Fluid Therapy

Question 1

what are the types of body fluid?

Answer 1

Intracellular - fluid inside tissue cells
extracellular - fluid outside of cells
- intravascular = blood vessels
- interstitial = dense connective tissue and between cells
- transcellular = specialised fluid, GI secretions

Question 2

why provide fluid therapy?

Answer 2

maintenance of fluid for patient unable to take oral fluids
- eg trauma to face/neck
- eg regurgitation/vomiting

to replace fluid losses and correct dehydration if the body can’t quickly enough
- e.g. from haemorrhage/diarrhoea/vomiting

to provide circulatory support
- eg. correcting shock/perfusion deficits

Question 3

what does the body use fluid/water for?

Answer 3

chemical reactions - hydrolysis
transportation - blood
waste products
thermoregulation
lubrication - saliva
electrolyte balance
digestion

Question 4

how is water taken in and lost?

Answer 4

taken in via:
- drinking
- eating - varies on dry vs wet

lost via:
- sensible loss - can be seen and measured - eg urine/blood/diarrhoea/vomit
- insensible loss - lost by evaporation - eg sweat/respiration

fluid loss is often increased via:
- vomit
- reflux
- diarrhoea
- heat
- blood loss
- shock
- malnutrition
- haemorrhage

Question 5

types of fluid therapy?

Answer 5

isotonic
- electrolyte content same as blood
- most often used

hypertonic
- higher electrolyte content
- forces water out of cells due to osmotic pressure
- use in shock dosage then isotonic immediately

hypotonic
- lower electrolyte content
- forces water into cells due to osmotic pressure
- not often used - correct high electrolytes

Question 6

clinical signs of varying hydration?

Answer 6

0-5%
- no specific signs
- maybe depressed and thirsty
- urine concentrated

5-7%
- sunken eyes
- dry MMs
- some tenting of skin

7-10%
- prolonged skin tenting
- hypovolemia symptoms (cold extremities/weak rapid pulse)

10-12%
- collapse and progressive shock
- organs begin to failure

12-15%
- severe shock
- death imminent

Question 7

how to assess hydration?

Answer 7

PCV
- cats = 24-45%
- dogs = 37-55%
- rabbits = 36-48%

total protein
- dogs = 50-70g/l
- cats = 60-80g/l

urinalysis
- volume = 1-2ml/kg/hr
- colour and smell
specific gravity
- cats = 1.035-1.060ug
- dogs = 1.015-1.045ug

Question 8

how do you calculate fluid rate?

Answer 8

maintenance fluid = maintenance x weight
÷ number of hours
÷ 60
x drip rate

Question 9

how to calculate fluids with a deficit?

Answer 9

fluid deficit = %dehydration x weight x 10

total requirement = maintenance fluid + fluid deficit
÷ number of hours
÷ 60
x drip rate

Question 10

how should you provide fluid therapy for blood loss/hypovolaemic shock?

Answer 10

Dogs: initial bolus of 10ml/kg-90ml/kg
Cats: initial bolus of 5ml/kg-50ml/kg

rate will depend on severity
continual monitoring is vital
reduce rate as soon as improvement
do not exceed 1 hour

Question 11

ideal fluid rate for anaesthesia support?

Answer 11

dogs: 5ml/kg/hour
cats: 3ml/kg/hour

Question 12

blood vs plasma administration?

Answer 12

blood
- contains RBCs, WBCs, platelets, clotting factors and plasma proteins
- used to aid oxygen delivery

plasma
- contains clotting factors and plasma proteins

in both cases, must monitor patient closely and not leave alone in-case of reaction

Question 13

use, collection and storage of blood?

Answer 13

often used for:
- blood loss and hypovolaemia
- shock
- anaemia
- DIC
- clotting disorders
- thrombocytopenia

collection:
- into a prepared collection bag
- may contain either Acid Citrate Dextrose (ACD) or Citrate Phosphate Dextrose (CPD)

storage
- use within 6hrs - reduce inactivation of platelets and clotting factors and risk of bacterial growth
- ACD: 1-6 degrees for 21 days
- CPD: 1-6 degrees for 28 days
- packed RBCs: 1-6 degrees for 21 days

Question 14

ideal administration rate of blood?

Answer 14

should not exceed 20% of total blood volume

administer slowly at 0.1ml/kg for first 10 minutes then proceed at correct rate
- dogs: 20ml/kg
- cats: 10-15ml/kg
- make sure to monitor PCV throughout

Question 15

why should we test blood typing and cross-matching?

Answer 15

not necessarily required for a first/isolated blood transfusion
- not yet any antibodies to interrupt
- good for emergency use

testing is performed to avoid reactions
- identifies presence and absence of antigens and antibodies
- detects serological incompatibility

it is required for any recurrent transfusions and important for cats as a reaction is often fatal

Question 16

use, collection and storage of plasma?

Answer 16

often used for:
- albumin loss
- IV volume expansion
- DIC - additional clotting factor

collection
- plasma collection kits are available
- blood can be centrifuged or allowed to settle then plasma decanted

storage
- freeze within 8 hours
- can be frozen at -30 degrees for a year

Question 17

clinical signs and management of transfusion reactions?

Answer 17

signs
- increased HR and RR
- pyrexia
- emesis
- trembling
- restlessness
- urticaria
- collapse

management
- immediately stop administration and aspirate catheter
- oxygen and fluid therapy
- antihistamines/corticosteroids
- keep calm and warm
- close monitoring
- have trach kit/intubation kit ready

Question 18

what is parenteral nutrition?
what considerations need to be made?

Answer 18

the intravenous administration of essential parts of nutrition
- used when the GI tract isn’t working or alongside nutrition if sick to aid recovery

types
- total parenteral nutrition - amino acids (protein), dextrose (carbs) and lipids (fat)
- partial parenteral nutrition - amino acids (protein) and dextrose (carbs)

TPN is light sensitive
- cover with black bag - hard to monitor
- make to use - once stopped must be binned

its high nutritive value is a medium for fungi and bacteria
- must monitor catheter site for infection
- not ideal if immune system is compromised
- composition must be sterile

when made the lipid component must be added last
- the acidic pH of carbs will destabilise the lipids
- protein will buffer this reaction