Appendix B: Calculating The Drug Infusion Solution - Codman AS 10 Manual Del Usuario

Appendix B: Calculating the Drug Infusion Solution

APPENDIX B: CALCULATING THE DRUG INFUSION SOLUTION
The drugs indicated for use with the ARCHIMEDES Implantable Infusion Pump must be
diluted only with sterile 0.9% saline solution to make the infusion solution.
CAUTION: Preservative-free morphine sulfate is supplied in various concentrations.
Be aware of the concentration before calculating the amount of drug to be infused.
In order to calculate the drug infusion solution, one must perform 3 steps:
• calculate the running time of the pump;
• calculate the amount of the drug required in [mg] or [μg]; then convert into [mL]; and
• calculate the amount of saline required.
CAUTION: Prepare an additional 3 mL of drug solution, in excess of the capacity of
the reservoir, to prime the refill assembly.
Calculate the running time of the pump:
Reservoir capacity
= Running time (days) [24 h]
Flow Rate/24 hours
Calculate the amount of the drug:
Required daily dosage Running time of the
x
of the drug infusion pump in
[mg/24 h] or [μg/24 h]
Convert the total amount of drug required from mg or μg to mL. In the case of drugs with
lower dosages (such as baclofen), please observe the conversion factor for converting mg
to μg (1 mg = 1000 μg).
Total amount of drug / Concentration of drug
[mg] or [μg] [mg/mL] or [μg/mL]
Calculate the amount of sterile 0.9% saline solution:
Total amount of
Reservoir capacity
–
[mL]
Appendix B – 22
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Total amount of
=
drug required
[24 h] days [mg] or [μg]
Total amount of
=
drug required
[mL]
Total amount of
=
drug required
saline [mL]
[mL]
Result: Total amount of infusion solution
Total amount of
Total amount of
+
drug required
saline [mL]
[mL]
Example of a Drug Calculation
Note: The preservative-free morphine sulfate concentration in this example is
10 mg/1 mL.
In this example:
• the daily dosage is 4 mg morphine
• the reservoir capacity is 20 mL
• the pump flow rate is 0.8 mL/24 hours
Step 1: Calculate the running time of the pump
20 mL reservoir capacity
0.8 mL flow rate/24 h
Step 2: Calculate the total amount of drug required
4-mg daily dosage x 25 days running time = 100 mg morphine
Step 2a: Calculate the number of morphine ampules (assuming 1 mL per ampule and
10 mg morphine/mL)
100 mg morphine
= 10 ampules @ 1 mL/ampule = 10 mL morphine
10 mg/mL
Step 3: Calculate the amount of saline
20 mL reservoir – 10 mL morphine = 10 mL saline
Total amount of
=
infusion solution
[mL]
= 25 days running time
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