IV Fluids

Question 1

What different mechanisms of movement between fluid compartments exist?

Answer 1

Electrochemical gradients, hydrostatic pressure, osmotic forces, oncotic pressure, primary and secondary AT

Question 2

What is the equation for calculating oxygen delivery to tissues?

Answer 2

CO x Hb conc x 1.34(mls O2/g Hb) x O2 sats % (0-1.00)

Question 3

What is the unit of DO2 (oxygen delivery to tissues)?

Answer 3

mls O2/min

Question 4

What is the unit for Hb?

Answer 4

g/litre

Question 5

What makes a solution hypotonic and hypertonic?

Answer 5

Amount of Sodium present
Hypotonic is when there is little sodium
Hypertonic is when there is too much sodium

Question 6

Why is it dangerous to give fluid that is hypotonic?

Answer 6

hypotonic hyponatraemia causing intracerebral osmotic shift and cerebral oedema

Question 7

How many grams of glucose do you require every day?

Answer 7

50-100g

Question 8

What is the breakdown of fluid in the body?

Answer 8

2/3 is intracellular

1/3 is extracellular broken down into interstitial and intravascular

Question 9

Comparing intracellular and extracellular compartments, which has higher sodium? potassium? calcium? magnesium? chloride? phosphate?

Answer 9

sodium - higher extracellularly
potassium - high intracellularly
calcium - higher extracellularly 
Magnesium - high intracellularly 
Chloride - high extracellularly 
Phosphate - higher intracellularly

Question 10

What are the 3 layers of blood vessels called and made of?

Answer 10

Tunica intima - endothelium single cell lining supported by basement membrane and CT
Tunica media - muscular layer
Tunica adventitia - CT

Question 11

Which layer of the blood vessels differs depending on the blood vessel type?

Answer 11

Tunica media as muscular layer only present in bigger vessels and not present in capillaries

Question 12

What is the pathophysiology of oedema occuring?

Answer 12

Causes leakage through the blood barrier (tunica intima) as well as larger molecules and cells leaking

Question 13

Is serum sodium and potassium a good indicator of total body?

Answer 13

Serum Na is good indicator but serum K is not

Question 14

Difference between crystalloids and colloids?

Answer 14

Crystalloids have smaller particles and can therefore pass through semipermeable membranes whereas colloids have larger particles and therefore largely remain within the intravascular system

Question 15

What can an excess of NaCl fluid cause?

Answer 15

Hyperchloraemic acidosis

Question 16

What should you never add to Hartmanns solution

Answer 16

Any additional electrolytes

Question 17

What happens to solute concentration when osmolality decreases?

Answer 17

Decreased conc making it more watery

Question 18

What happens when glucose 5% is administered

Answer 18

It is metabolised very quickly by the body leaving water which can distribute across all departement

Question 19

What situation would you administer colloid instead of crystalloids?

Answer 19

When you want a higher sodium concentration administration

Question 20

Name the principle natural colloid that can be given IV? potential risk?

Answer 20

Human albumin infusion wither 4.5% or 20%

Risk of transmitting infection

Question 21

What are the indications for administration of human albumin?

Answer 21

Low serum albumin in haemodynamically unstable patient 
Large volume paracentesis for ascites
Spontaneous bacterial peritonitis
Hepatorenal syndrome
Therapeutic plasma exchange

Question 22

2 artificial colloids that can be administered and their associated side effects?

Answer 22

Gelatin - anaphylaxis, coagulation effects
Dextrans - highly branched polysaccharide, coagnulation defects, anaphylaxis, coats RBC so can cause interference to cross matching, precipitate an AKI

Question 23

What 2 reasons is Dextrans primarily used for?

Answer 23

Microsurgery

VTE prophylaxis

Question 24

What is the definition of hyponatraemia and what are the categories of causes?

Answer 24

An Na less than 135 mmol/l

Can be hypotonic hyponatraemia, isotonic hyponatraemia, hypertonic hyponatraemia

Question 25

Which 8 categories of people do the norma IV fluid prescribing recommendations not apply to?

Answer 25

``` Those under 16 Pregnant Renal or liver failure Diabetes Burns traumatic brain injury Those who need inotropes Those on intensive monitoring ```

Question 26

5 Rs in fluid prescribing?

Answer 26

``` Resuss Routine Replacement Redistribution Reassess ```

Question 27

How often are fluid plans reassessed?

Answer 27

Usually every 24 hours unless long term and stable can be more infrequent If they are on resus or replacement therapy then may need more frequent monitoring

Question 28

What are the 4 types of shock and which 2 do not require fluid resuscitation?

Answer 28

Cardiogenic, distributive, obstructive or hypovolaemic | Cardiogenic shock and obstructive shock do not require fluid resuscitation

Question 29

In resus what volume of fluid bolus are given and up to what total volume before senior help needs to be called?

Answer 29

give 500ml bolus' | Up to 20ml/kg or max of 2000ml

Question 30

What fluid should be given as a resus bolus?

Answer 30

crystalloid like saline na 130-154 over 15 minutes

Question 31

When do you consider albumin in fluid resus?

Answer 31

When there is severe sepsis

Question 32

Why is maintenance therapy given? what 3 parts of maintenance therapy are there?

Answer 32

to account for insensible losses from the skin, respiratory, stools and UO Need water, electrolytes, glucose

Question 33

Fasting times for elective surgery?

Answer 33

6 hours food 4 hours breast milk 2 hours fluids 1 hour clear fluids in children

Question 34

Give some examples of where ongoing losses can occur?

Answer 34

``` Vomiting and diarrhoea NG tube Stoma sites - ileal, colostomy, jejunal fistula urinary losses Biliary drainage Bleeding Sweating, fever, dehydration ```

Question 35

What issues can cause problems with redistribution of fluids?

Answer 35

``` Sepsis Gross oedema Hypo or hypernatraemia Liver, renal or cardiac failure Post operative fluid retention Malnourished or refeeding issues ```

Question 36

What is the stress response, what happens when it is activated and why can it lead to fluid overload and hyponatraemia?

Answer 36

Stress response is the hormonal and metabolic changes that follow injury or trauma Causes increase in pituitary hormones to be released and SNS activation ADH release causes increased water reabsorbtion More chance for fluid retention overload and hyponatraemia

Question 37

excess vomiting or NG loss causes what type of electrolyte deficiency and go on to create what systemic state? management invovles what?

Answer 37

Hypochloraemic Hypokalaemic Metabolic alkalosis Need KCl

Question 38

Gastric fluid contains what amounts of what electrolytes?

Answer 38

K 14 mmol/l Cl 140mmol/l H+ 60-80mmol/l Na 20-60 mmol/l

Question 39

Biliary drainage loss would see what electrolytes predominantly and how much of them?

Answer 39

HCO3 30mmol/l Na 145 mmol/l K 5mmol/l Cl 105 mmol/l

Question 40

if the cause of ongoing losses was due to excess urinary losses, what electrolytes would you be particularly worried about?

Answer 40

Na K Monitor serum electrolytes closely

Question 41

Main difference in electrolyte loss between vomiting and diarrhoea?

Answer 41

Vomiting has high Cl ions | Diarrhoea has a high HCO3 content

Question 42

What questions is it important to ask about in a history of fluid status assessment?

Answer 42

``` Any vomiting or diarrhoea? Any diuresis? Any bleeding? Any sweating, rigors, temperatures? Are they thirsty? Any headaches? Any light headedness of standing? Are they fasting? ```

Question 43

What can you do on examination to assess someones fluid status?

Answer 43

``` CRT BP HR mucus membranes JVP UO - catheter Fluid balance chart Daily weights Postural changes in BP and HR RR Any oedema present for fluid overload ```

Question 44

What happens to UO after surgery and why?

Answer 44

Decreases due to stress response

Question 45

3 lab investigations to assess fluid status?

Answer 45

U&E FBC urinary sodium

Question 46

When should you do extra monitoring for urinary Na in patients on IV fluids?

Answer 46

If they have high volume GI losses

Question 47

When do you need to monitor Cl in IV fluid admin? How often?

Answer 47

When the patient is receiving over 120mmol/l of chloride ions in their fluids - NaCl 0.9% Risk of developing hyperchloraemic acidosis Measure daily

Question 48

How do you combat the fact fluid balance charts dont account for insensible losses?

Answer 48

Add 500mls to fluid balance in order to account for insensible losses and therefore calculate euvolaemia

Question 49

Losing 1kg in weight is equivalent to how much water loss?

Answer 49

1 litre

Question 50

Define the frank starling law?

Answer 50

SV will increase as EDV increases | reaches a point where SV starts to decrease as EDV increases further past a point

Question 51

Where are pressures measured inside the heart?

Answer 51

Atrias as without any obstruction the EDV pressure accurately reflects that of the ventricle

Question 52

What external location are cardiac pressures usually measured from? How is this done?

Answer 52

Usually a central venous catheter is inserted into the SVC or the right atrium along with the tip and transducer Central venous pressure accurately reflects right ventricle end diastolic pressure

Question 53

How can you measure the left atrial pressure indirectly?

Answer 53

Through the pulmonary capillary wedge pressure | Balloon into the pulmonary artery

Question 54

What types of heart problems can cause a raised LAP and therefore right ventricular end diastolic pressure increase

Answer 54

``` Mitral stenosis Mitral regurgitation Aortic stenosis Aortic regurgitation Pulmonary hypertension ```

Question 55

benefit of using CVP over pulmonary capillary wedge pressure?

Answer 55

CVP allows a constant measure of pressure whereas PCWP allows snap shots

Question 56

How does a low of high CVP affect your decision as to whether to administer a fluid bolus?

Answer 56

High CVP means they are unlikely to respond to fluids | Low CVP means they are more likely to respond

Question 57

How does CVP change as you administer fluids to a hypovolaemic patient?

Answer 57

Initially CVP does not change but HR decreases and BP increases As patient becomes normovolaemic, CVP will start to rise and normalise

Question 58

How does CVP change as you administer fluids to a hypervolaemic patient?

Answer 58

Abrupt and sustained rise in CVP

Question 59

What are arterial lines used for?

Answer 59

Close BP monitoring | Draw blood easier and send off blood tests

Question 60

What can be seen on an arterial line waveform that indicates a hypovolaemic state?

Answer 60

Venous returns falls cyclically with respiration Beat to beat changes in SV and pre-load are cause Swinging trace

Question 61

What methods are available to monitor cardiac pump function?

Answer 61

Echo Doppler Transpulmonary dilution with temperature or lithium Blood Pressure Curve Analysis