Transcript title of presentation inserted here

Insert Specialty School
of Paediatrics and Child Health
Safe Prescribing
TRUST NAME:
September 2011
www.londondeanery.ac.uk
insert Specialty School of Paediatrics
Objectives of this session are
• To understand the importance of safe prescribing
• To become familiar with the local drug chart
• To learn how to prescribe for children
insert Specialty School of Paediatrics
Why is prescribing important?
• Prescribing errors are common from all grades of
doctors
• Many clinical incidents are due to prescribing
errors
• Prescribing errors can be fatal
• Prescribing for children is different to prescribing
for adults
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Why is prescribing different in children?
Children are not small adults
Factors include:
• Body weight
• Body composition
• Surface area
• Nutritional status
• Organ maturation
insert Specialty School of Paediatrics
We will cover the following
–Dose calculation based on age and weight
–Prescribe fluids
–Prescribe neonatal fluids
insert Specialty School of Paediatrics
Principles of prescribing for children
• Many medications for children come in liquid form
• It is usually more appropriate to prescribe in actual dose
(e.g. mg) of drug rather than in volume (mL).
• Medications have different concentrations
– e.g. paracetamol can be 120mg/5mL or 250mg/5mL
• Importance of difference between micrograms and mg.
• Use generic drug names when prescribing
• Prescribe sensibly - It is important to consider drug
rounding
insert Specialty School of Paediatrics
Principles of prescribing for children:
age & weight
All drug charts must have a recent weight and DOB
• Calculations of drug doses depend on age, weight
or surface area of a child
• Medication is usually prescribed based on age or
weight
• The correct doses should be checked in the BNFC
or local guidelines
insert Specialty School of Paediatrics
Calculating drug doses:
example one: prescribing by weight
• Romeo, a 4-week-old infant weighs
5.5kg. He requires prophylactic
Trimethoprim for prevention of urinary
tract infection.
• How much would you give him?
Use the BNFC App: Click Here
• In this example, we will use the dose for children 1 month
to 12 years of age (2mg/kg, max 100mg at night)
• Workings:
– 5.5kg x 2mg/kg = 11mg at night (orally)
insert Specialty School of Paediatrics
Calculating drug doses:
example one: prescribing by weight
ENTER DOSE AGAINST TIME REQUIRED USE ONE
ROUTE ONLY FOR EACH ENTRY
DATE
DOSE
START
CHANGE CHANGE 07/03/2015
DRUG
DATE
07/03/2015
ROUTE ORAL
INITIALS AD
2000
180mg
180mg
11mg
180mg
REGULAR PRESCRIPTION
MONTH
YEAR
March
OTHER INSTRUCTIONS
TRIMETHOPRIM
2mg/kg at night
2015
SIGNATURE
A.Doctor
PHARMACY
insert Specialty School of Paediatrics
Calculating drug doses:
example two: prescribing by age
• Jimmy, a 4 year old child weighs 16kg
• He has a mild chest infection
• How much oral co-amoxiclav would
you prescribe for him?
• Use the BNFC: Click Here
• Workings:
– We will use the age range instead of weight
– Age = 4 therefore dose = 5mL of 125/31 suspension
three times per day (TDS)
insert Specialty School of Paediatrics
Calculating drug doses:
example two: prescribing by age
ENTER DOSE AGAINST TIME REQUIRED USE ONE
ROUTE ONLY FOR EACH ENTRY
DATE
DOSE
START
CHANGE
DATE
03/07/2011
ROUTE ORAL
INITIALS AD
6
9 5mls
14 5mls
18
22 5mls
CHANGE
REGULAR PRESCRIPTION
MONTH
YEAR
March
2011
07/03/2011
DRUG
OTHER INSTRUCTIONS
CO-AMOXICLAV
125/31 SUSPENSION
SIGNATURE
A.Doctor
PHARMACY
insert Specialty School of Paediatrics
Principles of prescribing fluids
• Usual maintenance fluid in this trust is [TRUST FLUID]
• Children on intravenous fluids will need daily U&Es (change
based on local trust guidelines)
• Ensure you prescribe:
– Fluid type (concentration)
– Volume (e.g. 500mL bag)
– Rate (mL/hour)
– Additives if required
– ?duration (some trusts)
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Calculating and prescribing
maintenance fluids
• This should be prescribed based on weight:
– For every kg up to 10kg
100mL/kg/day
– For every kg between 10-20 kg
50mLkg/day
– For every kg over 20kg
20mL/kg/day
– This will be the maintenance fluid required over 24 hours
– The total should therefore be divided by 24hours to give a rate in mL/hr
– Consider whether the child requires potassium
insert Specialty School of Paediatrics
Prescribing fluid:
example three – prescribing maintenance fluid
• Abigail, a 10 year old child weighs 32 kg.
• She requires maintenance fluid over the next 24 hours. Please prescribe this.
• If unsure, use the BNFC: Click Here
• Working:
– 10kg @ 100mL/kg/day = 1000mL
– 10kg @ 50mL/kg/day =
500mL
– 12kg @ 20mL/kg/day=
240mL
– 24 hour requirement:=
1740mL = 72.5mls / hour (for 24 hours)
insert Specialty School of Paediatrics
Prescribing fluid:
example three – prescribing maintenance fluid
Date
Infusion Fluid
Volume
Name of Drug to be
infused
Dose of
Drug
Added
Route
Infusion rate
Signature
14/3/11
O.9%NaCL/5%DEXTROSE
500mL
NIL
-
IV
73mL/HR
A.doctor
insert Specialty School of Paediatrics
Principles of Prescribing Fluids
Calculating deficit in dehydration
• This is based on child’s weight and % dehydration
• Calculation for fluid deficit for %dehydration:
–(%dehydration/100) x weight (kg) x 1000ml
THIS can be simplified to
– %dehydration x weight x 10= total fluid deficit (mls)
This should be replaced over 24-48 hours
This represents the extra fluid that is needed so should
be added to total maintenance requirements
insert Specialty School of Paediatrics
Prescribing fluid:
example four: prescribing rehydration fluid
• Chloe, a 10 year old child weighs 32 kg (the same as her friend Abigail in example 3)
• She is clinically 5% dehydrated due to gastroenteritis. Prescribe fluid to rehydrate her
over the next 24 hours. Please prescribe this.
• Working for maintenance:
– 10kg @ 100mls/kg/day = 1000mls
– 10kg @ 50mls/kg/day =
500mls
– 12kg @ 20mls/kg/day=
240mls
– 24 hour maintenance requirement:= 1740mls
• Additional fluid required:
– (%dehydration/100%) x weight (kg) x 1000ml/kg
– (5/100) x 32kg x 1000ml/kg = 1600mls
• Total fluid required in 24 hours= 1740mls + 1600mls = 3340mls
insert Specialty School of Paediatrics
Prescribing fluid:
example four: prescribing rehydration fluid
Date
Infusion Fluid
Volume
Name of Drug to
be infused
Dose of
Drug
Added
Route
Infusion rate
Signature
14/3/11
O.9%NACL/5%DEXTROSE
500ML
NIL
_
IV
139ML/H
R
A.doctor
insert Specialty School of Paediatrics
Principles of prescribing fluids
in neonates
• Requirements depend on gestation, age (day of life) and
weight
• The usual neonatal fluid is 10% dextrose
• Fluids may or may not require additives
– Usual sodium requirements are 2-6 mmol / kg / day
– Usual potassium requirements are 1-3 mmol / kg / day
– These may change depending on the clinical condition of
the patient
insert Specialty School of Paediatrics
Prescribing fluids:
example five - prescribing fluids for neonates
• Baby Alfie is born at 37/40
• He weighs 2.8kg
• He was born four hours ago
• Prescribe fluid for Alfie for the next 24 hours (day 1 of life)
• Workings:
– In our trust, we prescribe 60mL/kg/day on day 1 of life with no additives
Alfie will need 60mL/kg x 2.8kg =
168mL/24 hrs
7mL/hour
insert Specialty School of Paediatrics
Prescribing fluids:
example five - prescribing fluids for neonates
Date
Infusion Fluid
Volume
Name of Drug to be
infused
Dose of
Drug
Added
Route
Infusion rate
Signature
14/3/11
10% DEXTROSE
500mL
NIL
_
IV
7mL/HR
A.doctor
insert Specialty School of Paediatrics
Prescribing fluids:
example six - prescribing additives for neonates
• Baby Begum is born at 35 weeks gestation, weighing 2.5kg
• She is 3 days old and you have been asked to prescribe fluid at 120mL/kg/day with
2mmol/kg/day of potassium and 3mmol/kg/day of sodium.
• Workings:
– Fluid: 2.5kg x 120mL/kg/day = 300mL/day = 12.5mL/hour
– Sodium: 2.5kg x 3mmol/kg/day
= 7.5 mmol/day
– Potassium: 2.5kg x 2mmol/kg/day
= 5 mmol/day
– Therefore 300mls of 10% Dextrose + 7.5 mmol of Sodium + 5 mmol of potassium is the
daily requirement
– Fluids are administered in standard 500mL bags so the equivalent doses need to be
calculated to give the correct concentration of fluid.
– Sodium in 500mL bag=
– Potassium in 500mL bag=
(500/300) x 7.5mmol= 12.5mmol
(500/300) x 5mmol = 8.3mmol = 8mmol
insert Specialty School of Paediatrics
Prescribing fluids:
example six - prescribing additives for neonates
Date
Infusion Fluid
Volume
Name of Drug to be infused
Dose of Drug
Added
Route
Infusion rate
Signature
14/3/11
10% DEXTROSE
500mL
SODIUM CHLORIDE
POTASSIUM
CHLORIDE
12.5mmol
8.3mmol
IV
12.5
mL/HR
A.doctor
insert Specialty School of Paediatrics
Local drug chart
• [spend this time going over your drug chart]
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Trust guidelines & policies
[Outline any specific trust guidelines & policies here]
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Questions?
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Summary
• Don’t forget:
– Age
– Weight
– Show your calculations initially
– Always use local guidelines or BNFC to check doses
– Prescribe in dose rather than mls whenever possible
– If you are ever unsure, always ask for help from a senior
colleague or pharmacist