Fluid and electrolytes balance Flashcards
how much fluid lost in urine
1200ml
how much fluid lost in faeces
100ml
what is insensible loss and how much of it is lost
fluid loss via the skin and respiratory tract
- 400ml skin
- 400ml respiratory tract
- total 800ml
what is a normal stool weight
200ml in 24 hourse
what is abnormal stool weight
Volume greater than 200 ml constitutes diarrhoea
what causes diarrhoea
rapid propulsion –> decreased absorption –> fluid accumulation
what are colloids important for
in resuscitation
what does abnormal plasma osmolality cause
causes movement of water between compartments (plasma, intracellular fluid and interstitial fluid)
–> May cause cellular overhydration and oedema
What is The standard postoperative regimen for IV replacement
Saline and dextrose 2 :1
what are the lactate containing IV fluids
- Ringer Lactate
- Hartmann
when can RInger lactate be used
A substantial amount of bicarbonate is produced during lactate metabolism:
Thus Ringer-lactate solution may be used in metabolic acidosis caused by bicarbonate loss
what is the minimum daily potassium loss
60-80mmol per day
what is the effect of hypo and hyperkalaemia on heart function
cause complicated arrthymias and affect cardiac function
what can cause hypo and hyper kalaemia
Alkalosis leads to → hypokalaemia
Acidosis leads to → hyperkalaemia
This is due to K+/H+ antiporter on cell surfaces
what are the guidelines for K IV supplements
- Prescribe potassium in mmol, indicating final volume of the solution: e.g. “20 mmol/L in saline, over 8h”
- Maximum rate 10mmol/h : faster only if cardiac monitoring/ central line are available (up to 20 mmol/h)
- Concentrated potassium solution MUST BE DILUTED before use.
what are the maximum amounts of advised KCl before it becomes unsafe
- Maximum of 40mmol of KCl per litre of fluid
- Maximum of 20mmol of KCl per hour
- Maximum of 140mmol of KCL per day
child worldwide deaths due to diarrhoea are attributable to what
unsafe water, poor sanitation and poor hygiene.
what does osmolality mean and how does it work?
The concentration of a solution expressed as the total number of solute particles per kilogram.
water moves from low osmolality body compartment to high osmolality body compartment (osmosis)
what does high osmolality result in
High osmolality in the blood, results in cellular dehydration, since water is drawn from the cells and into the blood
what does low osmolaliy result in
Low osmolality in the blood, due to water being drawn up into cells, results in cellular over hydration and oedema.
what is the target osmolality wise
The target is to have iso-osmotic compartments (when both compartments have equal osmotic pressures)
