11 - Fluid Replacement Therapy Flashcards
What percentage of body weight is water in the following:
- Males
- Females
- Infants
- Elderly
- Males = 60%
- Females = 50-55%
- Infants = 73%
- Elderly = 45-50%
What is the major anion in ECF and ICF?
- Phosphate in ICF
- Cl- in ECF
How much water is in each body compartment in a 70kg man?
What happens to cells in hypernatremia and hyponatremia?
The sodium only shifts between interstitial and intervascular so it is water that moves to correct this
What happens if you give someone 1L of 5% Dextrose?
- If low b.p don’t give this as won’t raise intravascular very much
- Glucose can be taken up along all compartments
What happens if you give someone 1L of 0.9% saline?
Give if someone has low b.p as saline stays in ECF
What happens if you give someone 1L of Hartman’s solution??
Why would you give Hartman’s over saline?
- Less Na and Cl
- Lactate to get HCO3-
- Used to mirror blood more
What are the contents of Hartmann’s?
Why would you give someone dextrose saline over dextrose?
- Dextrose saline used to replace water losses
- Dextrose and saline can just be maintenance fluids if can’t take orally
What would happen if you gave someone 1L of 4% dextrose, 0.18% saline?
Why is glucose fluids isoosmotic but not isotonic?
- Isoosmotic as glucose metabolised quickly to water and CO2 so no change in osmoles but more water in cell changes tonicity
- Tonicity is what the solution will do to the cells
Why may patients need IV fluids?
What are some factors you need to think about when giving patients maintenance fluids?
- Maintenance fluids fill daily requirement and replace any losses, e.g from vomiting, but factors can change requirements
- Easy to cause fluid overload
How much water, sodium, potassium, chloride and glucose is needed for maintenance and what are some processes that can change this maintenance requirement?
- Diarrhoea
- Vomiting
- Sweaing
- Urine
- Bile and pancreatic drainage loss