Lecture 12 - IV fluids

Question 1

TBW percentage in men

Answer 1

60% - 42L

Question 2

TBW percentage in women

Answer 2

55%

Less muscle mass and more fat

Question 3

TBW percentage in elderly

Answer 3

50%

Less muscles mass
Decreased regulation of fluid

Question 4

TBW percentage in babies

Answer 4

75% - dehydrate quicker

Question 5

Hypotonic

Answer 5

Less solutes in ECF therefore water diffuses into cells causing swelling

Question 6

Hypertonic

Answer 6

More solutes in ECF therefore water diffuses out of the cell causing lysis

Question 7

Hypernatraemia presentation

Answer 7

Confusion
Seizures
Cell shrinkage as ECF is hypertonic so water moves out of cells

Question 8

Hyponatraemia presentation

Answer 8

Cerebral oedema
Headaches
Seizures

Cell swelling as ECF is hypotonic so water moves into cell

Worse for neurones

Question 9

Dextrose osmotic and tonic activity

Answer 9

Isosmotic but not isotonic

• Glucose is metabolised by cells therefore cell becomes more hypotonic as water left behind

Question 10

In which compartments does glucose get taken up in?

Answer 10

All compartments

Question 11

0.9% saline osmotic and tonic activity

Answer 11

Not isosmotic as slightly higher osmolarity but considered isosmotic

Isotonic

Question 12

In which compartments does Na+ get taken up in?

Answer 12

ECF only

Question 13

0.9% saline

Answer 13

Used in fluid resuscitation

Question 14

5% dextrose

Answer 14

Used as maintanence

Question 15

Hartman’s

Answer 15

Isotonic and Isomotic

Better reflection of blood
Lactate is metabolised to bicarbonate

Question 16

In which compartments does Hartman’s get taken up in?

Answer 16

ECF only

Question 17

4% dextrose/ 0.18 saline - mixed

Answer 17

800ml - 5% dextrose
200ml - Saline

Isosmotic not isotonic

Question 18

In which compartments does 4% dextrose /0.18% saline taken up in?

Answer 18

800 ml - Spread across all compartments

200 ml - ECF only

Question 19

Why do patients need IV?

Answer 19

Nill by mouth
Dehydration 
Fluid loss 
Abnormal electrolytes can be correctly quickly with IV
GIT defect

Question 20

Hospitalised patients

Answer 20

Increased ADH stimulated by:

• pain
• nausea
• drugs (morphine)
• low effective circulating volume

Generally do not sweat excessively

RAAS and catecholamines activated - stress response increasing water retention

Reduced calorie expenditure - inactive

Question 21

Daily losses

Answer 21

Urine - 1- 2.5 L

Water - 30ml/kg
Sodium - 1-2mmol/kg
Potassium - 0.5 - 1 mmol/kg
Chloride - 1 mmol/kg

Glucose - 50 - 100g (1L)

Question 22

Considerations for daily losses

Answer 22

Age - elderly lose less

Size

Question 23

Vomiting

Answer 23

Loses a lot of Cl- ions

Question 24

Diarrhoea

Answer 24

Loses a lot of HCO3- , K+ and Na+