Ascend TPN Calculator v.111505
the Ascend TPN calculator can do
Assign a category to TPN order-types
Edit units of measure
Create TPN groups
Select source attributes for each group
Add/edit TPN formulary items
Checking for common setup problems
Using the Ascend TPN Calculator: Methods
Enter TPN data by ingredient
Dosing by weight
Enter TPN data by attribute
Enter TPN data by ingredient AND by attribute
Questions and answers
What the Ascend TPN calculator can do
The Ascend TPN calculator:
TPN ingredients possess certain "attributes" that may be desirable for your patient. Generally, these include electrolytes and nutrients. Electrolyte/nutrient "attributes" include Sodium, Potassium, Calcium, Magnesium, Phosphate, Acetate, Chloride, Calories (KCal), Protein, Branch chain amino acids (BCAA), Lipids, Carbohydrates, and Non-protein calories (NP-KCal). During order entry, you can specify the desired values for most of these attributes and the calculator will select appropriate ingredients/amounts to provide these attributes, and calculate any unspecified attributes and intrinsic values that are also included. Attribute names are pre-defined within Ascend and should not be edited or deleted.
TPN ingredients also possess certain "intrinsic" values that are automatically included in the results of the calculation, but cannot be directly specified by the user. Intrinsic values include Nitrogen, Osmolality, Zinc, Copper, Manganese, Chromium, Selenium, Iodine, Aluminum, and other user-defined intrinsic values. During order entry, you cannot specify desired values for intrinsic items. However, you will be able to review the amounts of each intrinsic item provided by the ingredients, after the calculation is completed. For example, you can't specify how much Nitrogen you want because Nitrogen is an intrinsic value. You can, however, specify how much Protein (an "attribute") you want and then see how much Nitrogen will be provided as a result. A common TPN ingredient, "TRACE ELEMENTS", usually contains several intrinsic items such as Zinc, Copper, Manganese, Chromium, Selenium and Iodine. You can select TRACE ELEMENTS for the TPN solution and specify how many MLs you want; the calculator can tell you how much of each intrinsic item this provides. As another example, you can select ZINC SULFATE as an ingredient and specify how many milligrams of Zinc or millililters of the stock solution you want to add to the TPN; the calculator will add this Zinc quantity to the total intrinsic amounts when you calculate. However, you can't specify how much Selenium or Zinc you want via the intrinsics and have the calculator do the reverse calculation.
You can create your own intrinsic items if needed. Aluminum is an example of a user-defined intrinsic item.
Ascend allows you to assign inventory items to "groups" to make ingredient selection easier during order entry. Each inventory group may contain one or more inventory items. For example, "DEXTROSE 50% 500ML", "DEXTROSE 70% 500ML" and "DEXTROSE 50% 2000ML" might all belong to a "Dextrose" group. "SODIUM CHLORIDE 23% 30ML" AND "SODIUM CHLORIDE 40MEQ/20ML" might both belong to a "Sodium Chloride" group. Each inventory item that is assigned to the same group will also be assigned a "preference" ranking to enable the TPN calculator to know which item from the group you will normally prefer to use. In some cases, only one inventory item may occupy a "group".
Many TPN ingredients contain a variety of electrolyte/nutrient "attributes" and/or "intrinsics". In most cases, the "attribute" is the primary desired clinical component that the TPN ingredient supplies! When this is the case, the ingredient is said to be a primary "source" for that attribute. However, many ingredients provide multiple attributes. For example, the inventory item "AMINO ACIDS 8.5% 500ML" might contain Protein, Potassium and Acetate attributes. However, the solution can only be considered a clinically relevant "source" of Protein...the Potassium and Acetate attributes are present, and can be accounted for, but they not the primary clinical reason that AMINO ACIDS 8.5% are included in the TPN formulation. In a similar manner, the ingredient, "SODIUM PHOSPHATE 45MEQ/15ML", can be considered a "source" for the attributes, Phosphate and Sodium. The TPN calculator uses "source" information to determine which inventory items should be considered as a source for that electrolyte/nutrient attribute. To make it easier, Ascend lets you assign "source" status to attributes on a "group" level so you don't have to specify this information for every TPN-related inventory item. For example, for the "Dextrose" group mentioned previously, you can select the "source" attributes as being Calories, Carbohydrates, and Non-protein calories...this source assignment will automatically be applied to the three Dextrose solutions that are part of the example "Dextrose" group.
Preparations to use the Ascend TPN calculator include assigning TPN order type categories, editing units of measure, creating TPN groups, assigning source attributes to the groups, and adding/editing inventory records for use with the calculator.
Assign a category to TPN order-types:
To use the TPN Calculator with TPN orders, each TPN order-type must be pre-associated with the "Outpatient IV Infusion" category. If not, during order entry you may get a message to correct this situation when you attempt to view the "TPN" tab. It is common to have multiple TPN order-types to support a variety of billing needs. To associate a TPN order-type with this category:
Edit units of measure:
Inventory items, TPN attributes and TPN intrinsics must share units of measure (UOM) that are uniform in description and meaning. Furthermore, conversions from one unit of measure to another require preset formulas. Units of measure can be entered and edited as follows:
Unit of measure list with sample duplicates:
Mg Strength An exact duplicate (case doesn't matter). Delete it.
mgs Strength An unnecessary "similar" abbreviation. Delete it.
ml Per Not a duplicate (Type field is different). Keep it.
mls Per An unnecessary "similar" abbreviation. Delete it.
gms Strength An unnecessary "similar" abbreviation. Delete it.
Create TPN groups:
Ascend uses inventory "groups" for several purposes. In particular, then may be useful during order entry to limit the selection list to members of a selected group. However, an inventory item must belong to a TPN-related group if you will be using the TPN calculator to order by an "attribute" (e.g., specify the amount of "Sodium") that is provided by that inventory item (e.g., SODIUM CHLORIDE 23% INJ). On the other hand, you do not need to assign a TPN ingredient to a group, if it doesn't provide any TPN attributes or intrinsics. To begin, create the inventory "groups" that will be required to support your TPN-related inventory items. To do so:
Suggested TPN-related inventory groups (with suggested source attributes):
Suggested Source Attributes
Amino acids Protein
Amino acids - branched chain (BCAA) BCAA, Protein
Amino acid/Dextrose Premix Protein
Dextrose Calories, Carbohydrate, Non-protein calories
Electrolyte concentrate Sodium
Lipids Calories, Lipids, Non-protein calories
Magnesium sulfate Magnesium
Potassium acetate Acetate, Potassium
Potassium chloride Chloride, Potassium
Potassium phosphate Phosphate, Potassium
Sodium acetate Acetate, Sodium
Sodium chloride Chloride, Sodium
Sodium phosphate Phosphate, Sodium
Trace elements-5 * (Usually contains intrinsic items, but no source attributes)
Zinc sulfate (Contains Zinc intrinsic, but no source attributes)
Selenium injection (Contains Selenium intrinsic, but no source attributes)
* The absolute amount of each attribute/intrinsic may differ between members of a group as long as each item contains some of every shared source attribute. You will need to create a separate group for inventory items that do not share ALL of the source attributes that are provided by the other members of the same group. For example, "NaCL 23% 30ML" and "NaCl 9% 50ML" solutions could be in the same group since they both share the Sodium and Chloride source attributes, although in different amounts. "Calcium chloride 10%" and "Calcium gluconate 10%" can be in the same group because they share only one source attribute, "Calcium" (assuming Calcium chloride is not considered a source for Chloride)
Some TPN additives may not have to be members of an inventory group. For example, Multivitamins, Heparin, Insulin and Famotidine are often included in TPN formulations, but don't provide any TPN attributes or standard intrinsics. Therefore, you don't need to assign "HEPARIN 100 unit/ml INJ" to a "Heparin" TPN group, nor do you need to create a "Heparin" TPN group.
You may add other groups other than those that are listed, if you follow the established pattern. You may omit or delete any groups that are not needed.
Select which electrolytes/nutrients are source attributes for each group:
For each TPN-related group on the inventory group list (continued from above):
Note: DO NOT designate electrolyte attributes (e.g., Na, K, etc) as source attributes for "amino acid" groups or for "amino acid/dextrose premix" groups, or errors may be displayed during calculations. These amino acid groups should be "sources" of Protein only. (Don't worry, the dextrose and electrolytes, if any, will be included the calculations, even if they are not designated as "sources" for the group).
Note: "Electrolyte concentrate"
group solutions typically contain Sodium, Acetate, Calcium, Mg, K,
etc. Never-the-less, we recommend that "Sodium" be the only
attribute designated as a "source" for these concentrates. The
other non-source electrolyte attributes will be included in the
Inventory items belonging to a group must share the same source attributes. For example, if the "Potassium chloride" group is assigned the "Potassium" and "Chloride" source attributes, then all inventory items assigned to this group MUST provide the Potassium and Chloride source attributes. If an inventory item should have more, less or different source attributes than the group you are contemplating assigning to that inventory item, you may need to create a new group with the appropriate matching attributes. It is normal for several inventory items in one group to have different values or amounts for the shared attributes [e.g., DEXTROSE 70% and DEXTROSE 50% share the same attributes, "Calories", "Carbohydrate", and "Non-protein calories". However the amounts for each attribute will differ in each case (e.g., carbohydrate: 0.7GM/ML v.s. 0.5GM/ML respectively)]
In some cases, only one source attribute (e.g., Calcium) is assigned to one group (e.g., Calcium), which may, in turn, be assigned to just one inventory item (CALCIUM GLUCONATE 10% 10ML). This may seem unnecessarily complicated for such simple cases, but this hierarchy is necessary to support multiple inventory items belonging to one group all sharing the same source attributes.
Add/edit TPN inventory items:
For the most part, adding a TPN-related inventory item is no different than entering a normal item. The following instructions will assume the basic inventory item fields have already been added to an inventory record and will focus on the specific fields and additional steps that are unique or important for TPN-related items. The instructions will also assume that TPN "groups" have been created and "source" attributes have been assigned to them, as outlined above.
Note: If necessary, you may have to use the same value and unit of measure for the "strength" as you do for the "per" entries for some items. For example, "MVI 10ML (strength) / 10ML (per)".
DEXTROSE 50% 2000ML 1000GM 2000ML
AMINO ACIDS 10% 500ML 50GM 500ML
FAT EMULSION 20% 500ML 100GM 500ML
NA-PHOSPHATE 3mM/ML 15ML 45mM 15ML
TRACE METALS 5ML 5ML 5ML
Sample preferences: Group
Dextrose Dextrose 70% 500ml 2 (most preferred)
Dextrose Dextrose 50% 500ml 1 (least preferred)
Amino acid Aminosyn 15% 500ml 3 (most preferred)
Amino acid Aminosyn 10% 500ml 2
Amino acid Aminosyn 8.5% 500ml 1 (least preferred)
Calcium Calcium gluc 10% 10ml 2 (most preferred)
Calcium Calcium Chloride 10% 10ml 1 (least preferred)
Note: Amino acid solutions can have "Calories" as an attribute, but should not be assigned "Non-protein calories" as an attribute. Dextrose and lipids can, on the other hand, be assigned both.
Note: You must supply a value for source attributes (i.e., attributes that are assigned as a "source" for the "group" that this inventory item belongs to). You can also specify other attributes that are present, even if they are not "source" attributes (e.g., you can specify the amount of Acetate and Sodium provided by AMINO ACIDS 8.5% if you want the calculator to include them)
Note: Intrinsic values are optional and are not required by the Ascend TPN Calculator unless you want to know how much of a particular intrinsic item is provided by a TPN formulation.
Specifying the "Sterile Water" and "Fill Ingredient" fields
The TPN Calculator must know which item in your inventory will be used for "sterile water" and which item will be used as a "fill ingredient" (i.e., to "QS" TPN solutions up to the desired volume). In most cases, these items will be one and the same. An example would be "STERILE WATER FOR INJECTION 1000ML". To specify the "sterile water" and "fill ingredient":
Checking for common setup problems:
Ascend can often alert you to common setup problems at the time you enter the data, or when you attempt to save the data. Other common problems can be located by (1) using an Ascend utility and/or by (2) viewing your inventory with certain TPN filters. The Ascend utility cannot identify all problems. To use the Ascend utility:
You can also circumvent some problems by reviewing your inventory by various TPN filters. When you select a particular filter, the inventory items that match the filter criteria will be displayed in the inventory list. In this manner you can confirm that the inventory items on the list are linked to the TPN types, intrinsics, attributes, and group filters you expect. For example, selecting the "Attribute: Phosphate" filter should display all the inventory items for which you have specified a value for the Phosphate attribute. To use inventory filters:
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Using the Ascend TPN Calculator
There are three methods to enter TPN order data and use the Ascend TPN calculator: (1) by ingredient, (2) by attribute, or (3) a mixture of both methods. Each of these methods will be discussed below.
Enter TPN data by ingredient:
This method is almost identical to building regular (non-TPN) orders. This method can be used to build TPN orders even if you have not done the Setup steps outlined above. However, you may not use the TPN calculator to calculate missing attributes, intrinsics, or related TPN data if "Setup" has not been completed. This method assumes you will first select TPN order ingredients yourself (one at a time, or via a Common order set), and then optionally use the TPN calculator to determine the TPN electrolytes/nutrients and related TPN data provided by these order ingredients.
From the patient's profile:
Dosing by weight from the inventory item selection screen:
Optional fields on the "Inventory Item" form let you (1) dose the patient by weight or (2) view the current dose as a "per kilogram" value.
If you want to use these fields to perform a dosage calculation based upon the patient's weight, be sure to perform the following steps in this order:
- Select the proper weight measurement method [i.e., ideal body weight (IBW), actual weight, ideal dosing weight (IDW)] at the bottom of the item selection screen. The weight entered on the patient's intake/admission screen <General> tab will be the basis for any conversions.
- Edit the weight value if needed to compensate for special circumstances (e.g., amputee)
- Enter the "Dose per kilogram" value as either a "Strength" or "Per" value
- Be sure to select or <Tab> to another field after making the last entry to force the program to make a new calculation based upon your last entry. The other field values (quantity per dose, strength and per) will be recalculated accordingly.
- When you perform the TPN calculation, the calculator will use the absolute strength/per amounts calculated from your previous "per kg" conversion. Please note that if you are using a "per kg" unit of measure for ordered/calculated attribute(s), the calculated value will be based on the patient's actual weight.
If you want to use these fields to view the current dose as a "per kilogram" value, perform the following steps in this order:
- Select the proper weight measurement method [i.e., ideal body weight (IBW), actual weight, ideal dosing weight (IDW)]
- Edit the weight value if needed to compensate for special circumstances (e.g., amputee)
- Edit the "quantity per dose", "strength" or "per" values. Be sure to select or <Tab> to another field after making the last entry to force the program to make the final calculation based upon your last entry.
- The "Dose per kilogram" values will be recalculated accordingly.
Enter TPN data by attribute:
This method can be used to build TPN orders if you have done the Setup steps outlined above. This method assumes the TPN calculator will determine the order ingredients based upon the TPN attributes (electrolytes and nutrients), and other TPN-related fields that you specify.
From the patient's profile:
Balancing fields - Enter or edit any or all of the following fields:
- "Protein: [ ] % of total KCals" field - Enter the percentage of calories that you want to come from protein sources. The default is "0". If this field is used, you must specify a value for the "Calories" attribute in the attribute list. In general, you can specify "Protein" as an absolute amount (e.g., as an attribute in GMs), or as a percentage of "Calories", but not both.
- "Lipid" and "Carb" fields - Enter the percentage of calories (e.g., KCals) to be provided by Lipids and/or Carbohydrates respectively. Use the drop-down lists to specify whether the percentage is for "Non-protein KCals" or for "Total KCals" in each case. If either or both percentages are specified, you must also provide the attribute values for "Non-protein calories" and/or "Calories" (respectively) in the attribute list above. In general, you can specify "Lipids" and "Carbohydrates" as absolute amounts (e.g., as attribute values), or as a percentage of calories, but not both.
- BCAA - Enter the percentage of protein that is to be supplied as branched-chain amino acids.
- Ion mix - Select the ratio of chloride to acetate ions (i.e., Minimize chloride, Minimize acetate, or a Mixture of both). If the "Mix" option is selected, specify the percentage of chloride ions relative to total chloride plus acetate ions i.e. (100*Cl) / (Cl+Ac). For example, 35meq of Chloride and 45meq of Acetate are equivalent to a 44% "Chloride/Acetate" mix [35/(35+45) = 35/80 = 0.44 = 44%]. If the "Mix" option is selected and a percentage ratio specified, you cannot also preset the attribute values for "Chloride" and "Acetate". Alternatively, if one of the "Minimize..." options is used, you can specify the "Chloride" and/or "Acetate" attribute values.
- Mode - This option allows you to specify preferences for Sodium vs. Potassium ions. Choices allow the TPN calculator to preferentially select ingredients that promote the "exclusion" or "inclusion" of Sodium or Potassium additives when phosphate, acetate and chloride attributes are being calculated. However, the calculator may override your choice if it is unable to otherwise complete the calculation as originally ordered.
- Note: the remaining "Calculated" fields on the right side of the "Balancing" frame are completed during the calculation and cannot be directly edited by the user.
Volume fields - Enter or edit any or all of the following fields:
- QS Mode - Often a TPN solution requires the addition of sterile water for injection (or another fluid) to bring the total volume up to a desired amount (i.e, to "QS" the solution). However, some users want the the "total volume" to exclude the micro-additives, or the lipids, while others want to include these volumes in the calculation. Select the "QS mode" that you want to use as follows:
- Minimum volume - Formulate the TPN using the smallest volume (don't QS). The total volume of the order ingredients will used "as is" and no additional fill ingredient (e.g. sterile water) will be added. Note: the TPN Calculator may select the most concentrated ingredients, regardless of preference settings, to meet this requirement. It may also replace a less concentrated ingredient with a more concentrated one if necessary to meet volume limitations, even if you pre-selected, or set preferences for, a less concentrated ingredient.
- Base only - QS using the amino acid and dextrose "base" solution volumes only. Ignore micro-additive and lipid volumes. The calculator will add fill ingredient (e.g., sterile water) volume equal to the difference between your specified target volume and the volume provided by only the base solutions.
- Base + lipids - QS using the amino acid, dextrose and lipid solution volumes only. Ignore micro-additive volumes. The calculator will add fill ingredient volume equal to the difference between your desired volume and the volume provided by the base solutions and the lipids.
- Base + micro - QS using the amino acid, dextrose and micro-additive volumes only. Ignore lipid volume. The calculator will add fill ingredient equal to the difference between your target volume and the volume provided by the base solutions plus the micro-additives.
- All - QS using the volumes of all solutions and micro-additives. The calculator will add fill ingredient volume equal to the difference between your desired volume and the volume provided by all order ingredients.
- Volume - Enter the desired volume of the final TPN solution. This will be the amount the "QS mode" will aim for when adding sterile water unless the TPN solution volume already exceeds this amount, or unless "Minimize volume" is the chosen QS mode.
- Overfill - Enter the additional volume you require as an overfill amount. Typically, this is an estimated amount that would be left in the IV tubing and unavailable to the patient (e.g., 50ML). When the TPN calculator calculates your ingredient list, the overfill quantity, if any, will be included in the volumes of the ingredients on the screen and the Compound sheet. However, the calculated attributes and intrinsics on the screen will be based on the amount administered, i.e., excluding overfill amounts.
- Total volume - this field is completed during the TPN calculation and cannot be edited by the user.
Other fields - Enter or edit any or all of the following fields:
- TPN type - indicates if this is a "2 in 1" (Lipids, if any, are administered as a separate solution and are NOT mixed in with the primary TPN solution ingredients), or a "3 in 1" (Lipids are mixed in the main TPN solution along with the Amino acids, Dextrose and other additives)
- Frequency/IV rate/Infuse over - these three fields are duplicated on the <TPN> tab so you don't have to go back to the <General> tab to enter or view them. Therefore you can enter/view these values under either tab.
Dosing by weight using the TPN attributes:
The TPN Calculator lets you specify TPN attributes by patient weight
- Double-click on the desired attribute (e.g., Protein).
- Enter the desired dosage using a "per kilogram" (patient actual weight) value.
- Select the desired unit of measure from the drop-down list (e.g., GM/KG, KCAL/KG, MEQ/KG, etc). Note: the calculated attribute "unit of measure" will be the same.
- Repeat these steps for other attributes you wish to calculate on a weight basis.
- Note, the calculated "per kg" values will always reflect the patient's actual weight regardless of which patient weight method (actual, ideal, dosing, etc) might have been used on the item selection screen)
Enter TPN data by ingredient AND by attribute (a mixture of both methods):
This method employs a mixture of both of the previous methods. You must have completed the Setup steps to use this method. This method assumes that you want to specify some, but not all, of the TPN ingredients, and you want to specify some of the TPN electrolytes and/or nutrients, and/or some of the other TPN-related fields. This method assumes you want the TPN calculator to determine any unspecified ingredients, ingredient volumes, and unspecified TPN attributes/intrinsics/fields.
This method is ideal if a physician specifies a TPN order using a wide variety of measurement systems (i.e., percentages, ratios, absolute ion or ingredient amounts, specific ingredients, and etc). For example, a physician may order: "1 gram protein per kilogram", "2500 total calories", "20% calories from fat (lipids)", "Total volume of 3000ML", "50 meq NaCl", "15 mMole phosphate", "30meq K", "1 GM Ca-Gluconate", "8 Meq Mg-Sulfate" and a "50:50 ratio of Chloride to Acetate". This is how you would proceed:
- "1 gram protein per kilogram" - you could select "Amino acid 10%" solution from the "Inventory Item" list, enter the patients weight, then enter the "1gm/Kg" dose to calculate the "grams" (strength) of protein needed.
- "50 meq NaCl" - you could select a "Sodium Chloride" TPN additive solution and edit the "Strength" value to "50 meq". The "per" value (i.e., number of milliliters) should be calculated automatically.
- "1 GM Ca-Gluconate" and "8 Meq Mg-Sulfate" - these ingredients would be selected and added in the same manner as the Sodium Chloride in step "b".
- "2500 total calories" - you could select the "Calories" attribute and enter "2500" as the desired value
- "30 meq K" - you could select the "Potassium" attribute and enter "30" as the desired value
- "15 mMole phosphate" - you could select the "Phosphate" attribute and enter "30" as the desired value
- "20% calories from fat (lipids)" - you could select the "Lipid" drop-down option "of Total KCals" and enter "20" for the percentage value
- "50:50 ratio of Chloride to Acetate" - you could select the "Ion mix" drop-down option, "Mix of Chloride/Acetate", and enter "50" for the percentage value
- "Total volume of 3000ML" - you could select a "QS mode" of "All", a "TPN type" of "3 in 1", and enter a "Volume" of "3000".
- Enter any other fields not specified in the order but otherwise desired by the pharmacist. For example, an "Overfill" of "50" ml could be added.
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Questions and answers
How do I tell the calculator which of several stock TPN solutions I want it to use? In some cases you may want the calculator to use a specific inventory item over other (e.g., use "TPN Electrolyte Concentrate" rather than multiple individual electrolyte solutions). There are two ways to do this. (1) On-the-fly: At order entry time, pre-select the desired stock solutions as order ingredients. Check any ingredients' "Attributes will determine quantity" checkbox only if you want the calculator to determine how much of the ingredient to use. Then enter any attribute values you desire before performing the calculation. This option is useful if the substitution is to be made only occasionally (2) Predetermined: Set the "preference" value for the desired stock solutions (inventory items) to a higher "preference" value than all other inventory items in the same group. This option is better if you routinely prefer to use a certain inventory item over others. However, the TPN Calculator may overrule your choices if it is unable to meet other requirements for the calculation while using your original preferences.
How do I tell the calculator whether to use the attribute values, or the order ingredient values that are present in the order? The TPN calculator gives precedence to an item on the ingredient list if that ingredients' checkbox, "Attributes will determine quantity", is NOT checked. If the box IS checked, then the corresponding "Ordered" attribute will have precedence. Therefore, if you want the TPN Calculator to determine the appropriate amount of a pre-selected ingredient for you, then check the box, "Attributes will determine quantity" as you select the ingredient, and specify the attribute values you desire in the "Ordered" column. If you want the calculator to use your ingredients and volumes as entered, then leave the box, "Attributes will determine quantity" unchecked and don't bother to pre-specify the corresponding TPN attributes under the "Ordered" column. Notes: (a) If the TPN calculator adds an ingredient to your order, the checkbox, "Attributes will determine quantity", for that ingredient will be checked by default. If you enter an ingredient yourself, the box will be unchecked by default. (b) If the box on the TPN Calculator screen, "Calculator will calculate dosing based on attribute values", is checked, it has the same effect as checking each ingredient's checkbox, "Attributes will determine quantity".
How do I calculate Aluminum content? Aluminum can be added to the Ascend tables as an intrinsic item (if it is not already listed). Once it is in your database, you can set the Aluminum content for any TPN inventory item by adding the intrinsic, "Aluminum", and the amount, to its list of intrinsics. The TPN calculator can then calculate total Aluminum content of your TPN solutions that contain these items.
How do I add other ingredients such as Heparin, Multivitamins, Famotidine and Insulin? Items that do not provide TPN attributes or intrinsics, such as these, can be added to the order ingredient list if they have been specified as an "additive" TPN Type in their inventory record. Values for both the total strength and total volume (aka "Per" field) must also be entered on the <General> tab for these inventory items (e.g., for "FAMOTIDINE 20MG/ML 20ML VIAL"-->Strength=400MG Per=20ML; For "MVI 10ML"-->Strength=10ML Per=10ML)
How can I specify ingredient doses by patient weight and can I tell the TPN calculator which patient weight to use? (i.e., actual, IBW, IDW) Yes, you can specify the dosage by weight on the inventory item selection screens and choose from actual, ideal or ideal-dosing weights on that screen. If you are ordering by attribute, the actual patient weight must be used. See "Dosing by weight from the inventory item selection screen" or "Dosing by weight using the TPN attributes" for more information.
How do I specify TPN volume requirements? See "QS Mode" and "Volume" related fields.
Can I specify Chloride to Acetate ratios? You can specify the desired ratio as a Chloride:Acetate percentage, but you cannot simultaneously specify an absolute amount for the "Chloride" or "Acetate" attributes. To order Chloride and/or Acetete as absolute amounts, you must enter their attribute value(s) and then choose either "Minimize Chloride" or "Minimize Acetate" for the Ion Mix. See "Ion Mix" for more information.
How do I specify the amount, or percentage, of calories to be provided by protein, carbohydrate and/or fat? The TPN Calculator lets you specify protein, carbohydrate and lipid content by absolute amount, or as a percentage of calories (but not both). For example, you can set the attribute values for protein, carbohydrate and lipids (e.g., enter their values in GMs, KCALs, etc) and the calculator can determine the percentage of calories provided by each nutrient. Alternatively, you can specify the "Calories" attribute and/or the "Non-protein calories" attribute, then set the percentage of these to be provided by protein, carbohydrate and/or lipid. You have to be consistent. For example, you can't set a value for percentage of non-protein calories for "Lipids" without also providing a value for the "non-protein calories" in the attribute list. See "% of total KCals" for more information.
Do I have to add Sterile Water to the formulation and/or manually QS to a desired volume? Not necessarily. The TPN Calculator can do this automatically if you want. All you need to do is tell the calculator which formulary item to use to QS solutions (i.e., a one time step), and then specify the desired volume and volume-related fields in the order under the <TPN> tab before you calculate.
How do I specify specific gravity? Although the Baxa TPN compounder utilizes specific gravity data, the Ascend TPN calculator (which uses the Baxa TPN software) does not capture, calculate or transmit specific gravity data to the compounder.
How do I specify osmolarity? Osmolarity is an intrinsic value that can be set for any TPN inventory item. The TPN calculator will calculate the osmolarity of the final solution based on these inventory item values. Refer to Add/edit TPN inventory items, step #13 for more information on establishing intrinsic values.
An amount I ordered as an attribute (e.g., phosphate) appears correctly in the "Calculated" attributes column, but the total amount provided by the ingredients (i.e., on the left side of the screen; e.g., from Sodium Phosphate Inj, Potassium Phosphate Inj) appears to be less than the ordered amount. Why? Another TPN ingredient may be "secretly" contributing some of the attribute, or the attribute value for one or more ingredients is incorrect. To check this, go to your "Utilities"-->"Inventory" screen; Use the "Filter" list to select the electrolyte (e.g., "Containing attribute: Phosphate"). A list of inventory containing the attribute will appear. Comparing the list to your order, determine if other inventory items are "secretly" contributing some of this electrolyte to your order (e.g., Lipids, Amino acids, etc.?). If this is not the case, then recheck the attribute strength/volume for each inventory item containing the attribute.
The drop-down list of "units of measure" for the attributes includes the choices, "mEq/mlAV", "mEq/DLAV", "mEq/LAV", mm/mlAV, and "mg/mlAV". What does "/mlAV" mean? This means, "per milliliter of final Admixture Volume". For example, "Sodium 0.04 mEQ/mlAV" means there are 0.04 mEq of Sodium in each ML of the final TPN admixture. "/LAV" means per liter final admixture volume, and "/DLAV" is per 100ML. The unit of measure selected for the "Ordered" column will be used in the "Calculated" column (even if no "ordered" amount is specified)
How can I set the unit of measure for a "Calculated" attribute when I am ordering the corresponding ingredient with a different unit of measure (e.g., The "Sodium Chloride" ingredient is ordered as "50 mEq per 1000ml of final admixture volume" but you want the "Sodium" attribute to be displayed in "mEq")? Select the specific attribute from the attribute list on the right (as if you wanted to enter a value for the ordered amount of this attribute). Select the desired unit of measure from the drop-down list. You do NOT have to specify an ordered amount. After you perform the calculation, the "Calculated" amount of the attribute should be displayed with the unit of measure you pre-selected.
After I add an ingredient manually, then do a calculation, the ingredient I added disappears from the list. Why? These are two possible causes: (1) The checkbox option, "Calculator will calculate dosing based on attribute values", is available on the main TPN Calculator screen (i.e., at the bottom; this option can affect all the ingredients) AND/OR the checkbox, "Attributes will determine quantity" on the individual inventory item's specification screen (double click on the ingredient in the list to see this screen; this option only affects the selected ingredient). In either case, the option tells the TPN Calculator to use the values under the attribute "Ordered" column to adjust or remove inventory items from the ingredient list. Under these circumstances, unless your chosen ingredient contains one of the ordered attributes, it will be removed from the ingredient list. (2) The ingredient you selected is not recognized as a "TPN Type". Refer to the question, "How do I add other ingredients such as..." displayed above.
Why do the ingredient amounts on my TPN Data sheet differ from those on my Compound sheet? You are probably including an overfill volume in the TPN calculation. The Compound sheet includes the overfill volumes required to prepare the admixture whereas the TPN Data sheet excludes overfill volume. Therefore the TPN Data sheet should reflect the amounts of attributes, intrinsics, calories and volumes that are actually administered to the patient.
How can I specify TPN ingredients as a percentage of the final admixture (e.g., Final concentrations: Amino Acids 5%, Dextrose 20%)? This can be done two ways. (1) Using attributes with the example ingredients: Enter the Amino Acids as a "Protein" attribute, with "5" as the value and "GM%" as the unit of measure. Dextrose would be added as attribute "Carbohydrate" with a value of "20" and units of measure "GM%". (2) Using item/ingredient fixed admixture concentrations: After you select the desired Amino acid from inventory, enter the "Admixture conc." values (found at the bottom of the item selection screen) as "5" GM per "100" ML. After you select the desired Dextrose solution from inventory, enter the "Admixture conc." values as "20" GM per "100" ML. Regardless of final admixture volume, these percentages will be maintained by the calculation.
Why do some of the TPN Calculator screens and/or functions differ from how they are shown/described in this document? You may be on an older version of the program and/or documentation, or we may have added/changed a feature and not yet updated the documentation. The documentation on our website is always the latest version, whereas the version in your program may be older. If you are on a current program version and suspect the documentation on our website is outdated, please email the pertinent information to your technical support representative... and thanks for letting us know!
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