| IVF | Osm | Na | Cl | Glc | pH | buffer | K | Ca | Mg |
| Plasma | 289 | 140 | 103 | 4 – 7 | 7.4 | bicarb: 22-32 | 4 | 5 | 2 |
| NS | 308 | 154 | 154 | – | 5.0 | – | – | – | – |
| D5, NS | 560 | 154 | 154 | 50 | – | – | – | ||
| LR | 273 | 130 | 109 | – | 6.5 | lactate: 28 | 4 | 3 | – |
| Plasmalyte | 295 | 140 | 98 | – | 6.0 | gluconate: 23 acetate: 27 | 5 | – | 3 |
| D5 + 1/2 NS | 406 | 77 | 77 | 500 | 4.5 | – | – | – | – |
| D5 Water | 252 | – | – | 50 | – | – | – |
Maintenance:
- Na+ = 3 mEq/kg/day
- K+ = 2 mEq/kg/day
Deficit
- % dehydration x baseline weight
- [desired – measured mEq/L] x fD x weight (kg)
Distribution factor (fD):
- Na = 0.6
- K = 0.6
- Cl = 0.2 – 0.3
- HCO3 = 0.5
Concentration of electrolyte in fluid to be given = [maintenance + deficit] / daily volume
- note: every 4 mL/kg water lost increases Na by 1 mEq
Total Body Water (TBW) = 0.6 x weight (kg)
Insensible losses = 300 – 400 cc / m^2 /day
Daily volume needed = maintenance + deficit – boluses given
- hourly rate = daily volume / 24
- or, correct 1/2 the deficit in the first 8 hours and the remaining 1/2 in the subsequent 16 hours
Paediatric fluid replacement volumes by body weight (ideally based on normal body weight, as measured within the last 2 weeks):
- 100 cc /kg / day (4 cc / kg / hr) – for the first 10 kg body weight
- 50 cc / kg/ day (2 cc / kg / hr) – for the second 10 kg body weight
- 20 cc / kg / day (1 cc / kg/ hr) – for each subsequent kilogram of body weight
| maintenance fluid in mL / hour (watch out for [Na+] < 135 or > 145 mmol/L) | ||
| weight | full maintenance | 2/3 maintenance |
| 5 kg | 20 | 13 |
| 10 kg | 40 | 27 |
| 15 kg | 50 | 33 |
| 20 kg | 60 | 40 |
| 25 kg | 65 | 43 |
| 30 kg | 70 | 47 |
| 35 kg | 75 | 50 |
| 40 kg | 80 | 53 |
| 45 kg | 85 | 57 |
| 50 kg | 90 | 60 |
| 55 kg | 95 | 63 |
| 60 kg | 100 | 67 |
References
Clinical Practice Guidelines : Intravenous fluids (rch.org.au).