The Nursing Math Thread

Daytonite, BSN, RN · Jan 25, 2009

Order: Tylenol suspension 1/2 tsp po q4h prn for fever for a child weighing 32 lb.
The medication is supplied as 325 mg per 10 mL
The recommended dose is 25 - 35 mg/kg/day q4h prn
Is the ordered dose in the safe range?
Answer: Patient weight 14.5 kg
Each dose ordered 81.25 mg
Daily possible dose 487.5 mg/day
Safe range 363.6 mg/d - 507.5 mg/d
Yes, the dose ordered is within the safe range
Im not getting the right answer..I can get the safe range, but Im not understanding the dose ordered? Can someone please show me how to do this? I already failed the exam once, I only have one more try on tuesday...

Ordered: 1/2 teaspoon of 325 mg/10 mL for a 32 pound child

Safe dose: 25-35 mg/kg/day q4h (q4h is 6 doses in a 24 hour day)

Determine Safe Dose Range:

25 mg/kg x kg/2.2 pounds x 32 pounds/1 x 1/6 doses = 60.6060 mg

35 mg/kg x kg/2.2 pounds x 32 pounds/1 x 1/6 doses = 84.8484 mg

Determine Dose Ordered:

0.5 teaspoon

(dose desired)

/10 mL

(solution on hand)

x 325 mg/1

(amount of drug in solution on hand)

x 5 mL/1 teaspoon

(conversion factor)

= 81.25 mg

(amount of drug in dose you will give)

Question: Is the ordered dose in the safe range?

YES.

The 81.25 mg falls between tha safe range of 60.6060 mg to 84.8484 mg.

moncj66 · Jan 26, 2009

yes, I was looking for how they got those answer because I got completely different answers..THANKS SO MUCH..I will practice some more :) ur a lifesaver!

Evil Cactus RN · Jan 26, 2009

I need help please!!!!

Physician orders 300 ml NS over 1 hour. Tubing has gtts of 60. After the first hour, the physicial wants the rest of the solution to infuse at 125 ml per hour.

What is the flow rate in drops per minute during the first hour?

What is the flow rate in ml/hr during the first hour?

How much fluid had the patient recieved after 6 hours?

beth66335, BSN, RN · Jan 26, 2009

I need help please!!!!
Physician orders 300 ml NS over 1 hour. Tubing has gtts of 60. After the first hour, the physicial wants the rest of the solution to infuse at 125 ml per hour.
What is the flow rate in drops per minute during the first hour?
What is the flow rate in ml/hr during the first hour?
How much fluid had the patient recieved after 6 hours?

I'm a little confused by this...is 300ml the total solution to be infused? If it is I wouldn't think there would be any left if the Dr wants it infused over 1 hour. Are we talking about a bag of NS which could be 1000ml?

If so it would be ; 60gtts/min and 330ml/hr

1000-300=700ml remaining after 1st hour

700ml to infuse at 125ml per hr x 5 hrs= 625ml given in next 5 hours.

625 + 300 (from first hour)= 925ml given in 6 hours

Sorry if this isn't what you meant... Daytonite? Any thoughts?

moncj66 · Jan 27, 2009

I need more help!

QUestion: calculate IV fluids 1 1/4 fluid maintenance for a child weighing 21 kgs?

Daytonite, BSN, RN · Jan 27, 2009

i need help please!!!!
physician orders 300 ml ns over 1 hour. tubing has gtts of 60. after the first hour, the physician wants the rest of the solution to infuse at 125 ml per hour.
what is the flow rate in drops per minute during the first hour?
what is the flow rate in ml/hr during the first hour?
how much fluid had the patient received after 6 hours?

physician orders 300 ml ns over 1 hour. tubing has gtts of 60. after the first hour, the physician wants the rest of the solution to infuse at 125 ml per hour.

what is the flow rate in drops per minute during the first hour?

300 ml/1 hour

(amount to infuse)

x 60 gtts/ml

(drop factor of iv tubing to be used)

x 1 hour/60 minutes

(conversion factor of hours to minutes)

=

300 gtts/minutes

(flow rate in drops per minute during the first hour of the infusion)

what is the flow rate in ml/hr during the first hour?

this is information that is given to you in the problem:

300 ml/hour

how much fluid had the patient received after 6 hours?

(1 x 300 ml)

fluid received first hour +

(5 x 125 ml)

fluid received in next 5 hours

=

925 ml

Daytonite, BSN, RN · Jan 27, 2009

I need more help!
QUestion: calculate IV fluids 1 1/4 fluid maintenance for a child weighing 21 kgs?

What replacement formula are you supposed to use? The one I have for a 21 kg child is 1000 mL for the first 10 kg + 50mL/kg/24 hours for each kg over 10 kg. If 1 and 1/4 fluid maintenenace is ordered then that needs to be considered in the calculations.

moncj66 · Jan 28, 2009

I just wanted to say thanks daytonite, u helped me sooo much! I got a 100 on my retest thanks to u!! UR DEFINITELY A LIFESAVER and angel on this site..would love to meet u one day..hehe!! :)

beth66335, BSN, RN · Jan 28, 2009

i just wanted to say thanks daytonite, u helped me sooo much! i got a 100 on my retest thanks to u!! ur definitely a lifesaver and angel on this site..would love to meet u one day..hehe!! :)

congratulations!!! :yeah: :yeah: :yeah: :up: :):):d:p:clown:

Goldenatom · Jan 28, 2009

Bleh, I just found out that I failed my first medcalc exam! All rounding errors, stupid me. 2 more chances to fix it.

onlyfaith · Feb 5, 2009

I'm stumped! :uhoh21: Please help....

A Heparin solution with a strength of 20,000 U in 500 mL of D5W is ordered to infuse at a rate of 1000 U/hr IV with an administration set that delivers 60 drops/mL. Calculate the drip rate in drops/minute.

Answer= 25 drops/minute

Thanks in advance!

Daytonite, BSN, RN · Feb 6, 2009

I'm stumped! :uhoh21: Please help....
A Heparin solution with a strength of 20,000 U in 500 mL of D5W is ordered to infuse at a rate of 1000 U/hr IV with an administration set that delivers 60 drops/mL. Calculate the drip rate in drops/minute.
Answer= 25 drops/minute
Thanks in advance!

1000 units/hour (ordered infusion rate) x 500 mL/20,000 units (dose on hand) x 60 gtts/mL (drop factor of IV administration set) x 1 hour/60 minutes (conversion factor) = 25 drops/minute (drip rate)