Fluid Replacement Therapy Flashcards
(42 cards)
What % of the total body weight is fluid in a newborn baby?
75%
What % of the total body weight is fluid in the eldery?
45%
Decreasing muscle mass
What % of the total body weight is fluid in a man?
60%
What % of the total body weight is fluid in a female?
55%
Why does fluid take up more of the total body weight in men than women?
Men have more muscle mass
Water is stored in the muscle
outline the fluid compartments of the body
- intracellular space 2/3
- extracellular space 1/3 > intravascular space 25% + interstitium 75% + third space
What is the ‘third space’?
examples
- areas of the body that do not normally contain fluid
- peritoneal cavity > ascites
- joints > joint effusions
- pericardial cavity > pericardial effusions
- pleural cavity > pleural effusions
what is third spacing?
fluid shiifting into non functional third space > oedema, hypotension + reduced perfusion
Why do patients need fluids?
Nil by mouth
Malfunction in GI tract
Dehydration
Fluid loss
Abnormal electrolyte levels
What is insensible fluid loss?
fluid output that is difficult to measure e.g. respiration, sweat, stools, burns
What are the 5Rs of fluid prescription
Resuscitation
Routine Maintenance
Replacement + Redistribution
Reassessment
How can you add K+ to fluids?
As KCl
As 20 or 40mmol
What happens if you administer 5% dextrose in 1L bag?
- glucose taken up by cells rapidly
- H2O is left and distributed through all compartments
What happens if you administer 0.9% saline?
- osmolarity is similar to ICF so liquid says in ECF
- distributes proportionally between interstitium 75% and plasma 25%
- contains Na+ and Cl-
What happens when you administer Hartmann’s?
- osmolarity is similar to ICF so liquid says in ECF
- distributes proportionally between interstitium 75% and plasma 25%
- contains Na+, Cl-, K+, Ca+ and lactate (HCO3-)
What fluids are the first choice for resuscitation?
Hartmann’s
Saline
What happens when you administer 4% dextrose/0.18% saline in a 1000ml bag?
(200ml 0.9% saline + 800ml 5% dextrose)
- 800ml H2O reduces osmolarity across ALL compartments from 5% dextrose (+glucose taken up by cells)
- 200ml 0.9% saline remains in ECF + distributes proportionally across interstitium 75% + intravascular space 25%
When are maintenance fluids needed?
Patient is haemodynamically stable but unable to meet their daily fluid requirements via oral or enteral routes
e.g. Nil by mouth before surgery
When are resuscitation fluids needed?
Patients in hypovolaemic state
When are replacement fluids needed?
How do you decide what is needed?
- required to replace the loss of bodily fluids
- choice of fluid depends on what’s being lost
- context dependent: volume needed, is it ongoing?
What time should you administer maintenance fluids?
Why?
During the daytime
To prevent sleep disturbance
What are indicators that a patient may need urgent fluid resuscitation?
- Systolic BP <100mmHg
- > 90bpm
- Cap refil time >2 seconds
- Cold peripheries
- > 20 resp rate
- NEWS >5
- Passive leg raising suggests fluid responsiveness
How much water do you need a day?
25-30ml/kg/day
How much glucose is needed per day?
50-100g
Regardless of weight
