Fluid therapy in adults
Fluid therapy in adults
The prescription of intravenous fluids is one of the most common tasks that junior doctors need to do.In the 2013 guidelines NICE recommend the following requirements for maintenance fluids:
- 25-30 ml/kg/day of water and
- approximately 1 mmol/kg/day of potassium, sodium and chloride and
- approximately 50-100 g/day of glucose (to limit starvation ketosis - will not address patients' nutritional need)
So, for a 80kg patient, for a 24 hour period, this would translate to:
- 2 litres of water
- 80mmol potassium
For the first 24 hours NICE recommend the following::
When prescribing for routine maintenance alone, consider using 25-30 ml/kg/day sodium chloride 0.18% in 4% glucose with 27 mmol/l potassium on day 1 (there are other regimens to achieve this).
The amount of fluid patients require obviously varies according to their recent and past medical history. For example a patient who is post-op and is having significant losses from drains will require more fluid whereas a patient with heart failure should be given less fluid to avoid precipitating pulmonary oedema.
The table below shows the electrolyte concentrations (in millimoles/litre) of plasma and the most commonly used fluids:
| Na+ | Cl- | K+ | HCO3- | Glucose | |
|---|---|---|---|---|---|
| Plasma | 135-145 | 98-105 | 3.5-5 | 22-28 | - |
| 0.9% saline | 154 | 154 | - | - | - |
| 5% glucose | - | - | - | - | 50g |
| 0.18% saline with 4% glucose | 30 | 30 | - | - | 40g |
| Hartmann's solution | 131 | 111 | 5 | 29 | - |
Specific points
0.9% saline
- if large volumes are used there is an increased risk of hyperchloraemic metabolic acidosis
+PassMedicine Notes
The prescription of intravenous fluids is one of the most common tasks that junior doctors need to do.
In the 2013 guidelines NICE recommend the following requirements for maintenance fluids:- 25-30 ml/kg/day of water and
- approximately 1 mmol/kg/day of potassium, sodium and chloride and
- approximately 50-100 g/day of glucose (to limit starvation ketosis - will not address patients' nutritional need)
- 2 litres of water
- 80mmol potassium
For the first 24 hours NICE recommend the following::
When prescribing for routine maintenance alone, consider using 25-30 ml/kg/day sodium chloride 0.18% in 4% glucose with 27 mmol/l potassium on day 1 (there are other regimens to achieve this).
The amount of fluid patients require obviously varies according to their recent and past medical history. For example a patient who is post-op and is having significant losses from drains will require more fluid whereas a patient with heart failure should be given less fluid to avoid precipitating pulmonary oedema.
The table below shows the electrolyte concentrations (in millimoles/litre) of plasma and the most commonly used fluids:
_ Na+ _ Cl- _ K+ _ HCO3- _ Glucose| Plasma _ 135-145 _ 98-105 _ 3.5-5 _ 22-28 _ -| 0.9% saline _ 154 _ 154 _ - _ - _ -| 5% glucose _ -_ -_ - _ - _ 50g| 0.18% saline with 4% glucose _30_ 30_ - _ - _ 40g| Hartmann's solution _ 131 _ 111 _ 5_ 29 _ -|Specific points
0.9% saline- if large volumes are used there is an increased risk of hyperchloraemic metabolic acidosis