In the print window, choose “Save as PDF” to keep a copy on your device.
1Formulas and methods
Pediatric nursing
Method
Note the child’s age first: it sets the normal vital signs, the milestones and the right pain scale.
Assess airway, breathing and circulation, remembering that children compensate and then deteriorate fast.
Match the action to the development stage and involve the family.
Check that the answer is safe for a child: weight-based, no aspirin in viral illness, no codeine under 12.
Pediatric & critical-care dosing
Daily dose
mg/day = mg/kg/day × weight (kg)
Doses per day
number = 24 h / dosing interval (h)
Pounds to kilograms
kg = lb / 2.2
Infusion concentration
units/mL = units in bag / bag volume
Pump rate
mL/h = dose per hour / concentration
Titrated drip
mL/h = mcg/kg/min × kg × 60 / (mcg/mL)
Dose from pump rate
mcg/kg/min = mL/h × (mcg/mL) / (60 × kg)
Units
1 mg = 1000 mcg
IV fluids & fluid balance
Holliday–Segar per hour
4 mL/kg (first 10 kg) + 2 mL/kg (next 10 kg) + 1 mL/kg (each kg above 20)
Holliday–Segar per day
100 / 50 / 20 mL/kg for the same bands
Fluid balance
intake − output
Ice chips
count as half their volume
Urine output
mL/kg/h = mL / (kg × h)
Infusion time
time (h) = volume left (mL) / rate (mL/h)
Volume infused
mL = rate × time
2Practice problems
1.Pediatric nursingMedium
Which instruction about preparing powdered infant formula is correct?
AFollow the stated water-to-powder ratio exactly and do not warm bottles in a microwave
BAdd an extra scoop of powder to each bottle to help a small baby gain weight faster
CAdd extra water in hot weather so the baby gets more fluid
DWarm bottles in the microwave, as long as they are shaken first
2.Pediatric nursingHard
Which finding in an infant with diarrhoea suggests the most severe dehydration?
ASlightly dry lips and thirst
BLethargy, a capillary refill of 4 seconds and no wet nappy for 10 hours
CA normal fontanelle, moist mucous membranes and 4 wet nappies so far today
DA mild decrease in appetite
3.Pediatric & critical-care dosingMedium
Practice exercise (made-up values, not clinical guidance). A bag contains 25 000 units of heparin in 500 mL. The order is 16 units/kg/h for a patient who weighs 89 kg. At what rate R do you set the pump, in mL/h? Round to one decimal place.
25 000 units/500 mL16 units/kg/h89 kg
R = mL/h
4.Pediatric & critical-care dosingHard
Practice exercise (made-up values, not clinical guidance). A bag contains dopamine 800 mg in 500 mL. The order is 5 mcg/kg/min for a patient who weighs 106 kg. At what rate R do you set the pump, in mL/h? Round to one decimal place.
800 mg/500 mL5 mcg/kg/min106 kg
R = mL/h
5.IV fluids & fluid balanceMedium
Practice exercise (made-up values, not clinical guidance). The record shows a patient's intake and output for one 8-hour shift. The IV infusion ran at the rate shown for the whole shift. Find the fluid balance B = intake − output in mL (a negative answer means a net loss). Count ice chips as half their volume.
Practice exercise (made-up values, not clinical guidance). A 1000 mL bag runs by pump at 100 mL/h. At 15:00, 300 mL have already been infused. How many hours t until the bag is empty? Round to one decimal place.
1000 mL300 mL infused100 mL/h
t = h
3Solutions
1.Pediatric nursing
Answer: A · Follow the stated water-to-powder ratio exactly and do not warm bottles in a microwave
Why this is the answer
Formula that is too concentrated can cause dehydration and kidney strain, and over-diluted formula can cause poor growth and low sodium. Microwaves heat unevenly and can leave hot spots that burn the mouth.
Answer
A · Follow the stated water-to-powder ratio exactly and do not warm bottles in a microwave
2.Pediatric nursing
Answer: B · Lethargy, a capillary refill of 4 seconds and no wet nappy for 10 hours
Why this is the answer
Reduced consciousness, prolonged capillary refill and absent urine output suggest severe dehydration and possible shock. This needs urgent treatment, usually IV fluids.
Answer
B · Lethargy, a capillary refill of 4 seconds and no wet nappy for 10 hours
3.Pediatric & critical-care dosing
Answer: R = 28.5 mL/h
Heparin and insulin infusions: concentration = units in the bag/bag volume (units/mL). Pump rate (mL/h) = units per hour/concentration, and units per hour = mL/h × concentration. For a weight-based order, units/h = units/kg/h × weight first. A bolus volume = units needed/vial strength. The numbers are for practice only; at the bedside always follow local protocols and have high-risk doses double-checked.
Units per hour
16·89 = 1 424 units/h
Concentration
25 000/500 = 50 units/mL
Pump rate
R = 1424/50 = 28.48 ≈ 28.5 mL/h
Answer
R = 28.5 mL/h
4.Pediatric & critical-care dosing
Answer: R = 19.9 mL/h
Titrated drips: first find the concentration in mcg/mL (mg × 1000/mL). For a weight-based order, mcg/min = mcg/kg/min × weight. Then mL/h = mcg/min × 60/concentration. Working backwards, mcg/kg/min = mL/h × concentration/(60 × weight). The numbers are for practice only; at the bedside always follow local protocols and have high-risk doses double-checked.
Concentration
800 mg = 800 000 mcg
800 000/500 = 1600 mcg/mL
Dose per minute and per hour
5·106 = 530 mcg/min
530·60 = 31800 mcg/h
Pump rate
R = 31800/1600 = 19.88 ≈ 19.9 mL/h
Answer
R = 19.9 mL/h
5.IV fluids & fluid balance
Answer: B = −145 mL
Intake and output: intake counts everything that goes in (oral fluids, IV infusions, IV medications and flushes, tube feeds); ice chips count as half their volume. Output counts urine, drains, vomit and other losses. Balance = total intake − total output; a negative balance is a net loss. The numbers are for practice only; at the bedside always follow local protocols and have high-risk doses double-checked.
Total intake
oral: 120 + 350 + 100 = 570 mL
ice chips: 120/2 = 60 mL
IV infusion: 50·8 = 400 mL
IV antibiotic: 2·100 = 200 mL
total intake = 1230 mL
Total output
475 + 500 + 225 + 175 = 1375 mL
Balance
B = 1230 − 1375 = −145 mL
Answer
B = −145 mL
Negative: the patient lost more fluid than went in.
6.IV fluids & fluid balance
Answer: t = 7 h
Infusion time: time (h) = volume to infuse (mL)/rate (mL/h); use the volume still left in the bag, not the bag size. Volume infused = rate × time. Convert decimal hours to hours and minutes with the fraction × 60 (0.5 h = 30 min, not 50 min). The numbers are for practice only; at the bedside always follow local protocols and have high-risk doses double-checked.
Volume left
1000 − 300 = 700 mL
Time
t = 700/100 = 7 h
Answer
t = 7 h
That is about 7 h 00 min, so the bag runs out at about 22:00.