19 - Clinical Problem Solving: Electrolytes Flashcards
What should I know
- IV fluid management
- Types of fluid
- Fluid assessment
What should you ask before giving IVF?
- is my patient euvolaemic, hypovalaemic, hypervolaemic
- do they need IV fluid i.e. can they just drink? Why?
- how much do they need?
- what type of fluid do they need?
If they are hypovolaemic they are…
Dehydrated (low fluid vol)
Fluid overload?
- weight gain
- high BP
- swollen ankles and puffy eyes
- breathless
Dehydrated
weight loss, dry mouth, low bp, dizzy
When does a patient NOT need IV fluids?
They are already drinking enough, they are on enteral feeding, fluid overloaded/not dehydrated
When DOES a patient need IV fluids?
They are not drinking and has lost or is losing fluids (nil by mouth and can’t keep up orally)
3 reasons someone may need IV fluids
- Mainenance (keep eurovolaemic if nil by mouth)
- Replace losses
- Rescuscitation
What is a good level of maintenance fluids?
2-3L a day (how much we lose a day)
How do you lose fluid?
- (pee - not enough to get dehydrated)
- sweat (not much), diarrhoea, vomit, breathing
What fluid might you be replacing?
blood
diarrhoea
vomitting
third spacing (third spacing is fluid in a space where it shouldn’t be i.e. ascites! Although over all there is a lot of fluid in the body it is not in the right place to do any good)
In what situation is third spacing more likely to occur
When there is low albumin.
Fluid replacement summary
- need 2-3L a day to replace losses
- constantly assess fluid status i.e. weight and JVP
- patient record of losses (fluid balance charts)
When may you need IVF to rescuscitate?
- shocked patient i.e. sepsis, dehydration, bleeding
What do you need to consider when deciding what type of fluid?
- look at the patient’s fluid status
- what is their serum sodium (hyponatremic?)
What is generally the safest fluid
Isotonic (0.9% saline or plasmalyt)
> this assumes that there is free flow/passage of water from the cells into the ECF
When may you not use isotonic fluid?
Unless you are only doing maintenance fluid and you’re worried about overloading them (pul odema) or the sodium is very HIGH
When may you use a hypotonic solution? Eg?
5% dextrose (isotonic but metabolised)
> doing a little bit of maintenance but patient is on the verge of being overloaded
> if drugs need to be given to an overloaded patient
> hypotonic solutions may be useful if the serum sodium is very high (i.e. not enough water - need fluid but don’t want to make more salty. Need to do carefully don’t want to change sodium levels quickly!!)
What IVF do you give a patient that is overloaded i.e. doesn’t pee and has odema?
DON’T GIVE THEM FLUID
Will make worse
Hypertonic saline e.g.
3% saline
When do you use hypertonic solutions
- severe hyponatraemia as it makes water go into cells and make ECF conc of sodium increase
Hyponatraemia
- problem is water excess (BUT can still be dehydrated)
- low sodium conc
Fluid compartments?
(MALE)
60% fluid
2/3 ICF
1/3 ECF
20% plasma 80% interstitialWhat fluid compartment does IVF go into
ECF
