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IV Pushes
IV Pushes
When a patient needs medication fast, a push is just about as fast as anything. IV pushes are manually injected into the IV site or port on the IV tubing. Nurse must be careful to not push medications too fast or too slow. The drug manufacturers have recommendations on push times for most medications. IV pushes can be a little tricky, so we'll look at some ideas to simplify things
To Dilute or Not to Dilute
To Dilute or Not to Dilute
That is the great question many a nurse faces everyday in the hospital. The recommendation is to only dilute if it is necessary for safety or required by the manufacturer. Most medications do not need to be diluted. You will need to check your drug guide for information on diluting
If you do need to dilute, you must use the proper diluent and in the proper amount. Just follow the instructions supplied
Example: Lorazepam 1 mg IV is ordered. The vial supplied requires the dose to be diluted with an equal amount of NS prior to administration. The concentration supplied is 2 mg/ml. How would the nurse prepare this dose?
First figure out how much volume we need of the drug using the regular formula- 1 mg/ 2 mg x 1 ml = 0.5 ml (this is drawn up into the syringe)
Then follow the manufacturer's instructions and add an equal amount of NS to the 0.5 ml: 0.5ml NS + 0.5 ml drug concentrate = 1 ml
The total end volume to be given to the patient is 1 ml
Example: Famotidine 20 mg IV push is ordered. Supplied by pharmacy is famotidine 10 mg/ml with instructions to dilute with 5 ml NS. How will the nurse prepare this medication?
First figure out how much of the drug concentrate is needed- 20 mg/ 10 mg x 1 ml = 2 ml (this is drawn up into the syringe)
Then add the required diluent- 5 ml NS + 2 ml drug = 7 ml total in syringe
To Push Slow or to Push Fast
To Push Slow or to Push Fast
Most of the time, we need to push slow. There are very few drugs that require a fast push (adenosine, atropine, epinephrine). The rest are all to be pushed in a range from 15 seconds (ketorolac) to 5 minutes (morphine, antibiotics). The nurse needs to know how to break down the push time per ml or fraction of an ml in order to time the entire push correctly. If this is not done, the entire contents of the syringe could accidentally be pushed too fast. This could harm the patient
Example: The above 1 mg lorazepam has been prepared. The push syringe has 1 ml of volume. The recommended rate is 2 mg/min max. How much volume will the nurse push every 15 seconds?
Dose is 1 mg
Push Rate is 2 mg/min
1 mg/ 2 mg x 1 min = 0.5 minute
Total volume of syringe = 1 ml
Therefore, 1 ml per 0.5 minute... divide this by 2 to get volume pushed every 15 seconds... 1 ml/2 = 0.5 ml every 15 seconds- you can divide this further to better time your push... 0.25 ml per 7.5 seconds, etc.
Example: The above famotidine of 20 mg has been prepared and the total syringe volume is 7 ml. The recommendation is to push famotidine over 2 minutes. How fast will the nurse push each ml?
Dose does not matter in this case as the push time is 2 minutes
Volume of syringe is 7 ml
Taking 7 ml and dividing by 2 minutes will give us ml per minute... we want minutes per ml
Let's take 2 minutes (120 seconds) and divide by 7 ml... this gives us 17.14 seconds per ml... round to 17 seconds
Basically, if you want to know how fast to push each ml, you take the time in seconds and divide that by the volume in ml
If you want to know how many ml to push each minute, you take the volume in ml and divide that by the total number of minutes
There are plenty of practice questions below to get a good grasp on this
*It is always good practice to flush the line at the same rate as the push until the medication has all cleared the tubing. This usually means flushing 1 to 2 ml of NS at the same rate as the push. The nurse should also know the volume of the tubing that is being accessed. If there is 1 ml of tubing volume and 1 ml of volume in the push syringe, none of the medication will enter the patient's blood stream until the tubing is flushed. Thus, it is critical to time the flush just as if you were giving the medication
*If the volume of the push is too small to push accurately, you should dilute the medication to a more manageable volume
IV Drips
IV Drips
Many ICU patients are on critical medication drips that are titrated (adjusted) by the nurse based on the patient's condition (sedation, blood pressure, blood sugar, etc.). These drips are often based per minute, but can also be based per hour like a regular infusion. Most of the time they are also based on the weight of the patient in kilograms, just as we do with many pediatric medications.
In order to set the pump correctly, the nurse must know the patient's weight, the starting rate per kilogram, and the drug concentration. As the nurse titrates the medication, the titration parameters must also be followed. For example propofol can be titrated up by 5 to 10 mcg/kg/min each 5 to 10 minutes until the desired sedation is reached.
While assessment is of critical importance in titrating medications, this lesson will focus on the mathematical aspects of titration.
Drip Calculations
Drip Calculations
Most IV pumps will calculate mcg/min (or hour) and ml/min (or hour) automatically. The user enters the weight of the patient, then the desired dose per kg per minute... or hour. The pump does the rest of the calculations. That's nice. Let's do some of this math ourselves.
Example: A patient is being prepared for intubation in the ICU. Propofol IV is ordered to be given at 5 mcg/kg/min. The patient weighs 80 kg. Supplied is propofol 10 mg/ml for injection. What will the nurse initially set the pump to in mcg/min and ml/hour?
Weight is already in kg = 80
80 kg x 5 mcg = 400 mcg/min
Let's change that mcg to mg... 400 mcg = 0.4 mg
Use the formula- 0.4 mg/10 mg x 1 ml = 0.04 ml/min
Change that to hour... 0.04 ml/min x 60 min = 2.4 ml/hour
Example: A hypotensive patient in ICU is ordered to have a dopamine drip to increase cardiac output and blood pressure. Order is to start dopamine at 10 mcg/kg/min. Patient weighs 160 pounds. Supplied by pharmacy is dopamine 40 mg/ml for injection. What will the nurse set the pump to in mcg/min or ml/hour?
Weight needs to be converted- 160/2.2 = 72.73 after rounding
72.73 x 10 mcg = 727.3 mcg/min
Let's change that mcg to mg... 727.3 mcg = 0.7273 mg
Use the formula- 0.7273 mg/40 mg x 1 ml = 0.0181825 ml/min
Change that to hour... 0.0181825 x 60 = 1.1 ml/hr (follow hospital or school directions for rounding on drips. Some pumps might be able to do hundredths)
It's time to do some practice questions!
Order for furosemide 40 mg IV once. Available is furosemide 10 mg/ml. Recommended administration is undiluted at 20 mg/min. How much will the nurse draw up and how many seconds per ml will the nurse administer?
4 ml IV and 30 seconds per ml IV
40 mg/10 mg x 1 ml = 4 ml (volume to give)
40 mg/20 mg x 1 min = 2 minutes for total push
2 minutes (or 120 seconds)/ 4 ml= 0.5 minute or 30 seconds
A patient is in diabetic ketoacidosis will be started on an regular insulin drip. The initial loading dose will be given IV push in the amount of 40 units. Supplied is regular insulin 100 units/ml. The recommended push time is one minute for up to 50 units. The nurse decides to dilute the insulin by adding 1 ml of NS in order to make administration timing more accurate. How much will the nurse have in total volume in the syringe and how much volume will she push over each 15 seconds?
1.4 ml IV and 0.35 ml each 15 seconds IV
First get the dose volume- 40 units/100 units x 1 ml = 0.4 ml
Then add the 1 ml NS = 1.4 ml
This dose is given over 1 minute, so divide total volume by 4 (there are 4 sets of 15 seconds per minute)
1.4/4 = 0.35 ml per 15 seconds
Order for IV hydromorphone 5 mg for a patient in severe pain. Available from pharmacy is hydromorphone 4 mg/ml for injection. Suggested administration is undiluted in 3 minutes. How much volume will the nurse have in the syringe and how many seconds per 0.25 ml for the administration?
1.25 ml IV and 36 seconds per 0.25 ml IV
Get volume of syringe- 5 mg/4 mg x 1 ml = 1.25 ml (if the syringe has 0.25 markings, don't round. If the syringe only has 0.1 markings, you may need to round to 1.3 ml)
Push time is 3 minutes regardless of dose
Divide 1.25 ml by 0.25 ml = 5 (the number of 0.25 ml in a 1.25 ml syringe is 5)
3 minutes (or 180 seconds) divided by 5 = 36 seconds per 0.25 ml
Order for pantoprazole 40 mg IV push daily. Supplied is pantoprazole 40 mg/vial. Instructions for reconstitution are to add 10 ml NS for a total concentration of 4 mg/ml. The suggested push rate is to give over 2 minutes. How much will the nurse draw up into the syringe and how many ml per 30 seconds will be administered?
10 ml IV and 2.5 ml every 30 seconds
Follow directions and reconstitute vial with 10 ml NS
Then figure out desired volume- 40 mg/4 mg x 1 ml = 10 ml
Figure out how many groups of 30 seconds are in 2 minutes- 120 seconds/30 seconds = 4
Take volume to administer and divide by 4- 10 ml/4 = 2.5 ml every 30 seconds
Order for ceftriaxone 2 g IV for infection. Available are ceftriaxone 1 g vials with instructions to reconstitute with 10 ml sterile water for injection. The suggested push rate is 5 minutes. How much will the nurse draw up into the syringe and how many ml per 30 seconds will be administered?
20 ml IV and 2 ml every 30 seconds
How many vials are needed? 2 g/1 g x 1 vial = 2 vials
Reconstitute the vials by adding 10 ml sterile water per vial
Draw up contents of each vial = 20 ml
Push time is 5 minutes regardless of dose
Determine how many groups of 30 seconds are in 5 minutes- 300 seconds/30 seconds = 10
20 ml/10 = 2 ml every 30 seconds
The patient in DKA is now ready for the insulin drip. He weighs 320 pounds. Ordered is to start regular insulin at 0.1 unit/kg/hr. Available from pharmacy is regular insulin 1 unit/ml. What will the nurse set the infusion pump to in units/hr and ml/hr?
14.5 units/hr IV and 14.5 ml/hr IV
Convert weight to kg- 320/2.2 = 145.46 kg after rounding
Determine dose- 145.46 x 0.1 = 14.546 units/hr (will need to round to 14.5 units)
Determine volume- 14.5 units/1 unit x 1 ml = 14.5 ml
A 180 pound patient in septic shock is ordered to receive epinephrine 0.1 mcg/kg/min IV. Supplied by pharmacy is epinephrine 1 mg/250 ml. What will the nurse set the infusion rate to in mcg/min and ml/hour?
8.18 mcg/min IV and 122.7 ml/hr IV
Convert weight- 180/2.2 = 81.82 kg after rounding
Determine dose- 81.82 x 0.1 = 8.18 mcg/min (again, if pump can't do hundredths, you would choose 8.2 mcg/min)
Determine rate in ml/hr- 8.18/1,000 x 250 ml = 2.045 ml per minute (recall that 1mg = 1,000 mcg)
Now convert to hours instead of minutes- 2.045 x 60 = 122.7 ml/hr
You have made it through all the learning content. Great work! There are more practice questions for your convenience
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