Formulae
From Paeds.co.uk the online paediatrician's encyclopaedia
- NOTE: Always follow local and up-to-date clinical guidelines / protocols.
- This page is a guide only.
Contents |
Normal Clinical Parameters
Resuscitation
(after APLS)
- A- age
- W - weight: (age+4)x2
- E - energy. 4joules/kg
- T - tube. int diameter: (age/4)+4. Neonate 3.5mm
- F - fluid. 20 ml/kg (10mg/kg in trauma and DKA)
- A - adrenaline. 0.1 ml/kg 1:10 000 (10 mcg/kg)
- G - glucose iv bolus. 5ml of 10% per kg. Or 10ml of 5%
- Systolic Blood pressure ~ 80 + (2 X Age in years) /mmHg
Caution - Weight as estimated by 2(age + 4) is seriously inaccurate especially for older children. See Luscombe and Owens (ADC 2007;92;412-415). The underestimate on APLS formula is up to 20%. (3Xage)+7 proves much more accurate.
Fluid Calculations
General Paediatrics
- Fluid requirements.
- daily: 100 : 50 : 20 : 10 : 10 : 10 etc... ml per 10kgs per 24hrs
- hourly: 4+2+1 ml/hr
- dehydration correction: % dehy x 10 x weight in kg /ml
Neonatal Fluids
Fluids (milk or IV fluids) are usually calculated "per kg per day" ( ml/kg/day), with amounts increased from days 1 to 4 (follow your local hospital protocol).
Eg:
- Day 1: 60 ml/kg/day
- Day 2: 90 ml/kg/day
- Day 3: 120 ml/kg/day
- Day 4 and thereafter: 150 ml/kg/day
Fluid regimes may be altered depending on the condition of the baby, for example where there are concerns regarding hypoxic-ischaemic encephalopathy / cerebral oedema, cardiac lesions or a clinically significant persistent ductus arteriosus (PDA).
Once established on full fluids, amounts may be increased to promote growth / weight gain and good nutrition.
Blood Product Administration
- See the associated page Blood Product Administration
| Product | Prescription |
| Packed Red Cells | 4 x (rise in Hb required) x weight = Packed RBC (ml) Simple top-up: aim for Hb 10-12 g/dL GI bleed / varices / post-transplant: aim for Hb 8-10 g/dL |
| Platelets | 10 ml/kg over 30 minutes |
| Fresh Frozen Plasma | 10 ml/kg over 1 hour |
| Cryoprecipitate | 5 ml/kg over 30 - 60 minutes |
Electrolyte Corrections
- See the article page: Electrolyte Corrections
| Electrolyte | Treat if less than: | IV Correction | Daily Maintenance |
| Bicarbonate | pH 7.0 | 0.3 x base deficit x weight (over 30-60 mins) (Dilute 1 in 5 in 0.9% saline or 5% dextrose via central line) | |
| Calcium | 2 mmol/L | 0.5 ml/kg 10% Calcium Gluconate (max 20ml over 10 minutes) (Dilute 1 in 5 in 0.9% saline or 5% dextrose) | 1 mmol/kg |
| Glucose | 3 mmol/L | 3 - 5 ml/kg 10% dextrose | 4-6 mg/kg/min |
| Magnesium | 0.75 mmol/L | 0.5 mg/kg Magnesium Sulphate (max 10ml, over 10 minutes) | 0.2 mmol/kg |
| Phosphate | 0.8 mmol/L | 0.05 mg/kg/hour Sodium or Potassium Phosphate for 3-7 hours Dilute 1 in 10 0.9% saline or 5% dextrose | 0.4 - 1.5 mmol/kg |
| Potassium | 3 mmol/L | 0.25 - 0.5 mmol/kg Potassium Chloride over 1-2 hours with cardiac monitoring Dilutre to 4 mmol KCl per 10ml 0.9% saline via central line | 1 - 2.5 mmol/kg |
