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

Why are afterpains often stronger in multiparous women?

  1. ATheir uterus contracts and relaxes more irregularly
  2. BThey have a smaller uterus than first-time mothers
  3. CTheir uterus is always infected
  4. DThey produce no oxytocin after birth
2.Maternity & obstetric nursingHard

A woman at 12 weeks has light bleeding and mild cramping. The cervix is closed and fetal heart activity is seen on ultrasound. How is this classified?

  1. AIncomplete miscarriage
  2. BInevitable miscarriage
  3. CThreatened miscarriage
  4. DMissed miscarriage
3.Dosage calculationsMedium
1:10 000ampouleV = ? mL

A prefilled syringe of epinephrine (adrenaline) is labelled 1:10 000 (0.1 mg/mL). The prescription is 1 mg IV in cardiac arrest. What volume V do you give?

1:10 0001 mg
V = mL
4.Dosage calculationsHard
100 mg/5 mLV = ? mL

A child weighing 14 kg is prescribed 5 mg/kg per dose of an oral suspension that contains 100 mg in 5 mL. What volume V do you give?

14 kg5 mg/kg100 mg/5 mL
V = mL
5.IV infusion ratesMedium
V = ?15 gtt/mL30 gtt/min2 h

A drip runs at 30 gtt/min through a set of 15 gtt/mL. How many millilitres V does the patient receive in 2 hours?

30 gtt/min15 gtt/mL2 h
V = mL
6.IV infusion ratesHard
300 mL60 gtt/mL42 gtt/mint = ? h

A drip runs at 42 gtt/min through a set of 60 gtt/mL. There are 300 mL left in the bag. How many hours t until it is empty? Round to one decimal place.

42 gtt/min60 gtt/mL300 mL
t = h

3Solutions

1.Maternity & obstetric nursing

Answer: A · Their uterus contracts and relaxes more irregularly

Why this is the answer

In multiparas, and after overdistension such as twins, the uterus relaxes and contracts intermittently, causing stronger afterpains. Breastfeeding increases them through oxytocin.

Answer

A · Their uterus contracts and relaxes more irregularly
2.Maternity & obstetric nursing

Answer: C · Threatened miscarriage

Why this is the answer

Bleeding with a closed cervix and a viable pregnancy is a threatened miscarriage; many continue normally. An open cervix means an inevitable or incomplete miscarriage, and a missed miscarriage has no fetal heart activity.

Answer

C · Threatened miscarriage
3.Dosage calculations

Answer: V = 10 mL

Solution strengths: a percentage strength is grams per 100 mL, so 1% = 1 g/100 mL = 10 mg/mL. A ratio strength 1:1000 means 1 g in 1000 mL = 1 mg/mL; 1:10 000 is 0.1 mg/mL. For a dilution the amount of drug stays the same: C₁·V₁ = C₂·V₂.

Concentration

1:10 000 = 1 g/10000 mL = 0.1 mg/mL

Volume

V = 1/0.1 = 10 mL

Answer

V = 10 mL

US labels now state mg/mL (1 mg/mL = 1:1000; 0.1 mg/mL = 1:10 000). Never give 1 mg/mL epinephrine IV push.

4.Dosage calculations

Answer: V = 3.5 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.

Dose from weight

5·14 = 70 mg

Volume

V = (70/100)·5 = 3.5 mL

Answer

V = 3.5 mL
5.IV infusion rates

Answer: V = 240 mL

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.

Rate in mL/h

30·60/15 = 120 mL/h

Volume

V = 120·2 = 240 mL

Answer

V = 240 mL
6.IV infusion rates

Answer: t = 7.1 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.

Rate in mL/h

42·60/60 = 42 mL/h

Time left

t = 300/42 = 7.143 ≈ 7.1 h

Answer

t = 7.1 h

ExamProblems · examproblems.com/courses/maternity-nursing