6.6 Administering Medications IV Direct
Learning Objectives
By the end of this chapter, learners will be able to:
- identify factors that affect the rate of administration of IV direct medications
- create a dose, volume, and timetable for use in the administration of IV direct medications
- label a syringe to help keep track of the medication delivery rate
Identify Factors That Affect the Rate of Administration of IV Direct Medications
It is essential for medications administered directly into an IV line to be given at the correct rate to prevent complications. Information describing the appropriate rate will be available in the health agency’s drug reference manual. Ensure all factors about the patient’s context are considered when reviewing rate information in the reference manual. For instance, the rate may be different for a neonate versus an adult. In some cases, a variable rate is given and you will need to use critical thinking skills to determine the most appropriate rate, often in discussion with your nursing instructor or the most responsible nurse for the patient.
Create a Dose, Volume, and Timetable For Use in the Administration of IV Direct Medications
To determine how fast to administer an IV direct medication, you will need the following information:
- the medication order
- information about the patient’s context (eg. age, the reason for medication order, hepatic function…)
- the administration information from the drug reference manual
- the total volume of medication to be administered
Once the rate of administration of the drug is determined, the actual administration of the drug must be timed to ensure it is given at the correct rate. To administer the drug evenly over a particular period, nurses often calculate the volume of medication to be given over specific time intervals (for example, every 15 seconds) during the administration period. The drug information in the text box below will be used to exemplify this process. It is important to note the information presented here should not be used for direct patient care, always review your agency’s drug reference manual for up-to-date information regarding the drug and the administration policy of your institution.
diazepam
Status Epilepticus: 5-10 mg IV/IM q5-10min; not to exceed 30 mg, OR 0.5 mg/kg PR (using the parenteral solution), THEN 0.25 mg/kg in 10 minutes PRN
IV Direct: Administer undiluted over 3 min; no more than 5 mg/min
https://reference.medscape.com/drug/valium-diastat-diazepam-342902
1. Gather the information that will affect the rate of administration.
Supply: the concentration of diazepam in a vial is 5 mg : 1 mL
[latex]x\text{ mL}=\dfrac{\text{1 mL}}{\text{5 mg}}\times\text{10 mg}[/latex]
[latex]x\text{ mL}=\dfrac{\text{1 mL}}{5\cancel{\text{ mg}}}\times10\cancel{\text{ mg}}[/latex]
[latex]x\text{ mL}=\dfrac{1\text{ mL}\times{10}}{{5}}[/latex]
[latex]x\text{ mL}=2\text{ mL}[/latex]
2. Determine what volume of medication will be given at each time interval:
| Amount (mg) | Volume (mL) | Time Interval |
|---|---|---|
| 10 | 2 | 3 min (180 sec) |
| 5 | 1 | 90 sec |
| 2.5 | 0.5 | 45 sec |
| 1.25 | 0.25 | 22.5 sec |
| Amount (mg) | Volume (mL) | Time Interval |
|---|---|---|
| 10 | 2 | 3 min |
| 3.33 | 0.66 | 1 min (60 sec) |
| 1.11 | 0.22 | 20 sec |
| Amount (mg) | Volume (mL) | Time Interval |
|---|---|---|
| 10 | 2 | 3 min (180 sec) |
| 2 mg | 0.4 | 36 sec |
| 1 mg | 0.2 | 18 sec |
In this example, clinical judgment must be used to determine which one will give a volume and time interval easiest for a nurse to follow. The middle table might be the easiest to use in practice, as watching a timer and noting how much you have given every 20 seconds is easier to follow than watching for every 22.5 or 18 seconds. You may also find any number you divide by gives a difficult number to measure with the available syringes. In this case, you will need to round the number so the volume can be measured easily on the syringe. For example, if you calculated the final volume to be 1.08 mL you could round to 1 mL. If you are rounding down, you are giving slightly less volume over the allotted time and should be safe for the client to receive. You must be very cautious about rounding up, as the medication would be given slightly faster. Make sure to discuss the rationale for rounding with your preceptor or instructor to ensure you are making appropriate decisions.
Example 1
Complete a dose, volume, and timetable when administering the following medication:
Medication Order: ketorolac 30 mg IV prn q8h
Rate Information: undiluted over 1-2 minutes
Supply: ketorlac 30 mg/mL
Answer:
| Amount (mg) | Volume (mL) | Time Interval |
|---|---|---|
| 30 | 1 | 2 min |
| 15 | 0.5 | 1 min |
| 7.5 | 0.25 | 30 sec |
Example 2
Create a dose, volume, and time chart for the following medication order.
Medication Order: furosemide 40 mg IV BID
Rate Information: administer undiluted at a rate of 20 mg/min
Supply: 20 mg/1 mL ampule
Answer:
First, calculate the total volume of the injection.
[latex]x\text{ mL}=\dfrac{\text{1 mL}}{\text{20 mg}}\times\text{40 mg}\\[/latex][latex]x\text{ mL}=\dfrac{\text{1 mL}}{20\cancel{\text{ mg}}}\times40\cancel{\text{ mg}}\\[/latex][latex]x\text{ mL}=\dfrac{\text{40 mL}}{20}\\[/latex][latex]x\text{ mL}=\text{2 mL}[/latex]
Enter the total amount, volume, and time in the first row. In this case, the recommended rate of 20 mg/min is represented in the third row of the chart and thus meets the criteria for safe administration.
Next, choose an amount to divide each value by. In this answer, each value has been divided by 2.
| Amount (mg) | Volume (mL) | Time Interval |
|---|---|---|
| 40 | 2 | 2 min |
| 20 | 1 | 1 min |
| 10 | 0.5 | 30 sec |
Label a Syringe to Help Keep Track of the Medication Delivery Rate.
It can be challenging for some people to focus on the amount of volume being administered in each short time interval while in the practice setting, even while watching a timer. Distractions such as alarms, conversations, and/or questions from the patient or family and other interruptions can break the focus of the nurse during this process. When beginning to administer IV direct medications, it may be helpful to add a visual cue to the syringe label to help keep on track. In the image below, two components have been added to a syringe label for the administration of furosemide. Lines to indicate every 0.5 mL on the syringe and numbers representing the seconds remaining at each interval are added. These correspond to the dose, volume, time table created in the sample exercise above, in which 0.5 mL is given every 30 seconds.
Critical Thinking Question
When comparing the same dose of a particular medication given by IV direct versus an intermittent IV infusion, do you anticipate any differences in the onset, peak, and duration of the medication?
Answer:
The onset occurs when the medication enters the bloodstream and can take effect in the body. It varies with mechanism of action, dosage, and individual patient factors. The IV direct route is often delivered over a total shorter time than the intermittent IV route. If the medication is delivered into the vein more quickly, it is likely the onset will be earlier for IV direct than IV intermittent. It may affect the peak for some medications as well. The duration of the effect is more variable. The duration of IV intermittent may be longer, especially for infusions that are given over longer periods. If you think variations in onset, peak, and duration of various routes will affect the choice of route given to a patient, you should check the parenteral manual for guidelines on specific medications when preparing the medication.
Exercise Part A : Creating Dose, Volume, Time Tables
Create a dose, volume, time table for the following scenarios.
- Medication Order: dexamethasone 4 mg IV q6h
Rate Information: administer undiluted, no more than 8mg/min
Supply: 20 mg/5 mL vial - Medication Order: pantoprazole 40 mg IV OD
Rate Information: administer over 2 minutes
Supply: 40 mg powder in medication vial, to be reconstituted with 10 mL NS - Medication Order: benztropine 2 mg IV now
Rate Information: administer undiluted over 1 minute
Supply: 2 mg/2 mL ampule - Medication Order: morphine 2 mg IV q2h prn
Rate Information: dilute with 9 mL NS or SW for injection to give 1 mg/mL and give at a maximum rate of 2 mg/min
Supply: 10 mg/mL ampule - Medication Order: oxytocin 8 units once postpartum bolus
Rate Information: may dilute with 3 mL NS, given slowly over at least 1 minute
Supply: 10 units/mL vial - Medication Order: haloperidol 2 mg IV push PRN.
Rate Information: dilute with 5 mL SW and give rapid IV push over at least 1 minute.
Supply: 5 mg/mL (1 mL) ampule.
Odd Answers:
1) First, calculate the total volume of the injection.
[latex]x\text{ mL}=\dfrac{\text{5 mL}}{\text{20 mg}}\times\text{4 mg}\\[/latex][latex]x\text{ mL}=\dfrac{\text{5 mL}}{20\cancel{\text{ mg}}}\times4\cancel{\text{ mg}}\\[/latex][latex]x\text{ mL}=\dfrac{\text{20 mL}}{20}\\[/latex][latex]x\text{ mL}=\text{1 mL}\\[/latex]Enter the total amount, volume and time in the first row. Choosing to give 4 mg in 1 minute is giving the medication slower than the maximum rate of 8 mg/min, and meets the criteria for safe administration.
Next, choose an amount to divide each value by. In this answer, each value has been divided by 2.
| Amount (mg) | Volume (mL) | Time Interval |
|---|---|---|
| 4 | 1 | 1 min |
| 2 | 0.5 | 30 sec |
| 1 | 0.25 | 15 sec |
3) First, note the total volume of the injection (2 mg in 2 mL).
Enter the total amount, volume, and time in the first row.
Next, choose an amount to divide each value by. In this answer, each value has been divided by 2.
| Amount (mg) | Volume (mL) | Time Interval |
|---|---|---|
| 2 | 2 | 1 min |
| 1 | 1 | 30 sec |
| 0.5 | 0.5 | 15 sec |
5) First, calculate the total volume of the injection. [latex]x\text{ mL}=\dfrac{\text{1 mL}}{\text{10 units}}\times\text{8 units}\\[/latex][latex]x\text{ mL}=\dfrac{\text{1 mL}}{10\cancel{\text{ units}}}\times8\cancel{\text{ units}}\\[/latex][latex]x\text{ mL}=\dfrac{\text{8 mL}}{10}\\[/latex][latex]x\text{ mL}=\text{0.8 mL}\\[/latex]Enter the total amount, volume and time in the first row.
Next, choose an amount to divide each value by. In this answer, each value has been divided by 2.
| Amount (units) | Volume (mL) | Time Interval |
|---|---|---|
| 8 | 0.8 | 1 min |
| 4 | 0.4 | 30 sec |
| 2 | 0.2 | 15 sec |
Exercises Part B: Creating Dose, Volume, Time Tables
Create a dose, volume, time table for the following scenarios. Identify the final volume and time interval you would use when administering the medication.
- Medication Order: dexamethasone 15 mg IV once
Rate Information: max rate of 8 mg/min
Supply: 4 mg/mL vial - Medication Order: diphenhydrinate 35 mg IV push q4h.
Rate Information: dilute every 50 mg with 10 mL NS and administer over 2-4 minutes.
Supply: 50 mg/mL (1 mL) vial. - Medication Order: meropenum 600 mg IV q8h.
Rate Information: reconstitute with 20 mL NS or D5W and give over 3-5 minutes.
Supply: 1 g (powdered) vial. - Medication Order: thiamine 100 mg IV push once daily for 5 days.
Rate Information: give undiluted over 1 minute.
Supply: 100 mg/mL (1 mL) vial. - Medication Order: morphine 2.5 mg IV push q4h.
Rate Information: max rate of 2 mg/mL, diluted to 1 mg/mL with NS (10 mL of fluids).
Supply: 10 mg/mL - Medication Order: flumazenil 0.2 mg for suspected benzo overdose, possibly giving additional doses if inadequate results.
Rate Information: give over 30 seconds.
Supply: 0.1 mg/mL (5 mL) vial. - Medication Order: ampicillin 25 mg/kg/dose, for a 15 kg child, IV push for a mild infection.
Rate Information: give over 4 minutes at a max rate of 100 mg/minute, diluted to 250 mg/2.5 mL.
Supply: 250 mg (powdered) vial. - Medication Order: ketorolac 20 mg q4h IV push.
Rate Information: give over 1-2 minutes undiluted.
Supply: 30 mg/mL (1 mL) vial. - Medication Order: diazepam 8 mg q3h.
Rate Information: give undiluted 2-5 mg/minute.
Supply: 5 mg/mL (2 mL) ampule. - Medication Order: midazolam 0.2 mg/kg IV push loading dose, repeating q5 minute until seizure stops. This is for a 65 kg adult.
Rate Information: given at a rate of 2 mg/minute.
Supply: 1 mg/mL
Odd Answers:
1) First, calculate the total volume of the injection. [latex]x\text{ mL}=\dfrac{\text{1 mL}}{\text{4 mg}}\times\text{15 mg}\\[/latex][latex]x\text{ mL}=\dfrac{\text{1 mL}}{4\cancel{\text{ mg}}}\times15\cancel{\text{ mg}}\\[/latex][latex]x\text{ mL}=\dfrac{\text{15 mL}}{4}\\[/latex][latex]x\text{ mL}=\text{3.75 mL}\\[/latex]In this answer, in the table set up, each value has been divided by 2.
When you calculate a volume that is not a round decimal number, round to the number that you can measure in the syringe that you are using.
| Amount (mg) | Volume (mL) | Rounded Volume (mL) | Time Interval |
|---|---|---|---|
| 15 | 3.75 | 3.8 | 2 min |
| 7.5 | 1.875 | 1.9 | 1 min |
| 3.75 | 0.9375 | 1.0 | 30 sec |
| 1.875 | 0.46875 | 0.5 | 15 sec |
3) First, calculate the total volume of the injection. [latex]x\text{ mL}=\dfrac{\text{10 mL}}{\text{500 mg}}\times\text{600 mg}\\[/latex][latex]x\text{ mL}=\dfrac{\text{10 mL}}{500\cancel{\text{ mg}}}\times600\cancel{\text{ mg}}\\[/latex][latex]x\text{ mL}=\dfrac{\text{6000 mL}}{\text{500}}\\[/latex][latex]x\text{ mL}=\text{12 mL}\\[/latex]Enter the total amount, volume and time in the first row.
Next, choose an amount to divide each value by. In this answer, each value has been divided by 5 to start and then by 2 to get to 15-second increments.
| Amount (mg) | Volume (mL) | Time Interval |
|---|---|---|
| 600 | 12 | 5 |
| 120 | 2.4 | 1 |
| 60 | 1.2 | 30 sec |
| 30 | 0.6 | 15 sec |
5) First, calculate the total volume of the injection.[latex]x\text{ mL}=\dfrac{\text{1 mL}}{\text{1 mg}}\times\text{2.5 mg}\\[/latex][latex]x\text{ mL}=\dfrac{\text{1 mL}}{1\cancel{\text{ mg}}}\times2.5\cancel{\text{ mg}}\\[/latex][latex]x\text{ mL}=\dfrac{\text{2.5 mL}}{1}\\[/latex][latex]x\text{ mL}=\text{2.5 mL}\\[/latex]Enter the total amount, volume and time in the first row.
Next, choose an amount to divide each value by. In this answer, each value has been divided by 3 to start and then divided by 2 to get to 15-second increments.
| Amount (mg) | Volume (mL) | Time Interval |
|---|---|---|
| 2.5 | 2.5 | 1.5 min |
| 0.8 | 0.8 | 30 sec |
| 0.4 | 0.4 | 15 sec |
7) First, calculate the dose in mg from the weight of the patient given. [latex]\text{25 mg}\times\text{15 kg}=\text{375 mg/dose}[/latex]
Then, calculate the total volume of the injection.
[latex]x\text{ mL}=\dfrac{\text{2.5 mL}}{\text{250 mg}}\times\text{375 mg}\\[/latex][latex]x\text{ mL}=\dfrac{\text{2.5 mL}}{250\cancel{\text{ mg}}}\times375\cancel{\text{ mg}}\\[/latex][latex]x\text{ mL}=\dfrac{\text{937.5 mL}}{\text{250}}\\[/latex][latex]x\text{ mL}=\text{3.75 mL}\\[/latex]Enter the total amount, volume and time in the first row.
Next, choose an amount to divide each value by. In this answer, each value has been divided by 4 to start and then by 2 to get to 15-second increments.
| Amount (mg) | Volume (mL) | Time Interval |
|---|---|---|
| 375 | 3.75 | 4 min |
| 93.75 | 0.94 | 1 min |
| 46.9 | 0.47 | 30 sec |
| 23.4 | 0.23 | 15 sec |
From the table, 0.23 is not an easy volume to track over 15 seconds when giving a direct IV. Instead, you can round this number to 0.2 to track the volume you are giving better.
9) First, calculate the total volume of the injection.[latex]x\text{ mL}=\dfrac{\text{1 mL}}{\text{5 mg}}\times\text{8 mg}\\[/latex][latex]x\text{ mL}=\dfrac{\text{1 mL}}{5\cancel{\text{ mg}}}\times8\cancel{\text{ mg}}\\[/latex][latex]x\text{ mL}=\dfrac{\text{8 mL}}{5}\\[/latex][latex]x\text{ mL}=\text{1.6 mL}\\[/latex]Enter the total amount, volume and time in the first row.
Next, choose an amount to divide each value by. In this answer, each value has been divided by 2.
| Amount (mg) | Volume (mL) | Time Interval |
|---|---|---|
| 8 | 1.6 | 2 min |
| 4 | 0.8 | 1 min |
| 2 | 0.4 | 30 sec |
| 1 | 0.2 | 15 sec |
Exercises Part C: Creating Dose, Volume, Time Tables
Create a dose, volume, time table for the following scenarios. Identify the final volume and time interval you would use when administering the medication.
- Medication Order: diltiazem 0.25 mg/kg IV direct for a 55kg adult.
Rate Information: give undiluted over 2 minutes.
Supply: 5 mg/mL (10 mL) vial. - Medication Order: hydromorphone 0.5 mg IV direct q6h.
Rate Information: dilute to 5 mL with NS and administer slowly over 2 minutes.
Supply: 2 mg/mL vial. - Medication Order: labetalol 7 mg IV initial dose in a hypertensive emergency.
Rate Information: give over 2 minutes.
Supply: 5 mg/mL (20 mL) vial. - Medication Order: propofol 18 mg IV direct bolus.
Rate Information: given over 3 minutes.
Supply: 10 mg/mL (20 mL) ampule. - Medication Order: metoclopramide 10 mg IV for prophylactic postoperative vomiting.
Rate Information: given over 2 minutes.
Supply: 5 mg/mL (2 mL) vial. - Medication Order: hydrocortisone 200 mg IV direct.
Rate Information: dilute with 2 mL SW (diluted to 125 mg/mL), given over 1.5 minutes.
Supply: 250 mg vial. - Medication Order: ephedrine 20 mg IV repeat q5-10 minutes according to blood pressure response.
Rate Information: given over 10 mg/minute as a max rate.
Supply: 50 mg/mL (1 mL) vial. - Medication Order: meperidine 15 mg IV direct q4h PRN for severe pain.
Rate Information: diluted to 10 mg/mL, given over 5 minutes.
Supply: 50 mg/mL (1 mL) ampule. - Medication Order: fentanyl 75 mcg intrapartum q30 minutes IV direct.
Rate Information: given undiluted over 2 minutes.
Supply: 50 mcg/mL (5 mL) ampule. - Medication Order: octreotide 2 mg/kg/dose IV direct bolus for a 20 kg toddler with a severe gastrointestinal bleed.
Rate Information: given undiluted over 2 minutes.
Supply: 100 mcg/mL (1 mL) ampule.
Odd Answers:
1) First, calculate the dose in mg from the weight of the patient given.
[latex]\text{0.25 mg}\times\text{55 kg}=\text{13.75 mg}[/latex]
Then, calculate the total volume of the injection.
[latex]x\text{ mL}=\dfrac{\text{1 mL}}{\text{5 mg}}\times\text{13.75 mg}\\[/latex][latex]x\text{ mL}=\dfrac{\text{1 mL}}{5\cancel{\text{ mg}}}\times13.75\cancel{\text{ mg}}\\[/latex][latex]x\text{ mL}=\dfrac{\text{13.75 mL}}{5}\\[/latex][latex]x\text{ mL}=\text{2.75 mL}\\[/latex]Enter the total amount, volume and time in the first row.
Next, choose an amount to divide each value by. In this answer, each value has been divided by 2.
| Amount (units) | Volume (mL) | Rounded Volume (mL) | Time Interval |
|---|---|---|---|
| 13.75 | 2.75 | 2.75 | 2 min |
| 6.875 | 1.38 | 1.4 | 1 min |
| 3.437 | 0.69 | 0.7 | 30 sec |
| 1.718 | 0.34 | 0.3 | 15 sec |
3) First, calculate the total volume of the injection.[latex]x\text{ mL}=\dfrac{\text{1 mL}}{\text{5 mg}}\times\text{7 mg}\\[/latex][latex]x\text{ mL}=\dfrac{\text{1 mL}}{5\cancel{\text{ mg}}}\times7\cancel{\text{ mg}}\\[/latex][latex]x\text{ mL}=\dfrac{\text{7 mL}}{5}\\[/latex][latex]x\text{ mL}=\text{1.4 mL}\\[/latex]Enter the total amount, volume and time in the first row.
Next, choose an amount to divide each value by. In this answer, each value has been divided by 2.
| Amount (units) | Volume (mL) | Time Interval |
|---|---|---|
| 7 | 1.4 | 2 min |
| 3.5 | 0.7 | 1 min |
| 1.75 | 0.35 | 30 sec |
| 0.875 | 0.175 | 15 sec |
From the table, 0.175 is not an easy volume to track over 15 seconds when giving a direct IV. Instead, you can round this number to 0.2 to track the volume you are giving better.
5) First, calculate the total volume of the injection.[latex]x\text{ mL}=\dfrac{\text{1 mL}}{\text{5 mg}}\times\text{10 mg}\\[/latex][latex]x\text{ mL}=\dfrac{\text{1 mL}}{5\cancel{\text{ mg}}}\times10\cancel{\text{ mg}}\\[/latex][latex]x\text{ mL}=\dfrac{\text{10 mL}}{5}\\[/latex][latex]x\text{ mL}=\text{2 mL}\\[/latex]Enter the total amount, volume and time in the first row.
Next, choose an amount to divide each value by. In this answer, each value has been divided by 2.
| Amount (units) | Volume (mL) | Time Interval |
|---|---|---|
| 10 | 2 | 2 min |
| 5 | 1 | 1 min |
| 2.5 | 0.5 | 30 sec |
| 1.25 | 0.25 | 15 sec |
7) First, calculate the total volume of the injection.[latex]x\text{ mL}=\dfrac{\text{1 mL}}{\text{50 mg}}\times\text{20 mg}\\[/latex][latex]x\text{ mL}=\dfrac{\text{1 mL}}{50\cancel{\text{ mg}}}\times20\cancel{\text{ mg}}\\[/latex][latex]x\text{ mL}=\dfrac{\text{20 mL}}{\text{50}}\\[/latex][latex]x\text{ mL}=\text{0.4 mL}\\[/latex]Enter the total amount, volume and period of time in the first row.
Next, choose an amount to divide each value by. In this answer, each value has been divided by 2.
| Amount (units) | Volume (mL) | Time Interval |
|---|---|---|
| 20 | 0.4 | 2 min |
| 10 | 0.2 | 1 min |
| 5 | 0.1 | 30 sec |
| 2.5 | 0.05 | 15 sec |
9) First, calculate the total volume of the injection.[latex]x\text{ mL}=\dfrac{\text{1 mL}}{\text{50 mg}}\times\text{75 mg}\\[/latex][latex]x\text{ mL}=\dfrac{\text{1 mL}}{50\cancel{\text{ mg}}}\times75\cancel{\text{ mg}}\\[/latex][latex]x\text{ mL}=\dfrac{\text{75 mL}}{\text{50}}\\[/latex][latex]x\text{ mL}=\text{1.5 mL}\\[/latex]Enter the total amount, volume and time in the first row.
Next, choose an amount to divide each value by. In this answer, each value has been divided by 2.
| Amount (units) | Volume (mL) | Time Interval |
|---|---|---|
| 75 | 1.5 | 2 min |
| 37.5 | 0.75 | 1 min |
| 18.75 | 0.375 | 30 sec |
| 9.375 | 0.1875 | 15 sec |
From the table, 0.1875 is not an easy volume to track over 15 seconds when giving a direct IV. Instead, you can round this number to 0.2 to track the volume you are giving better.
