Iv Fluids

Question 1

Compare the percentage of a healthy weight adult Male/ female, older person and newborn of body mass that is fluid

Answer 1

Men: 60%
Women: 55%
Newborn: 75%
Older: 50%

Muscle contains more fluid than fat

Question 2

What are the main ions in ECF and ICF?

Answer 2

ECf: Na+, Cl- (1/3 body water)

ICF: K+, PO4 3- (2/3)

Question 3

What would happen if you injected Na+ into someone?

Answer 3

Na+ mostly remain in the blood (ECF) hypernatremia and so water would move out of cells -> cell shrinkage, confusion, seizures

Question 4

What would happen if you gave someone lots of water without any Na+?

Answer 4

Hyponatraemia, H20 would move into cells -> cell swelling, cerebral oedema, headache/ seizures

Question 5

What happens if you give someone 1000ml 5% dextrose?

Answer 5

50 g/l glucose

Glucose moves into all compartments, gets taken up by cells - if infusion relate quicker than uptake and metabolism -> hyperglycaemia

H20 reduces osmolarity of all compartments

Question 6

What happens if you give 1000ml 0.9% saline?

Answer 6

154 mmol Na+ + 154 mmol Cl-

Na stays in ECF and therefore so does H2O = no change in osmolarity

Roughly isosmotic to blood

Used for maintenance

Question 7

What happens if you give 1000 ml Hartman’s?

Answer 7

131mmol Na+
111 mmol Cl- 
5 mmol K+
2 mmol Ca2+
29 mmol lactate (HCO3-)

Majority retained in extracellular space as osmolarity maintained with effective osmoles

Most similar to plasma

Used for maintenance

Question 8

What happens when you give 1000ml 4% dextrose/ 0.18% saline?

Answer 8

31 mmol Na+
31 mmol Cl-
222 mmol glucose

H20 reduces osmolarity of all compartments

Saline remains in ECF

given in insulin dependent diabetics (type 1) as need constant glucose + maintenance fluid

Question 9

Difference between osmolarity and tonicity

Answer 9

Osmolarity - conc solute/ volume

Tonicity - behaviour, what a solution would do to a cell if it was placed in that solution e.g. hypotonic -> cells swell and hypertonic -> cells shrink (determined by osmolarity and ability of osmoles to enter the cell)

E.g. saline and 5% dextrose are isosmotic but glucose can move into the cell -> hypotonic and Na+ can’t -> isotonic

Question 10

Are all isosmotic solutions isotonic? All hyperosmotic solutions hypertonic and all hyposmotic solutions hypotonic?

Answer 10

No except hyposmotic solutions are always hypotonic (cell swells)

Question 11

Why do patients need IV fluids?

Answer 11

Nil by mouth

Malfunctioning gastro- intestinal tract

Dehydration

Fluid losses

Abnormal electrolytes

Question 12

What is often different about hospitalised patients that you need to consider before giving IV fluids?

Answer 12

Pain, pain relief, stress increases ADH,
Generally not sweating much, RAAS from stress, catecholamines stress, reduced cardiac expenditure lying down …

Reduced free H20 excretion (hyponatraemia)

Increased H20 and salt retention (volume overload)

Question 13

What the normal maintenance you need to give patients of water and electrolytes?

Answer 13

Water - 30ml/ kg / day 
Na+ - 1-2mmol/kg/ day
K+ - 0.5-1 
Cl- - 1 
Glucose - 50-100g to avoid starvation ketosis

Question 14

What do you mostly lose from vomiting? Diarrhoea?

Answer 14

Vomit- mostly Cl- loss (some Na, K, HCO3) ✅supplemental Cl- and K+

Diarrhoea - mostly lose Na (some K, HCO3-)

Question 15

What to five diabetics type one and two?

Answer 15

Type one (insulin dependent): constant glucose, 0.45% saline + 5% dextrose + 0.15% KCl 3 bags in 24hrs

Type two (non-insulin dependent): Hartmann’s 3 bags