Paediatric emergencies essentials

Paediatric airway: sizes, RSI and first ventilator settings

Reviewed Nov 2026·4 references
New· views rounded down, updated weekly

Endotracheal tube size and depth, laryngoscope blades and supraglottic airways by age/weight, a safe paediatric rapid sequence intubation, and lung-protective initial ventilation per PALICC-2.

Definition
The infant airway is anatomically different: large occiput, large tongue, high anterior larynx, floppy omega-shaped epiglottis, and the narrowest functional point at the cricoid/subglottis. Cuffed tubes are now preferred for all ages beyond the newborn, with cuff pressure monitoring.

At the bedside

Timed steps
  1. 1

    Decide and call for help

    Before

    Indications: failure to maintain/protect airway, refractory hypoxaemia or hypercapnia on HFNC/NIV, exhaustion, GCS ≤8, shock needing controlled ventilation, safe transfer. Call the most experienced airway operator available; children decompensate fast.

  2. 2

    Calculate sizes aloud

    Before

    Cuffed ETT ID = (age/4) + 3.5; uncuffed = (age/4) + 4. Keep one size above and below. Oral depth (cm at lips) = 3 × ID or (age/2) + 12. Write the weight, tube size, depth and drug doses on a whiteboard.

  3. 3

    Prepare

    Before

    Suction (Yankauer + catheter 2 × ETT ID in Fr), bag-valve-mask of correct size, appropriate blade, stylet, bougie, SGA one size ready, waveform capnography, oral airway, NG tube. Fluid bolus 10–20 mL/kg drawn up and adrenaline (push-dose or infusion) ready if shocked.

  4. 4

    Preoxygenate

    −3 min

    Head position (shoulder roll in infants, sniffing in older child); 100% O₂ by mask for 3 min, or HFNC/NIV if already on it; continue apnoeic oxygenation via nasal cannula during laryngoscopy.

  5. 5

    Induce and paralyse

    0

    Ketamine 1–2 mg/kg (0.5–1 mg/kg in profound shock) ± fentanyl 1–2 mcg/kg; rocuronium 1–1.2 mg/kg. Atropine 0.02 mg/kg is not routine; consider for bradycardia or in infants receiving suxamethonium.

  6. 6

    Intubate and confirm

    +45–60 s

    Video laryngoscope if available. Gentle bag-mask ventilation (low pressure) is acceptable if desaturating. Confirm with sustained waveform ETCO₂, chest rise and auscultation; cuff pressure <20–25 cmH₂O; chest X-ray for tip position (mid-trachea, T2–T3).

  7. 7

    Plan B/C

    Failed

    If two attempts fail: oxygenate with bag-mask + adjuncts or an SGA, call for help. Cannot intubate, cannot oxygenate: in children <8 years needle cricothyroidotomy (cannula) with jet/bag oxygenation as a bridge; surgical airway in older children. Keep the drawn-up dose list for re-attempts.

  8. 8

    Initial ventilation (PALICC-2)

    After

    Tidal volume 5–8 mL/kg predicted (ideal) weight; 3–6 mL/kg if poor compliance. Plateau ≤28 cmH₂O; driving pressure ≤15 cmH₂O; PEEP 5–8 then titrate to oxygenation and haemodynamics. SpO₂ 92–97% (88–92% acceptable in severe PARDS with PEEP ≥10). Permissive hypercapnia with pH ≥7.20, except in raised ICP or pulmonary hypertension.

Induction (haemodynamically safest)

Ketamine — paediatric

IV
Dose
1–2 mg/kg; 0.5–1 mg/kg in profound shock; IM 4–5 mg/kg if no access
Worked example
20 kg: 20–40 mg IV (shocked: 10–20 mg).

Neuromuscular blockade for RSI

Rocuronium — paediatric

IV
Dose
1–1.2 mg/kg
Worked example
20 kg: 20–24 mg (2–2.4 mL of 10 mg/mL).

Analgesic co-induction / post-intubation

Fentanyl — paediatric

IV
Dose
1–2 mcg/kg slowly; infusion 1–4 mcg/kg/h
Range
1–4 mcg/kg/h
Preparation
10 mcg/kg in 50 mL: 1 mL/h = 0.2 mcg/kg/h (or 50 mcg/mL undiluted for older children)
Worked example
20 kg: bolus 20–40 mcg; infusion 2 mcg/kg/h = 40 mcg/h = 0.8 mL/h of 50 mcg/mL.
Open infusion calculator

Bradycardia during intubation (not routine premedication)

Atropine — paediatric

IV/IO
Dose
0.02 mg/kg (max single dose 0.5 mg)
Worked example
20 kg: 0.4 mg.

Airway equipment by age

Age (approx. weight)Cuffed ETT ID (mm)Oral depth at lips (cm)Laryngoscope bladeSGA (LMA) size
Term newborn–<8 months (3–8 kg)3.09–10Miller 0–11 (<5 kg) / 1.5 (5–10 kg)
8 months–2 years (8–12 kg)3.510.5–12Miller 1 / Mac 11.5 (5–10 kg) / 2 (10–20 kg)
2 years (12 kg)4.012–13Mac 2 / Miller 22
4 years (16 kg)4.514Mac 22
6 years (20 kg)5.015Mac 22–2.5 (20–30 kg)
8 years (25–30 kg)5.516Mac 2–32.5
10 years (30–35 kg)6.017–18Mac 33 (30–50 kg)
12–14 years (40–50 kg)6.5–7.018–21Mac 33–4 (50–70 kg)

Cuffed ID = age/4 + 3.5 (≥2 years); uncuffed = age/4 + 4. Depth ≈ 3 × ID. Always confirm with ETCO₂ and chest X-ray; have half-size smaller tubes for croup or subglottic narrowing.

PARDS severity on invasive ventilation (PALICC-2)

SeverityOxygenation index (OI)Oxygen saturation index (OSI)
Mild/moderate4 to <165 to <12.3
Severe≥16≥12.3

OI = (FiO₂ × mean airway pressure × 100) / PaO₂; OSI uses SpO₂ (≤97%) in place of PaO₂.

Red flag · call your senior now
Bradycardia during laryngoscopy = hypoxia until proven otherwise: stop, oxygenate with bag-mask, then reattempt.
Red flag
Post-intubation arrest risk is high in shock: resuscitate first and have fluids and adrenaline ready before induction.
Red flag
Sudden deterioration in a ventilated child — DOPE: Displacement, Obstruction, Pneumothorax, Equipment failure. Disconnect and hand-bag with 100% O₂.
Red flag
Drooling, tripod posture, toxic look and soft stridor suggest epiglottitis: do not lie the child flat or examine the throat; get the most senior anaesthetist and ENT.
Pitfall
Over-inflating the cuff: subglottic stenosis risk; measure cuff pressure with a manometer, keep <20–25 cmH₂O.
Pitfall
Endobronchial intubation is common because the trachea is short (~4–5 cm in infants); listen in both axillae and check depth after every move.
Pitfall
Hyperventilating with the bag after intubation: drops venous return and causes hypocapnia; ventilate gently at an age-appropriate rate.
Pearl
Use a written paediatric intubation checklist and say the tube size, depth and drug doses aloud before induction — it reduces 10-fold and size errors.
Pearl
Gastric distension from bag-mask ventilation splints the diaphragm in infants — place an NG/OG tube early after intubation.

Calculators for this topic

Oxygenation index

OI = FiO₂(%) × mean airway pressure ÷ PaO₂.

SpO₂/FiO₂ ratio

Non-invasive oxygenation ratio; valid only when SpO₂ ≤ 97%. Global ARDS definition uses S/F ≤ 315.

Infusion rate from per-kg-per-hour dose

Pump rate for drugs dosed per kg per hour (insulin U/kg/h, midazolam mg/kg/h, propofol mg/kg/h, fentanyl mcg/kg/h, dexmedetomidine mcg/kg/h).

References

  1. 1

    Topjian AA, Raymond TT, Atkins D, et al. Part 4: Pediatric Basic and Advanced Life Support: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2020;142(16 suppl 2):S469-S523.

  2. 2

    Lasa JJ, Dhillon GS, Duff JP, et al. Part 8: Pediatric Advanced Life Support: 2025 American Heart Association and American Academy of Pediatrics Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2025;152(16 suppl 2):S479-S537.

  3. 3

    Weiss M, Dullenkopf A, Fischer JE, et al. Prospective randomized controlled multi-centre trial of cuffed or uncuffed endotracheal tubes in small children. Br J Anaesth. 2009;103(6):867-873.

  4. 4

    Emeriaud G, López-Fernández YM, Iyer NP, et al. Executive Summary of the Second International Guidelines for the Diagnosis and Management of Pediatric Acute Respiratory Distress Syndrome (PALICC-2). Pediatr Crit Care Med. 2023;24(2):143-168.

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