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

Which baby is at greatest risk of early-onset group B streptococcal infection?

  1. AA baby born by planned caesarean with intact membranes
  2. BA baby born at 40 weeks to a mother with no risk factors
  3. CA baby whose mother was GBS-negative at 36 weeks
  4. DA baby of a GBS-positive mother with no antibiotics
2.Maternity & obstetric nursingHard

Women with pre-eclampsia can develop complications after birth. Which statement in discharge teaching is correct?

  1. AAll risk ends once the placenta has been delivered
  2. BBlood pressure always returns to normal within 1 hour of birth
  3. CSeizures cannot happen after the baby and placenta are born
  4. DIt can still develop after birth, so report headache or visual changes
3.Dosage calculationsMedium
500 mg+ 1.8 mLV = ? mL

A vial contains 500 mg of powder. The label says: add 1.8 mL of water for injection to give a total volume of 2 mL. The prescription is 100 mg. What volume V of the reconstituted solution do you give?

500 mg+ 1.8 mL → 2 mL100 mg
V = mL
4.Dosage calculationsHard
40 mg/1 mLV = ? mL

A patient weighs 24.2 lb. The prescription is 5 mg/kg as a single dose, and the stock contains 40 mg in 1 mL. Using 1 kg = 2.2 lb, what volume V do you give? Round to one decimal place.

24.2 lb5 mg/kg40 mg/1 mL1 kg = 2.2 lb
V = mL
5.IV infusion ratesMedium
20 gtt/mL60 mL/h? gtt/min

An infusion is ordered at 60 mL/h, but no pump is available. It runs by gravity through a giving set of 20 gtt/mL. Find the drip rate R in drops per minute.

60 mL/h20 gtt/mL
R = gtt/min
6.IV infusion ratesHard
25 mg250 mL30 mL/h? mcg/min

An infusion of 25 mg in 250 mL runs at 30 mL/h. How many micrograms per minute D does the patient receive?

25 mg/250 mL30 mL/h
D = mcg/min

3Solutions

1.Maternity & obstetric nursing

Answer: D · A baby of a GBS-positive mother with no antibiotics

Why this is the answer

GBS colonisation, no intrapartum antibiotics, prolonged rupture of membranes, maternal fever and prematurity increase the risk. Intrapartum IV antibiotics greatly lower early-onset GBS disease.

Answer

D · A baby of a GBS-positive mother with no antibiotics
2.Maternity & obstetric nursing

Answer: D · It can still develop after birth, so report headache or visual changes

Why this is the answer

Pre-eclampsia and eclampsia can occur up to about 6 weeks after birth, most often in the first days. Women should report severe headache, visual disturbance, upper abdominal pain or shortness of breath.

Answer

D · It can still develop after birth, so report headache or visual changes
3.Dosage calculations

Answer: V = 0.4 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

500 mg/2 mL = 250 mg/mL

Volume

V = 100/250 = 0.4 mL

Answer

V = 0.4 mL
4.Dosage calculations

Answer: V = 1.4 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

24.2/2.2 = 11 kg

Dose

5·11 = 55 mg

Volume

V = (55/40)·1 = 1.375 ≈ 1.4 mL

Answer

V = 1.4 mL
5.IV infusion rates

Answer: R = 20 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.

Millilitres per minute

60/60 = 1 mL/min

Drip rate

R = 1·20 = 20 gtt/min

Answer

R = 20 gtt/min
6.IV infusion rates

Answer: D = 50 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

30·100 = 3000 mcg/h

Dose per minute

D = 3000/60 = 50 mcg/min

Answer

D = 50 mcg/min

ExamProblems · examproblems.com/courses/maternity-nursing