Fluids Flashcards
What are the three things you should consider before prescribing fluids?
Basal requirements
Existing deficit
Predicted losses
How would you consider the existing deficit of a patient?
Losses before admission
Intraoperative losses
Replacement
Which surgeries involve third space losses and what is this?
Bowel and intraabdo vascular surgery
This is when fluid moves from plasma volume to the interstitial fluid after acute injury (will usually resolve after 2-3 days)
How do you assess a patients predicted losses?
Are you expecting further loss (ie ongoing vomiting/ diarrhoea or loss into drains?
What should you document in fluid input of a fluid balance chart?
IV and oral intake of fluids
What should you document in fluid output of a fluid balance chart?
Urine output NG tube aspirate Vomit Drain fluid Diarrhoea Blood loss Insensible loss from skin and breathing
What is the normal UO?
0.5ml/kg/hr
What blood tests would you look for to assess hydration
Urea and creatinine
What is the normal daily requirement of Na
1-2 mol/kg
What is the normal daily requirement of K
1-2mmol/kg
NaCl compared to plasma contains what electrolytes
More Na and Cl than plasma but no Ca or K (plasma obviously has them too)
Rapid infusions of large quantities of NaCl eg in a resus situation can cause
Severe metabolic acidosis
Why give 5% glucose
There are no electrolytes, the glucose is metabolised by the liver so this means you are literally only giving water. Equilibrates with everything.
When give 5% glucose and when not to
Good for pure dehydration or maintenance but not good in resuscitation
What is Hartmans?
Contains Na Cl and K so more like plasma than saline
What is gelofusine and why would you use it
Same as saline however uses much larger molecules
Describe the compartments of fluid in the body
2/3 ICF and 1/3 ECF
ECF can be further divided into
Plasma and interstitial fluid
Which compartments of fluid are depleted in dehydration
All compartments
Which compartments of fluid are depleted in hypovolaemia
If caused by acute blood loss one compartment depleted would be plasma
Which compartments of fluid are depleted in vomiting and diarrhoea
Loss of electrolyte rich fluid causes depletion of ECF (both interstitial and plasma)
What happens to the compartments if you give saline or hartmans
Increase in ECF
What happens to the compartments if you give 5% glucose
All fluid compartments increase
What happens to the compartments if you give gelofusine
Plasma increases in volume but the big colloid osmotic particles actually draw water in from the interstitial compartment
