Paediatric Emergency Calculator

What is WETFLAG?

WETFLAG is a memory aid used in paediatric emergency medicine to recall key resuscitation parameters: Weight, Energy (defibrillation), Tube (endotracheal tube size & depth), Fluids, Lorazepam, Adrenaline, Glucose. This calculator uses APLS (Advanced Paediatric Life Support) and Resuscitation Council UK formulas, giving you fast, reliable data for paediatric emergencies.

How to Use This Calculator

• Enter the child’s age in years (0–18). For infants under 1 year, the weight estimation formula is not linear; the calculator uses standard weight-for-age tables or you can enter actual weight.
• If actual weight is known, enter it – the calculator will prioritise actual weight for all drug and fluid calculations. If left empty, the APLS estimated weight ( (age+4)×2 ) is used for children 1–10 years; outside this range, an evidence‑based approximation is shown with advisory.
• Click “Calculate Emergency Doses & Sizes” to get all results instantly.
• Results include endotracheal tube size (internal diameter), oral/nasal insertion length, defibrillation energy, fluid bolus volumes, and emergency drug doses.

Key Formulas (APLS / Resus Council UK)

• Weight (1‑10 years): (age + 4) × 2 kg
• Defibrillation energy: 4 J/kg (biphasic)
• Uncuffed ETT ID: (age/4) + 4 mm (cuffed ETT: ID ≈ (age/4) + 3)
• Oral tube length: (age/2) + 12 cm
• Nasal tube length: (age/2) + 15 cm
• Fluid bolus (medical/shock): 20 ml/kg (e.g. sepsis)
• Fluid bolus (trauma): 10 ml/kg (restricted resuscitation)
• Lorazepam: 0.1 mg/kg (max 4 mg) – alternative to midazolam in status epilepticus
• Adrenaline 1:10,000: 0.1 ml/kg IV/IO during cardiac arrest
• Glucose 10% Dextrose: 2 ml/kg for hypoglycaemia

Why This Calculator is More Advanced

• ✅ Dual weight input: uses actual weight when available, otherwise applies APLS estimation with clear age‑range handling.
• ✅ All WETFLAG components + advanced airway metrics (oral & nasal depth).
• ✅ UK-specific guidelines: aligned with Resus Council UK and APLS 2021 recommendations.
• ✅ Visual results grid with unit labels and clinical notes (max doses, cuffed tube adjustment hint).
• ✅ Responsive design, medical colour scheme, and clear safety disclaimer.

Important Clinical Notes

• Tube size formulas provide a starting point; always confirm with age‑appropriate equipment and clinical assessment. For cuffed tubes, consider downsizing by 0.5 mm ID.
• Lorazepam dose maximum is 4 mg. If using midazolam, consult local protocol.
• Fluid resuscitation volumes should be titrated to clinical response. The trauma fluid bolus is deliberately restricted in line with current major haemorrhage guidance.
• This tool is for healthcare professionals and should not replace individual clinical judgement.

Frequently Asked Questions

• What if the child is under 1 year old? — For infants, weight estimation is less accurate. Enter actual weight if known, otherwise the calculator provides a weight‑for‑age approximation based on WHO growth charts (displayed advisory).
• Why is there a trauma fluid option? — In paediatric trauma, restrictive fluid resuscitation (10 ml/kg) is recommended to avoid coagulopathy unless there is haemorrhagic shock.
• Does this replace a paediatric drug card? — No, it’s a supplementary decision‑support tool. Always use your local guidelines and double‑check drug doses.
• Which adrenaline concentration is used? — Adrenaline 1:10,000 (0.1 mg/ml) for IV/IO during cardiac arrest. This is consistent with UK Resuscitation Council guidance.