If the fetus cannot swallow, as in oesophageal atresia, amniotic fluid builds up and the stomach is not seen. Renal agenesis causes the opposite, severe oligohydramnios.
คำตอบ
C · Oesophageal atresia
3.การคำนวณขนาดยา
คำตอบ: m = 1000 mg
Solution strengths: a percentage strength is grams per 100 mL, so 1% = 1 g/100 mL = 10 mg/mL. A ratio strength 1:1000 means 1 g in 1000 mL = 1 mg/mL; 1:10 000 is 0.1 mg/mL. For a dilution the amount of drug stays the same: C₁·V₁ = C₂·V₂.
ความเข้มข้น
5% = 5 g/100 mL = 50 mg/mL
มวลของยา
m = 50·20 = 1000 mg
คำตอบ
m = 1000 mg
4.การคำนวณขนาดยา
คำตอบ: D = 287.2 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).
พื้นที่ผิวร่างกาย
BSA = √(179·91/3600) = √4.525 = 2.127 m²
ขนาดยา
D = 135·2.127 = 287.2 mg
คำตอบ
D = 287.2 mg
5.อัตราการให้สารน้ำทางหลอดเลือดดำ
คำตอบ: V = 240 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.
อัตราเป็น mL/h
40·60/20 = 120 mL/h
ปริมาตร
V = 120·2 = 240 mL
คำตอบ
V = 240 mL
6.อัตราการให้สารน้ำทางหลอดเลือดดำ
คำตอบ: R = 90 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).