Pediatric Safe Dosage Calc

[rsyed47]

Hello,

I would appreciate some help with these safe dosage calculation problems.

1. Diagnosis: Status Epilepticus

Order: midazolam/Versed 2mg IV push

Weight: 30 lbs ( 3 yr old)

supply: 2mg/2 mL (Midazolam injection, USP)

what is the recommended safe dose range:

Give:

According to my drug guide for status epilepticus IV children >2mo: loading dose is 0.15mg/kg followed by continuous infusion of 1mcg/kg/min; range: 1-18 mcg/kg min titrate upward q 5 mins until seizure is controlled.

So the loading dose would be for this child:

0.15mg/kg x 13.6 kg (child's wt.)= 2.04 --> 2mg (which is what the doc ordered) so it's safe. What do I do with the continuous infusion?

0.001mg/kg x 13.6 kg= 0.0136/min --> 0.01mg/min (do i add these onto 2mg?, do i multiply them by 5 min?)

0.018mg/kg x 13.6 kg= 0.2448/min --> 0.25mg/min

I'm guessing the safe dose range is 2.01mg- 2.25mg.

I would give 2 mL initially and then additionally anywhere from 0.01-0.25 mL until seizure is controlled?

2. Diagnosis: Heart failure

Order: captopril/capoten 3.5 mg po 4x a day

Wt: 20 lbs ( 1 yr old)

supply: 1mg per mL, syrup 25mL

recommended safe dose range:

Give:

Alright, so the first issue I'm having with this is whether to use infant or child dosage. According to my drug guide: infants 0.15-0.3 mg/kg/dose, titrate to max of 6mg/day in 1-4 divided doses

0.15mg/kg x 9.1 kg (child's wt)= 1.365 --> 1.4 mg

0.3 mg/kg x 9.1 kg= 2.73--> 2.7 mg

The order is for 3.5mg, so this is not safe as it doesnt fall between 1.4-2.7mg/dose.

Now for children the instructions are: 0.3 mg/kg–0.5 mg/kg/dose 3 times daily, titrate up to a maximum of 6 mg/kg/day in 2–4 divided doses

Math:

0.3 mg/kg x 9.1 kg= 2.7 mg

0.5 mg/kg x 9.1 kg= 4.55 --> 4.6 mg

Now initially I would think this is safe as 3.5 mg (ordered dose) falls in between 2.7-4.6mg. However, the instructions in the drug guide said for children it's 0.3-0.5mg/kg 3x daily. The ordered dose is 3.5mg 4x (which would equal 14mg total for the day). If i were to do 4.6 mg x 3 doses (drug guide) I would get 13.8mg total for the day. So 3.5 mg 4x day falls out of range and is not safe.

Am i thinking through this correctly? Very confused.

[chare]

Midazolam: As I am not sure which drug reference you are using, Did your drug reference not provide a dosing range? For example, we rarely use midazolam for seizure control. However, if we do, we administer bolus doses of 0.05 – 0.1 mg/kg. For a 30 lb (13.63 kg) patient we would administer 0.68 mg – 1.36 mg. However, using your dose of 0.15 mg/kg, 2 mg would be a safe dose.

Regarding the infusion. As you consider and calculate the infusion separate from the bolus dose, the safe dosing ranges are separate as well.

To calculate a weight based infusion, use the following formula:

(dose x weight x 60) / concentration

Also, if you are going to round, do not do so until you complete all of your calculations. In practice, I will round to either 1 or 3 decimal places, depending upon the pump that I am using.

Captopril: First, are you sure that the maximum safe dose for an infant is 6 mg/day? Epocrates list the infant captopril heart failure dose as 0.15 – 0.3 mg/kg/day, with total daily dose of 2.5 – 6 mg/kg/day. Using this data, what would the maximum daily dose for a 9.1 kg patient be?

[dream'n, BSN, RN]

One reason I never liked Pediatrics; too much weight based dosing.