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 is a common sign of iron deficiency anaemia in pregnancy?

  1. ATiredness, pallor and breathlessness
  2. BHigh blood pressure and headache
  3. CIncreased appetite and frequent urination
  4. DWeight gain and ankle swelling
2.Maternity & obstetric nursingHard

Monochorionic twins at 22 weeks show one twin with polyhydramnios and a large bladder and the other with almost no fluid. What condition is suspected?

  1. APlacenta praevia
  2. BRh isoimmunisation
  3. CGestational diabetes in one twin
  4. DTwin-to-twin transfusion syndrome
3.Dosage calculationsMedium
70 kg15 mg/kg/day3× per dayD = ? mg

A patient weighs 70 kg. The prescribed dose is 15 mg/kg per day, given in 3 equal doses. How many milligrams D are given per dose?

70 kg15 mg/kg/day3× per day
D = mg
4.Dosage calculationsHard
20k units250 mL? mL/h2000 units/h

An infusion contains 20000 units of a drug in 250 mL. The prescription is 2000 units per hour. At what rate R do you set the pump, in mL/h?

20000 units/250 mL2000 units/h
R = mL/h
5.IV infusion ratesMedium
15 gtt/mL200 mL/h? gtt/min

An infusion is ordered at 200 mL/h, but no pump is available. It runs by gravity through a giving set of 15 gtt/mL. Find the drip rate R in drops per minute.

200 mL/h15 gtt/mL
R = gtt/min
6.IV infusion ratesHard
500 mg500 mL8 mL/h? mg/h

A bag contains 500 mg of a drug in 500 mL and runs at 8 mL/h. How many milligrams per hour D does the patient receive?

500 mg/500 mL8 mL/h
D = mg/h

3Solutions

1.Maternity & obstetric nursing

Answer: A · Tiredness, pallor and breathlessness

Why this is the answer

Iron deficiency causes fatigue, pallor, breathlessness, palpitations and sometimes pica. A full blood count and ferritin confirm the diagnosis.

Answer

A · Tiredness, pallor and breathlessness
2.Maternity & obstetric nursing

Answer: D · Twin-to-twin transfusion syndrome

Why this is the answer

In monochorionic twins, unbalanced vascular connections can shunt blood from one twin to the other. The recipient becomes overloaded with polyhydramnios, while the donor has low fluid and growth restriction.

Answer

D · Twin-to-twin transfusion syndrome
3.Dosage calculations

Answer: D = 350 mg

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.

Total per day

15·70 = 1050 mg

Per dose

D = 1050/3 = 350 mg

Answer

D = 350 mg
4.Dosage calculations

Answer: R = 25 mL/h

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

20000/250 = 80 units/mL

Pump rate

R = 2000/80 = 25 mL/h

Answer

R = 25 mL/h
5.IV infusion rates

Answer: R = 50 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

200/60 = 3.333 mL/min

Drip rate

R = 3.333·15 = 50 gtt/min

Answer

R = 50 gtt/min
6.IV infusion rates

Answer: D = 8 mg/h

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.

Concentration

500/500 = 1 mg/mL

Dose rate

D = 1·8 = 8 mg/h

Answer

D = 8 mg/h

ExamProblems · examproblems.com/courses/maternity-nursing