Term
| What are the recommended potassium concentrations for preventing phlebitis in PPN? |
|
Definition
- Absolute concentration <60 mEq/L
- Preferably <40 mEq/L
|
|
|
Term
| How does potassium affect peripheral infusions? |
|
Definition
| Potassium can be irritating in peripheral veins and increase risk of phlebitis |
|
|
Term
| What is the smallest pore size filter that is recommended for TNA? |
|
Definition
| 1.2 um filter is smallest pore size recommended for TNA |
|
|
Term
| What type of filter is used for 2-in-1 and amino acid PN mixtures? |
|
Definition
| 0.22 um filter is used for 2-in-1 and amino acid PN mixtures |
|
|
Term
| Why are larger pore size filters allowed with 3-in-1 infusions? |
|
Definition
| The size of fat particles is generally between 0.1 and 1 um. IVFE can occlude 0.22 and 0.5 um filters, or the emulsion could become destabilized |
|
|
Term
| How is dextrose to be reported on the label of PN products (for example, as a percentage and volume [dextrose 50%, volume 500 mL])? |
|
Definition
| Grams of dextrose per day (e.g. dextrose, 250 g/day) |
|
|
Term
| What is the alternative carbohdyrate source for PN? |
|
Definition
|
|
Term
| How much calories does glycerol provide? |
|
Definition
|
|
Term
| What are the lipid components of IVFE in the United States? |
|
Definition
- 100% soybean oil
- 50:50 mix of soybean and safflower oil
|
|
|
Term
| What emulsifier is used in IVFE? |
|
Definition
|
|
Term
| Why is glycerin used in IVFE? |
|
Definition
| It makes the solution isotonic |
|
|
Term
| What are used to adjust the pH of IVFE? What is the pH? |
|
Definition
| Vitamin K and sodium hydroxide are used to adjust to pH range of 6 to 9 |
|
|
Term
| What are the different concentrations of IVFE and how many calories do they provide? |
|
Definition
- 10% (1.1 kcal/mL)
- 20% (2 kcal/mL)
- 30% (2.9 to 3 kcal/mL)
|
|
|
Term
| How can 30% IVFE be administered? |
|
Definition
| 30% IVFE is only approved for compounding of TNA, not for direct IV administration |
|
|
Term
| Why does the fat in TPN not provide 9 kcal/g? |
|
Definition
| The glycerol provides calories in addition to the fat |
|
|
Term
| What is the hang-time limit for IVFE, and why? |
|
Definition
| The hang-time limit for IVFE is 12 hours due to microbial growth potential for IVFE separate from dextrose and AA |
|
|
Term
| What is the hang-time limit for a mixture containing IVFE, dextrose, and amino acids in the same container? |
|
Definition
|
|
Term
| Why is the maximum hang time for TNAs longer than for IVFEs alone? |
|
Definition
| Bacterial growth is inhibited due to reduced pH (approximately 5.6 to 6) and because of the increased total osmolarity with the combination of all 3 substrates in one container |
|
|
Term
| What is the maximum IVFE infusion rate? |
|
Definition
| Maximum IVFE infusion rate should not exceed 0.11 g per kg per hour |
|
|
Term
| What is the risk of exceeding the maximum IVFE infusion rate? |
|
Definition
| Greater infusion rates are associated with an increased risk of side effects such as hypertriglyceridemia, infectious complications |
|
|
Term
| What is the assumed nitrogen content of amino acid products? |
|
Definition
| Amino acid products are assumed to be 16% nitrogen (6.25 g protein = 1 g nitrogen) |
|
|
Term
| What are the most common concentrations of amino acid stock solutions used for compounding? |
|
Definition
|
|
Term
| What is the daily PN requirement for sodium? |
|
Definition
|
|
Term
| What is the daily PN requirement for potassium? |
|
Definition
|
|
Term
| What is the daily electrolyte requirement for chloride? |
|
Definition
| As needed to maintain acid-base balance (along with acetate) |
|
|
Term
| What is the daily PN requirement for acetate? |
|
Definition
| As needed to maintain acid-base balance (along with chloride) |
|
|
Term
| What is the daily PN requirement for calcium? |
|
Definition
|
|
Term
| What is the daily PN requirement for magnesium? |
|
Definition
|
|
Term
| What is the daily PN requirement for phosphate? |
|
Definition
|
|
Term
| What are the preferred salt forms of calcium and magnesium for PN? |
|
Definition
| Calcium gluconate and magnesium sulfate |
|
|
Term
| What is the minimum amount of fat per week that adults should receive through TPN in order to avoid fatty acid deficiency? |
|
Definition
| Adults should receive a minimum of 100 g of fat per week in order to avoid EFAD |
|
|
Term
| Do patients on propofol require IVFE? |
|
Definition
|
|
Term
| Which populations should receive IVFE on a daily basis? |
|
Definition
- Glucose intolerance
- At risk for refeeding syndrome
- Pregnancy
|
|
|
Term
| What should be done in case of a PN calcium gluconate shortage? |
|
Definition
| Calcium should be removed from PN and ionized calcium levels should be monitored for signs of calcium deficiency. If needed, calcium chloride should be administered through a separate catheter from the PN. |
|
|
Term
| Should pediatric IV multivitamins be used in place of adult IV multivitamins in the case of a national shortage? Why? |
|
Definition
| No, because it may contribute to a shortage of pediatric products and the composition may differ from pediatric products |
|
|
Term
| What should be done in case of a national multivitamin shortage? |
|
Definition
| Reduce daily dose by half or provide multivitamin doses three times a week |
|
|
Term
| Can adult IV multivitamins be administered to neonates? Why? |
|
Definition
| No because they contain propylene glycol and polysorbate, which may create toxic side effects |
|
|
Term
| What should be done in case of a national trace element shortage? |
|
Definition
| Consider decreasing or eliminating the daily amount of trace elements added to PN formulations. Consider using a different concentration or salt form if available. |
|
|
Term
| How do specialty AA formulations for use in renal failure differ from standard formulations? |
|
Definition
| Renal failure formulations consist primarily of essential amino acids based on the theory that nonessential amino acids can be physiologically recycled from urea, while essential amino acids must be provided in the diet |
|
|
Term
| What are the indications for essential amino acid formulas? |
|
Definition
| Essential amino acid formulas offer no significant advantage over the standard formulations, and may result in metabolic complications. Therefore, indications for these formulations are very limited (e.g. renal failure). |
|
|
Term
| How do AA formulas designed for hepatic encephalopathy differ from standard formulas? Why? |
|
Definition
| They contain increased amounts of BCAAs and decreased amounts of aromatic amino acids (AAAs) compared to standard formulations. An altered metabolism in patients with hepatic failure can result in high serum ratio of AAA to BCAA. This imbalance is thought to cause increased transport of AAA into the brain, where they serve as precursors for neurotransmitters that may be responsible for altered mental status. |
|
|
Term
| How do modified amino acid formulations for use in metabolic stress, trauma, thermal injury, and hypercatabolic states differ from standard formulations? |
|
Definition
| They contain higher BCAAs based on the hypothesis that higher amounts of BCAAs are beneficial during severe metabolic stress because of increased skeletal muscle catabolism. |
|
|
Term
| Which BCAAs are provided in increased amounts in specialty AA formulations? |
|
Definition
| Leucine, isoleucine, valine |
|
|
Term
| What is the evidence regarding use of BCAA-enriched formulations in certain patient groups? |
|
Definition
| Use of BCAA-enriched formulations slightly improves nitrogen balance in certain patient groups, but clinical evidence does not support improved outcomes |
|
|
Term
| What are concentrated AA formulations used for? How do they differ from more dilute formulations and what must be done to compensate for this? |
|
Definition
| They are used for fluid restriction. Generally, acetate content is higher in more concentrated products. However, chloride salts may be used to balance the chloride-to-acetate ratio in the final PN formula to avoid acid-base disturbances. |
|
|
Term
| What clinical outcomes are associated with parenteral glutamine administration? |
|
Definition
| Parenteral glutamine administration is associated with a decrease in infectious complications, in hospital length of stay, and possibly in mortality in critically ill post-op or vent-dependent patients requiring PN. Glutamine may also be beneficial in patients undergoing major abdominal surgery and critically ill nonventilated patients requiring TPN |
|
|
Term
| What is glutamine and what is its importance for TPN? |
|
Definition
| Glutamine is an amino acid which is conditionally essential during periods of metabolic stress. Crystalline amino acid formulations do not contain glutamine, so there has been interest in adding it to TPN. |
|
|
Term
| How does parenteral glutamine affect adult hematopoietic stem cell transplant recipients receiving PN? |
|
Definition
| There is a trend toward fewer positive blood cultures with the use of parenteral glutamine in adult hematopoietic stem cell transplant recipients receiving PN |
|
|
Term
| How does parenteral glutamine affect adult burn and acute pancreatitis patients who require PN? |
|
Definition
| Parenteral glutamine may be beneficial in adult burn patients or in acute pancreatitis patients who require PN |
|
|
Term
| What are the guidelines for dosing with PN glutamine supplementation? |
|
Definition
| PN glutamine supplementation should probbaly be given early and in doses >0.2 g/kg/d in order to be effective |
|
|
Term
| What are the contraindications to parenteral glutamine? |
|
Definition
| There are no absolute contraindications to the use of parenteral glutamine, but LFT's should be monitored in all patients and it should be used with caution in hepatic failure patients and in patients with hepatic insufficiency |
|
|
Term
| How is parenteral glutamine obtained? |
|
Definition
| Parenteral free L-glutamine is available on an individual prescription, pharmacy-compounded basis in the US. |
|
|
Term
| What is the triglyceride makeup of IVFEs in the US? |
|
Definition
| IVFEs in the US are composed solely of long-chain triglycerides |
|
|
Term
| What are the primary fatty acids in US IVFEs? |
|
Definition
| linoleic>oleic>palmitic>linolenic>stearic |
|
|
Term
| How do IVFEs using the 50:50 mix of soybean oil and safflower oil compare to the 100% soybean oil in terms of fatty acid content? |
|
Definition
| Safflower oil contains only a trace of linolenic acid. Thus, IVFEs using the 50/50 mix of soybean oil and safflower oil contain half as much omega-3 fatty acid (linolenic acid) as IVFEs using 100% soybean oil |
|
|
Term
| Are MCT-LCT mixtures or structured lipid products available for IV use in the US? |
|
Definition
| No, neither is approved for IV use in the US |
|
|
Term
| What is a potential advantage of (investigational) MCT-LCT formulations for IVFE? |
|
Definition
| Such formulations may be useful for patients intolerant to currently available LCD products during critical illness and metabolic stress, and also useful in patients with carnitine deficiency because transport of MCTs into the mitochondria is carnitine independent |
|
|
Term
| What is the most significant potential use of IVFEs in omega-3 fatty acids? |
|
Definition
| Dramatic results have been seen in the treatment of PN-associated liver disease |
|
|
Term
| Do olive oil-based IVFEs risk fatty acid deficiency? |
|
Definition
|
|
Term
|
Definition
| Soy, MCT, Olive, Fish oil |
|
|
Term
| What is the biological function of carnitine? |
|
Definition
| Carnitine is necessary for the proper transport and metabolism of long-chain fatty acids |
|
|
Term
| Is carnitine present in PN formulations? |
|
Definition
| Carnitine is not present in any component of PN formulations. However, an IV form of L-carnitine is commercially available for the treatment of carnitine deficiency, AND is sometimes added to PN formulations |
|
|
Term
| What is one of the less emergent risks to running IVFEs over a fast infusion time (4-6 hours?) |
|
Definition
|
|
Term
| What are the formula recommendations for reducing risk of thrombophlebitis with PPN? |
|
Definition
- Osmolality should be <900
- Calcium and potassium concentrations should be low. For many institutions, this means calcium should be ≤5 mEq/L and potassium should be ≤40 mEq/L
- IVFE should be provided daily to increase calories and decrease osmolality
|
|
|
Term
| What is a way to piggyback IVFE into PPN without violating the 12-hour hang time limit? |
|
Definition
| The IVFE can be replaced at 12 hours so that IVFE are being infused for a total of 24 hours in order to decrease risk of thrombophlebitis |
|
|
Term
| Why does running IVFE concurrently with PPN decrease risk of thrombophlebitis? |
|
Definition
| The hypothesis is that it dilutes the PPN formulation and has buffering action on the vein |
|
|
Term
| What are some medication-related techniques for reducing risk of thrombophlebitis with PPN? |
|
Definition
- The addition of heparin and/or small amounts of hydrocortisone with PPN
- Use of a nitroglycerin patch at the venous insertion site
|
|
|
Term
| What are some advantages of TNA as it relates to compounding? |
|
Definition
- All components are aseptically compounded by the pharmacy
- Preparation is more efficient for the pharmacy personnel, especially if automated
|
|
|
Term
| What are some advantages of TNA as it relates to administration? |
|
Definition
- Less manipulation of the system during administration
- Less nursing time required for one container and no piggyback IVFE
- Less supply and equipment expense for only one infusion pump and IV tubing
|
|
|
Term
| What are some advantages of TNA as it relates to contamination? |
|
Definition
- Less risk of contamination during administration
- Inhibited or slower growth if contamination does occur compared with separate IVFE
|
|
|
Term
| What is the advantage of TNA in home settings? |
|
Definition
| More convenient storage, fewer supplies, and easier administration |
|
|
Term
| What are some advantages to TNA as they relate to patients? |
|
Definition
- Dextrose and venous access tolerance may be better in some situations
- Possible application in fluid restricted patients because IVFE 30% is restricted to use in TNA
- Fat clearance may be better when IVFE is administered over more than 12 hours
|
|
|
Term
| How does the cost of TNA compare with 2-in-1? |
|
Definition
| TNA may be more cost-effective overall in certain settings |
|
|
Term
| What is a disadvantage of TNA as it relates to filter size? |
|
Definition
| Larger particle size of IVFE precludes use of 0.22 micron filter and requires use of the larger pore-size filter of 1.2 microns |
|
|
Term
| How does TNA compare with 2-in-1 in terms of stability? |
|
Definition
- Admixed IVFE are less stable and prone to separation of lipid components
- Formulations are more sensitive to destabilization with certain electrolyte concentrations
- Formulations are more sensitive to destabilization with low concentrations of dextrose and amino acids
- Lower pH amino acid formulations may destabilize the IVFE portion of admixture
- Formulation may be unstable when the final concentration of IVFE is low
|
|
|
Term
| What are the disadvantages of TNAs as they relate to visualizing precipitates and catheter occlusion? |
|
Definition
- TNAs make it difficult to visualize precipitate or particulate matter in the opaque admixture
- Catheter occlusion is more common with daily IVFEs
|
|
|
Term
| How does medication compatibility affect TNA use? |
|
Definition
| Certain medications are incompatible with the IVFE portion of the admixture |
|
|
Term
| In general, how does the stability of TNA compare with 2-in-1? |
|
Definition
| TNA is less stable over time than 2-in-1 |
|
|
Term
| What are the USP low, medium, and high risk categories for compounded sterile preparations? |
|
Definition
- Low: a simple, closed-system aseptic transfer
- Medium: reconstitution of several sterile commercial products for transfer into several small-volume mini bags or or one large-volume parenteral preparation
- High: preparation from bulk nonsterile ingredients or the preparation from sterile ingredients that are exposed to less than ISO class 5 standards
|
|
|
Term
| What are examples for the low, medium, and high-risk levels of national standards for compounded sterile preparations? |
|
Definition
- Low: reconstitution of a single dose vial of a lyophilized powder with a sterile diluent for transfer into another container (e.g. pediatric PN multivitamins)
- Medium: mixing of multiple manufactured additives for transfer into a large-volume PN solution (e.g. PN formulations)
- High: prep of a nonsterile powder for IV infusion (e.g. supplemental glutamin for PN infusion)
|
|
|
Term
| What are the room-temperature beyond-use dating (expiration times) for low, medium, and high levels of compounded sterile preparations? |
|
Definition
- Low: 48 hours
- Medium: 30 hours
- High: 24 hours
|
|
|
Term
| What are the refrigeration beyond-use dating (expiration times) for low, medium, and high-risk sterile preparations? |
|
Definition
- Low: 14 days
- Medium: 9 days
- High: 3 days
|
|
|
Term
| What is the difference between an expiration date and a beyond use date? |
|
Definition
| The expiration date is based on drug stability. The beyond use date is based on chemical instability or product sterility |
|
|
Term
| What must be done to high-risk compounded sterile preparations prior to administration? |
|
Definition
| High-risk products must undergo some type of terminal sterilization prior to administration |
|
|
Term
| What are some of the advantages of automated compounded devices for PN formulations? |
|
Definition
- Instead of trying to compound easily-measured volumes, any volume of a formulation can be used
- Decreased pharmacy labor and supply costs for institutions making more than a few PN formulations per day
- Reduced risk of contaminants such as "coring" of rubber vial tops and fibers from alcohol swabs
|
|
|
Term
| What are some of the disadvantages of automated compounding devices for PN? |
|
Definition
| Not cost-effective for institutions which make only a few PN formulations per day |
|
|
Term
| What must be done after PN is compounded conventially (i.e. by hand rather than ACD) to ensure that it has been compounded accurately? |
|
Definition
| Additive vials and syringes must be inspected prior to dispensing the final product. A pharmacist other than the compounding personnel is preferred for confirming that the measured volumes in syringes correspond with the PN order |
|
|
Term
| What are the major methods for verifying the accuracy of the compounded process by ACDs? |
|
Definition
| Volumetric or gravimetric analysis |
|
|
Term
| How is gravimetric analysis for a given compounded mixture calculated? |
|
Definition
| Sum of the volume of each ingredient multiplied by its specific gravity |
|
|
Term
| Can gravimetric analysis be used for both manual compounding and ACDs? |
|
Definition
| Yes, it can be used for both |
|
|
Term
| How can gravimetric analysis be used to measure the validity of a compounded mixture? |
|
Definition
- Final PN admixture can be analyzed
- The weight for the containers of each individual component can be analyzed (before and after compounding)
|
|
|
Term
| How can refractometry be used to determine if PN formulations have been compounded properly? |
|
Definition
| The refractive index of dextrose and amino acids can be measured with a refractometer and compared with values established for known concentrations of dextrose and amino acids in PN formulations |
|
|
Term
| What are some limitations of refractometry with PN? |
|
Definition
- It cannot be used with IVFEs, so alternative measures must be used for TNAs
- Factors other than incorrect preparations can result in refractive indices from predicted values (for instance, when dextrose concentration exceeds 15%)
|
|
|
Term
| What can be done if dextrose concentrations in PN exceed the concentration required for accurate refractometric analysis? |
|
Definition
| Samples can be diluted and compared against control solutions |
|
|
Term
| What are the responsibilities of the pharmacist for monitoring compounded sterile preps after they leave the pharmacy for distribution? |
|
Definition
| Pharmacists are responsible for packaging, handling, and transport of the PN formulation to the patient or caregiver |
|
|
Term
| What can be done to help ensure the safety of PN formulations after they leave the pharmacy for distribution? |
|
Definition
- Written procedures must be developed to ensure that the PN formulation is not exposed to extremes in temperature or light
- The use of seals on all ports of PN containers can enhance product integrity during handling and transport
|
|
|
Term
| Why is particular attention to quality and control after dispensing required for home PN products? |
|
Definition
| There is significant time and handling between PN production in the pharmacy and delivery to patient or caregiver |
|
|
Term
| Why must premixed PN formulations be mixed to blend the dextrose and amino acid components immediately prior to use? |
|
Definition
| Mixing the dextrose and amino acid components prior to sterilization would create the Maillard reaction, which alters the integrity of both dextrose and amino acids |
|
|
Term
| What is available in terms of premixed PN formulations? |
|
Definition
| In addition to two premixed dextrose-amino acid products, there is a glycerol-based product (Procalamine) that is often used for short-term PPN administration |
|
|
Term
| What is the advantage to glycerol-based PPN? |
|
Definition
| Because glycerol is a sugar alcohol, the product can be premized and sterilized in a single bag without undergoing the Maillard reaction that precludes heat steriliation of mixed dextrose and AA solutions |
|
|
Term
| What are some of the advantages of premixed products? |
|
Definition
- Relatively long shelf life
- Require minimal admixing
|
|
|
Term
| How are vitamins added to premixed TPN products, and why? |
|
Definition
| All premixed products require the addition of multiple vitamin injection shortly before administration because vitamins are essential components of PN that are not stable when addded more than 24 hours in advance of use |
|
|
Term
| What is stability in the context of PN admixtures? |
|
Definition
| Degradation of nutritional components that change their original characteristics (e.g. Maillard reaction). Stability may also refer to the ability of PN additives, including medications, to maintain their chemical integrity and pharmacological activity (an example would be photodegradation of vitamins). |
|
|
Term
| What is compatibility in the context of PN admixtures? |
|
Definition
| Compatibility generally involves the formation of precipitates |
|
|
Term
| How does octreotide fare when added to PN formulations? |
|
Definition
| Glycosylation of octreotide and subsequent loss of activity may occur when drug is added to PN formulations (thus, it shouldn't be added to formulations) |
|
|
Term
| How should unstable substances be handled with TPN admixing? |
|
Definition
| Unstable substances should not be added to PN regardless of physical compatibility |
|
|
Term
| How does compatibility differ for TNA vs. 2-in-1 formulations? |
|
Definition
| Some drugs are compatible in dextrose-amino acids but not TNA formulation. There are also a few drugs (usually fat-soluble) that are compatible with TNA but not dextrose-amino acid formulations |
|
|
Term
| What can happen when the fat emulsion becomes unstable? |
|
Definition
| The fat globules aggregate into larger globules and can lodge in the pulmonary vasculature, compromising respiratory function |
|
|
Term
| What chemical factor ensures the stability of fat droplets in IVFE? |
|
Definition
| The surfact of the fat droplet has a negative charge that repels other fat droplets (also negatively charged). When the surface charge becomes less negative, fat droplets begin to aggregate into larger fat globules. |
|
|
Term
| What factors can alter the electrical charge of the fat droplet? |
|
Definition
- Reduction in pH
- Addition of electrolyte salts
|
|
|
Term
| What pH range is most favorable for IVFE stability? What happens when the IVFE is not in this range? |
|
Definition
| pH range of 6 to 9 is most favorable for IVFE stability. Lowering the pH below 5 or increasing the pH above 10 may crack the emulsion. |
|
|
Term
| Are cracked admixtures safe to use? |
|
Definition
|
|
Term
| What is the single most critical factor influencing pH of a PN formulation? |
|
Definition
| The crystalline amino acid solution used for compounding |
|
|
Term
| How does the pH of the amino acid solution affect the final pH of the PN formulation? |
|
Definition
| The final pH of the formulation is generally very near that of the amino acid solution unless the buffering capacity of the amino acids has been overwhelmed by other PN components |
|
|
Term
| How does the pH of amino acid solutions affect their appropriateness for PN? |
|
Definition
| Those with a pH of 5.3 or less are not appropriate for use in TNA because they risk lowering the final pH and cracking the IVFE |
|
|
Term
| How is amino acid solution pH different in the context of home care? |
|
Definition
| Using amino acids that are very high or low pH in home care is especially problemating because the PN is made several days in advance of use (and thus offers more time for the IVFE to crack) |
|
|
Term
| What is cysteine hydrochloride used for in PN? |
|
Definition
| Use of cysteine hydrochloride is routine in neonatal formulations and some pediatric formulations |
|
|
Term
| How does use of cysteine hydrochloride affect the final admixture? |
|
Definition
| Use of cysteine hydrochloride renders the final admixture pH less than 5, promoting IVFE destabilization |
|
|
Term
| What distinguishes pediatric AA products from adult ones? |
|
Definition
| Pediatric products are the only ones containing taurine |
|
|
Term
| Why might a pharmacist add cysteine hydrochloride to an adult PN formulation? |
|
Definition
| Pharmacists might add cysteine hydrochloride to an adult formulation in order to increase calcium phosphate solubility (for instance, when a patient is eliminating large amounts of calcium through foscarnet therapy) |
|
|
Term
| How should dextrose be added to IVFE and why? |
|
Definition
| A concentrated dextrose solution should not be added directly to IVFE because of its acidic pH. Rather, dextrose should be combined with the amino acid solution first during the compounding process. |
|
|
Term
| How does the final amino acid concentration affect the stability of TNA? |
|
Definition
| The amino acid solution serves as a buffer, and a low final concentration of amino acids (less than 4%) may not provide adequate buffering capacity to prevent TNA destabilization |
|
|
Term
| How does IVFE concentration affect TNA stability? |
|
Definition
| Low IVFE concentrations (especially below 2% or 2.5%) may result in unstable TNA |
|
|
Term
| How does IVFE concentration affect PN compounding when the solution is being prepared for 3 to 7 days in advance of use? |
|
Definition
| When compounding for 3 to 7 days in advance of use, IVFE concentration may need to be higher for a stable TNA formulation (especially if other components contribute to destabilization) |
|
|
Term
| How does pH affect the risk of calcium phosphate precipitation? |
|
Definition
| High pH increases risk of precipitation |
|
|
Term
| Why is L-cysteine sometimes added to pediatric PN formulations? |
|
Definition
| Relatively large doses of calcium and phosphorous are added to neonatal PN formulations to optimize bone function. Although pediatric amino acid products are formulated at lower pH, cystiene hydrochloride can be added to decrease pH and increase calcium phosphorous solubility (cysteine is also considered a semi-essential AA in premature infants). |
|
|
Term
| Why is caution required when formulating PN for pediatric formulations? |
|
Definition
| The lower pH necessary to prevent calcium-phosphorous precipitation can destabilize the IVFE. Thus, TNA is sometimes discouraged for this group. |
|
|
Term
| How does concentration of calcium and/or phosphorous affect risk of precipitation? |
|
Definition
| As the concentration for either micronutrient increases, the risk of precipitation increases as well |
|
|
Term
| What are the limits of using product-specific solubility curves for prevention of calcium-phosphate precipitation when formulating TPN? |
|
Definition
| Most of the curves were developed using fixed concentrations of amino acids, dextrose, calcium, and phosphate and omit other components that might influence calcium-phos solubility |
|
|
Term
| How should large doses of calcium be handled with TPN? |
|
Definition
| Verification with the prescriber can minimize risk of precipitation |
|
|
Term
| What qualifies as a large dose of PN calcium? |
|
Definition
| Greater than twice the RDA |
|
|
Term
| What are some causes of decreased calcium that would not be aided by increasing PN calcium? |
|
Definition
- Hypoalbuminemia
- Fluid retention
- Acid-base disturbances
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|
Term
| How should calcium concentrations be measured if hypoalbuminemia is present? |
|
Definition
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Term
| What should be done when PN calcium provision is below the recommended 10-15 mEq/day? |
|
Definition
| Metabolic bone disease must be considered when PN calcium does not meet recommendation, as serum calcium is maintained at the expense of bone calcium |
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|
Term
| How does the salt form of calcium in PN affect risk of precipitation? |
|
Definition
| Calcium gluconate and calcium gluceptate are less likely to produce precipitates than chloride salts |
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|
Term
| How are calcium-phosphorous solubility curves affected by the form of calcium salt added? |
|
Definition
| Solubility curves for calcium phosphate are specific for each calcium salt and cannot be interchanged. Most solubility curves are for calcium gluconate. |
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|
Term
| What should be done to prevent calcium-phosphate precipitation once the PN formulation is created? |
|
Definition
| High localized phosphate or calcium concentrations can occur if the final container is not sufficiently agitated or the contents are not sufficiently dispersed during the compounding process. |
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|
Term
| What are typical results of medication incompatibilities with PN formulations? |
|
Definition
- Precipitates
- Haziness
- Discoloration
- Emulsion disruption
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|
|
Term
| What pore size of filter is adequate for removing precipitates and particulate matter? |
|
Definition
|
|
Term
| What are 0.22 micron filters useful for? |
|
Definition
| They remove certain pathogens (unlike the larger filters used for IVFEs, which can only remove very large organisms) |
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|
Term
| What should be done when an occlusion alarm goes off during PN administration? |
|
Definition
| It sould be recognized as a potential sign of a precipitate forming and investigated by a healthcare practitioner |
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|
Term
| Should an occluded filter be removed to allow PN to infuse freely? |
|
Definition
| NO, under no circumstances |
|
|
Term
| Are in-line infusion filters recommended for the purpose of infection control? |
|
Definition
| No, because they reduce but do not eliminate the risk |
|
|
Term
| What is the maximum allowable amount of aluminum in large-volume parenterals (LVPs)? |
|
Definition
|
|
Term
| What factors influence the amount of aluminum in a product? |
|
Definition
| Aluminum content increases over time. Products with an affinity for aluminum can leach it from containers and closures. |
|
|
Term
| What can be done to prevent aluminum leaching? |
|
Definition
| Storing products in plastic containers results in less leaching than storing them in glass containers |
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|
Term
| Why is PN aluminum particularly concerning? |
|
Definition
| The body typically absorbs <1% of aluminum from the GI tract. However, the body has no effective barriers to aluminum contaminants |
|
|
Term
| Which patients are at risk of aluminum toxicity? |
|
Definition
- Significant renal dysfunction
- High intake of PN products
- Iron deficiency
|
|
|
Term
| How is aluminum excreted? |
|
Definition
|
|
Term
| What are the symptoms of aluminum toxicity? |
|
Definition
- Progressive encephalopathy
- Patchy osteomalacia
- Reduced parathyroid hormone secretion
- Epo+iron-resistant microcytic anemia
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|
|
Term
| What are common dextrose stock solution concentrations? |
|
Definition
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|
Term
| What are common amino acid stock solution concentrations used for MANUAL compounding? |
|
Definition
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