QUESTION 1
What rate of infusion will meet the threshold for converting for this patient?
- 45 mg / 50 ml = 45000 micrograms / 50 ml = 900 micrograms / ml
- Therefore, in 1.5 ml there is 900 micrograms / ml x 1.5 ml = 1350 micrograms/hour
- 1350 micrograms / hour / 7.2 kg = 187.5 micrograms/kg/hour
QUESTION 2
What rate of infusion will meet the threshold for converting for this patient?
- Threshold is 150 micrograms/kg/hour
- 150 micrograms/kg/hour x 7.2 kg = 1080 micrograms/hour
- 1080 micrograms/hour / 900 micrograms/ml = 1.2 ml/hour
QUESTION 3
From the value calculated in Question 2, project a total daily midazolam dose for this patient.
- At the threshold of 150 micrograms/kg/hour the hourly dose is 150 micrograms/kg/hour x 7.2 kg = 1080 micrograms/hour
- In a day this would equate to 1080 micrograms/hour x 24 hours = 25 920 micrograms/day = 25.92 mg/day
QUESTION 4
What is the oral diazepam total daily dose that this patient is likely to need?
- Diazepam dose = 0.3 x midazolam dose
- Daily midazolam dose = 25.92 mg/day x 0.3 = 7.776 mg
QUESTION 5
If the diazepam is going to be administered four times a day using 2 mg / 5 ml solution, what volume should be administered for each dose?
- To split the total daily dose into four, each dose will be 7.776 mg / day / 4 = 1.944 mg/dose
- The available solution is 2 mg / 5 ml = 0.4 mg/ml
- To give this dose exactly 1.944 mg/dose / 0.4 mg/ml = 4.86 ml/dose
- Pragmatically, rounding the dose to 2 mg and giving 5 ml per dose would not be unreasonable.