| Question | Answer |
| What is parenteral nutrition? | tube/catheter placed intravenously |
| what are electrolytes? | -substances that dissociate into +/- charged ions
-extracellular: sodium/calcium/bicarb/chloride
Intracellular: potassium/magnesium/phosphate |
| Indications of Parenteral Nutrition Support | -nonfunctioning GIT
-need for Bowel Rest
-severe malnutrition and EN not possible, or inadequate to meet needs
-Patients whose nutrition needs exceed what can be met enterally
-pre-operative repletion of malnourished patients |
| contraindications of Parenteral Nutrition Support | -Funtioning GIT
-Ethical contraindications |
| PN | Parenteral Nutrition |
| CPN | Central Parenteral Nutrition (Same as TPN) |
| TPN | Total Parenteral Nutrition (same as CPN) |
| PPN | Peripheral Parenteral Nutrition |
| what defines whether PN is Central of Peripheral? | defined by the position of the tip (NOT by the site of entry) |
| Components of PN | -crystalline Amino Acids
-Lipid emulsions (LCFA/MCFA)
-emulsified
-monohydrate glucose (Dextrose)
-vitamins
-minerals
-electrolytes |
| Non-tunneled central line | -most common short-term CPN
-catheter placed in subclavian vein
-threaded into superior vena cava |
| What are the 2 types of short term CPN? | -non-tunneled central line
-Peripherally inserted central catheter |
| Peripherally Inserted Central Catheter (PICC) | -central line via peripheral access
-entrance in antecubital vein
-threaded into subclavian vein
-catheter tip in superior vena cava |
| Name 4 other uses for central lines | -IV antibiotic therapy
-Blood
-Meds
-Chemo |
| What are the 2 types of long term CPN? | -tunneled catheters
-implanted ports |
| What is a tunneled catheter? | -long-term CPN
-placed in subclavian vein
-catheter tunneled away from vein to exit on anterior chest
-decreases risk for infection by separating exit and venipuncture sites |
| How do tunneled catheters decrease risk of infection? | -separates exit and ventipuncture sites
-less chance for self-contamination |
| What is an Implanted Port? | -long-term CPN
-placed in subclavian vein and threaded into superior vena cava
-catheter tunneled away from vein to port placed inot a subcutaneus pocket of anterior chest
-surgically placed
-directly under skin |
| Peripheral Parenteral Nutrition | -for short-term
-standard peripheral lines: site rotation every 48-72 hours
-extended dwell catheters: up to 4 weeks |
| How often should you rotate the standard peripheral line? | 48-72 hours |
| What are common complications of PPN? | -phlebitis
-phlebotomy |
| What is the CHO source for the typical PN solution? | -Monohydrate Glucose
-aka Dextrose |
| how many kcals are in dextrose monohydrate? | 3.4 kcal/g |
| What are the typical concentrations of Dextrose stock solutions? | -D50 (50% dextrose)
-D70 (70% dextrose) |
| What are the typical final dextrose concentrations? | -D15 (15% dextrose) TO D35 (35% dextrose) |
| What is the Maximum CHO load of a typical PN solution? | -5 mg/kg/min
-7 mg/kg/min may be tolerated in burns/trauma |
| what happens when the Maximum CHO load of typical PN solution is exceeded? | -the liver may not be able to clear it
-causes fatty liver |
| What is the typical ptotein source in a PN solution? | -crystalline amino acids
-EAA and NEAA |
| What are the typical concentration of Amino Acid Stock solutions? | -may vary in concentration
-8.5% and 10% common |
| what % of standard Amino Acid solutions made of Essential Amino Acids? | 40-50% |
| What % of standard Amino Acid solutions made of Non-essential Amino Acids? | 50-60% |
| How are Amino Acid compositions different for PN solutions for renal failure? | -more Essential Amino Acids
-little to no Non-Essential Amino Acids |
| How are Amino Acid compositions different for PN solutions for liver failure? | -increased Branched Chain Amino Acids |
| What kinds of lipids are found in the typical PN solution? | -safflower oil, soybean oil, or combo
-PLUS glycerol and lecithin |
| How much Essential Fatty acids are in the typical PN solution? | 50-65% linoleic acid |
| What is the caloric value of amino acids in TPN solution? | 4 kcal/g |
| What are the most common concentrations of Amino Acids in a stock solution? | -8.5%
-10% most common |
| What is the minimum amount of CHO needed in a TPN solution to prevent endogenous glucose production? | 100-150g/day |
| What are the most common stock solution concentrations found for lipid emulsions? | 10 or 20%
-20% more common |
| What is the caloric value of a typical TPN lipid emulsion? | -10 kcal/g
-additional kcal is from the glycerol backbone |
| what is the maximum amount of lipids that should be given in a TPN solution? | 1 g/kg/day
-this is in U.S. solutions |
| What adverse effects could result from exceeding the recommended maximum for lipid administration? | -fatty liver |
| What is the most common anion attached to Calcium as a standard additive of TPN solutions? | -gluconate |
| What is the benefit of adding Heparin to a TPN solution? | -prevents blood clots from forming |
| What is the benefit of adding pepcid to a TPN solution? | minimizes gastric secretions |
| Why is iron not added to PN solutions? | -because of incompatibility issues
-forms precipitates
-reduces immune system functions
-iron dextran associated with anaphylaxis |
| How are Structured Triglycerides produced? | -synthesized by random esterification of fatty acids onto a glycerol backbone
-Triglycerides are hydrolyzed, then re-esterified randomly into medium chain fatty acids |
| What is the benefit of medium chain fatty acids in a structured triglyceride PN formula? | -can bypass lymphatic system
-don't require carnitine for transport into mitochondria
-are rapidly oxidized |
| what is the caloric value of medium chain fatty acids? | 8.3 kcal/g |
| What are the long chain fatty acids found in structured triglyceride PN formulas? | -mostly omega-3 fatty acids
-omega-6
-omega-9 |
| What are the demonstrated benefits of a Structured Triglyceride PN formula compared to standard lipid emulsions? | -reduced nitrogen loss
-improved immune function
-reduced fatty infiltration of the liver |
| What are Olive Oil-based lipid emulsions? | -experimental lipid emulsion that is used in Europe, but not approved by FDA in US
-80% olive oil
-20% soybean oil
-ClinOleic is an example |
| What are Fish Oil lipid emulsions? | -experimental lipid emulsion that is used in Europ and elsewhere, but are not approved by the FDA in US
-100% fish oil
-Omegaven is an example |
| What is the benefit of using dipeptides containing glutamine for experimental PN solution? | -free glutamine is highly insoluble and cannot be added to PN solutions
-need to attach glutamine to dipeptides to make it more soluble
-interest in glutamine due to role in gut maintenance |
| What is the experimental evidence of benefits of Glutamine? | -improved muscle protein synthesis and nitrogen balance
-conflicting evidence regarding TPN-related GI mucosal atrophy |
| What is a "2-in-1" + lipids formulation? | -Dextrose and amino acids in 1 bag
-lipids in different bag |
| What is a "Total Nutrient Admixture" (TNA) formulation? | -dextrose, amino acids, and lipids all in the same bag |
| What is the ideal osmolarity of a peripheral infusion? | ~650 mOsm/L to prevent phlebitis |
| What is the result of too high of osmolarity of a peripheral infusion? | can cause phlebitis |
| What are the advantages of peripheral parenteral nutrition? | -non-surgical
-less risks
-less cost |
| what are the disadvantages of peripheral parenteral nutrition? | -osmolarity and volume issues
-maintenance of access (standard IV) |
| What are the advantages of central parenteral nutrition? | -can accomodate hypertonic solutions
-better for long-term |
| What are the disadvantages of central parenteral nutrition? | -technical placement
-higher risks
-higher cost |
