently receiving a total of 50 g/d AA and he weighs 85 kg.- Would you expect the TPN to cause this degree of rise in BUN?- Approximately how much would you expect the BUN to change from baseline based on ZC’s AA intake? • Yes; Increase ~ 20 • No; No change expected • No; Increase ~ 2-5 • No; Increase ~ 7-10
Nutritional Status Assessment • Other Assessment • Creatinine • Liver enzymes • Triglycerides • Glucose • Bilirubin • Prealbumin • I & O • Basics • Height • Weight • IBW/BMI • Weight change • GI function • Primary diagnosis • Co-morbidities • Liver disease • Kidney disease • Heart failure • Diabetes August D. JPEN 2002;26(suppl):9SA-10SA.
Nutritional Status Assessment • Physical findings • loss of subcutaneous fat • muscle wasting • edema • GI symptoms (anorexia, nausea, vomiting) • Oral intake • Strength/stamina • Metabolic demand – increased Resting Energy Expenditure (REE) • burns • sepsis • trauma • surgery August D. JPEN 2002;26(suppl):11SA.
Malnutrition • Decreased intake, impaired metabolism, over-nutrition • Affected by pre-morbid condition, illness, duration • Affects 30-55% of hospitalized patients • Signs/symptoms • Involuntary 10% increase/decrease in weight within 6 months or 5% within 1 month • Weight 20% over/under IBW • Inadequate intake due to impaired ingestion or absorption August D. JPEN 2002;26(suppl):9SA.
Malnutrition • Consequences • Delayed wound healing • Re-hospitalization • Increased length of stay • Increased mortality • Increased costs August D. JPEN 2002;26(suppl):9SA.
ZC is a 30 year old male who was admitted in July for bowel obstruction. ZC’s nutritional status was evaluated by the clinical dietician. The evaluation determined the following: - ZC has not dieted or routinely exercised in a year- Height 82 inches; IBW ~ 100 kg- January 2008: 100 kg- July 2008: 91 kg - August 2008: 85 kg- Is ZC malnourished? • Yes, based on July weight (lost 9 kg) • No, his amount of weight loss is within normal limits • Yes, based on August weight (lost 6 kg) • Yes, based on IBW
Enteral vs. Parenteral • Enteral • Functional GI tract • Tolerant of nutrients progress to oral • Benefits: cost, integrity of gut mucosa structure and function, infection risk, hospital length of stay • Parenteral • Inadequate enteral tolerance (high residuals) based on volume and rate • No functional GI tract • Disadvantages: cost, complex, morbidity August D. JPEN 2002;26(suppl):8SA,18SA.
TPN Indications • Malnourished/undernourished • Prior to hospital admission • > 7 days after hospitalization • Inadequate oral intake • Inadequate caloric intake 7-14 days • Expected inadequate intake > 7-14 days • Catabolic illness with normal energy/protein utilization August D. JPEN 2002;26(suppl):19SA.
Evidence for Parenteral Nutrition • Bowel obstruction • Intractable diarrhea • High output fistulas • Major abdominal surgery • Prolonged dysphasia (stroke) • Illness-related undernourished • Bone Marrow Transplant • Short bowel syndrome • Prolonged severe intestinal failure Souba WW. NEJM 1997;336(1):41-8.
TPN Goals • Preserve lean body mass • Support organ structure/function • Decrease morbidity and mortality • Support immune function
Peripheral vs. Central TPN • Osmolarity • 1 g Dextrose = 5 mOsm • 1 g AA = 10 mOsm • 1 g Lipids (20%) = 1.3-1.5 mOsm • 1 mEq Electrolytes = 1 mOsm • Peripheral • Central access not feasible (platelets, recurrent sepsis) • Short-term (< 7-14 days) • Moderate nutrient needs • Low osmolarity (< 900 mOsm/L) • Central • Fluid restricted (CHF, renal failure, hepatic failure) • Longer-term (14 days or more) • Maximum nutrient needs Mirtallo J. JPEN 2004;28(6):S45.
ZC’s PCP would like to start the following TPN. Dex 100 g/L, AA 25 g/L, NaCl 75 mEq/L, KAcetate 75 mEq/L@ 42 mL/hr (1L/day)- What is the osmolarity of the TPN? Can it be given thru a peripheral line? • 900 mOsm; Central only • 900 mOsm; Peripheral • 1050 mOsm; Central only • 1050 mOsm; Peripheral
Energy Expenditure Requirement • Predictive/estimated equations • Harris-Benedict – weight, height, age, stress factors • Ireton-Jones – weight, age, gender, injury, obesity • Fick – CO, Hgb, SaO2, SvO2, • Measured energy expenditure • Indirect calorimetry • Weight-based equations • Actual weight • Ideal body weight (IBW) • Adjusted weight Flancbaum L. Am J Clin Nutr 1999;69:461-6.
Energy Requirement Estimates Indirect calorimetry • Calculates actual REE; measures whole body O2 and CO2 • Expensive, 30 – 60 minute test, most accurate method • Indications • Fail to respond based on predictive equations • Individualize nutrition for varying metabolic stress • Nutrition requirements difficult to establish • Morbid obesity • Burn • Paralytics • Amputation • Multiple open wounds • Concern for overfeeding REE = Resting Energy Expenditure Wooley JA. Nutrition in Clinical Practice 2003;18:434-9.
Caloric Needs & Fluid Requirements • Calories derived from macronutrients • Based on energy expenditure estimates, activity/stress, malnutrition history • 20-35 kcal/kg/day • Total fluids • 30-40 mL/kg/d • 1-1.5 mL/kcal expended August D. JPEN 2002;26(suppl):22SA-23SA. Mirtallo J. JPEN 2004;28(6):S53.
TPN components • Other • Water • Medications • H2 blockers • Thiamine • Folic acid • Vitamin K • Insulin • Macronutrients • Amino Acids • Dextrose • Lipids • Micronutrients • Electrolytes • Vitamins • Minerals
Macronutrients – Amino Acids • Primary TPN element • Metabolic demands • Unstressed/maintenance: 0.8 – 1 g/kg/d • Catabolic: 1.2 – 2 g/kg • 4 kcals/g • Contain acetate (~75-150 mEq/L) • FreAmine III, HepatAmine, and Hepatasol contain phosphate (phosphoric acid buffer) August D. JPEN 2002;26(suppl):22SA.
Macronutrients - Dextrose • Provides majority of non-protein calories • Usually 70-85% of non-protein calories • Lipids provide other non-protein calories • Dose adjustable to meet caloric needs • Dextrose load dependent on glucose tolerance • Limits: 7 g/kg/d • 3.4 kcals/g August D. JPEN 2002;26(suppl):22SA. Mirtallo J. JPEN 2004;28(6):S53.
Macronutrients - Lipids • Provide non-protein calories; dose adjustable • Prevent essential fatty acid deficiency • TPN dextrose insulin release reduced adipose lipolysis linoleic acid deficiency • Need 0.5-2% of Kcals from linoleic or alpha linolenic acid • Cyclic hyperalimentation • Enteral or parenteral lipids • Limits: 2.5 g/kg/d • ~10 kcals/g • No clinical benefit when non-protein lipid calories > 30% August D. JPEN 2002;26(suppl):22SA. Bistrian BR. JPEN 2003;27(3):168-75. Mirtallo J. JPEN 2004;28(6):S53.
The clinical pharmacist would like to adjust ZC’s TPN formula and add lipids. The new TPN formula contains the following:Dex 100 g/L, AA 50 g/L, Lipids (20%) 50 g/L @ 42 mL/hr (1L/day)- How many kcals will the new TPN provide? • 1000 kcals • 1040 kcals • 1070 kcals • 1110 kcals
Micronutrients - Electrolytes • Dependent on organ dysfunction, medications, acid-base status, current serum levels • Dextrose concentration can affect serum levels • Aim for one source of anions (chloride, acetate, phosphate)
Micronutrients - Electrolytes • Sodium 1-2 mEq/kg • Potassium 1-2 mEq/kg • Chloride prn acid-base balance • Acetate prn acid-base balance • Calcium gluconate 10-15 mEq • Phosphate 20-40 mmol • Sodium phosphate 1 mmol ~ 1.3 mEq sodium • Potassium phosphate 1 mmol ~ 1.5 mEq potassium • Magnesium 8-20 mEq Acetate is converted to CO2 in the liver; may be alkalosis source August D. JPEN 2002;26(suppl):errata.
ZC has been on TPN for 2 days. His chemistry on day 3 shows the following serum electrolytes.Na 140 Cl 105 BUN 22 Gluc 145 Phos 2.1K 4.1 CO2 35 Cr 1.1 Ca 8.1 Mg 2.1The PCP would like to maintain the TPN potassium but switch potassium acetate75 mEq to potassium phosphate (KPhos). - How much KPhos should the R.Ph. add? • KPhos 50 mmol • KPhos 56 mmol • KPhos 75 mmol • KPhos 112.5 mmol
Micronutrients – Electrolytes • Calcium phosphate compatibility is directly proportional to: • AA concentration • AA product selection • Dextrose concentration • Acidic pH • Calcium salt form (gluconate > chloride) • Cooler temperature 1) Final TPN volume (L) 2) AA concentration (g/L) 3) Dextrose concentration (g/L) 4) Calcium concentration (mEq/L) 5) Phosphate concentration (mmol/L) 6) Use most appropriate curve based on Dextrose concentration Trissel’s Calcium and Phosphate Compatibility in Parenteral Nutrition 2001.
The MD writes an order to change the formula and add calcium gluconate 5 mEq to the Central TPN. The TPN now contains:AA 45 g/L (FreAmine III 10%)Dextrose 200 g/LLipids 20 g/LCalcium gluconate 5 mEq/LPotassium phosphate 30 mmol/LTotal Volume 1 L- Based on the current Calcium Phosphatecompatibility chart (handout),the calcium and phosphate doses are: • Compatible • Incompatible
Micronutrients – Vitamins & Minerals • Multivitamins • Provides RDA for vitamins • MVI 12 with Vitamin K includes Vitamin K 150 mcg • Trace Elements • MTE-4 • Chromium – sugar & fat metabolism • Copper – Hgb, RBC, bones, wound healing • Manganese – Vit C & B1 utilization • Zinc – immune system & wound healing • MTE-5 • Selenium included – free radicals & infection fighting • Supplement initially or after 1 month of MTE-4 • If total bilirubin is elevated, consider reduction (50%) or removal of trace elements (copper & manganese)
Micronutrients – Other • Zinc IV • Consider adding if high output fistula or ostomy, open wounds, or intractable diarrhea • 12 mg/d sufficient for positive zinc balance • Glutamine • Safe and inexpensive • Antioxidant, improved nitrogen balance, improved gut barrier function, decreased infections, decreased hospital stay • Burn and trauma – induce heat shock proteins • 0.2 – 0.5 g/kg/d Souba WW. NEJM 1997;336(1):41-7. McClave SA. JPEN 2008. Guidelines for Nutrition Therapy in Adult Critically Ill Patients. Draft. 14.
Special Considerations • Acute/Chronic Renal Failure • Hepatic dysfunction • Diabetes • Obese • Critical care
Renal Failure • CRF is associated with chronic inflammation promoting catabolism and anorexia • CRF not on dialysis: 0.6 – 0.8 g/kg/d AA • CRF on HD: 1.2-1.5 g/kg/d AA • CRF on CVVHD: 1.5-2.0 g/kg/d AA • ARF is associated with hypermetabolism, accelerated protein breakdown, impaired protein synthesis • ARF and severe malnourished or catabolic: 1.5-1.8 g/kg/d August D. JPEN 2002;26(suppl):78SA-79SA. Mirtallo J. JPEN 2004;28(6):S53.
Hepatic Dysfunction • Protein calorie malnutrition 27-87% in cirrhosis • 1 g/kg/d AA avoids negative nitrogen balance • Restriction to 1 g/kg/d AA reduces encephalopathy • Restriction not indicated for chronic hepatic disease • Visceral fat malabsorption due to decrease in bile acid production • Vitamin (A, D, E, K) and zinc deficiency prevalent • Avoid copper and manganese (MTE) in cirrhosis or hepatic dysfunction due to accumulation August D. JPEN 2002;26(suppl):66SA-67SA. Mirtallo J. JPEN 2004;28(6):S53.
Diabetes • Stress can cause peripheral insulin resistance • Goal is optimal glucose control • Minimize hyperglycemia by limiting calories from dextrose and insulin supplementation • Decrease infection • Avoid hypoglycemia August D. JPEN 2002;26(suppl):54SA.
Obese • Often protein depleted • Predictive methods variable, indirect calorimetry is optimal method • Hypocaloric, high-protein feeding/permissive underfeeding • Avoid overfeeding • Provide sufficient protein (positive nitrogen balance), minimizing catabolic loss • Caution in ARF, hepatic encephalopathy • 22-25 kcals/kg IBW or 11-14 kcals/kg actual body weight • 1-2 g/kg IBW AA results in positive nitrogen balance • BMI 30-39: 2 g/kg AA • BMI 40: 2.5 g/kg AA August D. JPEN 2002;26(suppl):53SA. Dickerson RN. Nutrition in Clinical Practice 2004; 19:245-54. McClave SA. JPEN 2008. Guidelines for Nutrition Therapy in Adult Critically Ill Patients. Draft. 15.
Critical Care • Hypermetabolic, hyperglycemic, accelerated lipolysis, protein catabolism • Calories: 25-35 kcals/kg/d • AA 1.2 – 2.0 g/kg/d • Visceral protein markers not validated in ICU setting August D. JPEN 2002;26(suppl):22SA, 90SA-91SA. Bistrian BR. JPEN 2003;27(3):168-75. McClave SA. JPEN 2008. Guidelines for Nutrition Therapy in Adult Critically Ill Patients. Draft. 8.
Critical Care • Lipid limits: 1 g/kg/d • Consider withholding lipids during acute inflammation/infection • Lipid free TPN during first week of hospitalization • Decreased infectious morbidity • Decreased hospital length of stay • Fatty acids lead to release of inflammatory markers and are immune modulators (Omega 6) • All patients should receive selenium (MTE-5) August D. JPEN 2002;26(suppl):22SA, 90SA-91SA. Bistrian BR. JPEN 2003;27(3):168-75. McClave SA. JPEN 2008. Guidelines for Nutrition Therapy in Adult Critically Ill Patients. Draft. 14-16.
TPN Rate Advancement • Initiation • Rate usually based on Dextrose (<250 g/day) • 2 g/kg dextrose/day • Hyperglycemic • Diabetes history • Severe malnourished • Advance to goal rate • Monitor for metabolic complications • Hyperglycemia (blood glucose < 150-200 mg/dL) • Electrolytes • Refeeding Syndrome • Goal rate in 2-3 days
TPN Management & Monitoring • Calories from other sources • Tube feed/enteral toleration • Dextrose IVF • Medications (i.e. propofol) • Medication therapy duplication • Electrolyte replacement trend • Metabolic effects
TPN Complications • Hyperglycemia • Refeeding syndrome • Uremia • Overfeeding organ dysfunction • IV lipid immunosuppression • Nutrient depletion • Absence of intestinal feeding intolerance • Fluid overload • Catheter-related infections • Hypertriglyceridemia
Hyperglycemia • TPN dextrose load (non-DM on insulin drip) • IV fluids • History of diabetes • Off medications or suboptimal dosing • Medication induced (steroids) • Metabolic stress (surgery) • Infection/sepsis
Refeeding Syndrome • Physiologic complications • Arrhythmias • Edema/heart failure • Respiratory arrest • Prevention • Electrolyte supplementation • Gradual advancement (up to 5-7 days) • Overfeeding or aggressive repletion • Potentially life-threatening • At risk • Prolonged inadequate intake • Alcoholics • Morbid obese & large weight loss • Metabolic complications • Hypophosphatemia • Hypokalemia • Hypomagnesemia • Vitamin deficiencies (thiamine) Dickerson R. Hospital Pharmacy 2002;37(7):770-5.
Metabolic Effects of Amino Acids • Estimating rise in BUN • 6.25 g AA = 1 g Nitrogen • Vd (L) = weight x 50-60% • Cp = (Nitrogen dose/Vd)(100)(0.5)= mg/dL • Example • 1 L 6% AA, 100 kg woman • Cp = (9.6 g/50 L)(100)(0.5) ~ 9.6 mg/dL
On day 4, the TPN is at goal. However, on rounds the medical resident notices that ZC’s BUN has risen from 20 mg/dL to 40 mg/dL, but he has good urine output. The patient is currently receiving a total of 50 g/d AA and he weighs 85 kg.- Would you expect the TPN to cause this degree of rise in BUN?- Approximately how much would you expect the BUN to change from baseline based on ZC’s AA intake? • Yes; Increase ~ 20 • No; No change expected • No; Increase ~ 2-5 • No; Increase ~ 7-10
Home Parenteral Nutrition • “Permanent” need (>90 days) • Strict reimbursement criteria • Estimated cost ~ $55,000/yr • Complications • Sepsis • Metabolic abnormalities • Air embolism • Organ dysfunction • Cycle TPN if possible • Cycle over 2-3 days • Cycle down to 12-18 hrs • Adjust electrolytes • Indication: • Non-terminal cancer • Ischemic bowel • Radiation enteritis • Bowel motility disorder • Bowel obstruction • High-output fistula • Celiac disease • Hyperemesis gravidarum August D. JPEN 2002;26(suppl):20SA.
Weaning • Begin when enteral route is tolerated • Calculate interim and final goals for enteral feeds • Determine adequate total caloric and protein intake • Prevent overfeeding, hyperglycemia, organ dysfunction • Transition to “natural” means of diet • No single best way to wean • Ensure patient has reached > 60% of goal calories or > 1000 kcals/d prior to TPN discontinuation
Helpful Resources • American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) – www.nutritioncare.org • The Society for Critical Care Medicine (SCCM)– www.sccm.org • The Oley Foundation – www.oley.org