Maternity Nursing: cram pack

Formula sheets, the key method steps for every topic and 6 practice problems, with full solutions at the back.

New problemsBack to the course

In the print window, choose “Save as PDF” to keep a copy on your device.

1Formulas and methods

Maternity & obstetric nursing

Method

  1. Place the woman in time: weeks of pregnancy, stage of labour or day after birth, and decide what is normal at that point.
  2. Look for the patient in danger: the mother, the fetus or the newborn, or more than one of them.
  3. Link the finding to its cause: VEAL CHOP for decelerations, the four Ts for bleeding, BUBBLE-HE after birth.
  4. Choose the action that improves blood flow and oxygen first (side-lying, stopping oxytocin, fundal massage), then escalate.

Dosage calculations

Dose from strength
volume = dose / strength
Weight-based dose
dose = mg/kg × body weight
Tablets
number = dose / tablet strength
Units
1 g = 1000 mg, 1 mg = 1000 mcg

Method

  1. Convert the ordered dose and the stock strength to the same unit.
  2. Use desired over have times quantity: (D/H) × Q.
  3. For weight-based doses, multiply by the weight in kg first, then divide the daily dose by the number of doses.
  4. Estimate first and check that the answer is reasonable.

IV infusion rates

Pump rate
mL/h = volume (mL)/time (h)
Drip rate
drops/min = volume (mL) × drop factor / time (min)
Infusion time
time (h) = volume (mL)/rate (mL/h)

Method

  1. Pump rate in mL/h: volume divided by time in hours.
  2. Drip rate in drops/min: volume × drop factor divided by time in minutes.
  3. For time remaining: volume left divided by the rate.
  4. Round as the question or the equipment requires.

2Practice problems

1.Maternity & obstetric nursingMedium

A breastfeeding mother asks how she will know her baby is getting enough milk. Which sign is reassuring by day 5 or 6?

  1. AThe baby feeds for exactly 5 minutes each side
  2. BHer breasts never feel full
  3. CAt least 6 wet nappies a day and yellow stools
  4. DThe baby sleeps for 8 hours without feeding
2.Maternity & obstetric nursingHard

The partner of a woman receiving magnesium sulfate asks what the drug is for. Which answer is accurate?

  1. AIt is the main drug that lowers her blood pressure
  2. BIt speeds up labour
  3. CIt stops the baby from growing too large
  4. DIt helps prevent seizures caused by pre-eclampsia
3.Dosage calculationsMedium
1 g+ 3.4 mLV = ? mL

A vial contains 1 g of powder. The label says: add 3.4 mL of water for injection to give a total volume of 4 mL. The prescription is 300 mg. What volume V of the reconstituted solution do you give?

1 g+ 3.4 mL → 4 mL300 mg
V = mL
4.Dosage calculationsHard
200 mg/5 mLV = ? mL

A patient weighs 30.8 lb. The prescription is 15 mg/kg as a single dose, and the stock contains 200 mg in 5 mL. Using 1 kg = 2.2 lb, what volume V do you give? Round to one decimal place.

30.8 lb15 mg/kg200 mg/5 mL1 kg = 2.2 lb
V = mL
5.IV infusion ratesMedium
500 mL20 gtt/mL12 h? gtt/min

Infuse 500 mL over 12 hours with a giving set of 20 gtt/mL. Find the drip rate R in drops per minute. Round to the nearest whole number.

500 mL12 h20 gtt/mL
R = gtt/min
6.IV infusion ratesHard
25 mg250 mL24 mL/h? mcg/min

An infusion of 25 mg in 250 mL runs at 24 mL/h. How many micrograms per minute D does the patient receive?

25 mg/250 mL24 mL/h
D = mcg/min

3Solutions

1.Maternity & obstetric nursing

Answer: C · At least 6 wet nappies a day and yellow stools

Why this is the answer

Signs of adequate intake include 6 or more wet nappies and several yellow stools a day by day 5 or 6, steady weight gain and a content baby after feeds. Most babies regain birth weight by about 2 weeks.

Answer

C · At least 6 wet nappies a day and yellow stools
2.Maternity & obstetric nursing

Answer: D · It helps prevent seizures caused by pre-eclampsia

Why this is the answer

Magnesium sulfate is given to prevent and treat eclamptic seizures. It is not an effective antihypertensive, so severe hypertension needs separate drugs.

Answer

D · It helps prevent seizures caused by pre-eclampsia
3.Dosage calculations

Answer: V = 1.2 mL

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.

Concentration after mixing

1000 mg/4 mL = 250 mg/mL

Volume

V = 300/250 = 1.2 mL

Answer

V = 1.2 mL
4.Dosage calculations

Answer: V = 5.3 mL

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.

Weight in kg

30.8/2.2 = 14 kg

Dose

15·14 = 210 mg

Volume

V = (210/200)·5 = 5.25 ≈ 5.3 mL

Answer

V = 5.3 mL
5.IV infusion rates

Answer: R = 14 gtt/min

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.

Time in minutes

12·60 = 720 min

Drip rate

R = 500·20/720 = 13.89 ≈ 14 gtt/min

Answer

R = 14 gtt/min

At the bedside you round to the nearest whole drop: 14 gtt/min.

6.IV infusion rates

Answer: D = 40 mcg/min

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).

Concentration

25000 mcg/250 mL = 100 mcg/mL

Dose per hour

24·100 = 2400 mcg/h

Dose per minute

D = 2400/60 = 40 mcg/min

Answer

D = 40 mcg/min

ExamProblems · examproblems.com/courses/maternity-nursing