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 finding in a term newborn's first hours is normal?

  1. AA respiratory rate of 80 at rest with retractions
  2. BShort breathing pauses with no colour change
  3. CCentral cyanosis of the lips and tongue
  4. DPauses in breathing of 30 seconds with bradycardia
2.Maternity & obstetric nursingHard

A small for gestational age baby is born at term. Which complications should the nurse anticipate?

  1. AHyperglycaemia, fever and anaemia
  2. BMacrosomia and shoulder dystocia
  3. CHypoglycaemia, hypothermia and polycythaemia
  4. DRespiratory distress from surfactant deficiency only
3.Dosage calculationsMedium
500 mg+ 1.8 mLV = ? mL

A vial contains 500 mg of powder. The label says: add 1.8 mL of water for injection to give a total volume of 2 mL. The prescription is 100 mg. What volume V of the reconstituted solution do you give?

500 mg+ 1.8 mL → 2 mL100 mg
V = mL
4.Dosage calculationsHard
00.10.20.30.40.50.60.70.80.911 mL

The prescription is 165 micrograms. The ampoule contains 0.5 mg/mL. Draw up the dose in the 1 mL syringe: what volume V do you give?

165 mcg0.5 mg/mL
V = mL
5.IV infusion ratesMedium
500 mL60 gtt/mL5 h? gtt/min

Infuse 500 mL over 5 hours with a giving set of 60 gtt/mL. Find the drip rate R in drops per minute.

500 mL5 h60 gtt/mL
R = gtt/min
6.IV infusion ratesHard
2 g250 mL? mL/h0.5 mg/min

A bag contains 2 g of a drug in 250 mL. The order is 0.5 mg per minute. At what rate R do you set the pump, in mL/h?

2 g/250 mL0.5 mg/min
R = mL/h

3Solutions

1.Maternity & obstetric nursing

Answer: B · Short breathing pauses with no colour change

Why this is the answer

Newborns breathe irregularly, with short pauses of a few seconds and no change in colour or heart rate. Apnoea of 20 seconds or more, or any pause with cyanosis or bradycardia, is abnormal.

Answer

B · Short breathing pauses with no colour change
2.Maternity & obstetric nursing

Answer: C · Hypoglycaemia, hypothermia and polycythaemia

Why this is the answer

SGA babies have low glycogen and fat stores, leading to hypoglycaemia and hypothermia. Chronic intrauterine hypoxia increases red cell production, causing polycythaemia.

Answer

C · Hypoglycaemia, hypothermia and polycythaemia
3.Dosage calculations

Answer: V = 0.4 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.

Concentration after mixing

500 mg/2 mL = 250 mg/mL

Volume

V = 100/250 = 0.4 mL

Answer

V = 0.4 mL
4.Dosage calculations

Answer: V = 0.33 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.

Same units

0.5 mg/mL = 500 mcg/mL

Volume

V = 165/500 = 0.33 mL

Answer

V = 0.33 mL
5.IV infusion rates

Answer: R = 100 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

5·60 = 300 min

Drip rate

R = 500·60/300 = 100 gtt/min

Answer

R = 100 gtt/min
6.IV infusion rates

Answer: R = 3.75 mL/h

Dose-based infusions: concentration = amount of drug in the bag/bag volume. Pump rate (mL/h) = dose per hour/concentration, and dose per hour = mL/h × concentration. Convert per-minute doses to per-hour (× 60) and keep the mass units the same (1 g = 1000 mg, 1 mg = 1000 mcg).

Concentration

2000 mg/250 mL = 8 mg/mL

Dose per hour

0.5·60 = 30 mg/h

Pump rate

R = 30/8 = 3.75 mL/h

Answer

R = 3.75 mL/h

ExamProblems · examproblems.com/courses/maternity-nursing