Paediatric anaesthesia
Weight and BMI
Normal Physiological Values
SBP mmHg (– mmHg)*
HR – bpm†
RR – bpm†
*50th centile (5th – 95th)
†5th – 95th centile
Airway and Ventilation
Supraglottic airway device (SAD)
LMA
i-Gel
Endotracheal tube (ETT)
Laryngoscope
Uncuffed ETT
Cuffed ETT
Depth at lips cm
Bougie
Breathing circuits
T-piece 0–20 kg
Infant (Micro) circle 0–10 kg
Paediatric (Mini) circle 10–30 kg
Adult circle >20 kg
Ventilation
Tidal volume (6–8 ml/kg)
Neonates / ARDS (4–6 ml/kg)
Emergency Intubation
Induction
Fentanyl 1–2 mcg/kg mcg
Ketamine 1–2 mg/kg mg
Rocuronium 1 mg/kg mg
Maintenance infusions
Morphine 10–40 mcg/kg/h
0.5–2 ml/h
Midazolam 1–3 mcg/kg/min
1–3 ml/h
Propofol 1–4 mg/kg/h
Emergency Drugs
Atropine Max 600 mcg 20 mcg/kg mcg
Adrenaline IV
1:10,000 100 mcg/ml 		0.1 mL/kg
10 mcg/kg 		mcg
Suxamethonium IV mg
Sux. IM Max 150 mg mg/kg mg
Other
Fluid bolus 10–20 mL/kg mL
Glucose 10% 2 mL/kg mL
Defibrillation energy 4 J/kg J
Estimated blood volume mL

For other drugs and infusions, use Paediatric Emergency Tools: Apple / Android.

Premedication & Sedation
Midazolam - PO 0.5 mg/kg mg
1 month–18 yrs. Max 20 mg per dose. Peak effect at 20-30 mins.
Midazolam - NAS mg
Max 10 mg. Given via short atomiser: 0.1 ml dead space. Peak effect at 10 mins. Can be repeated within 5–15 minutes to a max 0.5 mg/kg.
Buccal Midazolam 0.3 mg/kg mg
6 months–18 yrs. Max 10 mg.
Dexmedetomidine - NAS 2–4 mcg/kg mcg
≥1 year. Max 200 mcg per dose. Given 30 mins before intervention.
STPN Best Practice Guidance for Procedural Sedation of Children and Young People
Routine General Anaesthesia
Induction
Fentanyl 1–2 mcg/kg mcg
Propofol 3–5 mg/kg mg
Rocuronium 0.6 mg/kg mg
Atracurium 0.5 mg/kg mg
Antiemetics
Dexamethasone Max 6.6 mg 0.15 mg/kg mg
Ondansetron 0.15 mg/kg mg
Cyclizine
 0.5–1 mg/kg mg
Intraoperative IV analgesia
Paracetamol mg
Ibuprofen Max 400 mg 5–10 mg/kg mg
Ketorolac 0.5–1 mg/kg mg
Diclofenac 1 mg/kg mg
Morphine mg
Reversal of neuromuscular blockade
Neostigmine &
Glycopyrulate 2.5 mg &
500 mcg/1 mL 		0.02 mL/kg mg
Sugammadex 2 mg/kg mg

Moderate block: Return of T2 in response to TOF.
Sugammadex 4 mg/kg mg

Deep block: 1-2 PTCs, no twitch responses to TOF.
Postoperative Oral analgesia
Paracetamol mg
Ibuprofen Max 400 mg mg
Morphine mg
Emergency Drugs
Atropine Max 600 mcg 20 mcg/kg mcg
Suxamethonium IV mg
Sux. IM Max 150 mg 4 mg/kg mg
Antibiotics - Surgical prophylaxis
Amoxicillin Max 1 g mg
Cefuroxime Max 1.5 g mg
Co-Amoxiclav Max 1.2 g mg
Flucloxacillin (Soft tissue) Max 1 g mg
Flucloxacillin (Open orthopaedic surgery) Max 2 g mg
Metronidazole Max 500 mg mg
Teicoplanin mg
Teicoplanin (Open fractures) mg
Gentamicin Max 160 mg mg
Gentamicin (high-dose) Max 480 mg mg
Lines and Suction catheters
Arterial lines - Radial
Neonates/Infants <10 kg 24 G
Pressure transducer: 150 mmHg (generates a flow rate of 1.5 mL/hr)
Children >10 kg 22 G
Pressure transducer: 300 mmHg (generates a flow rate of 3 mL/hr)
Children >50 kg 20 G
Arterial lines - Femoral
Neonates 22 G, 8cm
Children 20 G, 8cm
Patient Weight CVL Diameter Insertion Length (cm)
Jugular Femoral
2–2.9 kg4 Fr45
3–4.9 kg4–4.5 Fr58
5–6.9 kg4–4.5 Fr68
7–9.9 kg4–4.5 Fr78
10–12.9 kg4.5–5.5 Fr813
13–19.9 kg4.5–5.5 Fr913
20–29.9 kg5.5–7 Fr1016
30–39.9 kg5.5–7 Fr1116
40–49.9 kg7–8.5 Fr1216–20
50–59.9 kg7–8.5 Fr1316–20
60–69.9 kg7–8.5 Fr1416–20
70–79.9 kg7–8.5 Fr1516–20
≥80 kg7–8.5 Fr1616–20
EZ-IO Intraosseous needle sizing
Pink 15 mm / 15 G 3–39 kg
Typically <6 months
Blue 25 mm / 15 G ≥3 kg
Typically >6 months
Yellow 45 mm / 15 G ≥40 kg and/or excessive tissue depth
Proximal tibia (first choice) Distal tibia
Distal femur (infants, e.g. 0–12 months)
Proximal humerus (older children, e.g. >5 years)
Suction catheters
Age ETT size (mm) Suction catheter (Fr)
Premature 2.5 6 Fr
Newborn 3.0 6 Fr
6 months 3.5 6 Fr
18 months 4.0 8 Fr
3 years 4.5 8 Fr
5 years 5.0 10 Fr
6 years 5.5 10 Fr
8 years 6.0 10 Fr
12 years 6.5 10 Fr
16 years / small adult 7.0 12 Fr
Adult female 7.5 12 Fr
Adult male 8.0+ 14 Fr
Useful Links and Guidelines

Other calculators

Retrieval teams

Specific Emergency Guidelines

Airway Guidelines

Calculations and tables
Weight (kg)
Age 1-12 months

0.5 x Age (months) + 4
Age 1-5 years

2 x Age (years) + 8
Age 6-14 years

2 x Age (years) + 8

3 x Age (years) + 7
Airway and Ventilation
ETT size

Uncuffed ETT size = (Age/4) + 4 [Cole formula]

Cuffed ETT size = (Age/4) + 3.5 [Modified Cole]
ETT depth (oral)

Above 1 year: Depth ≈ Age/2+12

    Neonates
  • Depth ≈ 1.17 × Birth weight (kg) + 5.58 (Tochen)
  • 123–789 rule: 7 cm for a 1 kg baby, 8 cm for a 2 kg baby, and 9 cm for a 3 kg baby at the lips.
ETT depth (nasal)

Above 1 year: Depth ≈ Age/2+15
Circulation
Lowest acceptable SBP

<1 month: ≥60 mmHg

1 month to 1 year: ≥70 mmHg

1–10 years: 2 x Age + 70 mmHg
Lowest acceptable MAP

Age (in years) x 1.5 + 40 mmHg
Premature Neonates

Gestational age ≈ Mean Arterial Pressure