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 woman in late pregnancy has numbness and tingling in her thumb and first fingers, worse at night. What is the most likely cause?

  1. AA stroke caused by pre-eclampsia
  2. BLow blood calcium
  3. CCarpal tunnel syndrome
  4. DVitamin K deficiency
2.Maternity & obstetric nursingHard

A woman at 31 weeks with contractions has a negative fetal fibronectin test. What does this result mean?

  1. AThe fetus has an infection
  2. BBirth within the next 1 to 2 weeks is unlikely
  3. CThe membranes have ruptured
  4. DBirth will certainly occur within 48 hours
3.Dosage calculationsMedium
15 kg25 mg/kgD = ? mg

A patient weighs 15 kg and is prescribed 25 mg/kg as a single dose. Find the dose D in mg.

15 kg25 mg/kg
D = mg
4.Dosage calculationsHard
47 kg153 cmBSA = √(h·w/3600)250 mg/m²D = ? mg

A patient is 153 cm tall and weighs 47 kg. The prescription is 250 mg/m². Using the Mosteller formula BSA = √(height (cm) × weight (kg)/3600), find the dose D in mg.

153 cm47 kg250 mg/m²
D = mg
5.IV infusion ratesMedium
1000 mL10 gtt/mL8 h? gtt/min

Infuse 1000 mL over 8 hours with a giving set of 10 gtt/mL. Find the drip rate R in drops per minute. Round to the nearest whole number.

1000 mL8 h10 gtt/mL
R = gtt/min
6.IV infusion ratesHard
200 mg50 mL30 mL/h? mg/h

A bag contains 200 mg of a drug in 50 mL and runs at 30 mL/h. How many milligrams per hour D does the patient receive?

200 mg/50 mL30 mL/h
D = mg/h

3Solutions

1.Maternity & obstetric nursing

Answer: C · Carpal tunnel syndrome

Why this is the answer

Fluid retention in pregnancy can compress the median nerve in the carpal tunnel. A wrist splint at night often helps, and symptoms usually resolve after birth.

Answer

C · Carpal tunnel syndrome
2.Maternity & obstetric nursing

Answer: B · Birth within the next 1 to 2 weeks is unlikely

Why this is the answer

Fetal fibronectin is a protein that binds the membranes to the uterine lining. A negative result has a high negative predictive value, meaning birth within 7 to 14 days is unlikely; a positive result is less predictive.

Answer

B · Birth within the next 1 to 2 weeks is unlikely
3.Dosage calculations

Answer: D = 375 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.

Dose

25·15 = 375 mg

Answer

D = 375 mg
4.Dosage calculations

Answer: D = 353.3 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).

Body surface area

BSA = √(153·47/3600) = √1.998 = 1.413 m²

Dose

D = 250·1.413 = 353.3 mg

Answer

D = 353.3 mg
5.IV infusion rates

Answer: R = 21 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

8·60 = 480 min

Drip rate

R = 1000·10/480 = 20.83 ≈ 21 gtt/min

Answer

R = 21 gtt/min

At the bedside you round to the nearest whole drop: 21 gtt/min.

6.IV infusion rates

Answer: D = 120 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

200/50 = 4 mg/mL

Dose rate

D = 4·30 = 120 mg/h

Answer

D = 120 mg/h

ExamProblems · examproblems.com/courses/maternity-nursing