Fluids

Question 1

What factors would decrease fluid requirements?

Answer 1

Renal impairement
Hepatic impairement
cardiac failure
head injury

Question 2

What factors would increase fluid requirements?

Answer 2

vomitting/diarrhoea
high output stoma
fistulas in gut
burns- barrier to fluid lodges = lost in damage to skin

Question 3

When may iv fluids be indicated?

Answer 3

• Correct losses or maintain homeostasis- blood loss
• Prolonged failure of oral intake e.g. mucositis caused by chemo- too painful to swallow
• Self-neglect
• Excessive losses- e.g n+v, diarrhoea
• Extreme heat= dehydration
• Excess diuretic use
• Nil by mouth e.g. post op

Question 4

How can dehydration be identified?

Answer 4

Thirst
Decreased skin turgor
Dry mucosal membranes e.g. eyes, mouth
Increased capillary refill time- press finger- goes white, then should quickly go pink
Tachycardia
concentrated urine-dark colour

Question 5

Can you give just IV water?

Answer 5

NO- water is not isotonic and so can cause haemolysis- the breakdown of RBCs and is very painful

Question 6

What are the types of fluids that can be given?

Answer 6

Blood
Colloids
Crystalloids

Crystalloids: Most clinically used type!
Solutions of small molecules in water e.g. ions such as Na+, Cl- and/or glucose

Colloids
Dispersion of large organic molecules in a carrier solution e.g
albumin- derives from human serum- good in shock e.g. burns, trauma, haemorrhage

Question 7

Why can’t dextrose saline be used longterm?

Answer 7

Doesn’t have an additional electrolytes- if over 24-48hr consider electrolyte needs of the patient

Question 8

What is a good examples of a crystalloid fluid?

Answer 8

Hartmann’s solution- is a balanced salt solution that is the most comparable to plasma- Na+, K+, Bicabronate, Cl-, Ca2+, pH, Osmolarity
No glucose
- Can be used for routine maintenance or resuscitation

Question 9

What are the advantages and disadvantages of colloidal and crystalloid fluids?

Answer 9

CRYSTALLOID:
+ Inexpensive
+ Low risk of adverse drug reactions
+ Widely available
+ maintain osmotic gradient
- Short half life- short action

COLLOID:
+ Smaller volumes needed- good if fluid restricted
+ Faster to give
+ longer half-life - longer DOA
- Max volumer per day
- Adverse drug reactions e.g. often complain of itching, also can cause allergies, anaphylaxis
- Expensive

Question 10

When is blood given as a fluid replacement?

Answer 10

Only if blood lost has exceeded 20% of normal patient blood volume (if not this substantial, use other fluids)
e.g in haemorrhage

Question 11

What are the 3 types of blood replacements?

Answer 11

Whole blood- RBC, WBC, platelets = all blood
Packed-cells: Platelet-rich plasma has been removed and blood given is packed with RBCs- same o2 carrying capacity as whole blood but without the volume
Plasma- everything but RBCs- good in some clotting disorders

Question 12

What are the 5 Rs to be considered for all IV fluid patients?

Answer 12

RESUCITATION:
- Where acute circulatory chock or volume depletion = medical emergency
- Give 500ml of bolus crystalloid over 15 minutes- this should contain sodium e.g. NaCl 0.9%
- needs continuous monitoring during this critical period

ROUTINE MAINTENANCE:
e.g. after op
- 25-30 ml/kg/day fluid - max 2.5 L - If IBW is obese up to 1mmol/kg/day

REPLACEMENT + REDISTRIBUTION:
Adjust IV prescription for existing electrolyte defects and ongoing loss

REASSESSMENT:
reassess needs and adjust at least daily
- monitor for adverse effects e.g. fluid overload

Question 13

What is important regarding giving potassium?

Answer 13

POTASSIUM CHLORIDE CONCENTRATE CAN BE FATAL!
- The ampoules look similar to water for injection- cautious
- if concentrated potassium chloride is inappropriately administered = heart can stop = cardiac arrest and death

Now- everyone should use a pre-mixed potassium bag where possible
The ampoules by law must:
- have distinguished labelling
- separate storage

Question 14

What are the 3 routes for administration of IV fluids?

Answer 14

PERIPHERAL VENOUS ACCESS:
- Typically in forearm or back hand via a catheter in small vein
- short- mid term use
- Replace every 24 hours

CENTRAL VENOUS ACCESS:
- For IV therapy >10 days
- Or if pt has poor peripheral access
- PICC line is inserted into elbow and passed into a central vein

SUBCUTANEOUS ADMINISTRATION:
- “Hypodermoclysis” - SC administration of fluids- is an off-label use
- Used in prolongation of fluids e.g. palliative care, elderly care
- used for slow delivery- unstable for rapid administration