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 do newborns become cold so easily?

  1. ATheir blood is thicker than adult blood
  2. BThey sweat more than adults
  3. CThey have a large surface area and little fat
  4. DThey cannot produce heat at all
2.Maternity & obstetric nursingHard

A newborn whose mother had a fever and prolonged rupture of membranes is well at birth. Why does the nurse monitor this baby closely?

  1. AThe baby is likely to be post-term
  2. BThe baby has a higher risk of hip dysplasia
  3. CThe baby has a higher risk of early sepsis
  4. DThe baby will certainly develop jaundice
3.Dosage calculationsMedium
024681010 mL

A child weighing 33 kg is prescribed 4 mg/kg of a drug. The stock solution contains 20 mg/mL. Draw up the dose: what volume V do you give?

33 kg4 mg/kg20 mg/mL
V = mL
4.Dosage calculationsHard
120 mg/5 mLV = ? mL

A child weighing 12 kg is prescribed 15 mg/kg per dose of an oral suspension that contains 120 mg in 5 mL. What volume V do you give?

12 kg15 mg/kg120 mg/5 mL
V = mL
5.IV infusion ratesMedium
710 mLleft? mL/h8 h left

1000 mL was ordered over 12 hours. After 4 hours you find that 710 mL is still in the bag, and the order must still finish on time. To what rate R in mL/h must the pump be reset?

1000 mL / 12 hafter 4 h: 710 mL
R = mL/h
6.IV infusion ratesHard
450 mL15 gtt/mL40 gtt/mint = ? h

A drip runs at 40 gtt/min through a set of 15 gtt/mL. There are 450 mL left in the bag. How many hours t until it is empty? Round to one decimal place.

40 gtt/min15 gtt/mL450 mL
t = h

3Solutions

1.Maternity & obstetric nursing

Answer: C · They have a large surface area and little fat

Why this is the answer

Newborns have a large surface area relative to body mass, little subcutaneous fat and thin skin with blood vessels near the surface. They rely on brown fat and cannot shiver effectively.

Answer

C · They have a large surface area and little fat
2.Maternity & obstetric nursing

Answer: C · The baby has a higher risk of early sepsis

Why this is the answer

Maternal fever, prolonged rupture of membranes and intra-amniotic infection are risk factors for early-onset sepsis. Many protocols require observation of vital signs and feeding, and sometimes blood tests or antibiotics.

Answer

C · The baby has a higher risk of early sepsis
3.Dosage calculations

Answer: V = 6.6 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 = 4·33 = 132 mg

Volume

V = 132/20 = 6.6 mL

On the syringe

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

Answer

V = 6.6 mL
4.Dosage calculations

Answer: V = 7.5 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

15·12 = 180 mg

Volume

V = (180/120)·5 = 7.5 mL

Answer

V = 7.5 mL
5.IV infusion rates

Answer: R = 88.75 mL/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.

Original rate

1000/12 = 83.33 mL/h

New rate

R = 710/8 = 88.75 mL/h

Answer

R = 88.75 mL/h

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

6.IV infusion rates

Answer: t = 2.8 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

40·60/15 = 160 mL/h

Time left

t = 450/160 = 2.813 ≈ 2.8 h

Answer

t = 2.8 h

ExamProblems · examproblems.com/courses/maternity-nursing