Dose calculation: the amount to give equals what is prescribed divided by what you have, times the quantity it comes in: amount = (desired dose/stock strength) × stock volume. Always keep the units the same (convert g to mg, mg to mcg first) and check that the answer is sensible.
混合後の濃度
500 mg/10 mL = 50 mg/mL
体積
V = 100/50 = 2 mL
答え
V = 2 mL
4.投与量の計算
答え: D = 81.39 mg
Body-surface-area dosing: many cytotoxic and some paediatric doses are prescribed per square metre of body surface area: dose (mg) = dose per m² × BSA (m²). The Mosteller formula estimates BSA = √(height (cm) × weight (kg)/3600).
体表面積
BSA = √(144·46/3600) = √1.84 = 1.356 m²
投与量
D = 60·1.356 = 81.39 mg
答え
D = 81.39 mg
5.点滴速度
答え: V = 1200 mL
Infusion rates: a pump is set in mL/h = volume/time in hours. A gravity drip is counted in drops per minute: gtt/min = volume (mL) × drop factor (gtt/mL)/time (min). The drop factor is printed on the tubing package: macrodrip sets deliver 10, 15 or 20 gtt/mL (blood sets often 10 gtt/mL in the US, 15 in the UK) and microdrip sets 60 gtt/mL. Always use the drop factor the question or package gives.
流量(mL/h)
50·60/15 = 200 mL/h
体積
V = 200·6 = 1200 mL
答え
V = 1200 mL
6.点滴速度
答え: R = 22.5 mL/h
Dose-based infusions: concentration = amount of drug in the bag/bag volume. Pump rate (mL/h) = dose per hour/concentration, and dose per hour = mL/h × concentration. Convert per-minute doses to per-hour (× 60) and keep the mass units the same (1 g = 1000 mg, 1 mg = 1000 mcg).