Prescribing IV fluids

Question 1

Outline the distribution of body fluids

Answer 1

Water makes up 60% and 55% of the total body weight of men and women respectively. There is about 30L of intracellular fluid, 11L of interstitial and 5L of vascular fluid in the human body.

Question 2

What are indicators for prompt fluid resuscitation?

Answer 2

> SBP <100mmHg
> HR >90bpm
> Cap refill >2 secs
> Cold periphery 
> RR >20

Question 3

What are indicators for blood transfusion?

Answer 3

> Massive or ongoing haemorrhage
If Hb <8
If Hb 8-10 but they are symptomatic and have cardiac/respiratory/cerebrovascular disease

Question 4

What are the risks of blood transfusion?

Answer 4

Immune reactions, infections, volume overload, electrolyte imbalance and religious objections.

Question 5

When would you give irradiated blood in a transfusion?

Answer 5

Stem cell patients, those with leukaemia or anaemia

Question 6

What are signs of volume depletion (hypovolaemia)?

Answer 6

o	Reduced capillary refill
o	Tachycardic
o	Hypotensive (and postural hypotension)
o	Low/absent JVP
o	Decreased skin turgor and dry mucosa
o	Oliguria (less volume of urine)
o	Decrease in their daily weight chart

Question 7

What are signs of volume overload (hypervolaemia)?

Answer 7

o Occasionally tachycardic
o Raised JVP
o Pulmonary oedema, pleural effusion, ascites, peripheral oedema
o Increase in their daily weight chart

Question 8

What are crystalloids?

Answer 8

Water with varying levels of salts

Question 9

What are colloids?

Answer 9

Protein-rich solution with salts as well as water

Question 10

Give 3 examples of crystalloids.

Answer 10

Normal saline (0.9%), 5% dextrose, Ringers lactate (Hartmann’s solution)

Question 11

Give 3 examples of colloids.

Answer 11

Gelofusine, volplex, haemaccel

Question 12

What is Ringer’s lactate also known as?

Answer 12

Hartmann’s solution

Question 13

What’s the maximum IV potassium a patient can be administered per hour?

Answer 13

20mmol/hour!

Question 14

How does administering 1L of saline affect the intracellular and extracellular fluid levels of a patient?

Answer 14

Adminstering 1L of normal saline will cause an increase of 1L in the extracellular fluid, but not in the intracellular fluid

Question 15

How does administering 1L of 5% dextrose affect the intracellular and extracellular fluid levels of a patient?

Answer 15

Administering 1L of this will lead to an increase of 330ml in the extracellular fluid and an increase in 670ml in the intracellular fluid (as there is glucose and just water, it follows the movement of salt, which leads to it travelling in several places rather than just in the ECF)

Question 16

What complication can occur from giving normal saline?

Answer 16

Administering too much saline may lead to hyperchloramia and a metabolic acidosis (as it tips the acid base towards the production of HCl, be wary in ITU for example.

Question 17

What complication can occur from giving Ringers lactate/Hartmann’s solution?

Answer 17

Contain K+ so be careful not to administer if a patient has hyperkalaemia –> can kill them.

Question 18

What is the most common adverse reaction to colloids?

Answer 18

Allergic reaction

Question 19

What is the daily requirement that needs to be met with fluid maintenance?

Answer 19

25-30ml/kg/day of water, 1mmol/kg/day of sodium and potassium, alongside 50-100g/day of glucose

Question 20

Give an example of a prescription of IV fluids for routine maintenance only

Answer 20

25-30ml/kg/day 0.18% sodium chloride (saline) in 4% glucose/dextrose with 27 mmol/L K+ on day 1.

Question 21

What monitoring is required for patient’s receiving IV fluids containing chloride concentrations >120mmol/L

Answer 21

Serum chloride daily

Question 22

Describe the different cannula sizes, their colours and how long they take to infuse 1L of fluid

Answer 22

> 22G (BLUE)  – 22 minutes to infuse 1L
> 20G (PINK) – 15 minutes to infuse 1L 
> 18G (GREEN) – 10 minutes to infuse 1L
> 16G (GREY) – 6 minutes to infuse 1L
> 14G (RED) – 3.5 minutes to infuse 1L