Answer: 32 mL

Constant rate infusions are not something that an entry level technician would typically perform. However, the VTNE may have some questions on CRI and it will benefit you to know how to do these calculations. To solve this problem, break down the basic parts to make it less overwhelming:

1) Convert pounds to kilograms- Note that in this problem the units are already in kg so no conversion is necessary. Make sure to pay attention to this.

2) Calculate the number of hours an infusion will last by dividing the volume in the bag (1 Liter, or 1,000 mL) by the rate per hour: 1,000 mL/100mL/hr = 10 hours

(If the problem asks for a dose per minute, you will need to multiply the hours by 60 to convert to minutes, but since this problem asks for ug/kg/HOUR, you do not need to further convert)

4) Now plug into the equation: 4 ug/40kg/10 hours= 1600 ug

5) Now convert the ug into mg by dividing by 1,000: 1600/1,000 = 1.6 mg

6) Calculate the quantity of fentanyl to add by now dividing the 1.6 mg by the concentration of the drug (0.05 mg/mL) : 1.6mg/0.05mg/mL = 32 mL

To be truly accurate when adding drugs to a bag like this, you should discard 32 mL of fluids from the bag prior to adding the 32 mL of fentanyl. Answer: 75 ml

Constant rate infusions are not something that an entry-level technician would typically perform. However, the VTNE may have some questions on CRI, and it will benefit you to know how to do these calculations. To solve this problem, break down the basic parts to make it less overwhelming.

*Note that a 2% solution is the same as 20 mg/mL (add a zero to the % number, so 1% is 10mg/mL, 20% is 200 mg/mL, etc.)

1) Convert pounds to kilograms-55 pounds/2.2 pounds per kg = 25 kg

2) Calculate the number of hours an infusion will last by dividing the volume in the bag (1 liter, or 1,000 ml) by the rate per hour: 1,000 ml/80ml/hr = 12.5 hours

3) Now take the number of hours (12.5) and multiply by 60 to calculate how many minutes this is: 12.5 X 60 = 750 minutes

4) Plug into the equation: 80 ug/25kg/750min= 1,500,000 ug

5) Now convert the ug into mg by dividing by 1,000: 1,500,000/1,000 = 1500 mg

6) Calculate the quantity of lidocaine to add by dividing the 1500 mg by the concentration of the drug (20mg/ml): 1500mg/20mg/ml = 75 ml

To be truly accurate when adding drugs to a bag like this, you should discard 75 ml of fluids from the bag prior to adding the 75 ml of lidocaine. Answer: 1.86 mL

Constant rate infusions are not something that an entry level technician would typically perform. However, the VTNE may have some questions on CRI and it will benefit you to know how to do these calculations. To solve this problem, break down the basic parts to make it less overwhelming:

1) Convert pounds to kilograms- 66 pounds/2.2 pounds per kg = 30 kg

2) Calculate the number of hours an infusion will last by dividing the volume in the bag (1 Liter, or 1,000 mL) by the rate per hour: 1,000 mL/120mL/hr = 8.3 hours

3) Now take the number of hours (8.3) and multiply by 60 to calculate how many minutes this is: 8.3 X 60 = 498 minutes

4) Now plug into the equation: 5 ug/30kg/498min= 74,700 ug

5) Now convert the ug into mg by dividing by 1,000: 74,700/1,000 = 74.7 mg

6) Calculate the quantity of dopamine to add by now dividing the 74.7 mg by the concentration of the drug (40mg/mL) : 74.7mg/40mg/mL = 1.86 mL

To be truly accurate when adding drugs to a bag like this, you should discard 1.86 mL of fluids from the bag prior to adding the 1.86 mL of dopamine.