Fluids

Question 1

What are the three things you should consider before prescribing fluids?

Answer 1

Basal requirements
Existing deficit
Predicted losses

Question 2

How would you consider the existing deficit of a patient?

Answer 2

Losses before admission
Intraoperative losses
Replacement

Question 3

Which surgeries involve third space losses and what is this?

Answer 3

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)

Question 4

How do you assess a patients predicted losses?

Answer 4

Are you expecting further loss (ie ongoing vomiting/ diarrhoea or loss into drains?

Question 5

What should you document in fluid input of a fluid balance chart?

Answer 5

IV and oral intake of fluids

Question 6

What should you document in fluid output of a fluid balance chart?

Answer 6

Urine output
NG tube aspirate 
Vomit 
Drain fluid 
Diarrhoea
Blood loss 
Insensible loss from skin and breathing

Question 7

What is the normal UO?

Answer 7

0.5ml/kg/hr

Question 8

What blood tests would you look for to assess hydration

Answer 8

Urea and creatinine

Question 9

What is the normal daily requirement of Na

Answer 9

1-2 mol/kg

Question 10

What is the normal daily requirement of K

Answer 10

1-2mmol/kg

Question 11

NaCl compared to plasma contains what electrolytes

Answer 11

More Na and Cl than plasma but no Ca or K (plasma obviously has them too)

Question 12

Rapid infusions of large quantities of NaCl eg in a resus situation can cause

Answer 12

Severe metabolic acidosis

Question 13

Why give 5% glucose

Answer 13

There are no electrolytes, the glucose is metabolised by the liver so this means you are literally only giving water. Equilibrates with everything.

Question 14

When give 5% glucose and when not to

Answer 14

Good for pure dehydration or maintenance but not good in resuscitation

Question 15

What is Hartmans?

Answer 15

Contains Na Cl and K so more like plasma than saline

Question 16

What is gelofusine and why would you use it

Answer 16

Same as saline however uses much larger molecules

Question 17

Describe the compartments of fluid in the body

Answer 17

2/3 ICF and 1/3 ECF

Question 18

ECF can be further divided into

Answer 18

Plasma and interstitial fluid

Question 19

Which compartments of fluid are depleted in dehydration

Answer 19

All compartments

Question 20

Which compartments of fluid are depleted in hypovolaemia

Answer 20

If caused by acute blood loss one compartment depleted would be plasma

Question 21

Which compartments of fluid are depleted in vomiting and diarrhoea

Answer 21

Loss of electrolyte rich fluid causes depletion of ECF (both interstitial and plasma)

Question 22

What happens to the compartments if you give saline or hartmans

Answer 22

Increase in ECF

Question 23

What happens to the compartments if you give 5% glucose

Answer 23

All fluid compartments increase

Question 24

What happens to the compartments if you give gelofusine

Answer 24

Plasma increases in volume but the big colloid osmotic particles actually draw water in from the interstitial compartment