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 factors help start the newborn's first breath?

  1. AChemical, thermal, mechanical and sensory cues
  2. BOnly the pressure from the obstetrician's hand
  3. COnly the baby's first cry from hunger
  4. DOnly the cutting of the umbilical cord
2.Maternity & obstetric nursingHard

A woman with an epidural in labour now has a temperature of 38.0 °C (100.4 °F). Which statement is most accurate?

  1. AFever with an epidural is always caused by the epidural
  2. BFever in labour can be ignored if the baby is moving
  3. CFever with an epidural always means the catheter is infected
  4. DThe epidural may cause it, but infection must be ruled out
3.Dosage calculationsMedium
30 kg7.5 mg/kg/day3× per dayD = ? mg

A patient weighs 30 kg. The prescribed dose is 7.5 mg/kg per day, given in 3 equal doses. How many milligrams D are given per dose?

30 kg7.5 mg/kg/day3× per day
D = mg
4.Dosage calculationsHard
00.10.20.30.40.50.60.70.80.911 mL

The prescription is 340 units of a drug that comes as 1000 units/mL. Draw up the dose in the 1 mL syringe: what volume V do you give?

340 units1000 units/mL
V = mL
5.IV infusion ratesMedium
340 mLleft? mL/h2 h left

1500 mL was ordered over 10 hours. After 8 hours you find that 340 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?

1500 mL / 10 hafter 8 h: 340 mL
R = mL/h
6.IV infusion ratesHard
100 mg250 mL15 mL/h? mg/h

A bag contains 100 mg of a drug in 250 mL and runs at 15 mL/h. How many milligrams per hour D does the patient receive?

100 mg/250 mL15 mL/h
D = mg/h

3Solutions

1.Maternity & obstetric nursing

Answer: A · Chemical, thermal, mechanical and sensory cues

Why this is the answer

Falling oxygen and rising carbon dioxide (chemical), cooler air (thermal), recoil of the chest after the birth canal (mechanical) and touch, light and sound (sensory) trigger the first breaths.

Answer

A · Chemical, thermal, mechanical and sensory cues
2.Maternity & obstetric nursing

Answer: D · The epidural may cause it, but infection must be ruled out

Why this is the answer

Epidurals are associated with a rise in maternal temperature, but this cannot be assumed. Intra-amniotic infection must be considered, especially with prolonged rupture of membranes or fetal tachycardia.

Answer

D · The epidural may cause it, but infection must be ruled out
3.Dosage calculations

Answer: D = 75 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

7.5·30 = 225 mg

Per dose

D = 225/3 = 75 mg

Answer

D = 75 mg
4.Dosage calculations

Answer: V = 0.34 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.

Volume

V = 340/1000 = 0.34 mL

On the syringe

On this 1 mL syringe every small line is 0.01 mL.

Answer

V = 0.34 mL
5.IV infusion rates

Answer: R = 170 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

1500/10 = 150 mL/h

New rate

R = 340/2 = 170 mL/h

Answer

R = 170 mL/h

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

6.IV infusion rates

Answer: D = 6 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

100/250 = 0.4 mg/mL

Dose rate

D = 0.4·15 = 6 mg/h

Answer

D = 6 mg/h

ExamProblems · examproblems.com/courses/maternity-nursing