Emergency Calculations


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All your important calculations in one place…

Resus Drugs

DrugDoseIndicationSide effects/other info
Vasopressin0.5-0.8 units/kg IVAlternative vasopressor to adrenaline
SuxamethoniumNeonate: 3mg/kg IVnChild: 2mg/kg IVMuscle relaxant for RSIBradycardia and asystole. Should give with atropine.
Sodium bicarbonate1 mmol/kg IV (1 ml/kg of 8.4%) over 5 minsSevere metabolic acidosis (pH <7.1)S/E - hypernatraemia, hyperosmolality, myocardial dysfunction
Rocuronium0.6-1.2 mg/kg stat, then 0.1-0.2 mg/kg boluses or 5-15 mcg/kg/minMuscle relaxant
Procainamide10-15 mg/kg IV over 30-60 minsHaemodynamically stable SVT and VT
Potassium0.03-0.07 mmol/kg IV by slow injection; or infusion of 0.2-0.5 mmol/kg/hr (max 1 mmol/kg/hr)Hypokalaemia
NaloxoneFor post-operative respiratory depression or over-sedation, give 0.002 mg/kg/dose (i.e. dilute 0.4mg to 20ml and then give 0.1ml/kg/dose). Repeat every 2 minutes x4 if required, then commence infusion by adding 0.3mg/kg to 30ml 5% dextrose and running at 0-1ml/hr (0.01mg/kg/hr).nnFor opiate overdose, give 0.01 mg/kg (max 0.4 mg) (i.e. dilute 0.4mg to 10ml and give 0.25ml/kg/dose). Repeat every 2 minutes x4 if required, then commence infusion by adding 0.3 mg/kg to 30ml 5% dextrose and running at 0-1 ml/hr (0.01mg/kg/hr)For reversal of post-op respiratory depression or opiate overdose
Magnesium0.1-0.2 mmol/kg IV bolus 25-50 mg/kg n(this is the same as 0.05-0.1 ml/kg of 50% (2 mmol/ml)Hypomagnesaemia; antidysrhythmic for polymorphic ventricular tachycardia (due to long QT)
Lignocaine1 mg/kg IV of 1% lignocaineOnly recommended in cardiac arrest if amiodarone is not available (or when IV/IO access is impossible as can be given via ETT)
Flumazenil5 mcg/kg every 60 seconds to a maximum total of 40 mcg/kg then 210 mcg/kg/hrAntidote for benzodiazepines
Dextrose0.5 ml/kg of 50% dextrose IV; or 2 ml/kg of 10% dextrose IVHypoglycaemiaMaintenance requirement is usually 5-8 mg/kg/min
Calcium0.2 ml/kg of 10% calcium chloride IV; or 0.7 ml/kg of 10% calcium gluconate IV (20 mg/kg). For calcium channel blocker antidote.Management of arrhythmia caused by hyperkalaemia, hypocalcaemia, hypermagnesaemia or calcium channel blocker.S/E - extravasation; myocardial and cerebral injury, coronary artery vasospasm, bradycardia with rapid administration. Don't give routinely in cardiac arrest.
Atropine20 mcg/kg IV; 30 mcg/kg via ETTBradycardia caused by vagal stimulation or cholinergic drug toxicityUse adrenaline instead for bradycardia with hypotension.
Amiodarone5 mg/kg IV bolus (usually diluted with 5% dextrose to a concentration of 15mg/ml over 3 mins)Good for ventricular arrhythmias - shock-resistant VF and pulseless VT. Also SVT, JET, atrial tachycardias.S/E - hypotension, bradycardia, heart block. Lignocaine can be used as an alternative.
Adrenaline10 mcg/kg (0.1 ml/kg of 1 in 10,000) IV; 100 mcg/kg via ETT; or 0.1-0.2 mcg/kg/min infusion into a large vein.Asystole, bradycardia, VF, EMD.S/E - vasoconstriction, hypertension, tachdysrrhythmias
Adenosine0.05-0.1 mg/kg IV bolus; repeat after 1-2 mins if not reverted to sinus increasing the amount given by 0.05-0.1 mg/kg until sinus rhythm or dose of 0.3 mg/kg is reached. Adult dose is 6mg then 12mgSVT

ETT Size

Neonates (up to 4kg)Infants (up to 1 year)Children (1-16 years)
Nasal length (cm)weight + 7weight/2 + 9age/2 + 14
Oral length (cm)weight + 6weight/2 + 8age/2 + 12
ETT Size (mm)3.0-4.04.0age/4 + 4

DC shock

VF, pulseless VT  – all shocks 4J/kg unsynchronised

Pulsatile VT – 2J/kg synchronised

SVT – 1J/kg synchronised

Fluid management

Option 1 – 4:2:1 rule for the hourly requirement

4 ml/kg/hr for the first 10 kg, then 2 ml/kg/hr for the second 10 kg, then 1 ml/kg/hr for each subsequent kg

For example a 22kg child – (4 x 10) + (2 x 10) + (1 x 2) = 62 ml/hr

Option 2 – 100:50:20 rule for the daily requirement

100 ml/kg/hr for the first 10 kg, then 50 ml/kg/hr for the second 10kg, then 20 ml/kg/hr for each subsequent kg

For example a 22kg child – (100 x 10) + (50 x 10) + (20 x 2) = 1540 ml/day


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