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Dosage calculation RN Proctored exam herzing university
Total Questions : 14
Showing 10 questions, Sign in for moreA client is receiving Phenylephrine IV at 160 mL/hr. It is available as Phenylephrine IV 300 mg in 500 mL D5W. What is the flow rate in mg/min? Round to the nearest tenths place where applicable and enter numeric value only (no commas or labels) ________ mg/min
Explanation
Step 1 is to identify the available concentration of the medication
Available concentration = Total mg ÷ Total mL
Available concentration = 300 ÷ 500
300 ÷ 500 = 0.6 mg/mL
Step 2 is to calculate the dosage delivered per hour
mg per hour = mL/hr × mg/mL
mg per hour = 160 × 0.6
160 × 0.6 = 96 mg/hr
Step 3 is to calculate the dosage delivered per minute
mg per minute = mg/hr ÷ 60 minutes
mg per minute = 96 ÷ 60
96 ÷ 60 = 1.6 mg/min
Step 4 is to round to the nearest tenth
1.6 = 1.6
Answer: 1.6
Order: Lidocaine IV to infuse at 7 mg/min. The solution available is 1.5 g of lidocaine in 125 mL D5W. Determine the IV flow rate in mL/hr. Round to the nearest tenths place where applicable and enter numeric value only (no commas or labels) ________ mL/hr
Explanation
Step 1 is to convert the available grams to milligrams
mg = grams × 1000
1.5 × 1000 = 1500 mg
Step 2 is to calculate the concentration of the available solution
mg per mL = Total mg ÷ Total mL
1500 ÷ 125 = 12 mg/mL
Step 3 is to calculate the required milligrams per hour
mg per hour = mg/min × 60 minutes
7 × 60 = 420 mg/hr
Step 4 is to calculate the flow rate in mL per hour
mL/hr = mg/hr ÷ mg/mL
420 ÷ 12 = 35 mL/hr
Step 5 is to round to the nearest tenth
35 = 35.0
Answer: 35.0
Order: Hydrocortisone 1000 mg IV push stat. It is available as Hydrocortisone 125 mg per 2 mL. How many mL will the nurse administer? Round to the nearest tenths place where applicable and enter numeric value only (no commas or labels) ________ mL
Explanation
Step 1 is to identify the ordered dose and available concentration
Ordered dose: 1000 mg
Available: 125 mg / 2 mL
Step 2 is to calculate the volume to be administered
Volume = (Ordered dose ÷ Available dose) × Available volume
Volume = (1000 ÷ 125) × 2
1000 ÷ 125 = 8
8 × 2 = 16 mL
Step 3 is to round to the nearest tenth
16 = 16.0
Answer: 16.0
Order: Nitroglycerin IV to infuse at 90 mcg/min. It is available as Nitroglycerin 150 mg in 300 mL D5W. What is the infusion rate in mL/hr? Round to the nearest tenths place where applicable and enter numeric value only (no commas or labels) ________ mL/hr
Explanation
Step 1 is to convert the total milligrams in the bag to micrograms
mcg = mg × 1000
150 × 1000 = 150,000 mcg
Step 2 is to calculate the concentration of the solution in mcg/mL
mcg per mL = Total mcg ÷ Total mL
150,000 ÷ 300 = 500 mcg/mL
Step 3 is to calculate the micrograms delivered per hour
mcg per hour = mcg/min × 60 minutes
90 × 60 = 5400 mcg/hr
Step 4 is to calculate the flow rate in mL per hour
mL/hr = mcg/hr ÷ mcg/mL
5400 ÷ 500 = 10.8 mL/hr
Step 5 is to round to the nearest tenth
10.8 = 10.8
Answer: 10.8
Order: Zosyn IV 2 grams to infuse over 15 minutes. It is available as Zosyn 2 grams in 50 mL NS. What is the infusion rate in mL/hr? Round to the nearest tenths place where applicable and enter numeric value only (no commas or labels) ________ mL/hr
Explanation
Step 1 is to identify the total volume to be infused and the time in minutes
Total volume = 50 mL
Time = 15 minutes
Step 2 is to calculate the infusion rate in mL per hour using the hour conversion
mL/hr = (Total volume ÷ Time in minutes) × 60 minutes
(50 ÷ 15) × 60 = Result
50 ÷ 15 = 3.3333...
3.3333... × 60 = 200
Step 3 is to round to the nearest tenth
200 = 200.0
Answer: 200.0
Order: Infuse 0.45% NS IV at 75 mL/hr. The tubing has a drop factor of 15 gtt/mL. What is the flow rate in gtt/min? Round to the nearest whole number and enter numeric value only (no commas or labels) ________ gtt/min
Explanation
Step 1 is to identify the flow rate in mL/hr and the drop factor
Flow rate = 75 mL/hr
Drop factor = 15 gtt/mL
Step 2 is to calculate the total drops per hour
Total drops per hour = mL/hr × drop factor
75 × 15 = 1125 gtt/hr
Step 3 is to calculate the drops per minute
gtt/min = Total drops per hour ÷ 60 minutes
1125 ÷ 60 = 18.75 gtt/min
Step 4 is to round to the nearest whole number
18.75 ≈ 19
Answer: 19
Order: Humulin regular IV to infuse at 12 units/hr. The IV solution is available as Humulin regular insulin IV 250 units in 250 mL of 0.9% NS. At what rate in mL/hr should the IV infuse? Round to the nearest tenths place where applicable and enter numeric value only (no commas or labels) ________ mL/hr
Explanation
Step 1 is to calculate the concentration of the insulin solution in units/mL
Units per mL = Total units ÷ Total mL
250 ÷ 250 = 1 unit/mL
Step 2 is to calculate the flow rate in mL/hr
mL/hr = Units per hour ÷ Units per mL
12 ÷ 1 = 12 mL/hr
Step 3 is to round to the nearest tenth
12 = 12.0
Answer: 12.0
An IV of 500 mL D5W is to infuse at 75 mL/hr. The IV was started at 10:00 PM. At what time would the IV infusion be completed? Enter answer in military time. Round to the nearest whole number of minutes and enter numeric value only (no commas or labels) Answer in military time. ________
Explanation
Step 1 is to calculate the total infusion time in hours
Total hours = Total volume ÷ mL/hr
500 ÷ 75 = 6.6666... hours
Step 2 is to convert the decimal portion of the hours into minutes
Minutes = 0.6666... × 60 minutes
0.6666... × 60 = 40 minutes
Total time = 6 hours and 40 minutes
Step 3 is to convert the start time to military time
10:00 PM = 2200
Step 4 is to add the infusion time to the start time
2200 + 0640 = Result
2200 + 0200 (to reach midnight) = 2400 (or 0000)
Remaining time to add = 4 hours and 40 minutes
0000 + 0440 = 0440
Answer: 0440
Order: Magnesium sulfate 2 g IV to infuse over 2 hours. It is available as Magnesium sulfate 2 g in 500 mL D5W. What is the infusion rate in mL/hr? Round to the nearest tenths place where applicable and enter numeric value only (no commas or labels) ________ mL/hr
Explanation
Step 1 is to identify the total volume to be infused and the total time in hours
Total volume = 500 mL
Total time = 2 hours
Step 2 is to calculate the infusion rate in mL per hour
mL/hr = Total volume ÷ Total hours
500 ÷ 2 = 250
Step 3 is to round to the nearest tenth
250 = 250.0
Answer: 250.0
Order: Dobutamine IV to infuse at 6 mcg/kg/min. It is available as Dobutamine 300 mg in 250 mL D5W. The client weighs 100 kg. Calculate the flow rate in mL/hr. Round to the nearest tenths place where applicable and enter numeric value only (no commas or labels) ________ mL/hr
Explanation
Order: Dobutamine IV to infuse at 6 mcg/kg/min. It is available as Dobutamine 300 mg in 250 mL D5W. The client weighs 100 kg. Calculate the flow rate in mL/hr. Round to the nearest tenths place where applicable and enter numeric value only (no commas or labels) ________ mL/hr
Correct answer: 30.0
Rationale:
Step 1 is to calculate the total dosage required per minute
mcg per minute = Weight in kg × Dosage (mcg/kg/min)
100 × 6 = 600 mcg/min
Step 2 is to calculate the total dosage required per hour
mcg per hour = mcg/min × 60 minutes
600 × 60 = 36,000 mcg/hr
Step 3 is to convert the hourly mcg dose to milligrams (mg)
mg per hour = mcg/hr ÷ 1000
36,000 ÷ 1000 = 36 mg/hr
Step 4 is to calculate the concentration of the available solution in mg/mL
mg per mL = Total mg ÷ Total mL
300 ÷ 250 = 1.2 mg/mL
Step 5 is to calculate the flow rate in mL per hour
mL/hr = mg/hr ÷ mg/mL
36 ÷ 1.2 = 30
Step 6 is to round to the nearest tenth
30 = 30.0
Answer: 30.0
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