Maternity Nursing: cram pack

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

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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

After birth of the baby, the placenta has not been delivered after a long time despite active management. What is this called?

  1. APlacental abruption
  2. BRetained placenta
  3. CPlacenta praevia
  4. DUterine inversion
2.Maternity & obstetric nursingHard

A woman has had a large postpartum haemorrhage and is receiving several units of blood. Which other complication should the nurse watch for?

  1. AHypertension caused by the volume of blood lost
  2. BHypoglycaemia from the transfused blood
  3. CCoagulopathy from loss of clotting factors
  4. DPostpartum depression within the hour
3.Dosage calculationsMedium
024681010 mL

A child weighing 25 kg is prescribed 4 mg/kg of a drug. The stock solution contains 25 mg/mL. Draw up the dose: what volume V do you give?

25 kg4 mg/kg25 mg/mL
V = mL
4.Dosage calculationsHard
00.10.20.30.40.50.60.70.80.911 mL

The prescription is 0.14 mg. The ampoule contains 1000 micrograms per mL. Draw up the dose in the 1 mL syringe: what volume V do you give?

0.14 mg1000 mcg/mL
V = mL
5.IV infusion ratesMedium
60 gtt/mL30 mL/h? gtt/min

An infusion is ordered at 30 mL/h, but no pump is available. It runs by gravity through a giving set of 60 gtt/mL. Find the drip rate R in drops per minute.

30 mL/h60 gtt/mL
R = gtt/min
6.IV infusion ratesHard
830 mLleft? mL/h4 h left

1000 mL was ordered over 6 hours. After 2 hours you find that 830 mL is still in the bag, and the order must still finish on time. By what percentage Δ must the original pump rate be increased?

1000 mL / 6 hafter 2 h: 830 mL
Δ = %

3Solutions

1.Maternity & obstetric nursing

Answer: B · Retained placenta

Why this is the answer

A retained placenta is one that has not been delivered within the expected time, usually about 30 minutes with active management. It increases the risk of haemorrhage and may need manual removal.

Answer

B · Retained placenta
2.Maternity & obstetric nursing

Answer: C · Coagulopathy from loss of clotting factors

Why this is the answer

Massive haemorrhage and transfusion of red cells can deplete clotting factors and platelets, leading to further bleeding. Massive transfusion protocols include plasma, platelets and sometimes fibrinogen.

Answer

C · Coagulopathy from loss of clotting factors
3.Dosage calculations

Answer: V = 4 mL

Drawing up a dose: volume = (prescribed dose/stock strength) × stock volume. Convert to the same units first, then check that the volume fits the syringe and lands on one of its graduations.

Dose from body weight

D = 4·25 = 100 mg

Volume

V = 100/25 = 4 mL

On the syringe

On this 10 mL syringe every small line is 0.2 mL.

Answer

V = 4 mL
4.Dosage calculations

Answer: V = 0.14 mL

Drawing up a dose: volume = (prescribed dose/stock strength) × stock volume. Convert to the same units first, then check that the volume fits the syringe and lands on one of its graduations.

Same units

0.14 mg = 140 mcg

Volume

V = 140/1000 = 0.14 mL

Answer

V = 0.14 mL
5.IV infusion rates

Answer: R = 30 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

30/60 = 0.5 mL/min

Drip rate

R = 0.5·60 = 30 gtt/min

Answer

R = 30 gtt/min

With a microdrip set (60 gtt/mL), gtt/min equals mL/h.

6.IV infusion rates

Answer: Δ = 24.5 %

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.

Original rate

1000/6 = 166.7 mL/h

New rate

R = 830/4 = 207.5 mL/h

Percentage change

Δ = (207.5 − 166.7)/166.7·100% = 24.5%

Answer

Δ = 24.5%

Many hospitals allow such an adjustment up to 25% without a new order; check local policy.

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